Independent metallurgical test work facilities used over the Project life included SGS Laboratories, Durango, Mexico; SGS in Lakefield, Canada (SGS Lakefield), ALS, Kamloops, British Columbia, Canada; and Corporación Química Platinum S.A. de C.V. located in Silao, Guanajuato, Mexico.
Palmarejo Operations have an on-site analytical and metallurgical laboratory that assays concentrates, in-process samples, and geological samples. The on-site metallurgical laboratory is used for testing flotation reagents, grind analysis, and process characterization of new ores. The on-site laboratories are not independent and are audited with third parties.
There is no international standard of accreditation provided for metallurgical testing laboratories or metallurgical testing techniques and selection of laboratories is based on experience and reputation within the industry.
The focus of the historical test work was to obtain representative metallurgical samples; conduct mineralogy examinations; determine the most favorable processing routes; collect sufficient design information to select equipment that fit the preferred processing flow sheet; and provide guidance for operating performance.
These parameters were used to construct the process plant as outlined in Chapter 14.
Test programs were conducted from 2007–2014. These included mineralogical studies, whole ore bottle roll cyanidation, rougher flotation followed by tailing cyanidation, and gravity separation.
Electrum and native gold were the primary gold species. Acanthite, argentite, and native silver were the primary silver species. Sulfides included sphalerite, galena, chalcopyrite, chalcocite, enargite, bornite, and tennantite–tetrahedrite.
Of the methods tested, the best results were achieved by flotation followed by tailing leaching. Whole ore cyanidation was shown to be less suitable because of lower recoveries. The poorest overall recovery was found with the gravity concentrate method.
The 2013 flotation test results indicated that the Guadalupe ore sample achieved an average gold and silver recovery of 80.4% and 78.3%. Flotation, followed by tails leaching results, indicates that gold and silver recoveries could be improved. The achieved overall recoveries were 94.8% and 95.6%, respectively.
The 2014 test work on Guadalupe North ores were amenable direct agitated cyanidation treatment at nominal P80 = 75 µm feed size with minor conversion of plant parameters required with the transition for Palmarejo ore to Guadalupe. Gold and silver recoveries tended to increase with increasing grade. Gold and silver recoveries were improved significantly after flotation tailings were subjected to whole cyanidation. Global Gold laboratory recoveries for flotation/tailings cyanidation unadjusted for plant solution losses ranged from 94.2% to 98.1% and averaged 95.7%. Global Silver laboratory recoveries for flotation/tailings cyanidation unadjusted for plant solution losses ranged from 93.6% to 97.2% and averaged 97.2%.
Testwork on the Independencia Oeste and Este deposits was conducted from 2014–2015. Work completed included mineralogy, multi-element ICP scan, whole-rock analyses, and carbon and sulfur speciation analyses, BWi, timed grinding series, bulk rougher flotation tests, and bottle roll tests, matching Palmarejo plant specifications.
Independencia Oeste mineralization was found to contain 68% silver–copper sulfide, 19% acanthite/argentite, 6% native silver/electrum, 5% silver–copper–arsenic sulfide, and the remaining 2% comprises various sulfides. The BWi was estimated to be 16.4 kWh/t. This value was considered to be moderate to hard for ball milling and within the operating capabilities of the Palmarejo grinding circuit. The master composite flotation test recovered 90% of the silver and 89% of the gold into a bulk concentrate that pulled 21% of the initial mass. Duplicate bottle roll cyanidation leach tests averaged 81% silver and 86% gold extraction in solution. As is common for cyanidation, silver leached slower than gold.
Independencia Este flotation test results showed the mass pulls were generally 15–23%; silver recoveries were variable. Flotation response demonstrated that flotation could separate silver and gold into a rougher concentrate with low concentrate to bulk ore ratios. The kinetic extraction curves from the bottle roll tests demonstrated typical rapid gold extraction and slower silver extraction. Cyanidation extraction values were better than the flotation lab results. This observation agreed with similar test results using both flotation and cyanidation for the Independencia master composite. Composites responded well to bulk conventional flotation treatment at a P80 minus 106 μm feed size. Combined (flotation + tailings cyanidation) proved to be more effective on recoveries above recoveries obtained by separate whole ore cyanidation or flotation circuits. Leach cyanide consumption rates were low on flotation tailings.
Testwork was performed in 2016–2019, on samples from the La Nación, La Nación Central, and La Nación Sur areas, using the Palmarejo plant specifications and mineralogy, bottle roll tests, head analysis, multi-element ICP scan and carbon sulfur speciation analyses, and whole ore cyanidation tests were performed.
The La Nación composites tested in 2016 were amenable to whole ore milling cyanidation treatment with respect to gold recovery but were more varied with respect to silver extraction and recovery. Silver solution extraction rates were slower than for gold.
La Nación composites tested in 2017 were amenable to whole ore milling cyanidation treatment with respect to gold recovery. Gold leach rates were generally rapid and substantially peaked the first eight hours of leaching. Gold in solution obtained from the 72-hour leach tests ranged from 81.0–99.8% and averaged 94.3%. Composites were more varied with respect to silver extraction in solution by whole ore milling cyanidation. Silver extractions obtained from the 72-hour leach tests ranged from 43.6–96.6% and averaged 86.0%. Whole ore leaching cyanide consumptions were generally high and ranged from 2.8–4.0 kg/t NaCN ore (3.42 kg/t NaCN ore, avg.) for the 72-hour tests. No strong evidence of the high cyanide consumption was related to sulfide content in the evaluated composites. pH control lime requirements were low and averaged 1.08 kg/t ore.
Tests on material from La Nación Central and Sur were conducted in 2019. Eight size fractions from La Nación Central were subject to mineralogical study. The predominant silver mineral in each of the size fractions was argentite, with small quantities of stromeyerite and native silver. Argentite was primarily associated with quartz in each of the size fractions. Silver liberation was not detected in the size fractions >37 µm. Gold was found only in the 44 and 53 µm size fractions, as electrum associated with quartz with a size of <1 µm.
Mineralogy test work on La Nación Sur composites was performed on eight size fractions. The predominant silver mineral in each of the size fractions was argentite. The argentite was primarily associated with quartz with less than 10% associated with pyrite in the coarse size fractions. Liberation was relatively low in the coarse fractions (<5% liberated in particle sizes >53 µm). The liberation increased with reducing particle size with a 70% liberation in the +37-micron size fraction and 98% liberation in the -37 µm fraction. Gold was found only in the +74 and +53 µm size fractions in the form of electrum associated with quartz with a size of <2 µm.
The manganese minerals psilomelane and coronadite were present throughout all size fractions at La Nación Central and Sur. These minerals can potentially lead to lower silver recovery. Sulfide minerals present in minor quantities included galena, sphalerite, and covellite.
A sample from the Palmarejo milling circuit tails stream was submitted to SGS Lakefield for bulk mineralogy, heavy liquid separation preconcentration and silver deportment studies in early 2020. The flotation tails sample contained a relatively high grade at 1.64 g/t Au and 45.6 g/t Ag. Bulk mineralogy was completed using quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN) analysis and supported by X-ray diffraction analysis. The primary minerals were quartz and calcite, with minor amounts of potassium feldspar, clays, iron oxides and trace amounts of dolomite, chlorite.
Results from the preconcentration showed that it would not be an effective method.
The microscopic silver examination of the tails composite sample showed 49.1% of the silver being liberated, 37.6% exposed and 13.2% locked. The primary silver minerals were acanthite, naumannite and jalpaite with minor amounts of electrum, aguilarite, native silver and others. The exposed and locked silver minerals were primarily associated with quartz with moderate amounts associated with lead oxide, and minor amounts associated with willemite, iron oxide, dolomite, and calcite.
A tails slurry sample from the Palmarejo circuit was submitted for solid-–liquid separation, rheology testing, and counter-current decantation washing modeling as part of 2020 testwork conducted by SGS Lakefield. Flocculant scoping tests were performed to match flocculant to sample recovery and thickening/clarification results. Additional dynamic tests were conducted to compare outcomes. Even at higher flocculant dosage the current flocculant could not achieve similar clarity or comparable total suspended solids levels. Other competitive flocculants were tested with variable dosage to test dosage to overflow total suspended solids rates. The solution densities on the underflow and yield stress were also calculated and tracked during the process providing results ranging from 57.1–58.2% solids depending on solids loading and residence time.
The critical solids density was calculated to be approximately 54% solids at a shear stress of 40Pa under unsheared flow conditions and 15 Pa under sheared conditions.
The resulting samples following the previous testwork were used to for various counter-current decantation modeling scenarios, using fixed parameters of cyanide leached discharge at 42% solids, silver and gold tenor in feed solution at 26 mg/L and 1.3mg/L, underflow on thickener at 55% solids, and perfect mixing at each wash stage. The results showed that the best response was achieved using a tested market flocculant at fixed dosage. Underflow slurry characteristics were within specifications for pumping.
Current recovery estimates for each deposit are summarized in Table 10‑1.
The LOM forecast average gold blended recovery is 90%. The LOM forecast average blended silver recovery is 82.5%.
Samples selected for metallurgical testing were representative of the various locations, ore types, and minerology. Additional samples were selected at periods during mining to test or reconcile results. Individual and composite tests were selected and taken to provide sufficient sample mass.
The anticipated gold and silver recoveries could be affected by alteration states. Highly oxidized material is not responsive to the flotation process. Highly oxidized ore will significantly affect recovery if blended at a high ratio. Ores that have a high clay content increase slurry viscosity, which has a detrimental effect on precious metals recovery in flotation.
No other deleterious elements are known from the processing perspective.
Industry-standard studies were performed as part of process development and initial plant designs. Subsequent production experience and focused investigations, as well as marketing requirements, have guided process improvements and changes.
Testwork programs, both internal and external, continue to be performed to support current operations and potential improvements.
Current metallurgical test work confirms the material to be mined as having similar response to the flotation-leach process as historically mined ores. Metal recovery assumptions are derived from past performance of the plant.
The QPs reviewed the information compiled by Coeur, as summarized in this Chapter, and performed a review of the reconciliation data available to verify the information used in the LOM plan.
Based on these checks, in the opinion of the QPs the metallurgical testwork results and production data support the estimation of mineral resources and mineral reserves and can be used in the economic analysis.
Mineral Resources are estimated for the following deposits. The database closeout date for all estimates was July 13, 2021.
Composites exhibit near log normal distributions. Statistics were compiled and compared for raw drill hole data, length weighted drill holes, composites, declustered composites, and capped declustered composites to ensure that the grade distribution and true mean of the system were documented and conserved through the estimation process. The coefficient of variation was analyzed to determine if domaining produced sufficient stationarity for the estimate.
Mineralization is hosted in primary northwest-trending, northeast- and southwest-dipping structures, and secondary diverging structures. The main mineralization type is defined by epithermal quartz vein breccias surrounded by a low-grade halo, consisting of various types of mineralized structures including discontinuous splays and vein arrays. Many of the deposits consist of various anastomosing quartz vein breccias with a sigmoidal geometry. There is also a broad geotechnical domain, used to estimate rock mass rating, or RMR.
The implicit modelling algorithm in Leapfrog Geo software was used to create all the estimation domains through interpretation of relevant intervals of drill data, digitized mapping, and underground production data.
The density determinations discussed in Chapter 8.3 were used in interpolation. Density was estimated using inverse distance weighting to the second power (ID2).
Note: Figure prepared by Coeur, 2021.
Caps for each estimation domain were determined using various methods such as histograms, probability plots and a metal loss calculation. Histograms and probability plots were examined for changes in slope and data distribution, while metal loss was calculated to keep the effect of capping to a maximum metal loss of 10%. The ranges of applied capping values are provided in Table 11‑1. Grade caps ranged from 100–3,500 g/t Ag and from 0.5–70 g/t Au, depending on estimation domain.
Core samples were composited at 2 m intervals by estimation domain for gold and silver. The composite length was chosen as one of the most common sample lengths and reduces the amount of sample splitting during the compositing process. Unsampled intervals were given a value of 0.001 ppm, as these intervals were deemed to be waste by the logging geologist and were not assayed. Composites were broken at domain boundaries, and composites <2 m at boundaries were distributed to the other composites within the domain. Natural rock caverns and drill intervals with no recovery, logged as “voids”, were omitted from the estimate.
Los Bancos, Zapata, and La Bavisa zones are full thickness composites within the domain. This resulted in a single variable length composite per drill hole within the estimation domain. This method of compositing is useful for discrete planar deposits of relatively consistent and narrow width, as it allows for the execution of a two-dimensional estimate.
Variogram searches were oriented along strike of the domains, with the major axis horizontal on-strike, the secondary axis down dip, and the minor axis across the width of the domain. Silver and gold variograms for each of the 12 estimation domains were created. Orthogonal variograms were fitted for gold and silver, consisting of three variograms oriented along the anisotropy. Downhole variograms were also fitted to provide the nugget. Where orthogonal variograms were not possible, omni-directional variograms were used.
Two and three structure, general relative, pairwise relative, and semi-variogram models were fitted to the experimental variograms. The Guadalupe–La Bavisa zone does not employ variography as it was estimated using ID2.
The various deposits were estimated using ordinary kriging (OK), with hard boundaries between geologic units. The enveloping disseminated domain was estimated using ID2. Search orientations were locally adjusted using dynamic anisotropy. The Guadalupe–La Bavisa zone was estimated using ID2.
Block models were constrained using the estimation domains. Models were rotated in two dimensions to represent the general strike and dip of the deposits. The parent block size was 2 x 25 x 25 m (X, Y, Z). The block size was based on the minimum mining width, composite length, and the average drill spacing of 40–50 m in the Y–Z plane. The block size was generally selected as one-half to one-third of the drill spacing. To provide a volumetric fit when filling the wireframes, the block models were sub-celled to a minimum of 1.0 x 2.5 x 2.5 m. Estimation took place in the parent cells, therefore, all sub-cells within a parent cell have the same grade. The estimation used a discretization grid of 1 x 5 x 5, which was based on the discrete dimensions in the X direction, and that a discretization of >5 in the Y and Z dimensions was inefficient and did not improve the block variance.
The full thickness model parent block size was set to the variable width of the vein in the X-dimension, and 30 x 30 m in the Y–Z dimensions. These models are not sub-celled and use a discretization grid of 1 x 3 x 3 m.
The search parameters for the estimate are summarized in Table 11‑2. The maximum number of samples was optimized by minimizing kriging variance while maximizing slope of regression, while attempting to maintain some degree of localization to improve production reconciliation. Each domain was estimated with one set of search ranges in one pass to achieve the optimal number of samples, and to avoid estimation artifacts created when using a multiple-pass method.
A high-grade search ellipse restriction was employed for the Independencia silver estimate, which applied the restriction at 75% of the capping value. Constant search volumes and number of samples were used for each domain.
The block model was depleted using the in-situ variable, proportionally depleting from 100 (in situ) to 0 (completely mined).
The grade estimates were validated visually by stepping through sections and comparing the drill data and composites with the block values. Local bias validation was completed using swath plots. Reconciliation factors for mill to model reconciliation were used for global bias validation, as well as to drive iterative improvements in the estimation parameters. Geologic interpretation was validated and improved through underground mapping, channel sampling, and ore control drilling.
The measured classifications are based on proximity to ore control and production data. This limits the classification of measured material to the area around current mining where there is a very good understanding of the deposit geometry and grade distribution.
Indicated blocks were classified using a script and then manually modified using polygons (in the plane of the domain) based on geologic confidence.
All remaining estimated material is classified as inferred, as the geological solids are considered conservative and do not extrapolate unsupported distances beyond or between data points.
Classification distances are based on variable grade continuity for each zone quantified with variography.
Following analysis that classified the mineral resource estimates into the measured, indicated, and inferred confidence categories, uncertainties regarding sampling and drilling methods, data processing and handling, geological modelling, and estimation were incorporated into the classifications assigned. The areas with the most uncertainty were assigned to the inferred category, and the areas with fewest uncertainties were classified as measured.
For each resource estimate, an initial assessment was undertaken that assessed likely infrastructure, mining, and process plant requirements; mining methods; process recoveries and throughputs; environmental, permitting, and social considerations relating to the proposed mining and processing methods, and proposed waste disposal, and technical and economic considerations in support of an assessment of reasonable prospects of economic extraction.
Mineral resources are confined within conceptual mineable shapes that use the assumptions in Table 11‑4.
Note: Figure prepared by Coeur, 2021. Red is measured, orange is indicated, and blue is inferred. Section looks west.
The gold and silver prices used in resource estimation are based on analysis of three-year rolling averages, long-term consensus pricing, and benchmarks to pricing used by industry peers over the past year. The estimated timeframe used is the eight-year LOM that supports the mineral reserves estimates. The gold price forecast for the mineral resource estimate is US$1,700/oz and the silver price is US$22/oz. The QP reviewed the forecasts as outlined in Chapter 16.
The mineral resources are reported using a cut-off of 1.59 to 2.21 g/t gold equivalent (AuEq). Gold equivalent cut-off grades were calculated for the deposits, with mineral resources estimated and reported above this cut-off. The AuEq cut-off was calculated as follows:
Where mining, processing and G&A are costs expressed as US dollars per tonne, and gold price and refining costs are expressed as US dollars per troy ounce. The payability refers to the percentage of metal payable after refining.
A gold:silver value ratio was used to convert silver grades to gold equivalent grades and is calculated using the following formula:
where AuEq, gold and silver are the gold equivalent grade, gold grade, and silver grade, respectively, in g/t.
The input parameters to the cut-off grades and the resulting grade cut-off for mineral resources reporting was provided in Table 11‑4.
The QP is of the opinion that any issues that arise in relation to relevant technical and economic factors likely to influence the prospect of economic extraction can be resolved with further work. The mineral resource estimates are performed for deposits that are in a well-documented geological setting. Coeur is very familiar with the economic parameters required for successful operations in the Palmarejo area; and Coeur has a history of being able to obtain and maintain permits, social license and meet environmental standards. There is sufficient time in the four-year timeframe considered for the commodity price forecast for Coeur to address any issues that may arise, or perform appropriate additional drilling, testwork and engineering studies to mitigate identified issues with the estimates.
Mineral resources are reported using the mineral resource definitions set out in SK1300 and are reported exclusive of those mineral resources converted to mineral reserves. The reference point for the estimate is in situ.
Measured and indicated mineral resources are summarized in Table 11‑5 and inferred mineral resources in Table 11‑6. Mineral resources are current at December 31, 2021.
The Qualified Person for the estimate is Mr. Joseph Ruffini, RM SME, a Coeur employee.
Table 11‑5: Gold and Silver Measured and Indicated Mineral Resource Statement as at December 31, 2021 (based on US$1,700/oz gold price and US$22/oz silver price)
Table 11‑6: Gold and Silver Inferred Mineral Resource Statement at December 31, 2021 (based on US$1,700/oz gold price and US$22/oz silver price)
| 12.0 | MINERAL RESERVE ESTIMATES |
Mineral reserves are estimated at Guadalupe, Independencia, and
La Nación mines (Figure 12‑1 to Figure 12‑9). All estimates envisage underground mining methods. Mineral reserves were converted from measured and indicated mineral resources. Inferred mineral resources were set to waste. The mine plans assume underground mining using longhole open stoping using trackless equipment and cemented rock fill (CRF) backfill. Target mining rates are 150,000 t/month.
| 12.2 | Development of Mining Case |
The mineral reserve estimate is based on the following inputs and considerations:
| • | Mineral resource block model, with estimated tonnage, gold, and silver grades; |
| • | Cut-off grade calculations; |
| • | Stope and development designs; |
| • | Geotechnical and hydrogeological information; |
| • | Estimates for mining recovery and dilution; |
| • | Depletion from previous mining; |
| • | Consideration of other modifying factors. |
Deswik mine planning software was used for the mine design, 3D modeling, and interrogation of the 3D mining model against the block model.
The surveyed “as-built” mining excavations were depleted from the designed solids and the resource block model.
Mining, geotechnical, and hydrological factors were considered in the estimation of the mineral reserves, including the application of dilution and ore recovery factors.
Mining excavations (stopes and ore development) were designed to include mineralized material above the cut-off grade. These excavations were then assessed for economic viability. In addition to the mining cut-off grade, an incremental cut-off grade (excluding the mining cost) was calculated to classify mineralized material mined as a result of essential development to access higher grade mining areas. Mineralized material above this cut-off grade will add value, and is therefore, included as process plant feed. Mineralized material below the incremental cut-off will be disposed of on surface in waste rock storage facilities (WRSFs) or will be used underground as backfill.
| Figure12‑1: | Deposit Layout Plan |
Note: Figure prepared by Coeur, 2021.
Figure 12‑2: Guadalupe Looking Northeast
Note: Figure prepared by Coeur, 2021. Legend key included as Figure 12‑9.
| Figure 12‑3: | Zapata Looking South |
Note: Figure prepared by Coeur, 2021. Legend key included as Figure 12‑9
| Figure 12‑4: | Independencia Looking Northeast |
Note: Figure prepared by Coeur, 2021. Legend key included as Figure 12‑9
| Figure 12‑5: | La Bavisa Looking Northeast |
Note: Figure prepared by Coeur, 2021. Legend key included as Figure 12‑9
| Figure 12‑6: | La Nación Looking Southwest |
Note: Figure prepared by Coeur, 2021. Legend key included as Figure 12‑9
| Figure 12‑7: | Los Bancos Looking Northeast |
Note: Figure prepared by Coeur, 2021. Legend key included as Figure 12‑9
| Figure 12‑8: | Hidalgo Looking Northeast |
Note: Figure prepared by Coeur, 2020. Legend key included as Figure 12‑9.
| Figure 12‑9: | Mine Layout Legend Key |
Note: Figure prepared by Coeur, 2021.
All designed excavations in the Mineral Reserve meet or exceed the cut-off grade. However, other costs not included in the cut-off grade calculation, will be incurred, such as costs related to capital development, underground infrastructure installations, capital equipment purchases, and sustaining capital. In addition to these costs, there are taxes and royalties that are payable based on net income.
The resulting mine plan was analyzed in a financial model and is economically viable.
Stope designs were generated for the planned mining methods using the cut-off grade to target material for inclusion. Stope designs were completed using the Deswik Stope Optimizer software. Centerlines representing ore development drives were digitized to represent ore development and were used to create a 3D solid model. The stope solids were cut using the ore development solids, using Boolean routines in the planning software. The resulting 3D model formed the basis of the mineral reserve estimate.
Gold equivalent (AuEq) cut-off grades were calculated for the deposits, with mineral reserves estimated and reported above this cut-off. The AuEq cut-off was calculated as follows:
where mining, processing and G&A are costs expressed as US$ per tonne, and gold price and refining costs are expressed as US$ per troy ounce and do not reflect the realized gold price from the Franco-Nevada royalty. The payability refers to the percentage of metal payable after refining.
A gold:silver value ratio was used to convert silver grades to gold equivalent grades and is calculated using the following formula:
Gold equivalent grades were calculated using the following formula:
where AuEq, Au and Ag are the gold equivalent grade, gold grade, and silver grade, respectively, in g/t.
The input parameters to the cut-off grades and the resulting grade cut-off for Mineral Reserves reporting is provided in Table 12‑1.
| 12.5 | Ore Loss and Dilution |
The following sources of dilution were identified:
| • | Overbreak into the hanging wall or footwall rocks following drilling and blasting operations; |
| • | Rock failures (slough) from rock walls adjacent to the stope boundaries as a result of weak rock mass characteristics; |
| • | Unconsolidated rockfill (backfill) from over mucking into the stope floor. |
Operational experience shows that dilution from the cemented rockfill (CRF) material is negligible, and this has not been considered as a dilution source.
Ore dilution factors to account for overbreak and wall slough (waste rock dilution) from the hanging wall and footwall surfaces were estimated based on the consideration of geotechnical information and stope reconciliations and were applied to stope shapes in the stope optimization software. One meter of dilution was applied to the hanging wall, and 0.5 m to the footwall. No dilution is assigned to ore development. No gold or silver grades were assigned to the rockfill (RF) dilution.
CRF and RF are used to backfill mined-out stopes in order to enhance ore recovery, provide mine stability, and eliminate the need for permanent ore pillars to be left.
Ore losses can occur during mining as a result of:
| • | Stope under-break and unrecoverable bridging; |
| • | Unrecovered ore stocks due to flat dipping footwalls and stope draw point geometry; |
| • | Misclassification of material resulting in ore hauled inadvertently to waste dumps; and |
| • | Abandoned ore stocks due to excessive dilution from stope wall failures. |
To account for potential ore losses, a factor of 5% was applied to primary, secondary, and longitudinal stopes, and ore mine development.
| Table 12‑1: | Input Parameters to Cut-off Grade Determination, Mineral Reserves |
| Parameter | Units | Value/Value Range (from/to) |
| Gold price | $/oz | 1,400 |
| Silver price | $/oz | 20.00 |
| Gold mining duty and refining cost | $/oz Au | 0.491 |
| Silver mining duty and refining cost | $/oz Ag | 0.491 |
| Gold recovery | % | 93.1 |
| Silver recovery | % | 81.9 |
| Gold payable | % | 99.88 |
| Silver payable | % | 99.86 |
| Au:Ag value ratio | Au:Ag | 81.59 |
| Mining cost | $/t | 36.01–41.75 |
| Surface ore haulage | $/t | 3.52 |
| Processing | $/t | 27.29 |
| G&A | $/t | 11.00 |
| Other | $/t | 3.19 |
| AuEq cut-off grade | g/t | 1.94–2.51 |
| Marginal development AuEq cut-off grade | g/t | 1.08 |
The gold and silver prices used in mineral reserve estimation are based on analysis of three-year rolling averages, long-term consensus pricing, and benchmarks to pricing used by industry peers over the past year. The estimated timeframe used is the nine-year LOM that supports the mineral reserves estimates. The gold price forecast for the mineral resource estimate is US$1,400/oz, and the silver price forecast is US$20/oz. The QP reviewed the forecast as outlined in Chapter 16.
| 12.7 | Mineral Reserve Statement |
Mineral reserves are reported using the mineral reserve definitions set out in SK1300. The reference point for the mineral reserve estimate is the point of delivery to the process plant. Mineral reserves are reported in Table 12‑2. Mineral reserves are current at December 31, 2021. Estimates are reported on a 100% basis.
The Qualified Person for the estimate is Mr. Peter Haarala, RM SME.
| Table 12‑2: | Gold and Silver Proven and Probable Mineral Reserve Statement as at December 31, 2021 (based on US$1,400/oz gold price and US$20/oz silver price) |
| Zone/Deposit | Mineral Reserve Classification | Tonnes (kt) | Grade | Contained Ounces | Gold Equivalent Cut-off Grade (g/t AuEq) | Metallurgical Recovery |
Ag (g/t) | Au (g/t) | Ag (koz) | Au (koz) | Ag (%) | Au (%) |
| Guadalupe | Proven | 2,005 | 120 | 2.09 | 7,736 | 135 | 1.97–2.51 | 81.9 | 93.1 |
| Probable | 6,527 | 121 | 1.82 | 25,412 | 381 | 1.97–2.51 | 81.9 | 93.1 |
| Subtotal proven and probable | 8,532 | 121 | 1.88 | 33,147 | 516 | 1.97–2.51 | 81.9 | 93.1 |
| Independencia | Proven | 1,044 | 190 | 2.68 | 6,377 | 90 | 1.99–2.07 | 81.9 | 93.1 |
| Probable | 3,551 | 137 | 1.76 | 15,588 | 201 | 1.99–2.07 | 81.9 | 93.1 |
| Subtotal proven and probable | 4,595 | 149 | 1.97 | 21,965 | 291 | 1.99–2.07 | 81.9 | 93.1 |
| La Nación | Proven | 357 | 206 | 1.96 | 2,367 | 22 | 1.94–1.98 | 81.9 | 93.1 |
| Probable | 934 | 162 | 1.81 | 4,876 | 54 | 1.94–1.98 | 81.9 | 93.1 |
| Subtotal proven and probable | 1,291 | 175 | 1.85 | 7,242 | 77 | 1.94–1.98 | 81.9 | 93.1 |
| Total proven and probable mineral reserves | Total proven | 3,405 | 151 | 2.26 | 16,480 | 247 | 1.94–2.51 | 81.9 | 93.1 |
| Total probable | 11,012 | 130 | 1.80 | 45,875 | 637 | 1.94–2.51 | 81.9 | 93.1 |
| Total proven and probable | 14,418 | 135 | 1.91 | 62,355 | 884 | 1.94–2.51 | 81.9 | 93.1 |
Notes to Accompany Mineral Reserves Table:
| 1. | The Mineral Reserve estimates are current as of December 31, 2021 and are reported using the definitions in Item 1300 of Regulation S–K (17 CFR Part 229) (SK1300). |
| 2. | The reference point for the mineral reserve estimate is the point of delivery to the process plant. The estimate is current as at December 31, 2021. The Qualified Person for the estimate is Mr. Peter Haarala, RM SME, a Coeur employee. |
| 3. | The estimate uses the following key input parameters: assumption of conventional underground mining; gold price of US$1,400/oz and silver price of US$20/oz; reported above a gold cut-off grade of 1.94–2.51 gold equivalent and an incremental development cut-off grade of 1.08 g/t AuEq; metallurgical recovery assumption of 93.1% for gold and 81.9% for silver; mining dilution assumes 1 meter of hanging wall waste dilution; mining loss of 5% was applied; variable mining costs that range from US$36.01–US$41.75/t, surface haulage costs of US$3.52/t, process costs of US$27.29/t, general and administrative costs of US$11.00/t, and surface/auxiliary support costs of US$3.19/t. Mineral reserves exclude the impact of the Franco-Nevada gold stream agreement at Palmarejo in estimation. |
| 4. | Rounding of tonnes, grades, and troy ounces, as required by reporting guidelines, may result in apparent differences between tonnes, grades, and contained metal contents. |
| 12.8 | Uncertainties (Factors) That May Affect the Mineral Reserve Estimate |
Factors that may affect the Mineral Reserve estimates include:
| • | Commodity prices: the mineral reserve estimates are most sensitive to metal prices. Coeur’s current strategy is to sell most of the metal production at spot prices, exposing the company to both positive and negative changes in the market, both of which are outside of the company’s control. Gold is subject to a streaming agreement with Franco-Nevada where 50% of the gold ounces produced from a portion of the Project are sold to Franco-Nevada at US$800/oz; |
| • | Metallurgical recovery: long term changes in metallurgical recovery could also have an impact on the mineral reserve estimates. For example, a 10% change in metallurgical recovery has approximately the same impact as a 10% change in metal prices. However, the metallurgy is well understood, and as a result, the mineral reserve estimates are considered to be less sensitive to long-term factors affecting metallurgical recovery, compared to the sensitivity to metal prices, which tend to have greater variances; |
| • | Mining method will change from transverse to longitudinal longhole stoping over time as narrower portions of veins are mined which could result in higher cost, lower productivities and higher dilution quantities which can impact grade. All of these factors could impact cut-off grades, reserve estimates and economics; |
| • | Operating costs: higher or lower operating costs than those assumed could also affect the mineral reserve estimates. While the trend over 2014 to 2020 showed operating cost reductions at the Palmarejo Operations, this trend could reverse and costs could increase over the life of the Project, due to factors outside of the company’s control. However, of the factors discussed in this section, the QP considers the mineral reserve to be least sensitive to changes in operating costs; |
| • | Dilution: additional dilution has the effect of increasing the overall volume of material mined, hauled and processed. This results in an increase in operating costs and could result in mineral reserve losses if broken stocks are diluted to the point where it is uneconomic to muck, haul, and process the material and the broken stocks are abandoned. The operations have developed a number of methods to control dilution, including the installation of stope support, a flexible mine plan with the ability to limit stope wall spans, and good development practices that avoid undercutting the stope hanging wall. To assist in these efforts, site geotechnical reviews are regularly completed by external consultants, and a geotechnical engineer is employed by the mine. In the opinion of the QP, sufficient controls are in place at the Palmarejo Operations to manage dilution, and the risk of material changes to the mineral reserve from dilution above the amounts used in the mineral reserve estimate is low. |
| • | Geotechnical: geotechnical issues could lead to additional dilution, difficulty accessing portions of the ore body, or sterilization of broken or in situ ore. In addition to the controls discussed in the dilution section there are significant management controls in place to effectively mitigate geotechnical risks. Designed openings are evaluated for stability using the Modified Stability Graph method. There is regular underground geotechnical mapping, and comprehensive geotechnical reviews are held on a weekly basis. The QP considers that sufficient controls are in place at the Palmarejo Operations to effectively manage geotechnical risk, and the risk of significant impact on the mineral reserve estimate is low. |
| • | Hydrogeological: unexpected hydrogeological conditions could cause issues with access and extraction of areas of the Mineral Reserve due to higher than anticipated rates of water ingress. The QP considers the risk of encountering hydrogeological conditions that would significantly affect the mineral reserve estimate is low. |
| • | Geological and structural interpretations: changes in the underlying geology model including changes in local interpretations of mineralization geometry and continuity of mineralized zones, changes to geological and mineralization shape and geological and grade continuity assumptions, and density and domain assignments could result in changes to the geology model upon which mineral reserve estimate is based. |
| • | Permitting and social license: inability to maintain, renew, or obtain environmental and other regulatory permits, to retain mineral and surface right titles, to maintain site access, and to maintain social license to operate could result in the inability to extract some or all of the mineral reserves. |
The Guadalupe, Independencia and La Nación mines use conventional underground mining methods and conventional equipment. The overall production rate is approximately 165,000 t/month.
| 13.2 | Geotechnical Considerations |
The Palmarejo Operations technical services department maintains a Ground Control Management Plan that is updated annually and serves to provide mine personnel with operating, monitoring, and quality control/assurance guidance. The Ground Control Management Plan specifies ground support standards and identifies where there are applicable in the mines.
Golder Associates (Golder) performed a geotechnical assessment of the mine area in 2011 and provided guidance on developing RMR logging procedures and calculated rock mass rating (RMR76). Most of the rock types show similar RMR76 values, with the bulk of the values in the range of 40–60, or a “Fair” rock quality.
Ingeroc SpA of Chile (Ingeroc) was commissioned in 2015 to perform additional geotechnical characterizations and provide onsite engineering support. Starting in 2017, this was replaced with an inhouse geotechnical team to support onsite engineering, planning and operations.
Pakalnis and Associates of Canada performed geotechnical design and operations reviews from 2011–2019. In 2019, Ingeroc was contracted to provide operations support with biannual reviews.
Due to highly variable rock mass quality and the intersection of dissolution voids during early development and operations, a geotechnical block model was developed in 2018. This model is continually updated with infill drilling and development mapping to support geotechnical design and mine planning. The model provides RMR ranges demarcated by six quality types which are then matched to minimum support requirements as part of the design and planning process. These ranges are represented by color coded blocks in a three-dimensional computer model and documented in the Ground Control Management Plan, matching minimum ground support requirements to the material classification.
Initial stope dimensions were developed using the Modified Stability Graph method, which predicts equivalent linear overbreak slough values (Pakalnis, 2016). Modifications based on variability and update geotechnical models were made as the mine developed. Updated designs are modelled using two and three-dimensional numerical simulation software to provide final design for each access and stope.
Based on the calculated modified stability number (N’) values, the majority of the planned stope surfaces at Guadalupe are estimated to have equivalent linear overbreak slough values of <1.0 m for unsupported stope hanging wall surfaces and <0.5 m for unsupported stope footwall surfaces for stope spans of up to 14 m along strike. Primary and secondary stope spans range from 10–14 m, and longitudinal stopes can range from 14 m along strike up to 20 m, depending on vein dimensions, structural interpretation, and rock quality locally.
Standard ground support initially consisted of pattern welding wire mesh pinned by rock bolting. With advanced development, and installation of a modernized shotcrete plant in 2020, fibercrete and bolting is currently replacing bolts and mesh in areas of higher quality rock. In poor ground, hanging wall support, or at intersections, the option of 6 m length cable bolts is available and installed in addition to shotcrete and mesh.
The most recent geotechnical review was conducted in June 2021 to review updated support methods, maximum allowable stable stope spans, mining sequence, and overall mine stability.
Pakalnis provided geotechnical inputs for startup design and operation from 2015–2019 with Ingeroc providing ongoing operational review support from 2019 to present. A geotechnical model was developed in 2017 due to poorer overall rock quality encountered in Independencia versus earlier development in Guadalupe.
Most stope surfaces at Independencia were designed to have equivalent linear overbreak slough values of <1.0 m for unsupported stope hanging wall surfaces, and <0.5 m for unsupported stope footwall surfaces. Rock quality in Independencia is considered to range between very low to moderate quality with variability requiring local changes to design to maintain stability. Similar support methods are available between mines following range classification as outlined in the Ground Control Management Plan that covers the operation. Common to Independencia, areas of Very Poor-quality rock typically require installation of horizontal steel spilling bars in advance of development for perimeter control, followed by reinforced shotcrete arches in addition to typical mesh and bolting standard support.
The most recent geotechnical review was conducted in June 2021 to review updated support methods, maximum allowable stable stope spans, mining sequence, and overall mine stability.
The geotechnical conditions at La Nación are classified with rock qualities ranging from Poor to Good. Conditions are similar to Guadalupe with most geotechnical concerns controlled by structure versus Poor rock quality. Pakalnis (2017) provided guidance and approval to increase stope heights from 20 m in Guadalupe and Independencia to 25 m in La Nación based on the orebody geometry and rock quality. This increase in stope height was implemented, and extraction has been proven effective.
Based on the calculated N’ values, stopes at La Nación were designed initially to have equivalent linear overbreak slough values of <1.0 m for unsupported stope hanging wall faces. Transverse stopes have a maximum primary/secondary exposure of 20 m for ore with >55% RMR, and a maximum hanging wall exposure of 32 m for hanging wall material with >65% RMR. Longitudinal stoping has a maximum hanging wall exposure of 32 m for hanging wall material with >65% RMR.
Similar methods of support are available to La Nación as other areas of operation following the Ground Control Management Plan released in 2016 and updated annually.
The most recent geotechnical review was conducted in June 2021 to review updated support methods, maximum allowable stable stope spans, mining sequence, and overall mine stability.
| 13.3 | Hydrogeological Considerations |
Permeability of the volcanic rock units in all mines is low to very low. Persistent inflows generally occur within larger fault structures. Flows increase and decrease seasonally if the structure is connected to the surface. Access ramps encountered significant water inflows from these structural features during early development; however, over time, inflows into the mine have diminished as local storage is removed. Increases in flow currently are directly related to opening new developments laterally or ramping downward to lower levels. A primary sump and pumping station is located on the 1,140 m level and fed by a series of level and ramp sumps that allow final settling before pumping from the mine to the water treatment plant on surface.
GRE prepared a hydrogeological model for the operations in 2017. The largest predicted inflows for Guadalupe will occur in year 2022 and result in a total flow of approximately 800 m3/day coinciding with the maximum lateral development of new mines at Animas and Zapata. Through 2021, flows are matching predicted values.
Water inflows tend to occur mainly where the development intersects larger scale structures, such as faults and shear zones. These structures are typically located in the footwall accesses and ore zones with generally higher flows than other mines due to the higher degree of brittle fracture and permeability along structures. Initial development encountered highest flows that diminished over time as local storage is drained. Outside of structures, similar host rock types of low overall permeability and storage to Guadalupe are present.
The primary sump and a pumping station is located on the 1090 m level to manage these inflows from satellite sumps and pumping systems located on various levels. The central pump station sends the water from settling sumps to the water treatment plant on surface for further sediment removal.
GRE prepared a hydrogeological model for the mine in 2017 with the highest predicted flow expected to be in 2021 of 2,600 m3/day. Actual water inflows in 2021 were slightly off the predicted flow estimate with a peak at 2,100 m3/day. This may increase through to 2023 with the development of the lower levels and Independencia and access development laterally to the north for the Hidalgo mine.
La Nación is located midway between the Guadalupe and Independencia mines. Hydrological conditions in the mine were affected by the development and dewatering of the two adjacent mines. Zones of intermediate inflow into the mine were intercepted along structures similar to those encountered in both Guadalupe and Independencia, but at much lower rates. This had little effect on mine development rates. Mine dewatering in the area is accomplished using satellite sumps on each level that drain down to the 1140 m level entry ramp access. Water collected from the 1140 m level sump is drained back to the primary sump and pump station on the 1090 m level in Independencia for transfer to the water treatment plant.
Primary access to the Guadalupe mine is from surface via two ramps. The West (Poniente) Decline and East (Oriente) Level are located 700 m north of the deposit in the hanging wall. A third portal for primary ventilation is the South Portal (Portal Sur) which is situated on the southern strike extent of the the deposit footwall approximately 2,200 m south–southeast from the main access portals. The West Decline serves as the primary access for haulage, while the East provides both haulage and support access. Both main ramps are used for primary ventilation intake while the main fans at South Portal are in operation. When the South Portal fans are down for maintenance, a secondary system is engaged providing intake on the East and exhaust on the South and West. The South portal is used as a primary exhaust for the mine as well as secondary escapeway for extended work areas of Guadalupe and Animas.
Two new developments at Zapata and Animas are underway as extensions of the Guadalupe mine. The Zapata deposit is located approximately 250 m from the footwall of Guadalupe. Two accesses have been developed to connect the Guadalupe ramp system to the Zapata ramp system. First ore development from Zapata was in 2021. The Animas extension is located at the far south end of the Guadalupe mine and is accessed via a single ramp. Development will have extended to first ore in late 2021. Ventilation and secondary egress will be provided via a ventilation raise to surface and an escapeway.
Mine access drifts were advanced through the ore structure and into the footwall where ramps were developed for vertical access to the level footwall drives. The access ramps are designed at 5.5 m high x 5.0 m wide and have been driven at 15% grades.
Key input parameters to the mine design include mechanized diesel and electric drill, load, and haulage systems. A preliminary production rate of 150,000 t/month was increased to 165,000 t/month in 2021 with the development of new orebodies and accelerated development rates. The material handling system uses a load-haul-dump (LHD) and truck transport system of ore loading and hauling to an interim surface stockpile. Ore is separated at surface into stockpiles to support blending prior to transport to the plant run-of-mine (ROM) stockpile. Waste from development is either directly transported from development to backfilling pockets in active stopes or stockpiled underground for later use as backfill.
Mining methods used at Guadalupe include both transverse and longitudinal sublevel stoping. The operation has changed from principally transverse longhole stoping from startup in 2014 where veins were wider to narrow vein longitudinal stoping in 2021. The continuous nature of the mineralized zones, significant orebody thickness, favorable deposit geometry and generally good ground conditions resulted in productive longhole stoping with low costs.
Access to transverse stoping areas is via footwall drives developed parallel to the orebody strike. Drawpoints are developed perpendicular to the footwall sublevels to access the stopes. A sequence of primary and secondary stopes is developed and extracted in sequence along strike of the vein. The primary stopes (roughly 10 m of strike) are excavated and backfilled with cemented backfill providing pillar support for the extraction of the secondary. The secondaries are then backfilled with waste to support ramping up to the next level. Access to longitudinal stopes is along and within the ore zones where drifts are driven along strike within the vein and extraction is in sequence from level to level in 15–20 m increments depending on ground conditions. The open stope is backfilled, and the extraction continues in sequence. Level or stope heights in Guadalupe are generally 20 m.
Lateral development is completed using conventional mechanized drilling and blasting methods. Drift rounds are drilled using twin boom, electric/hydraulic drill jumbos. Ground support is installed using mechanical/electrical bolting machines and (when required) shotcrete is applied with a shotcrete machine. Mine services (air, water, compressed air, electrical and communication cables) are extended to the working areas.
Longhole production drilling of stopes is completed using electric/hydraulic vertical hammer drill rigs. Production drilling is mainly done in pattern format in a down dip configuration, with the holes drilled parallel to the dip of the orebody.
The North and South declines provide access to the deposit and provide secondary intake (south) and primary exhaust ventilation (north) for the mine. The access ramps are designed at 5.5 m high x 5.0 m wide and have been driven at a grade of -15%. Primary ventilation intake is from a vertical surface raise and fan system constructed in the La Nación Mine and connected via dual ramps to the La Nación orebody on the 1140 and 1260 levels.
The design philosophy and key mine design parameters for the Independencia mine are similar to those described for the Guadalupe mine. Mine access drifts were advanced through the ore structure and into the footwall where ramps were developed for vertical access to the level footwall drives. The access ramps were designed at 5.5 m high x 5.0 m wide and were driven at 15% grade. Starting in 2021, ramps and accesses were reduced to 5.3 x 5.0 m to provide support for increased development rates and reduced unit costs.
Mining methods used at Independencia include both transverse and longitudinal sublevel stoping. The operation transitioned from principally transverse longhole stoping from startup in 2016 where veins were wider to narrow vein longitudinal stoping in 2021. Due to the sinusoidal nature of the mineralized zones, reduced orebody thickness, and generally poorer ground conditions, productive longhole stoping has been achieved, but at higher costs due to slower development and mining rates and increased support requirements. Stope and level heights in Independencia are 20 m.
Preliminary designs were completed for the development of the Hidalgo extension anticipated for production in 2023. The plans call for dual access ramps, one from Independencia along the north extension and the second located from surface approximately 200 m north of Independencia north portal. Current designs are in conceptual, with final designs to be completed in early 2022.
The mine can be accessed from two levels, one from the south decline ramp access on the 1140 level from Independencia, and the other from the footwall drive at the 1260 level.
The two drifts provide access to the deposit along with primary intake and exhaust ventilation for both the La Nación and Independencia mines. The access ramps are designed at 5.5 m high x 5.0 m wide with a gradient of 2%. The access ramps from Independencia are connected via a spiral ramp developed in the footwall of the La Nación orebody to connect the lower and upper part of the orebody and access to the sublevels.
The La Nación deposit is mined using similar equipment, personnel, and mining methods as the adjacent Independencia and Guadalupe mines. Much of the ore mining will be completed using longitudinal sublevel stoping due to the narrow width of the vein. Mine level and stope heights were increased to 25 m following a rock mechanics study supporting increasing the stope heights.
Primary stopes as extracted using transverse sublevel method are filled with cemented rock fill once the ore is drilled, blasted, and extracted. The cemented rock fill is produced on surface directly from a 3000 t/d mixing plant and hauled underground to the stope location. The majority of cemented backfill is used specifically for this method with secondary placement required for sill pillars and curtains where longitudinal retreat extraction method is applied. Sill pillars require the backfill of cemented fill along the entire length of the sublevel. All three active mines have completed sill pillars within the vertical profile of the orebody.
Curtains are designed and backfilled in those areas where longitudinal retreat mining requires the installation of a curtain to allow backfilling of the stope prior to continuing stope extraction. This curtain is required every 15–25 m depending on the design span distance as determined from a calculated hydraulic radius. In areas where the Avoca method is applied, cemented backfill is limited or not required.
Waste rock backfill from development mining is the principal backfill for secondary transverse stopes and for longitudinal stopes. In most cases, the rock fill is loaded on to trucks from waste development headers outside the orebody and delivered directly to the stope. Extra material is stored underground on previously-mined levels to be used later where needed.
The primary ventilation system is powered by two 224 kW central fans located at the South Portal. A second set of fans is installed in the East Portal for contingency and are only activated when the primary is down. When the central fans are active, air is drawn from the East and West portals and vented out the South portal directing air from north to south along the length of the orebody. Secondary ventilation is directed through booster fans installed on levels and directed through sublevel raises vertically and laterally along horizontal drives to the work areas. Vertical raises are installed level to level using a raisebore.
The capacity of the primary ventilation circuit is approximately 250 m3/sec.
The primary ventilation fans consist of two 224 kW fresh air intake fans installed in a ventilation bypass drift developed in the South ramp, and two 224 kW fans installed on the 1260 level in La Nación that pull air from a raisebored shaft connected to surface. The North portal provides a single exhaust exit from the mine for both intake points. Additional booster fans are installed underground to direct intake air to the active mining blocks. Ventilation raises are developed by longhole drill and blast methods or bored with a raisebore machine.
The capacity of the primary ventilation circuit is approximately 300 m3/sec when three of the four primary fans are operating.
The mine ventilation is designed and configured to support both Independencia and La Nación. Two access drifts developed from the Independencia mine provide exhaust routes from the mine. A vertical raise was constructed from the lower 1140 level through to surface as part of early development to support ventilation for the entire mine. The main fans are located on the 1260 level and consist of two 224 kW fans in parallel. During the early stages of development and operation, a single fan is in operation. As both La Nación and Independencia mature, and mining distances increase the second fan will be brought online.
| 13.7 | Blasting and Explosives |
Longhole drilling of stope production holes are completed using electric/hydraulic downhole hammer drills. Drill and blast design is customized to match individual conditions found in each stope and development headings. Blasting is conducted using controlled spacing and timing method via a central electronic timing and detonation system.
| 13.8 | Underground Sampling and Production Monitoring |
Preliminary in situ channel sampling is conducted across the vein intercepts by the geologists to support preliminary ore control. Follow-up samples are taken during and post extraction from individual stope stockpiles on surface to support blending and reconciliation with the plant on a continuous basis as part of day-to-day operations.
| 13.9 | Infrastructure Facilities |
Infrastructure for the operation is discussed in Chapter 15. All underground operations share the same surface infrastructure excluding stockpiles and compressed air and ventilation systems.
Underground maintenance facilities in Guadalupe and Independencia support field and preventative maintenance activities. Primary maintenance is conducted in joint facilities located on surface between the mine portals and a large main facility located at the Palmarejo office and plant site. An additional facility is planned for construction in Zapata in 2023 to support ongoing operations.
Underground magazines in Guadalupe support Zapata and Animas, and in Independencia support La Nación.
The Palmarejo Operations have nine years of mine life remaining overall. The Guadalupe mine has a remaining nine-year mine life with the
expansion components of Zapata and Animas. Independencia has a remaining nine-year mine life with expansions to the north and south and addition of the Hidalgo deposit. La Nación has five years of mine life remaining.
A production schedule is provided in Table 13‑1.
The equipment listed in Table 13‑2 is shared between the three underground mines.
Surface mining equipment consists of trucks, loaders, drills, and dozers. Some ex-open pit equipment is used for ore haulage from the underground mines to the ROM pad; as well as ore blending, backfill operations, road construction, and road maintenance. The main surface equipment assets are listed in Table 13‑3.
The equipment on site is sufficient to meet LOM plan requirements.
Mining operations are forecast to employ approximately 330 persons over the LOM.
| Table 13‑1: | Production Schedule |
| | Units | 2022 | 2023 | 2024 | 2025 | 2026 | 2027 | 2028 | 2029 | 2030 | LOM |
| Underground Guadalupe |
| Ore mined | kt | 941 | 962 | 940 | 983 | 1,251 | 1,329 | 1,226 | 681 | 218 | 8,532 |
| Silver grade mined | g/t | 118.5 | 126.1 | 98.6 | 116.4 | 115.2 | 123.4 | 121.4 | 146.2 | 157.5 | 120.8 |
| Gold grade mined | g/t | 1.9 | 2.0 | 1.6 | 1.9 | 2.0 | 2.2 | 2.0 | 1.6 | 0.3 | 1.9 |
| Silver contained metal | koz | 3,583 | 3,903 | 2,980 | 3,679 | 4,637 | 5,273 | 4,786 | 3,199 | 1,106 | 33,147 |
| Gold contained metal | koz | 57 | 61 | 49 | 60 | 79 | 92 | 80 | 34 | 2 | 516 |
| Vent Rise | m | 386 | 275 | 168 | 128 | — | — | — | — | — | 957 |
| Meters capital cost | m | 3,180 | 2,791 | 2,140 | 1,985 | — | 185 | — | — | — | 10,280 |
| Meters operating cost waste | m | 1,157 | 1,091 | 1,773 | 937 | 848 | 673 | 145 | — | — | 6,625 |
| Meters operating cost ore | m | 2,909 | 4,094 | 3,630 | 3,513 | 2,687 | 1,570 | 249 | — | — | 18,652 |
| Waste mined | kt | 303 | 266 | 267 | 197 | 63 | 63 | 13 | — | — | 1,171 |
| Underground Independencia |
| Ore mined | kt | 547 | 516 | 561 | 795 | 511 | 435 | 405 | 573 | 251 | 4,595 |
| Silver grade mined | g/t | 176.2 | 155.0 | 148.7 | 138.1 | 131.6 | 143.9 | 141.6 | 158.7 | 140.5 | 148.7 |
| Gold grade mined | g/t | 2.5 | 2.1 | 2.1 | 1.9 | 2.1 | 2.1 | 1.7 | 1.5 | 1.6 | 2.0 |
| Silver contained metal | koz | 3,102 | 2,570 | 2,680 | 3,532 | 2,164 | 2,015 | 1,845 | 2,923 | 1,135 | 21,965 |
| Gold contained metal | koz | 43 | 35 | 38 | 49 | 34 | 29 | 22 | 27 | 13 | 291 |
| Vent Rise | m | 21 | 141 | 271 | 151 | - | 394 | 515 | 36 | — | 1,528 |
| Meters capital cost | m | 856 | 2,662 | 2,982 | 1,608 | 63 | 836 | 1,012 | 212 | — | 10,230 |
| Meters operating cost waste | m | 396 | 414 | 497 | 1,043 | 352 | 95 | 522 | 51 | — | 3,369 |
| Meters operating cost ore | m | 834 | 1,422 | 2,539 | 2,781 | 748 | 959 | 1,260 | 590 | — | 11,133 |
| Waste mined | kt | 86 | 202 | 230 | 171 | 26 | 77 | 124 | 19 | — | 934 |
| Underground La Nación |
| Ore mined | kt | 313 | 326 | 410 | 156 | 86 | — | — | — | — | 1,291 |
| Silver grade mined | g/t | 141.2 | 187.5 | 200.2 | 182.9 | 108.8 | — | — | — | — | 174.5 |
| | Units | 2022 | 2023 | 2024 | 2025 | 2026 | 2027 | 2028 | 2029 | 2030 | LOM |
| Gold grade mined | g/t | 1.5 | 2.1 | 2.2 | 1.6 | 0.7 | — | — | — | — | 1.9 |
| Silver contained metal | koz | 1,420 | 1,967 | 2,641 | 914 | 300 | — | — | — | — | 7,242 |
| Gold contained metal | koz | 15 | 22 | 29 | 8 | 2 | — | — | — | — | 77 |
| Vent Rise | m | 247 | 30 | — | — | — | — | — | — | — | 278 |
| Meters capital cost | m | 1,543 | 189 | — | — | — | — | — | — | — | 1,732 |
| Meters operating cost waste | m | 453 | 81 | — | — | — | — | — | — | — | 534 |
| Meters operating cost ore | m | 1,992 | 422 | — | — | — | — | — | — | — | 2,414 |
| Waste mined | kt | 146 | 19 | — | — | — | — | — | — | — | 165 |
| Underground Total |
| Ore mined | kt | 1,801 | 1,804 | 1,911 | 1,934 | 1,848 | 1,765 | 1,632 | 1,253 | 470 | 14,418 |
| Silver grade mined | g/t | 140.0 | 145.5 | 135.1 | 130.7 | 119.5 | 128.5 | 126.4 | 151.9 | 148.4 | 134.5 |
| Gold grade mined | g/t | 2.0 | 2.0 | 1.9 | 1.9 | 1.9 | 2.1 | 1.9 | 1.5 | 1.0 | 1.9 |
| Silver contained metal | koz | 8,106 | 8,440 | 8,301 | 8,126 | 7,100 | 7,288 | 6,631 | 6,122 | 2,241 | 62,355 |
| Gold contained metal | koz | 116 | 118 | 117 | 118 | 115 | 122 | 102 | 62 | 15 | 884 |
| Vent Rise | m | 654 | 446 | 439 | 279 | - | 394 | 515 | 36 | — | 2,763 |
| Meters capital cost | m | 5,578 | 5,641 | 5,122 | 3,593 | 63 | 1,021 | 1,012 | 212 | — | 22,242 |
| Meters operating cost waste | m | 2,006 | 1,586 | 2,270 | 1,980 | 1,200 | 768 | 667 | 51 | — | 10,529 |
| Meters operating cost ore | m | 5,734 | 5,938 | 6,169 | 6,294 | 3,435 | 2,530 | 1,510 | 590 | — | 32,199 |
| Waste mined | kt | 534 | 487 | 496 | 368 | 89 | 140 | 137 | 19 | — | 2,270 |
Note: numbers have been rounded.
| Table 13‑2: | Underground Mining Equipment |
| Equipment Type | Make/Model | Peak Number |
| Wheel loader | Caterpillar R1700G, R1600G, R1700K; Sandvik Toro 006, Toro 1400; Atlas Copco ST1030 | 21 |
| Articulated truck | Caterpillar AD45B, AD30; Sandvik T40D; | 19 |
| Mine truck | Atlas Copco MT42 | 4 |
| Boltecs | Atlas Copco B235, Boltecs | 11 |
| Boltmaster | Atlas Copco RDH, 200EH | 1 |
| Drills | Atlas Copco 1254, M4CITH, J281, J282, S1D; Redpath 40S; Boart Longyear Stope Mate; Termite AQTK; Ingetrol 60E, 75E, Minitroner | 22 |
| Cabletec | Atlas Copco Cabletec LC | 2 |
| ANFO | Getman A64; RDH 150H | 5 |
| Concrete/shotcrete | EJC concrete mixer, 415; RDH 600R; Normet LF600, SB307, BS7622; Kubota; Transcrete P20 pump; | 21 |
| Auxiliary (pallet, scissor, utili lifts) | Getman A64; Marcotte M40; RDH 600R; Normet MF540 | 12 |
| Motor grader | Caterpillar 120K | 1 |
| Telehandler | Caterpillar TL1255, TL1255D | 11 |
| Backhoe loader | Caterpillar 430D, 450E, 420F | |
| Lube truck | Getman A64; RDH | 3 |
| Pallet handler | Getman A64 | 1 |
| Forklift | Caterpillar R80T | 1 |
| Table 13‑3: | Surface Mining Equipment |
| Item | Manufacturer | Model | Number |
| Loader | Caterpillar | 988H | 2 |
| Loader | Caterpillar | 992G, 992K | 3 |
| Truck | Caterpillar | 777F | 11 |
| Truck | Caterpillar | 740E | 4 |
| Water Truck | Caterpillar | 770F | 1 |
| Lube Truck | Caterpillar | 725E | 1 |
| Grader | Caterpillar | 140H, 140M, 14H | 3 |
| Excavator | Caterpillar | 315D, 330D, 336D2, 365C | 4 |
| Dozer | Caterpillar | D10T, D4G, D5K2, D9T | 7 |
| Compactor | Caterpillar | CS536D, E | 2 |
| Integrated Tool Carrier | Caterpillar | IT62H | 1 |
| Mobile Crusher | Metso | LT106 | 2 |
| Backhoe Loader | Caterpillar | 420F2 | 2 |
| Drill | Atlas Copco | CM780 | 1 |
| Telehandler | Caterpillar, JCB | Various models | 5 |
| Forklift | Caterpillar | DP40K, P5000 | 3 |
| 14.1 | Process Method Selection |
The process design is based on a combination of metallurgical test work, study designs and industry-standard practices, together with debottlenecking and optimization activities through the operational history of the plant since operations startup in 2007. The design is conventional to the silver and gold industry and has no novel parameters.
The processing plant is located immediately south and overlooks the village of Palmarejo at an elevation of approximately 880 m. The plant is designed to operate 365 days per year at 91.3% availability. The plant design mill throughput is 6,000 t/day of ore with upgrades providing a nominal throughput up to 7,000 t/day.
A schematic of the flowsheet is provided as Figure 14‑1.
The flow sheet consists of a standard crushing and grinding circuit (jaw crusher, semi-autogenous grind (SAG) mill and ball mill), followed by flotation circuit, where the flotation concentrate is directed to a sequence of clarification tanks then to agitated cyanidation tanks. Floatation tailings are directed to and treated in agitated cyanidation tanks. A Merrill Crowe circuit is used to recover gold and silver from the leachates of concentrate and tailings solutions through a carbon in leach (CIL)- absorption, desorption, recovery (ADR) system.
Ore is delivered from the underground mines to a ROM stockpile located adjacent to the primary crusher area and feed to the primary crusher dump hopper. The dump hopper has a fixed grizzly on top with an approximate opening of 51 cm and an apron feeder at the discharge. The ROM is fed with a front-end loader with secondary breakage using a rockhammer for oversize to the crusher. The primary crusher is a Nordberg C-140 jaw crusher with an approximate opening of 1.1 m x 1.4 m capable of handling 350 t/hr at a 12.7 cm close side setting.
Crushed ore is discharged vertically from the jaw crusher onto a conveyor and delivered to a 1,250-t capacity interim coarse ore stockpile. Two variable vibrating feeders reclaim the crushed ore through a vertical feed onto a belt conveyor for delivery to the SAG mill for grinding.
| Figure 14‑1: | Process Flowsheet |
Note: Figure prepared by Coeur, 2021.
Coarse ore from the primary crusher is directly fed to the grinding circuit from the interim crushed ore stockpile. The grinding circuit consists of a SAG mill and a ball mill operating in a circuit with a series of cyclones for classification and passing to flotation or return to grind. Both mills are 6.7 m in diameter and 7.5 m long equipped with 2,500 kW motors. The grinding circuit feed and product is controlled and varied depending on ore type and blend from the mines.
The cyclone battery consists of nine 203 cm Krebs cyclones with an apex opening of 10.8 cm and vortex opening of 15.2 cm. Cyclone operational pressure is maintained in a range from 96–110 kPa. The cyclone battery underflow reports to the ball mill to maintain a recirculating load to have better control of the flotation feed size, while the cyclone overflow reports to flotation.
The ball mill cyclone overflows at a nominal P80 minus 75 µm in size with a pulp density of 30% solids flows by gravity to the rougher flotation conditioner tank, where the slurry is conditioned with Aero 404 and potassium amyl xanthate (PAX). The conditioner tank overflows to feed a bank of five 100 m3 capacity rougher flotation cells. Rougher flotation occurs at the first bank of two tank cells, and scavenger flotation occurs sequentially down the bank. Frother and PAX are added to rougher feed and during the scavenging flotation.
Rougher flotation concentrates report either to the cleaner concentrate tank, where they are combined with the cleaner concentrate, or to the scavenger concentrate tank, where they are combined with the scavenger concentrate. Scavenger concentrate reports to a bank of two 17 m3 capacity cells where the first cleaner stage is provided. The first cleaner concentrate reports to a conditioning tank for additional reagents adjustment, and then flows to a bank of three 17 m3 capacity cells, where the final cleaner flotation is obtained. The final cleaner concentrate is pumped to the concentrate thickener for dewatering. The concentrate thickener overflow reports to the grinding circuit as recycled water. The thickener underflow, at approximately 65% solids, is pumped to the concentrate leach circuit for intense cyanide mixing and agitation. The blended solution is passed to the clarifiers for final processing as discussed in Chapter 14.4.4.
Cleaner flotation tailings are recycled to the rougher flotation conditioner tank or alternatively to the 3rd rougher cell for additional treatment.
Flotation underflow is transferred to a thickener for dewatering with the fluid overflow reporting back to the grinding circuit as recycled water. Thickener underflow, at approximately 60% solids, is transferred to an agitated leach circuit for cyanide leaching and dissolution of residual gold and silver values to be recovered in the ADR circuit discussed in Chapter 14.4.6.
| 14.4.4 | Flotation Concentrate Leaching |
The concentrate leaching circuit is located in the leaching/recovery area of the mill facilities and is comprised of four agitated leach tanks, each with a nominal capacity of 200 m3, providing a total average leaching time of roughly 48 hours.
Thickened flotation concentrate is diluted from 65% solids to approximately 50% solids and sodium cyanide solution is added to maintain a concentration of 10 g/L NaCN. The plant switched from air injection using compressors prior to 2019 to liquid oxygen which is injected into the concentrate solution to enhance the silver-CN bonding process at lower cyanidation rates resulting in lower cyanide consumption and reduced power.
The mixed concentrate is pumped from the concentrate leach circuit to a triple stage countercurrent clarification (CCD) circuit to recover the gold and silver bonded to the cyanide in solution. Each stage consists of a high-rate, 9.0 m diameter clarifier-thickener and an inter-stage mixing tank to enhance washing efficiency. Pregnant solution containing the recoverable metal is collected from the overflow at the first CCD thickener. This solution is pumped to the pregnant solution tank for delivery to the Merrill Crowe circuit at the refinery building for metal extraction. Thickened underflow from the final CCD thickener is pumped to an agitated leach circuit with the flotation underflow for additional leaching and potential recovery of residual metal values.
| 14.4.5 | Flotation Tailings Leaching |
The flotation tailings leaching circuit is also located in the leaching/recovery area of the mill facilities.
The leach circuit comprises a total of eight leach tanks. The tanks each have different capacities, ranging from 2,000 m3 to 1,162 m3 for tanks No. 1 and No. 8, respectively, providing an overall retention time of 24 hours.
Activated carbon is introduced to the last four tanks of the circuit (tanks 4 to 8) with the main objective of capture dissolved gold and silver values content in solution before it is transferred to the final tailing thickener. The loaded carbon is washed, bagged, and shipped to an outside refinery facility for processing.
Thickened flotation tails are pumped to the tailings leach circuit. The slurry is combined with the concentrate leached residue; the slurry is diluted to approximately 42% solids, and the sodium cyanide solution and lime slurry are added along with injected oxygen through the agitator shafts in Tank No. 1 and compressed air for tanks No. 2, No. 3, No. 4, No. 5 and No. 7.
Liquid oxygen is injected in tank No. 1. The liquid oxygen has proven success enhancing silver-cyanide leaching reaction resulting in additional silver values extraction and a significant cyanide consumption reduction. The leaching circuit tailings slurry is transferred to the cyanide detoxification circuit.
This circuit was re-introduced the second quarter of 2018. Prior to this the carbon was shipped to external refineries from 2016–2018. The circuit was upgraded with an ADR stripping circuit to support recovery improvement efforts on the flotation tailings circuit.
| 14.4.7 | Carbon Regeneration |
As part of the carbon desorption and ADR project in 2018, a carbon regeneration furnace was added to reduce carbon consumption by reactivating stripped carbon. This system was active through 2021.
| 14.4.8 | Merrill Crowe and Refining |
Pregnant solution from the flotation concentrate leach CCD first thickener overflow is pumped to one of three batch solution tanks, and then pumped to the primary Merrill Crowe system. The primary Merrill Crowe circuit capacity is 83 m3/hr.
A secondary Merrill Crowe unit handles low-grade pregnant solution from the floatation tailings leach circuit. The final tailings thickener overflow is the source of this low-grade pregnant solution, which is pumped throughout the secondary Merrill Crowe circuit. The secondary Merrill Crowe circuit has a capacity of 175 m3/hr. The secondary Merrill Crowe system was designed to handle higher grade pregnant solution from the flotation concentrate leach CCD circuit.
In the Merrill Crowe process, total suspended solids are first removed from the pregnant solution using a series of clarification filters. The clarified pregnant solution is routed to a deaeration tower to impact a bed of high-surface area plastic tower packing. As the solution travels down the packing, dissolved oxygen is removed from the solution and routed through the vacuum system piping to the vacuum pump, and then to the atmosphere. The dissolved oxygen is removed to a concentration of approximately to <0.7 ppm. Once the pregnant solution has been clarified and de-aerated, it is ready for precious metal precipitation by zinc cementation. The precipitated gold and silver resulting from the zinc cementation reactions are routed to the precipitate filters. The spent solution is pumped back to different points of the flotation tailings leaching circuit and/or the concentrate leach circuit for slurry washing and dilution.
The precipitate produced by Merrill Crowe is dried in two electrical dryer ovens before being smelted in a 600 kg/hr capacity electric induction furnace and poured into 30 kg doré ingots. Dore ingots are shipped directly to an offsite refinery.
| 14.4.9 | Cyanide Detoxification |
Flotation tailings leaching slurry at approximately 48% solids is transferred to a tailings thickener for water and cyanide recovery purposes, prior to delivery to the cyanide detoxification circuit. Thickener overflow is pumped to the secondary Merrill Crowe circuit or recycled back to the leaching circuit, while the thickened underflow is pumped to two 534 m3 capacity agitated tanks in series for detoxification.
The final tailings detoxification circuit is based on the use of trademarked cyanide destruction reagents and oxygen for neutralization of slurry prior to final thickening and disposal in the tailing's facility.
The equipment is sized for a design plant throughput of 5,500–7,000 t/d mill feed. Variability is built into the design to address ranges of grade and grind indices.
The major equipment list is provided in Table 14‑1.
| 14.6 | Power and Consumables |
The average monthly electrical power consumption is 6,218 MWhrs at a cost of $0.081/kWhr. Power is supplied by the Federal Electricity Commission (CFE).
The processing circuit cycles approximately 6,650 m3 of water daily; this consists of approximately 650 m3 of fresh water from a local dam and the remaining 6,000 m3 being water reclaimed from the TSF and reused in the mill.
The consumables used in the process include:
The personnel requirements in the process plant for the LOM total 128.
| Table 14‑1: | Major Equipment List |
| Area | Equipment |
| Primary crusher | Jaw crusher is a Nordberg C-140 (350 t/hr) |
| Grinding area | Allis Chalmer SAG and Ball mills, 6.7 m in diameter and 7.5 m length (250 t/hr) |
| Classification area | Cyclone battery consists of nine 203cm Krebs cyclones |
| Flotation area | Six 100 m3 capacity tank cells. Rougher flotation occurs at the first bank of two tank cells, and scavenger flotation occurs sequentially down the bank. The cleaners bank consists of two 17 m3 capacity cells where the first cleaner stage is provided. Then the first cleaner concentrate reports to a conditioning tank for additional reagents adjustment, and then flows to a bank of three 17 m3 capacity cells |
| Flotation concentrate leaching | The leach area is comprised of four agitation leach tanks for flotation concentrate, each with a nominal capacity of 200 m3. Leached slurry from the concentrate leach circuit is then pumped to a triple-stage countercurrent decantation circuit. Each stage consists of a high rate, 9.0 m diameter clarifier |
| Flotation tailings leaching | The leach circuit comprises a total of eight leach tanks. The tanks each have different capacities, ranging from 2,000 m3 to 1,162 m3 for tanks No. 1 and No. 8, respectively. Leached slurry from the tailing leach circuit is then pumped to a double stage countercurrent decantation. Each stage consists of a high rate, 23.0 m diameter clarifier (thickener) |
| ADR circuit | The ADR comprises an acid wash column, elution column, and regeneration kiln, for process 4 of carbon tons per cycle. |
| Merrill Crowe | Pregnant solution from the flotation concentrate leach countercurrent decantation is pumped to a Merrill Crowe system (#1) at a flow rate ranging from 85–92 m3/hr. Pregnant solution from the flotation tailing leach countercurrent decantation is pumped to a second Merrill Crowe system (#2), at a flow rate ranging from 285–295 m3/hr. |
| Cyanide detoxification | Thickened underflow is pumped to two 534 m3 capacity agitated tanks in series |
Infrastructure to support operations is in place, and includes:
| • | Three operating underground mines: |
| o | Underground ventilation systems, including ventilation fans, raises, primary bulkheads, airlock doors and booster fans; |
| o | Settling sumps and primary pump stations; |
| o | Blasting agent and explosives magazines; |
| o | Electrical substations and switch gears; |
| o | High and low voltage electrical cabling; |
| o | Mine communications system leaky feeder and fiber optic; |
| o | Cabling for central blasting system; |
| o | Underground lunchrooms and portable refuge stations; |
| o | Underground maintenance facilities (electrical and equipment); |
| o | Secondary egress raises with ladders; |
| o | Mine services (piping for dewatering, process water and compressed air); |
| • | Two shotcrete mixing plants; |
| • | Backfill cement mixing plant; |
| • | ROM pads at the mine portal areas and plant; |
| • | TSF and associated tailings pipelines, pumps and tailings water return infrastructure; |
| • | Heavy and lift vehicle maintenance facilities (underground and surface); |
| • | Materials storage areas and laydown facilities; |
| • | Various support facilities including warehouse, administration, contractor and temporary offices, raw water storage, fuel storage, core processing facilities, clinic and emergency response facilities, gatehouse, change rooms, personnel training facilities, information technology (IT) communications setups and towers, environmental monitoring facilities, sewage treatment plants, and reagents shed; |
| • | Electrical substations and power transmission lines, including an overhead high voltage power line from the main substation near the Palmarejo process plant to the Guadalupe substation and associated electrical substations and switch gear; |
| • | Emergency powerhouse with 12 diesel generators; |
| • | Water pipelines and pumping stations; |
| • | Mine permanent camp and contractor facilities and kitchens. |
An infrastructure layout map is provided as Figure 15‑1.
Road access to the operations is discussed in Chapter 4.2.
The state road between San Rafael and Palmarejo was upgraded in late 2007 for the mobilization of equipment and construction materials. Coeur Mexicana maintains this road on an on-going basis to support majority of logistic material delivery to support operations along this route. A secondary poorly maintained route exists to the west through Chínipas to the state of Sonora, which provides limited access for material and site personnel. Coeur also constructed and maintains the access/ore haulage road from the Guadalupe and Independencia portals to the Palmarejo process plant. The road allows CAT 777F haul truck transit used as primary transport or ore from the mine portals to the ROM stockpiles located at the process plant.
The Palmarejo Operations currently maintain limited ROM stockpiles with multistage load-transport-feed sequencing to manage blending at the mine and plant. A set of stockpiles are located at the mine portals at Independencia and Guadalupe. And larger pad areas are located to the south of the primary crusher at the plant site.
| Figure 15‑1: | Infrastructure Layout Plan |
Note: Figure prepared by Coeur, 2020.
| 15.4 | Waste Rock Storage Facilities |
A series of WRSFs are located at the currently closed Palmarejo open pit operation. No mine waste has been added to the WRSFs since 2015 when the pit was closed. Waste is currently being excavated and processed to support backfill operations underground. Following the current LOM underground plan these WRSFs will continue to be excavated to support waste rock and cemented backfill requirements underground and surface projects, including tailings raises, road works, and various civil projects to support on-going operations.
| 15.5 | Tailings Storage Facilities |
The TSF was constructed and commissioned in 2010. It is a zoned downstream earthfill dam with progressively coarser fill zones to reduce seepage and facilitate seepage collection with the finest zone adjacent to the upstream slope and the coarsest zone adjacent to the downstream slope. The upstream slope is constructed at 2H:1V and lined with a high-density polyethylene geomembrane and keyed into the foundation materials. The downstream slope is also 2H:1V. Instrumentation installed include vibrating wire piezometers, vibrating wire settlement plates, and survey prisms. The facility has been raised through a series of stages with the current Stage 5 scheduled for completion in May, 2022. An emergency spillway was constructed in mid-2021 to support final design and closure requirements.
The initial stage created a crest elevation of 790 m and was raised to 818 m in four stages using the downstream construction method. The fifth stage is currently being constructed to raise the crest elevation to 823 m in three stages (5a, 5b, and 5c) using a modified-centerline construction method. The facility is projected to reach capacity in Q1 2023 at a capacity of 15.4 Mm3, by which time the operation will transition to disposal of tailings in the mined-out Palmarejo open pit. A follow-up design of Stage 6 was completed to support a 1.5 m raise and eight months of storage capacity as contingency to support this transition.
The proposed TSF facility in the abandoned open pit will include an underdrain system within the abandoned underground below the pit, surface tailings discharge and pump-back systems, and a high compression thickener to provided high solids tails and increased water recovery.
| 15.6 | Water Management Structures |
The three primary water management structures located at the TSF are a freshwater diversion dam, freshwater diversion channel, and an environmental control dam.
The freshwater diversion dam is a zoned earthfill dam constructed to divert a large drainage around the tailings basin and provide limited permitted water support to the plant. A bituminous geomembrane is installed on the upstream face of the freshwater diversion dam as erosion protection and seepage control. Construction of the freshwater diversion dam was completed in 2009 and filling of the freshwater diversion dam basin commenced immediately thereafter.
The freshwater diversion channel was constructed to convey stormwater from the freshwater diversion dam basin around the tailings pond to the environmental control dam basin located downstream of the tailings facility. Construction of the freshwater diversion channel was completed in 2009–2010. The channel apex is located approximately 10 m below the top of the freshwater diversion dam to accommodate and control flood release during heavy rain events.
The environmental control dam is a roller-compacted concrete dam constructed to provide a single collection and discharge location for all potentially impacted flow from the diversion and lateral streams entering the basin. The dam was designed as an overtopping structure with a stepped spillway constructed on the downstream face under high flow conditions. The facility is managed dry during most of the year with underflow pipe to manage and release smaller flows and maintain flow through within the basin. Construction of the environmental control dam was completed in June 2009. Since the dam was constructed, flow over the environmental control dam spillway has occurred serval times periodically during the wet season. Since 2018, the underflow drain has remained open to eliminate long term storage and limit the topping to a single event.
In 2016, a water treatment plant was constructed to treat and release excess water from the tailings pond. A water discharge permit obtained from the Mexican National Water Regulatory Agency (CONAGUA) allows discharge of a maximum of 2.0 Mm3/a of treated water into a downstream creek. The water treatment system can treat the outstanding water over balance in the TSF and comply with water quality requirements as per the CONAGUA permit.
Groundwater from the underground mines is collected in level sumps constructed in the underground mines. The collected water is drained and pumped to central collection sumps in each mine to allow suspended solids to settle before it is pumped to a surface treatment plant, constructed in 2019, for further clarification. The water is then cycled both back to the underground mine to support operations, and to the plant, via a pipeline constructed in 2020, to support process at the plant.
Water for the process facilities is obtained from a variety of sources. Reclaimed water from the wet tailings including underflow collection is recycled back to the plant from the TSF. When needed, additional make-up water is pumped from the underground mines, additional subsurface sources from areas wells, limited permit options from the freshwater diversion dam, and a pump station located at the Chínipas River.
Domestic use water is purchased from local municipalities or is trucked to site from various stations that hold water sourced from the Chínipas River. All gray water is stored and blended for use in the process cycle at the plant.
| 15.8 | Camps and Accommodation |
The mine camp facilities and kitchen support the requirements of the workforce. Contractors and employees live at the camp while working on site. The camp has a capacity of 532 beds. Satellite camp complexes accommodate housekeeping, security, and kitchen staff with a capacity of 126 beds.
The main substation for the Palmarejo Operations has a 115 kV/13.8 kV transformer, with capacity of 20/25 mVA (one in back up). The system includes a 66 km overhead 115 kV distribution line ceded to the CFE that was built in 2009. The process plant and all other electrical loads are connected to this grid. The overall power requirement for the operation is 18 MW, and the maximum capacity of the current infrastructure is 21 MW.
A 5.9 km-long power line is in place from the main substation to the Guadalupe and Independencia mines, with capacity for 115 kV, although it is currently operating on 13.8 kV. This infrastructure will allow for power capacity expansion in the future. Substations have been constructed on the surface at the Guadalupe and Independencia mines, and underground at the La Nación mine. The estimated capacity for Guadalupe, Independencia, and La Nación complexes (at full production) is approximately 5.0 MW.
An emergency powerhouse is located near the process plant and contains 12 diesel generators that operate during main power outages. The total installed emergency power capacity is 21.9 MW, which is sufficient for LOM requirements.
| 16.0 | MARKET STUDIES AND CONTRACTS |
No market studies are currently relevant as the Palmarejo Operations consist of operating mines producing a readily-saleable commodity in the form of doré. Gold and silver are freely traded, at prices that are widely known, and the prospects for the sale of any production are well understood.
Together with public documents and analyst forecasts, these data support that there is a reasonable basis to assume that for the LOM plan, that the key products will be saleable at the assumed commodity pricing.
There are no agency relationships relevant to the marketing strategies used.
Product valuation is included in the economic analysis in Chapter 19 and is based on a combination of the metallurgical recovery, commodity pricing, and consideration of processing charges.
Coeur sells its payable silver and gold production on behalf of its subsidiaries on a spot or forward basis, primarily to multi-national banks and bullion trading houses. Markets for both silver and gold bullion are highly liquid, and the loss of a single trading counterparty would not impact Coeur’s ability to sell its bullion.
Coeur’s strategy on hedging silver and gold is focused on providing downside protection. To accomplish that, the company may enter into derivative contracts to protect the selling price for a certain portion of the production if terms are attractive.
To mitigate the risks associated with gold and silver price fluctuations, Coeur may enter into option contracts to hedge future production. Coeur is targeting to hedge up to 50% of expected gold production through 2021 and 2022 and may in the future layer on additional hedges as circumstances warrant.
| 16.2 | Commodity Price Forecasts |
Coeur uses a combination of analysis of three-year rolling averages, long-term consensus pricing, and benchmarks to pricing used by industry peers over the past year, when considering long-term commodity price forecasts.
Higher metal prices are used for the mineral resource estimates to ensure the mineral reserves are a sub-set of, and not constrained by, the mineral resources, in accordance with industry-accepted practice.
The long-term gold price forecasts are:
| • | Mineral reserves: US$1,400 US$/oz; |
| • | Mineral resources: US$1,700 US$/oz; |
The long-term silver price forecasts are:
| • | Mineral reserves: US$20.00/oz; |
| • | Mineral resources: US$22.00/oz. |
The price forecasts used in the cashflow analysis for gold vary from US$1,400/oz to US$1,750/oz and US$22/oz to $US24/oz for silver.
All commodity prices are advised by the corporate investment committee and revised as necessary throughout the budget and forecast process. This guidance is used to keep all sites using the same basis for revenue. The sites do not advise prices or deviate from the prices provided.
The Palmarejo Operations produce silver and gold doré, which is transported from the mine site to the refinery by a secure transportation provider. The transportation cost consists of a fixed charge plus a liability charge based on the declared value of the shipment and is approximately $0.065/oz of doré shipped.
Coeur Mexicana has contracts with one U.S. based refiner and one Switzerland-based refiner, which refine the Palmarejo Operations’ doré bars into silver and gold bullion. The bullion meets certain benchmark standards set by the London Bullion Market Association, which regulates the acceptable requirements for bullion traded in the London precious metals markets. The terms of these contracts include:
| • | A treatment charge based on the weight of the doré bars received at the refinery; |
| • | A metal return percentage applied to recoverable gold; |
| • | A metal return percentage applied to recoverable silver; |
| • | Penalties charged for deleterious elements contained in the doré bars. The total of these charges can range from $0.30–$0.40/oz doré. |
Currently, there are contracts in place at the Palmarejo Operations to provide supply for all major commodities used in mining and processing, such as equipment vendors, power, explosives, cyanide, tire suppliers, raise boring, ground support suppliers and drilling contractors. The terms and rates for these contracts are within industry norms. These contracts are periodically put up for bid or negotiated to ensure the rates remain favorable to Coeur.
For the purposes of the gold and silver price forecasts used in the mineral resource and mineral reserve estimates, the QPs reviewed the corporate pricing provided by Coeur, and accepted these prices as reasonable. The reviews included checking the pricing used in technical reports recently filed with Canadian regulatory authorities, pricing reported by major mining company peers in recent public filings, the current spot gold and silver pricing, and three-year trailing average pricing.
The US$1,400/oz Au and US$20/oz Ag prices are considered to be a reasonable forecast for the nine-year mine life envisaged in the mine plan. The US$1,700/oz Au and US$22/oz Ag mineral resource price is, as noted, selected to ensure that the mineral reserves are a subset of the mineral resources and assume that there is sufficient time in the nine-year mine life forecast for the mineral reserves for the mineral resources to potentially be converted to mineral reserves.
Overall, the QPs conclude that there is sufficient time in the nine-year timeframe considered for the commodity price forecasts for Coeur to address any issues that may arise, or perform appropriate additional drilling, testwork and engineering studies to mitigate identified issues with the estimates or upgrade the confidence categories that are currently assigned.
| 17.0 | ENVIRONMENTAL STUDIES, PERMITTING, AND PLANS, NEGOTIATIONS, OR AGREEMENTS WITH LOCAL INDIVIDUALS OR GROUPS |
The environmental permitting process in Mexico requires the presentation of two different documents at the federal level: an Environmental Impact Statement (MIA in the Spanish acronym) and a Land Use Change (CUS in the Spanish acronym). These documents are reviewed and approved by Mexico’s environmental authority SEMARNAT. In addition, authorization from CONAGUA is needed for water use, effluent discharge, and for the construction of facilities in federal watersheds.
| 17.2 | Baseline and Supporting Studies |
Baseline studies and monitoring reports were required for each mine permit obtained.
Several environmental studies were completed in support of permitting activities. These studies included:
| • | Seismicity and natural hazards; |
| • | Groundwater and surface water quality; |
| • | Biodiversity, terrestrial and aquatic; |
| • | Soils characteristic, uses, and potential use; |
| • | Geochemical mineral waste characterization; |
| • | Archaeology/cultural heritage; |
| • | Socioeconomics and cultural aspects. |
| 17.3 | Environmental Considerations/Monitoring Programs |
Coeur Mexicana conducts routine monitoring of physical and biological parameters required in the MIA approval resolution and the MIA document itself. These include groundwater and surface water quality, air quality, emissions to the air, biodiversity, water discharges, etc. Results from these monitoring activities are presented to the authorities through their official digital platform.
As part of the environmental management program of the Palmarejo Operations, there is a continuous evaluation of the acid rock drainage (ARD) potential for waste rock and tailings in the extraction process. The initial ARD testing by Environmental Geochemistry International Pty Ltd. in 2005 indicated a very low ARD potential for waste rock and tailings.
In 2012, a long-term humidity cell test was conducted on composite tailings samples to assess the potential for the generation of acid. Results from testing conclusively indicate that pre-2012 tailings deposited in the TSF will not present problems with acid generation. Additional studies conducted in 2016 and 2017 indicate that the potential for acid generation of the tailings in the TSF is low and that the tailings are essentially anoxic and incapable of oxidizing while inundated with water.
In November 2017, Knight Piésold collected samples from tailings and waste rock as part of their Site Wide Closure Plan, including samples from Guadalupe and Independencia. From their study, Knight Piésold concluded that the samples collected are not potentially acid generating nor metal leaching and do not pose a threat to the environment.
Coeur continuously updates the information with data from the material mined from the underground operations. Concurrent sampling and paste pH testing of the underground works at Guadalupe and Independencia support the absence of ARD and the strong neutralization potential of the waste rock.
Wildlife and biodiversity monitoring is conducted by CIMA Consultores, a Chihuahua-based consulting firm, four times during the year. The most recent study was conducted in August and reported on September 2021.
| 17.4 | Closure and Reclamation Considerations |
The SEMARNAT Environmental and Forestry Authorizations for the Project and NOM-141-SEMARNAT-2003 requires a restoration and monitoring program for mining areas that will recover the soil for landscape restitution and restore pre-mining land-use and ecosystem conditions.
Coeur conducts an annual review of its potential reclamation responsibilities company wide. A site-wide Closure Plan was prepared by Knight Piésold Consulting in December 2017. This document served as the base for potential closure and reclamation cost estimation, prepared by KC Harvey Environmental in October 2021. The 2021 year-end closure assessment for the actual disturbance for final reclamation at the Palmarejo Operations, is estimated at US$40.6 M.
| 17.5.1 | Environmental Impact Statements |
Coeur Mexicana submitted its initial MIA for Palmarejo in March 2008 (Palmarejo Phase 1) and received its first environmental authorization from SEMARNAT in May 2008 for a period of 13 years (including 11 years of operation and two years for closure and reclamation). This authorization covered the Palmarejo Phase 1 project that included all production facilities (process plant, tailings area, most waste deposits, open pit and underground facilities), for a total of 378 ha. Under the first environmental license, Coeur was authorized to operate Palmarejo until May 2017, followed by two years of reclamation activities until May 2019. This first authorization was extended for an additional 6.5 years in 2017 and is valid for production through October 2023 followed by a two-year closure period.
Coeur Mexicana filed for, and received, approval for a second environmental authorization (Palmarejo Phase 2) for an additional 290.34 ha, which was issued in 2010 for 10 years, ending in December 2020. This authorization was extended for five additional years and is valid through November 2025.
Coeur Mexicana submitted separate MIAs for some aspects of the Palmarejo Operations, including:
| • | Development of the Guadalupe and Independencia mines for an additional 43.93 ha, expiring on November 2023 plus the closure stage; |
| • | Construction of a haul road between Palmarejo and Guadalupe covering 4.38 ha, expires November 2027; |
| • | The power line and electric substation for Guadalupe, covering 6.47 ha, expires October 2025; |
| • | The Guadalupe and Independencia South Portal, expires June 2027; |
| • | Water treatment plant, expires May 2023; |
| • | Los Gavilanes–El Guamuchil aqueduct, expires December 2028. |
As noted in Chapter 3.7.1, Coeur has initiated the process of obtaining an MIA-R. In late July 2021, SEMARNAT requested additional information to the MIA-R document. This was supplied by Coeur on August 10, 2021. It is expected that the MIA-R will be approved in the first quarter of 2022. When approved the MIA-R will add 10 additional years to the current present environmental license, will consolidate 13 different authorizations under a single global license, and will include all new facilities and mine development expected for the LOM in this Report.
| 17.5.2 | Change in Land Use Authorizations |
Following the acceptance of the various MIAs, a vegetation disturbance permit or change in land use authorization (Cambio de Uso de Suelo, or CUS) was applied for. The original Palmarejo Phase I CUS was approved in 2008 for a period of 10 years, and then extended in 2016 for five additional (Dec 2021) years covering 327.3 ha for land disturbance. Concurrently, Palmarejo Phase II has a CUS approval for 290.34 ha, granted in 2010 for a seven-year period, extended for additional 3.5 years until December 2021. To date, the Project has CUS approval for mining activities over a total of 723 ha, including 668 ha for Palmarejo, 43 ha for Guadalupe, and 12 ha for other related facilities. The operations also have CUS approval for 3.8 ha for exploration activities at La Patria.
The Phase I MIA and corresponding CUS authorizations were extended by SEMARNAT through a relatively simple notification procedure for additional time equivalent to one-half of the initial authorized period. In the case of Palmarejo Phase I MIA, this represents 6.5 years of additional environmental authorization, starting May 2019.
The CUS is an authorization to clear natural vegetation and within the Phase I and Phase II areas, required areas were cleared during the construction phase. There is no need to further extend these authorizations. If additional land disturbance for mining activities is required, it can be added through a new CUS request. Payment to the Forestry Fund, in accordance with the additional disturbance, would be required.
Coeur Mexicana was granted full authorization for open pit and underground gold and silver mining activities within the areas outlined in the different MIAs. This includes permits for exploration, construction, and operation of the underground gold and silver mines, and land use/disturbance permits. The key authorizations and their terms are summarized in Table 17‑1. The authorizations required for production are in good standing.
Current permitting includes the cyanide leaching process, refining and cyanide detoxification of the tailings prior to TSF discharge. In 2012, SEMARNAT set a specific limit for cyanide concentrations in the tailings disposed in the TSF; this limit is consistent with other Coeur operations at 50 ppm weakly acid-dissociable cyanide. Coeur continues to meet the standards recommended in the International Cyanide Management Code.
All MIAs will expire prior to the planned end of mine life except one, “MIA Culvert extension at GPE”. Coeur is in the process of obtaining a new environmental license, MIA-R (refer to discussion in Chapter 17.5.1), to cover the remining LOM.
| 17.6 | Social Considerations, Plans, Negotiations and Agreements |
Coeur actively engages with the local community with a series of cultural social and economic programs divided into four main categories:
| • | Local hiring and local purchases: through the apprentice program, local youth are trained for different job opportunities and several of the apprentices are hired by the company. Priority is given to local providers and contractors; |
| • | House improvement program: the community relations group together with the projects department has developed the house improvement program that consists of community house roof and floor repair, installation of rainwater collection systems, backyard vegetable gardens, fruit tree donations, and hen coops for egg supply; |
| • | Social investment in vulnerable groups: families with vulnerable members are supported through a series of social programs: a) the 65+ program for vulnerable elderly through the sale of scrap metal, b) grocery donation programs; |
| • | Productive community programs: a) handcrafted soap and shampoo, b) herbs and medicinal plants/ointments and creams. |
The surrounding communities are supportive of the Palmarejo Operations, and the employment and benefits that the mines provide.
| Table 17‑1: | Granted Authorizations |
| Authorization Name | Granting Authority | Date Granted | Term Granted | Comment |
| MIA Palmarejo I | SEMARNAT | 23-May-06 | 29-Oct-25 | Extended for 7.5 years. Production until May 29, 2023, followed by closure period up to Oct 29, 2025. |
| CUS Palmarejo I | SEMARNAT | 14-Jul-08 | 31-Dec-21 | |
| MIA Palmarejo II | SEMARNAT | 7-Dec-10 | 16-Nov-25 | Extended for 5 years. Operative until Nov 16th 2023 plus 2 year closure up to Nov 16 2025 |
| CUS Palmarejo II | SEMARNAT | 3-Nov-10 | 03-Nov-21 | |
| MIA Guadalupe I | SEMARNAT | 24-Sep-10 | 26-Nov-23 | Plus 2 years of closure stage. |
| CUS Guadalupe I | SEMARNAT | 26-Nov-10 | 26-Nov-19 | No extension required. No additional soil use changes necessary. |
| CUS Guadalupe II | SEMARNAT | 27-Feb-13 | 16-Apr-17 | No extension required. No additional soil use changes necessary. |
| MIA Hauling Road I | SEMARNAT | 30-May-11 | 11-Jan-15 | New MIA approved on 11 Nov 2015 for hauling road expansion. |
| CUS Hauling Road I | SEMARNAT | 11-Jul-11 | 11-Jul-16 | No extension required |
| CUS Hauling Road II | SEMARNAT | 8-May-14 | 8-May-16 | No extension required |
| MIA WTP FTD | SEMARNAT | 31-May-13 | 31-May-23 | Authorization for PTAR 3 operation, located at FTD, not included in previous MIAs |
| MIA ICA/GPE S Portal | SEMARNAT | 4-Mar-16 | 16-Jun-27 | |
| CUS ICA/GPE S Portal | SEMARNAT | 16-Jun-16 | 16-Jun-26 | |
| MIA Power Line GPE | SEMARNAT | 19-Mar-15 | 15-Oct-25 | |
| CUS Power Line GPE | SEMARNAT | 23-Jun-15 | 15-Oct-17 | No extension required |
| MIA Water line Gavilanes-Guamuchil | SEMARNAT | 5-Dec-08 | 5-Dec-28 | |
| MIA Borrow Materials Area | SEMARNAT | 6-Feb-18 | 6-Feb-22 | 3.5 ha), to use in FTD Stage 5 construction in 2018. No extension required. |
| CUS Borrow Materials Area | SEMARNAT | 8-Aug-18 | 8-Aug-22 | |
| MIA PJO-GPE Hauling Road Expansion | SEMARNAT | 11-Nov-15 | 19-Nov-27 | |
| CUS PJO-GPE Haul Road Expansion | SEMARNAT | 13-Aug-18 | 13-Aug-21 | No extension required |
| MIA Deposit dredged material from ECD | SEMARNAT | 10-Apr-18 | 10-Apr-28 | Material dredged from environmental control dam and freshwater diversion channel stabilization |
| CUS Deposit dredged material from ECD | SEMARNAT | 13-Aug-18 | 13-Aug-21 | No extension required |
| MIA Culvert extension at GPE | SEMARNAT | 6-Jun-18 | 6-Jun-48 | |
| CUS Culvert extension at GPE | SEMARNAT | 28-Aug-18 | 28-Aug-20 | No extension required |
| CUS Spillway construction | SEMARNAT | 30-Apr-19 | 30-Apr-20 | No extension required |
| CUS modification for Spillway | SEMARNAT | 30-Apr-19 | 30-Apr-20 | No extension required |
| Water extraction permit, location change | CONAGUA | 16-Nov-14 | 16-Nov-34 | Water extraction license modification, relocation from environmental control dam embankment to freshwater dam embankment. |
| Water well | CONAGUA | 9-Jun-17 | 9-Jun-27 | Water extraction license for 189,216 m3/year. Valid for 10 years. |
| Water discharge permit, PTAR 3 | CONAGUA | 25-Feb-16 | 25-Feb-26 | Discharge permit for Palmarejo tailings area, water treatment plant PTAR3. Authorized discharge volume: 2,628,000 m3/year |
| Water discharge permit, PTAR 1 | CONAGUA | 28-Jan-09 | 28-Jan-24 | water treatment plant authorized discharge volume: 34,700 m3/year |
| Water discharge permit, PTAR 2 | CONAGUA | 3-Aug-12 | 3-Aug-22 | Water treatment plant authorized discharge volume: 37,250 m3/year |
| Explosive use and storage | SEDENA | 1-Jan-21 | 31-Dec-22 | Secretaria de la Defensa Naciónal (SEDENA) Permit # 4361-Chih. |
| Sanitary Landfill | SEDUE | 23-Apr-19 | 30-Apr-24 | Secretaría de Desarrrollo Urbano y Ecológico (SEDUE) |
Note: Acronyms used in table: MIA: Manifestación de Impacto Ambiental or Environmental Impact Statement; CUS: Cambio de uso del suelo or soil change use for vegetation clearing; GPE: Guadalupe mine; ICA: Independencia mine; FTD: Final tailings dam
Coeur Mexicana received the distinguished Social Responsibility Award from the Mexican Center of Philanthropy-CEMEFI on February 26, 2021. This award is bestowed on companies that have demonstrated a commitment to promoting social responsibility within the company as well as in the communities in which the company operates. This is the 11th year that Coeur Mexicana was an award recipient.
| 17.7 | Qualified Person’s Opinion on Adequacy of Current Plans to Address Issues |
Based on the information provided to the QP by Coeur (see Chapter 25), there are no material issues known to the QP that will require mitigation activities or allocation of remediation costs in respect of environmental, permitting, closure or social license considerations beyond what is included in the existing plans. Currently Coeur Mexicana is a mature mining operation that has demonstrated its ability to maintain environmental compliance, attain permits in a timely manner and has a strong social license to operate within its local communities.
| 18.0 | CAPITAL AND OPERATING COSTS |
Capital and operating cost estimates are at a minimum at a pre-feasibility level of confidence, having an accuracy level of ±25% and a contingency range not exceeding 15%.
| 18.2 | Capital Cost Estimates |
Major LOM capital costs include, but are not limited to mine development, plant expansions or upgrades, equipment replacement, and tailings storage.
Capital costs are based on recent prices or operating data. No allowance for contingency is included.
The basis of the capital estimates is derived from expected equipment needs and Project plans and is determined with the assistance of vendor and contractor quotes, previous buying experience and/or experience with construction of similar projects using Owner equipment and labor. The capital cost estimate includes consideration of historical capital cost estimates reconciled where Owner equipment and labor are used.
Capital expenditures consist largely of mining and processing equipment upgrades and replacement, capital leases, TSF construction and raises, small projects to support community or logistics, and general and administrative (G&A) support equipment, leases, and offices. Capital costs are split into:
| • | Sustaining capital: Costs support the existing LOM plan. |
| • | Non-sustaining capital: Costs are for a long-term structure or external project that does not necessarily relate directly to the mine plan. Non-sustaining capital allocations include TSF raises and closure costs, as well as community support projects. |
Labor assumptions for capital projects are based on third-party contractor costs, internal employee wage rates plus benefits, or a combination of the two where combined support is required.
Material costs are based on current prices for consumables without market or inflation rate assumed.
Owner labor costs to support mechanical rebuilds or internal projects that are included in capital costs at operating rates. Where the labor is to be provided by a contracted entity, contractor labor costs are included in the estimate.
Mine capital costs are estimated based on historic and reconciled Owner operating cost-plus adjustments. Rebuilds and equipment replacement costs are estimated based on current material and part costs. Major mine equipment fleet replacements are assumed to be conducted on an as-needs basis, depending on equipment condition, utilization, and hours. A capital cost of US$167.0 M is estimated for the LOM.
A major sustaining capital cost at Palmarejo is underground development for a LOM total of US$71.1 M.
Process capital costs include estimates of approximately US$2.7 M plus another average of US$1.5 M per year for process sustaining capital for a total of US$9.2 M. The LOM mobile equipment capital is estimated at US$34.0 M. The TSF and in-pit tailing disposal facilities have US$20.1 M estimated capital spend remaining over the Project life.
General and administrative capital costs average US$0.7 M per year in sustaining capital costs. Total general and administrative capital costs are US$3.9 M over the LOM.
The total reclamation and closure capital cost is estimated at US$40.6 M, with costs spread over the last four years of mine life.
| 18.2.2 | Capital Cost Summary |
Capital expenditure for the LOM is estimated at US$167.0 M from January 1, 2022. Estimated capital expenditures are shown in Table 18‑1.
| 18.3 | Operating Cost Estimates |
Operating costs were developed based on historical cost performance and first principal calculations based on current commodity costs, labor rates, and equipment costs. The costs are provided for each major cost center: mining, processing, selling expense, and G&A. The total operating cost estimate includes all site costs, off-site costs associated with gold and silver metal sales, gold stream payments, and corporate overheads. The cost estimates are based on budgeted and expected LOM costs.
Mine operating costs are estimated by area, based on an average mining rate of approximately 5,000 t/d. Mine and transport unit costs are estimated at US$53.80/t milled.
Processing costs include all activities related to crushing, grinding, flotation concentrate and tailings leaching, carbon elution and regeneration, cyanide destruction, electrowinning and refining, tailings storage facility, water reclaim, reagent systems, and the metallurgical laboratory. Processing costs are modelled as variable and period costs. Variable costs are costs that change with throughput rate, consisting largely of consumables/supplies and power costs, as well as maintenance and other allocations. Period costs are time related costs incurred regardless of production, including labor, contractors, and a portion of maintenance and other distributed costs. Total process costs vary year over year depending on the operational plan. The process operating cost is estimated to average US$34.05/t milled over the process LOM.
| Table 18‑1: | Estimated Capital Expenditures by Year (US$ M) |
| Area | 2022 | 2023 | 2024 | 2025 | 2026 | 2027 | 2028 | 2029 | 2030 | Total |
| Mine development | 17.5 | 17.4 | 16.4 | 11.6 | 0.2 | 3.9 | 4.0 | 0.7 | — | 71.7 |
| Infrastructure | 6.4 | 3.6 | 4.7 | 3.4 | - | 2.8 | 0.8 | 0.4 | — | 15.8 |
| Mobile equipment | 5.2 | 5.2 | 6.5 | 6.5 | 5.3 | 5.3 | — | — | — | 34.0 |
| GPE substation | 1.8 | 2.5 | — | — | — | — | — | — | — | 4.3 |
| Process equipment | 2.7 | — | — | — | — | — | — | — | — | 2.7 |
| Process sustaining capital | 1.9 | 2.1 | 1.5 | 1.5 | 1.5 | 0.75 | — | — | — | 9.2 |
| Mine & site capital | 3.0 | 2.3 | — | — | — | — | — | — | — | 5.3 |
| G&A & others | 1.7 | 0.7 | 0.5 | 0.5 | 0.5 | — | — | — | — | 3.9 |
| Tailings/water treatment | 15.8 | 4.3 | — | — | — | — | — | — | — | 20.1 |
| Total Capital Cost Estimate | 49.0 | 37.8 | 29.7 | 23.0 | 8.5 | 12.7 | 5.3 | 1.1 | — | 167.0 |
Note: Numbers have been rounded.
Infrastructure and other distributable costs such as power, light vehicles, maintenance, fuel, travel, and camp are distributed through the mining, processing, and site general costs as applicable.
General and administrative costs are modelled as period costs. These include period costs for administrative labor and supplies costs, information technology services, health and safety, environmental, security, supply chain, and accounting costs. Total G&A costs vary year over year depending on the operational plan. The G&A cost is projected to average $11.37/t milled.
General and administrative costs are modelled as period costs. These include period costs for administrative labor and supplies costs, information technology services, health and safety, environmental, security, supply chain, and accounting costs. Total G&A costs vary year over year depending on the operational plan. The G&A cost is projected to average US$15.76/t milled.
Selling expenses include treatment and refining costs of the doré and product transport from site to refinery for a LOM total of US$23.4 M for an average of US$0.44/oz Ag.
| 18.3.2 | Operating Cost Summary |
Operating expenditure for the LOM is estimated at $US1,500.3 M from January 1, 2022 to forecast end of the LOM in 2030.
Operating costs are summarized in Table 18‑2.
| Table 18‑2: | Operating Costs by Year (US$ M) |
| Operating Cost Type | 2022 | 2023 | 2024 | 2025 | 2026 | 2027 | 2028 | 2029 | 2030 | Total |
| Underground mining | 91.0 | 92.0 | 97.9 | 103.8 | 102.4 | 81.7 | 82.9 | 63.9 | 28.4 | 711.8 |
| Surface haulage | 5.7 | 5.9 | 5.9 | 6.0 | 6.0 | 5.7 | 5.5 | 4.8 | 2.8 | 48.2 |
| Processing | 59.3 | 59.7 | 63.6 | 64.3 | 61.8 | 60.2 | 56.5 | 44.7 | 19.9 | 490.1 |
| General and administrative | 27.6 | 27.6 | 28.4 | 28.9 | 28.1 | 28.3 | 26.6 | 21.3 | 10.0 | 226.8 |
| Transportation, refining, and sales costs | 2.9 | 3.0 | 3.0 | 3.0 | 2.8 | 2.9 | 2.6 | 2.4 | 0.8 | 23.4 |
| Total Operating Costs | 173.0 | 192.5 | 190.1 | 187.0 | 186.0 | 166.8 | 159.1 | 132.6 | 57.0 | 1,500.3 |
Note: Numbers have been rounded.
Capital and operating cost estimates are at a minimum at a pre-feasibility level of confidence, having an accuracy level of ±25% and a contingency range not exceeding 15%. The estimate accuracies and ranges comply with the stated accuracy and contingency ranges required to meet a pre-feasibility level of study under SK1300. The QPs considered the risks associated with the engineering estimation methods used when stating the accuracy and contingency ranges
and preparing the cost estimate forecasts.
The capital and operating cost estimates are presented for an operating mine, with an 11 year production history. Analogues to prior similar environments are not relevant to the Palmarejo Operations given the production history and that the mine was in production as at year-end December 31, 2021.
| 19.1 | Forward-looking Information Caution |
Results of the economic analysis represent forward- looking information that is subject to several known and unknown risks, uncertainties and other factors that may cause actual results to differ materially from those presented here.
Other forward-looking statements in this Report include, but are not limited to: statements with respect to future metal prices and concentrate sales contracts; the estimation of mineral reserves and mineral resources; the realization of mineral reserve estimates; the timing and amount of estimated future production; costs of production; capital expenditures; costs and timing of the development of new ore zones; permitting time lines; requirements for additional capital; government regulation of mining operations; environmental risks; unanticipated reclamation expenses; title disputes or claims; and, limitations on insurance coverage.
Factors that may cause actual results to differ from forward-looking statements include: actual results of current reclamation activities; results of economic evaluations; changes in Project parameters as mine and process plans continue to be refined, possible variations in mineral reserves, grade or recovery rates; geotechnical considerations during mining; failure of plant, equipment or processes to operate as anticipated; shipping delays and regulations; accidents, labor disputes and other risks of the mining industry; and, delays in obtaining governmental approvals.
Coeur records its financial costs on an accrual basis and adheres to U.S. Generally Accepted Accounting Principles (GAAP).
The financial costs used for this analysis are based on the 2022 LOM budget model, which was built on a zero-based budgeting process that was validated through a historical cost comparison from the previous financial year. All the figures in this section are LOM averages and may vary from year to year depending on capital and production needs.
The gold price used in the financial analysis varies from US$1,750 to $1,400/oz Au and the silver price varies from US$24.00 to $22.00/oz Ag.
| 19.3 | Financial Model Parameters |
| 19.3.1 | Mineral Resource, Mineral Reserve, and Mine Life |
The mineral resources are discussed in Chapter 11, and the mineral reserves in Chapter 12.
The mineral reserves support a mine life of nine years to 2030.
| 19.3.2 | Metallurgical Recoveries |
Forecast metallurgical recoveries are provided in Chapter 10.
| 19.3.3 | Smelting and Refining Terms |
Smelting and refining terms for the gold concentrates are outlined in Chapter 16.
Metal price assumptions are provided in Chapter 16.
| 19.3.5 | Capital and Operating Costs |
Capital and operating cost forecasts price assumptions are outlined in Chapter 18.
Working capital is based upon historical trends for movement in payables and receivables. This is adjusted year over year for changes in spending levels. Inventory movement is also adjusted annually for production levels. In future years the working capital is adjusted from recent historical values based upon the timing of the remaining mine life.
| 19.3.7 | Taxes and Royalties |
Royalties are discussed in Chapter 3.7. The Franco-Nevada agreement is included in the cashflow analysis. No other royalties are included in the cashflow analysis as there are no mineral resources or mineral reserves within the other royalties referenced in Chapter 3.7.
The economic model includes the Extraordinary Mining duty of 0.5% applied to all metal sales, and the Special Mining Duty of 7.5% applied to the pre-tax cash flow.
The income tax rate is 30%.
| 19.3.8 | Closure Costs and Salvage Value |
The 2021 year-end closure assessment for the actual disturbance for final reclamation at the Palmarejo Operations, is estimated at US$40.6 M and is discussed in Chapter 17.4.
No salvage value is assumed or included in the economic analysis.
The economic analysis is reported on a 100% Project ownership basis.
The economic analysis assumes constant prices with no inflationary adjustments.
The NPV 5% is US$229.5 M.
As the cashflows are based on existing operations where all costs are considered sunk to December 31, 2021, considerations of payback and internal rate of return are not relevant.
A summary of the financial results is provided in Table 19‑1. An annualized cashflow statement is provided in Table 19‑2.
The active mining operation ceases in 2030; however, closure costs are estimated to be paid out the last four years of operation for the purposes of the financial model.
The sensitivity of the Project to ± 20% changes in metal prices, grade, sustaining capital costs and operating cost assumptions was tested and can be seen in Table 19‑3.
The Project is most sensitive to metal prices, less sensitive to grade, less sensitive to operating costs, and least sensitive to capital costs.
| Table 19‑1: | Cashflow Summary Table |
| Item | Units | Value |
| Revenue |
| Average gold price | US$/oz | 1,644 |
| Average silver price | US$/oz | 22.56 |
| Gross revenue | US$M | 2,230.0 |
| Operating Costs |
| Mining | US$M | (760.0) |
| Processing | US$M | (490.1) |
| General and administrative | US$M | (226.8) |
| Smelting and refining | US$M | (23.4) |
| Total Operating Costs | US$M | (1,500.3) |
| Cash Flow |
| Operating cash flow* | US$M | 729.7 |
| Capital expenditures | US$M | (167.0) |
| Reclamation | US$M | (40.6) |
| Total Pre-Tax Cash Flow (Net Cash Flow) | US$M | 522.1 |
| 30% corporate income tax | US$M | (173.0) |
| 7.5% special mining duty | US$M | (59.5) |
| 0.5% extraordinary mining duty | US$M | (11.2) |
| Total After-Tax Cashflow (Net Cash Flow) | US$M | 278.4 |
| Total After-Tax NPV (5% Discount Rate) | US$M | 229.5 |
Note: * Operating cash flow is inclusive of the Franco Nevada encumbrance. Numbers have been rounded.
| Table 19‑2: | Annualized Cashflow (2022–2030) |
| Item | Units | 2022 | 2023 | 2024 | 2025 | 2026 | 2027 | 2028 | 2029 | 2030 |
| Revenue |
| Gross revenue* | US$M | 306.7 | 315.6 | 302.3 | 284.3 | 268.8 | 271.9 | 239.6 | 186.9 | 53.9 |
| Operating Costs |
| Mining | US$M | (96.7) | (97.9) | (103.8) | (102.4) | (96.5) | (87.4) | (82.9) | (63.9) | (28.4) |
| Processing | US$M | (59.3) | (59.7) | (63.6) | (64.3) | (61.8) | (60.2) | (56.5) | (44.7) | (19.9) |
| General and administrative | US$M | (27.6) | (27.6) | (28.4) | (28.9) | (28.1) | (28.3) | (26.6) | (21.3) | (10.0) |
| Smelting and refining | US$M | (2.9) | (3.0) | (3.0) | (3.0) | (2.8) | (2.9) | (2.6) | (2.4) | (0.8) |
| Total operating costs | US$M | (186.5) | (188.3) | (198.8) | (198.7) | (189.2) | (178.8) | (168.6) | (132.3) | (59.2) |
| Cash Flow |
| Operating cash flow | US$M | 120.2 | 127.4 | 103.5 | 85.6 | 79.6 | 93.1 | 71.0 | 54.7 | (5.3) |
| Capital expenditures | US$M | (49.0) | (37.8) | (29.7) | (23.0) | (8.5) | (12.7) | (5.3) | (1.1) | |
| Reclamation | US$M | | | | | | (10.0) | (10.0) | (10.0) | (10.6) |
| Total pre-tax cash flow (net cash flow) | US$M | 71.2 | 89.6 | 73.7 | 62.6 | 71.1 | 70.4 | 55.7 | 43.6 | (15.9) |
| 30% corporate income tax | US$M | (28.6) | (29.6) | (23.8) | (20.9) | (19.6) | (22.7) | (16.3) | (11.6) | — |
| 7.5% special mining duty | US$M | (9.5) | (10.1) | (8.4) | (7.0) | (6.6) | (7.5) | (5.8) | (4.5) | — |
| 0.5% extraordinary mining duty | US$M | (1.5) | (1.6) | (1.5) | (1.4) | (1.3) | (1.4) | (1.2) | (0.9) | (0.3) |
| Total after-tax cashflow (net cash flow) | US$M | 31.6 | 48.2 | 40.0 | 33.3 | 43.7 | 38.8 | 32.3 | 26.5 | (16.2) |
Note: * Gross revenue includes Franco-Nevada encumbrance. Numbers have been rounded.
| Table 19‑3: | Sensitivity Analysis (US$ M) |
| Parameter | -20% | -10% | -5% | Base | 5% | 10% | 20% |
| Metal price | -6.5 | 111.5 | 170.5 | 229.5 | 288.5 | 347.4 | 465.2 |
| Operating cost | 388.8 | 309.3 | 269.5 | 229.5 | 189.6 | 149.7 | 69.8 |
| Capital cost | 242.3 | 236.2 | 232.7 | 229.5 | 226.3 | 223.1 | 216.7 |
| Grade | -0.1 | 114.8 | 172.2 | 229.5 | 286.9 | 344 | 458.3 |
Note: Numbers have been rounded. Base case is highlighted.
This Chapter is not relevant to this Report.
| 21.0 | OTHER RELEVANT DATA AND INFORMATION |
This Chapter is not relevant to this Report.
| 22.0 | INTERPRETATION AND CONCLUSIONS |
The QPs note the following interpretations and conclusions within their areas of expertise, based on the review of data available for this Report.
| 22.2 | Mineral Tenure, Surface Rights, Water Rights, Royalties and Agreements |
Coeur’s wholly-owned subsidiary, Coeur Mexicana, as the operating entity.
The Palmarejo Operations consist of 71 mining concessions (27,227 ha).
Coeur has occupancy agreements in place with selected ejidos for exploitation or exploration purposes, collectively covering an area of 15,111.19 ha.
Water rights held are sufficient to support the LOM plan.
There are numerous net smelter return (NSR) royalties that cover the Palmarejo Operations area and range from 1–3% depending on the royalty agreement. The majority of the royalties are not payable under the LOM plan envisaged in this Report.
Coeur Mexicana agreed to sell to Franco–Nevada 50% of the refined gold produced from selected mining concessions at a gold price of $800/oz, in consideration of Franco–Nevada providing investment capital for Project development. The Agreement has a 40-year term, starting in 2016.
| 22.3 | Geology and Mineralization |
The deposits within the Palmarejo Operations area are considered to be examples of epithermal deposits displaying both intermediate- and low-sulfidation features.
The geological understanding of the settings, lithologies, and structural and alteration controls on mineralization is sufficient to support estimation of mineral resources.
| 22.4 | Exploration, Drilling, and Sampling |
The exploration programs completed by Coeur to date and predecessor companies are appropriate for the mineralization styles.
The quantity and quality of the lithological, collar and down hole survey data collected in the exploration program completed are sufficient to support mineral resource estimation. No drilling, sampling, or core recovery issues that could materially affect the accuracy or reliability of the core samples have been identified.
The collected sample data adequately reflect deposit dimensions, true widths of mineralization, and the deposit style.
Sampling is representative of the gold and silver values, reflecting areas of higher and lower grades.
The independent analytical laboratories used by Coeur and predecessor companies, where known, are accredited for selected analytical techniques.
Sample preparation used procedures and protocols that are/were standard in the industry and has been adequate throughout the history of the Project. Sample analysis uses procedures that are standard in the industry.
The QA/QC programs adequately address issues of precision, accuracy and contamination, and indicate that the analytical results are adequately accurate, precise, and contamination free to support mineral resource estimation.
The sample preparation, analysis, and security procedures are adequate for use in the estimation of mineral resources.
The QP undertook QA/QC verification, participated in programs to verify drill data prior to mineral resource estimation, checked selected gold and silver assay data, conducted drill hole lockdown, including checks of assay certificates, collar and downhole surveys, geology, and QA/QC reports, and signed off in 2014–present definition drill holes and the 2021 drilling.
The QP is of the opinion that the data verification programs for Project data adequately support the geological interpretations, the analytical and database quality, and therefore support the use of the data in mineral resource and mineral reserve estimation, and in mine planning.
| 22.6 | Metallurgical Testwork |
Metallurgical testwork was conducted by reputable laboratories and is supported by nearly a decade of production data. Test results were used as a guideline for plant design. Metallurgical testing results were consistent in the recommended methods of process design, extraction and recovery estimates.
Recovery factors estimated are based on appropriate metallurgical test work and confirmed with production data. Recovery factors are appropriate to the mineralization types and the selected process route. The LOM forecast average gold blended recovery is 90%. The LOM forecast average blended silver recovery is 82.5%.
Based on extensive operating experience and testwork, there are no known processing factors of deleterious elements that could have a significant effect on the economic extraction of the mineral reserve estimates.
| 22.7 | Mineral Resource Estimates |
The mineral resource estimate is reported using the mineral resource definitions set out in SK1300 and are reported exclusive of those mineral resources converted to mineral reserves. The reference point for the estimate is in situ. The estimate is current at December 31, 2021.
The estimate is primarily supported by core drilling. The estimate was constrained using reasonable prospects of economic extraction that assumed longhole stoping underground mining methods.
Factors that may affect the mineral resource estimates include: metal price and exchange rate assumptions; changes to the assumptions used to generate the gold cut-off grade; changes in local interpretations of mineralization geometry and continuity of mineralized zones; changes to geological and mineralization shape and geological and grade continuity assumptions; density and domain assignments; changes to geotechnical, mining and metallurgical recovery assumptions; changes to the input and design parameter assumptions for the underground mine designs constraining the estimates; assumptions as to the continued ability to access the site, retain mineral and surface rights titles, maintain environment and other regulatory permits, and maintain the social license to operate.
| 22.8 | Mineral Reserve Estimates |
The mineral reserve estimate is reported using the mineral reserve definitions set out in SK-1300. The reference point for the estimate is the point of delivery to the process facilities. Mineral reserves are current at December 31, 2021.
Mineral reserves were converted from measured and indicated mineral resources. Inferred mineral resources were set to waste. The mine plans assume underground mining using longhole open stoping using trackless equipment and cemented rock fill backfill. Target mining rates are 150,000 t/month.
Factors that may affect the mineral resource estimates include: metal price and exchange rate assumptions; changes to the assumptions used to generate the gold cut-off grade; changes in local interpretations of mineralization geometry and continuity of mineralized zones; changes to geological and mineralization shape and geological and grade continuity assumptions; density and domain assignments; changes to geotechnical, mining and metallurgical recovery assumptions; changes to the input and design parameter assumptions that pertain to the assumptions for the mineable shapes constraining the estimates; and assumptions as to the continued ability to access the site, retain mineral and surface rights titles, maintain environment and other regulatory permits, and maintain the social license to operate.
The Palmarejo Operations use conventional underground equipment and mining methods. The underground operations have been active since 2014.
Geotechnical conditions are reasonably understood. Depending on the deposit, rock mass quality is variable, and ranges from Poor to Good. Modifications based on variability and update geotechnical models were made as the mines developed.
There are few hydrogeological aspects to be considered beyond natural inflow of water to the workings. The permeability of the volcanic rock units in all mines is low to very low.
Stoping and cemented rock backfill mining methods were selected and implemented based on the orebody location, ground conditions and geological settings. Mining design assumptions for each mining region are typically standardized for each area and mining method assumed.
Ventilation is provided by fans and ventilation raises.
Backfill is a combination of CRF and straight waste fill.
The Palmarejo Operations have nine years of mine life remaining. The Guadalupe mine has a remaining nine-year mine life with the expansion components of Zapata and Animas. Independencia has a remaining nine-year mine life with expansions to the north and south and addition of the Hidalgo deposit. La Nación has five years of mine life remaining.
The process plant design was based on a combination of metallurgical testwork, study designs and industry standard practices, together with debottlenecking and optimization activities once the mill was operational. The design is conventional to the gold industry and has no novel parameters.
All major infrastructure required to support operations has been constructed and is operational. Facilities include: three operating underground mines; two shotcrete mixing plants; backfill cement mixing plant; water treatment plants and associated infrastructure; ROM pads; process plant; TSF and associated infrastructure; maintenance facilities; materials storage and laydown areas; various support facilities; electrical facilities including an emergency powerhouse; gravel airstrip; and a mine permanent camp and contractor facilities and kitchens.
The Palmarejo Operations currently maintain limited ROM stockpiles. Waste is currently excavated from the WRSFs around the former open pit and used underground as backfill.
The TSF, a zoned downstream earthfill dam, is projected to reach capacity in Q1 2023 at a capacity of 15.4 Mm3, by which time the operation will transition to disposal of tailings in the mined-out Palmarejo open pit.
Water treatment plants treat water pumped from underground to the surface, and water from the tailings pond.
Electrical power is supplied by the Mexican grid. A backup power generating facility is on site.
Water for the process facilities is obtained from a variety of sources, including wet tailings, the underground mines, additional subsurface sources from areas wells, limited permit options from the freshwater diversion dam, and a pump station located at the Chínipas River.
Coeur sells its payable silver and gold production on behalf of its subsidiaries on a spot or forward basis, primarily to multi-national banks and bullion trading houses. Markets for both silver and gold bullion are highly liquid, and the loss of a single trading counterparty would not impact Coeur’s ability to sell its bullion.
To mitigate the risks associated with gold and silver price fluctuations, Coeur may enter into option contracts to hedge future production.
Coeur uses a combination of analysis of three-year rolling averages, long-term consensus pricing, and benchmarks to pricing used by industry peers over the past year, when considering long-term commodity price forecasts.
Higher metal prices are used for the mineral resource estimates to ensure the mineral reserves are a sub-set of, and not constrained by, the mineral resources, in accordance with industry-accepted practice.
Coeur Mexicana has contracts with one U.S. based refiner and one Switzerland-based refiner, which refine the Palmarejo Operations’ doré bars into silver and gold bullion that meet certain benchmark standards set by the London Bullion Market Association.
Currently, there are contracts in place at the Palmarejo Operations to provide supply for all major commodities used in mining and processing, such as equipment vendors, power, explosives, cyanide, tire suppliers, raise boring, ground support suppliers and drilling contractors. The terms and rates for these contracts are within industry norms. These contracts are periodically put up for bid or negotiated.
| 22.13 | Environmental, Permitting and Social Considerations |
Baseline studies and monitoring were required in support of Project permitting.
The 2021 year-end closure assessment for the actual disturbance for final reclamation at the Palmarejo Operations, is estimated at US$40.6 M.
All required local, state, and federal permits for operation have been issued. The authorizations required for production are in good standing.
Coeur initiated the process of obtaining an MIA-R. In late July 2021, SEMARNAT requested additional information to the MIA-R document. This was supplied by Coeur on August 10, 2021. It is expected that the MIA-R will be approved in the first quarter of 2022. When approved the MIA-R will add 10 additional years to the current present environmental license, consolidate 13 different authorizations under a single global license, and include all new facilities and mine development expected for the LOM in this Report.
Coeur actively engaged with the local community with a series of cultural, social, and economic programs. The surrounding communities are supportive of the Palmarejo Operations, and the employment and benefits that the mines provide.
Coeur Mexicana received the distinguished Social Responsibility Award from the Mexican Center of Philanthropy-CEMEFI on February 26, 2021, the eleventh time the company has been so recognized.
| 22.14 | Capital Cost Estimates |
Capital cost estimates are at a minimum at a pre-feasibility level of confidence, having an accuracy level of ±25% and a contingency range not exceeding 15%.
Capital expenditure for the LOM is estimated at US$167.0 M from January 1, 2022.
| 22.15 | Operating Cost Estimates |
Operating cost estimates are at a minimum at a pre-feasibility level of confidence, having an accuracy level of ±25% and a contingency range not exceeding 15%.
Operating expenditure for the LOM is estimated at $US1,500.3 M from January 1, 2022, to the end of the LOM in 2030.
The mineral reserves support a mine life of nine years to 2030.
The NPV at a discount rate of 5% is US$229.5 M. As the cashflows are based on existing operations where all costs are considered sunk, considerations of payback and internal rate of return are not relevant.
The sensitivity of the Project to changes in metal prices, mined grade, exchange rate, sustaining capital costs and operating cost assumptions was tested using a range of 20% above and below the base case values. The Project is most sensitive to metal price, less sensitive to grade, less sensitive to operating cost, and least sensitive to capital cost
| 22.17 | Risks and Opportunities |
Factors that may affect the mineral resource and mineral reserve estimates were identified in Chapter 11 and Chapter 12.
Other risks noted include:
| • | Commodity price increases for key consumables such diesel, electricity, tires and other consumables would negatively impact the stated mineral reserves and mineral resources; |
| • | Labor cost increases or productivity decreases could also impact the stated mineral reserves and mineral resources, or impact the economic analysis that supports the mineral reserves; |
| • | Mining method will change from transverse to longitudinal longhole stoping over time as narrower portions of veins are mined which could result in higher cost, lower productivities and higher dilution quantities which can impact grade. All of these factors could impact cut-off grades, reserve estimates and economics; |
| • | Metallurgical recovery assumptions used in planning and operations are reasonable and based on historic performance. Any changes to metallurgical recovery assumptions could affect revenues and operating costs. This could also require revisions to cut-off grades and mineral reserve estimates; |
| • | Geotechnical and hydrological assumptions used in mine planning are based on historical performance, and to date historical performance has been a reasonable predictor of current conditions. Any changes to the geotechnical and hydrological assumptions could affect mine planning, affect capital cost estimates if any major rehabilitation is required due to a geotechnical or hydrological event, affect operating costs due to mitigation measures that may need to be imposed, and impact the economic analysis that supports the mineral reserve estimates; |
| • | The mineral resource and reserve estimates are sensitive to metal prices. Lower metal prices require revisions to the mineral resource estimates; |
| • | Changes in climate could result in drought and associated potential water shortages that could impact operating cost and ability to operate; |
| • | Assumptions that the long-term reclamation and mitigation of the Palmarejo Operations can be appropriately managed within the estimated closure timeframes and closure cost estimates; |
| • | Political risk from challenges to: |
| o | Coeur’s right to operate; |
| • | Changes to assumptions as to governmental tax or royalty rates, such as taxation rate increases or new taxation or royalty imposts. |
Opportunities include:
| • | Conversion of some or all the measured and indicated mineral resources currently reported exclusive of mineral reserves to mineral reserves, with appropriate supporting studies; |
| • | Upgrade of some or all the inferred mineral resources to higher-confidence categories, such that such better-confidence material could be used in mineral reserve estimation; |
| • | Higher metal prices than forecast could present upside sales opportunities and potentially an increase in predicted Project economics; |
| • | Ability to expand mineralization around known veins through exploration; |
| • | Discovery and development of new exploration targets across the district; |
| • | Potential to find or gain access to new mineralization that could be processed at the existing Palmarejo process facilities; |
| • | Ability to add additional process plant throughput as additional mineral resources are converted to mineral reserves. Coeur Mexicana has a track record of success on this in recent years as the mill was originally design for a larger open pit operation. |
Under the assumptions in this Report, the operations evaluated show a positive cash flow over the remaining LOM. The mine plan is achievable under the set of assumptions and parameters used.
As the Palmarejo Operations consist of operating mines, the QPs have no material recommendations to make.
Ammtec Ltd., 2005: Comminution Testwork Conducted Upon Samples of Ore from the Palmarejo Gold and Silver Deposit: report prepared for Bolnisi Gold NL, Report Number A9848, September, 2005.
Coeur, 2012: Coeur Expl_QAQC Procedures and Protocols: version 01_31_2012_Final_Spanish, 2012.
Condor Consulting, Inc., 2014: Processing, Analysis & Interpretation of a ZTEM airborne EM and magnetics survey, Palmarejo project, Chihuahua, Mexico: report prepared for Coeur Mining, Inc., October, 2014
Davies, R.C., "Guadalupe Project Structural Study", internal memorandum of Bolnisi Gold NL, 2007.
Galvan, V., 2012: Palmarejo Carbonate - Base Metal Epithermal Ag-Au District, Chihuahua, México: PhD dissertation, Mar. 2012
KC Harvey Environmental, 2021: 2021 Reclamation and Closure Annual Asset Retirement Obligation for the Palmarejo, Guadalupe, Independencia, and South Guadalupe Mines, October 2021
Knight Piésold, 2017, Coeur Mexicana, S.A. de C.V. Palmarejo Mine Site-wide Closure Plan, 2017, October 2017
Laurent, I., “Palmarejo/Trogan Project: Annual Technical Report, 1st July 2003 – 30th June 2004”, internal report of Planet Gold, S.A. de C.V., 2004.
Mahar, A.L., Goodell, P.C., Ramirez, A., and Garcia, J., 2019: Timing and Origin of Silici Volcanism in Northwestern Mexico: Insights from Zircon U–Pb Geochronology, Hf Isotopes and Geochemistry of Rhyolite Ignimbrites from Palmarejo and Guazapares in Southwest Chihuahua: Lithos 324–325, pp. 246–264, 2019.
Molina, C., 2016: Geology and mineralization controls surrounding the Palmarejo mining district - a compilation of remote and hands on exploration techniques: PhD dissertation, Dec. 2016
Murray, B.P., and Busby, C.J., 2015: Epithermal Mineralization Controlled by Synextensional Magmatism in the Guazapares Mining District of the Sierra Madre Occidental Silicic Large Igneous Province, Mexico: Journal of South American Earth Sciences 58.
Murray, B.P., Busby, C.J., Ferrari, L., and Solari, L.A., 2013: Synvolcanic Crustal Extension During the Mid-Cenozoic Ignimbrite Flare-Up in the Northern Sierra Madre Occidental, Mexico: Evidence from the Guazapares Mining District Region, Western Chihuahua: Geosphere published online 13 September 2013
Orway Mineral Consultants Pty. Ltd., undated: Analysis and Comminution Circuit Modeling: draft report prepared for Planet Gold.
Pakalnis & Associates, 2016: Independencia/Guadalupe Mine Operations – Site Visit/Technical Review: October 2016.
Pakalnis & Associates, 2017: La Nación Geotechnical Assessment: December 2017.
Melchor, A., 2010: Mineralogy of Guadalupe Au-Ag Vein Deposit: report prepared by Petrolab Laboratorio de InveStigaciones Geologicas, January, 2010.
Rhys, D., 2017: Geological observations regarding ore controls and new exploration target areas in the Palmarejo district: report prepared by Panterra Geoservices Inc. for Coeur Mining, Inc., May 24, 2017
Rhys, D., Lewis, P., and Rowland, J., 2020: Structural controls on ore localization in epithermal gold-silver deposits: A mineral systems approach: in Reviews in economic geology, Applied structural geology of ore-forming hydrothermal systems: Jan, 1, 2020
Stewart, H. H., "Progress report for the Guadalupe/Las Animas Target May 3, 2005", internal memorandum of Bolnisi Gold NL, 2005.
Sillitoe, R.H., 2010: Comments on Geology and Exploration of the Palmarejo Epithermal Silver-Gold Deposit and Environs, Chihuahua, Mexico: report prepared for Coeur d’Alene Mines Corporation, August 2010.
SRK Consulting (Canada) Inc., 2014: Geological Mapping Program and Aeromagnetic Interpretation of the Palmarejo Property, Chihuahua State, Mexico: report prepared for Coeur Mining, Inc., September 6, 2014
Wilson, S., Gustin, M., and Pennstrom, W., 2014: Technical report and Preliminary Economic Assessment for the San Miguel project, Guazapares mining district, Chihuahua, Mexico: report prepared by Metal Mining Consultants Inc. for Paramount Gold and Silver Corp., August 22, 2014
Weis, T., 2021: Palmarejo project, Magnetic Interpretation, Geophysical Report: report prepared by Thomas Weis and Associates Inc. for Coeur Mining, Inc., May, 14, 2021
Zesati, C., 2016: GIS and Remote Sensing applied to generate targets of exploration in Epithermal Deposits, Case Study: Palmarejo Mining District, Chihuahua, Mexico: MSc dissertation, Mar. 2016.
| 24.2 | Abbreviations and Units of Measure |
| Abbreviation/Symbol | Term |
| ' | minutes (geographic) |
| " | seconds (geographic) |
| # | number |
| % | percent |
| < | less than |
| > | greater than |
| µm | micrometer (micron) |
| g | gram |
| g/t | gram per tonne |
Abbreviation/Symbol | Term |
| HQ | 2.5 inch core size |
| in | inches |
| km | kilometer |
| koz | thousand ounces |
| kV | kilovolt |
| kW | kilowatt |
| kWhr | kilowatt hour |
| m | meter |
| Ma | million years ago |
| masl | meters above sea level |
| mesh | size based on the number of openings in one inch of screen |
| MW | megawatts |
| NQ | 1.87 inch core size |
| º | degrees |
| oz | ounce/ounces (troy ounce) |
| pH | measure of the acidity or alkalinity of a solution |
| ppm | parts per million |
| PQ | 3.35 inch core size |
| t/d | tons per day |
| t/day | Tons per day |
| t/hr | tons per hour |
| AA | atomic absorption spectroscopy |
| ARD | acid-rock drainage |
| AuEq | gold equivalent |
| CRF | cemented rock fill |
| DGPS | differential global positioning system |
| EIS | Environmental Impact Statement |
| GPS | global positioning system |
| ICP | inductively-coupled plasma |
| ICP ES | inductively-coupled plasma emission spectroscopy |
Abbreviation/Symbol | Term |
| ICP-OES | inductively-coupled plasma optical emission spectrometry |
| ID2 | inverse distance interpolation; number after indicates the power, e.g., ID2 indicates inverse distance to the 2nd power. |
| LOM | life-of-mine |
| NSR | net smelter return |
| OK | ordinary kriging |
| QA/QC | quality assurance and quality control |
| QP | Qualified Person |
| RC | reverse circulation |
| RMR | rock mass rating |
| ROM | Run-of-mine |
| RQD | rock quality designation |
| SAG | semi-autogenous grind |
| Term | Definition |
| acid rock drainage/ acid mine drainage | Characterized by low pH, high sulfate, and high iron and other metal species. |
| adjacent property | A property in which the issuer does not have an interest; has a boundary reasonably proximate to the property being reported on; and has geological characteristics similar to those of the property being reported on |
| argillic alteration | Introduces any one of a wide variety of clay minerals, including kaolinite, smectite and illite. Argillic alteration is generally a low temperature event, and some may occur in atmospheric conditions |
| azimuth | The direction of one object from another, usually expressed as an angle in degrees relative to true north. Azimuths are usually measured in the clockwise direction, thus an azimuth of 90 degrees indicates that the second object is due east of the first. |
| ball mill | A piece of milling equipment used to grind ore into small particles. It is a cylindrical shaped steel container filled with steel balls into which crushed ore is fed. The ball mill is rotated causing the balls themselves to cascade, which in turn grinds the ore. |
| Bond work index | A measure of the energy required to break an ore to a nominal product size, determined in laboratory testing, and used to calculate the required power in a grinding circuit design. |
| bullion | Unrefined gold and/or silver mixtures that have been melted and cast into a bar or ingot. |
Term | Definition |
| comminution/crushing/grinding | Crushing and/or grinding of ore by impact and abrasion. Usually, the word "crushing" is used for dry methods and "grinding" for wet methods. Also, "crushing" usually denotes reducing the size of coarse rock while "grinding" usually refers to the reduction of the fine sizes. |
| concentrate | The concentrate is the valuable product from mineral processing, as opposed to the tailing, which contains the waste minerals. The concentrate represents a smaller volume than the original ore |
| cut-off grade | The grade (i.e., the concentration of metal or mineral in rock) that determines the destination of the material during mining. For purposes of establishing “prospects of economic extraction,” the cut-off grade is the grade that distinguishes material deemed to have no economic value (it will not be mined in underground mining or if mined in surface mining, its destination will be the waste dump) from material deemed to have economic value (its ultimate destination during mining will be a processing facility). Other terms used in similar fashion as cut-off grade include net smelter return, pay limit, and break-even stripping ratio. |
| cyanidation | A method of extracting gold or silver by dissolving it in a weak solution of sodium cyanide. |
| data verification | The process of confirming that data has been generated with proper procedures, has been accurately transcribed from the original source and is suitable to be used for mineral resource and mineral reserve estimation |
| decline | A sloping underground opening for machine access from level to level or from the surface. Also called a ramp. |
| density | The mass per unit volume of a substance, commonly expressed in grams/ cubic centimeter. |
| depletion | The decrease in quantity of ore in a deposit or property resulting from extraction or production. |
| development | Often refers to the construction of a new mine or; Is the underground work carried out for the purpose of reaching and opening up a mineral deposit. It includes shaft sinking, cross-cutting, drifting and raising. |
| dilution | Waste of low-grade rock which is unavoidably removed along with the ore in the mining process. |
| dip | |
| drift | A horizontal mining passage underground. A drift usually follows the ore vein, as distinguished from a crosscut, which intersects it. |
| Areas of land owned by the property owner, but in which other parties, such as utility companies, may have limited rights granted for a specific purpose. |
| electrowinning. | The removal of precious metals from solution by the passage of current through an electrowinning cell. A direct current supply is connected to the anode and cathode. As current passes through the cell, metal is deposited on the cathode. When sufficient metal has been deposited on the cathode, it is removed from the cell and the sludge rinsed off the plate and dried for further treatment. |
| elution | Recovery of the gold from the activated carbon into solution before zinc precipitation or electro-winning. |
| An interest or partial right in real property which diminished the value of ownership, but does not prevent the transfer of ownership. Mortgages, taxes and judgements are encumbrances known as liens. Restrictions, easements, and reservations are also encumbrances, although not liens. |
Term | Definition |
| exploration information | Geological, geophysical, geochemical, sampling, drilling, trenching, analytical testing, assaying, mineralogical, metallurgical, and other similar information concerning a particular property that is derived from activities undertaken to locate, investigate, define, or delineate a mineral prospect or mineral deposit |
| feasibility study | A feasibility study is a comprehensive technical and economic study of the selected development option for a mineral project, which includes detailed assessments of all applicable modifying factors, as defined by this section, together with any other relevant operational factors, and detailed financial analysis that are necessary to demonstrate, at the time of reporting, that extraction is economically viable. The results of the study may serve as the basis for a final decision by a proponent or financial institution to proceed with, or finance, the development of the project. A feasibility study is more comprehensive, and with a higher degree of accuracy, than a pre-feasibility study. It must contain mining, infrastructure, and process designs completed with sufficient rigor to serve as the basis for an investment decision or to support project financing. |
| flotation | Separation of minerals based on the interfacial chemistry of the mineral particles in solution. Reagents are added to the ore slurry to render the surface of selected minerals hydrophobic. Air bubbles are introduced to which the hydrophobic minerals attach. The selected minerals are levitated to the top of the flotation machine by their attachment to the bubbles and into a froth product, called the "flotation concentrate." If this froth carries more than one mineral as a designated main constituent, it is called a "bulk float". If it is selective to one constituent of the ore, where more than one will be floated, it is a "differential" float. |
| flowsheet | The sequence of operations, step by step, by which ore is treated in a milling, concentration, or smelting process. |
| footwall | The wall or rock on the underside of a vein or ore structure. |
| frother | A type of flotation reagent which, when dissolved in water, imparts to it the ability to form a stable froth |
| gravity separation | Exploitation of differences in the densities of particles to achieve separation. Machines utilizing gravity separation include jigs and shaking tables. |
| hanging wall | The wall or rock on the upper or top side of a vein or ore deposit. |
| indicated mineral resource | An indicated mineral resource is that part of a mineral resource for which quantity and grade or quality are estimated on the basis of adequate geological evidence and sampling. The term adequate geological evidence means evidence that is sufficient to establish geological and grade or quality continuity with reasonable certainty. The level of geological certainty associated with an indicated mineral resource is sufficient to allow a qualified person to apply modifying factors in sufficient detail to support mine planning and evaluation of the economic viability of the deposit. |
| inferred mineral resource | An inferred mineral resource is that part of a mineral resource for which quantity and grade or quality are estimated on the basis of limited geological evidence and sampling. The term limited geological evidence means evidence that is only sufficient to establish that geological and grade or quality continuity is more likely than not. The level of geological uncertainty associated with an inferred mineral resource is too high to apply relevant technical and economic factors likely to influence the prospects of economic extraction in a manner useful for evaluation of economic viability. A qualified person must have a reasonable expectation that the majority of inferred mineral resources could be upgraded to indicated or measured mineral resources with continued exploration; and should be able to defend the basis of this expectation before his or her peers. |
Term | Definition |
| internal rate of return (IRR) | The rate of return at which the Net Present Value of a project is zero; the rate at which the present value of cash inflows is equal to the present value of the cash outflows. |
| liberation | Freeing, by comminution, of particles of specific mineral from their interlock with other constituents of the ore. |
| life of mine (LOM) | Number of years that the operation is planning to mine and treat ore, and is taken from the current mine plan based on the current evaluation of ore reserves. |
| locked cycle flotation test | A standard laboratory flotation test where certain intermediate streams are recycled into previous separation stages and the test is repeated across a number of cycles. This test provides a more realistic prediction of the overall recovery and concentrate grade that would be achieved in an actual flotation circuit, compared with a simpler batch flotation test. |
| measured mineral resource | A measured mineral resource is that part of a mineral resource for which quantity and grade or quality are estimated on the basis of conclusive geological evidence and sampling. The term conclusive geological evidence means evidence that is sufficient to test and confirm geological and grade or quality continuity. The level of geological certainty associated with a measured mineral resource is sufficient to allow a qualified person to apply modifying factors, as defined in this section, in sufficient detail to support detailed mine planning and final evaluation of the economic viability of the deposit. |
| merger | A voluntary combination of two or more companies whereby both stocks are merged into one. |
| Merrill-Crowe (M-C) circuit | A process which recovers precious metals from solution by first clarifying the solution, then removing the air contained in the clarified solution, and then precipitating the gold and silver from the solution by injecting zinc dust into the solution. The valuable sludge is collected in a filter press for drying and further treatment |
| mill | Includes any ore mill, sampling works, concentration, and any crushing, grinding, or screening plant used at, and in connection with, an excavation or mine. |
| mineral reserve | A mineral reserve is an estimate of tonnage and grade or quality of indicated and measured mineral resources that, in the opinion of the qualified person, can be the basis of an economically viable project. More specifically, it is the economically mineable part of a measured or indicated mineral resource, which includes diluting materials and allowances for losses that may occur when the material is mined or extracted. The determination that part of a measured or indicated mineral resource is economically mineable must be based on a preliminary feasibility (pre-feasibility) or feasibility study, as defined by this section, conducted by a qualified person applying the modifying factors to indicated or measured mineral resources. Such study must demonstrate that, at the time of reporting, extraction of the mineral reserve is economically viable under reasonable investment and market assumptions. The study must establish a life of mine plan that is technically achievable and economically viable, which will be the basis of determining the mineral reserve. The term economically viable means that the qualified person has determined, using a discounted cash flow analysis, or has otherwise analytically determined, that extraction of the mineral reserve is economically viable under reasonable investment and market assumptions. The term investment and market assumptions includes all assumptions made about the prices, exchange rates, interest and discount rates, sales volumes, and costs that are necessary to determine the economic viability of the mineral reserves. The qualified person must use a price for each commodity that provides a reasonable basis for establishing that the project is economically viable. |
Term | Definition |
| mineral resource | A mineral resource is a concentration or occurrence of material of economic interest in or on the Earth’s crust in such form, grade or quality, and quantity that there are reasonable prospects for economic extraction. The term material of economic interest includes mineralization, including dumps and tailings, mineral brines, and other resources extracted on or within the earth’s crust. It does not include oil and gas resources as defined in Regulation S-X (§210.4-10(a)(16)(D) of this chapter), gases (e.g., helium and carbon dioxide), geothermal fields, and water. When determining the existence of a mineral resource, a qualified person, as defined by this section, must be able to estimate or interpret the location, quantity, grade or quality continuity, and other geological characteristics of the mineral resource from specific geological evidence and knowledge, including sampling; and conclude that there are reasonable prospects for economic extraction of the mineral resource based on an initial assessment, as defined in this section, that he or she conducts by qualitatively applying relevant technical and economic factors likely to influence the prospect of economic extraction. |
| modifying factors | The factors that a qualified person must apply to indicated and measured mineral resources and then evaluate in order to establish the economic viability of mineral reserves. A qualified person must apply and evaluate modifying factors to convert measured and indicated mineral resources to proven and probable mineral reserves. These factors include, but are not restricted to: mining; processing; metallurgical; infrastructure; economic; marketing; legal; environmental compliance; plans, negotiations, or agreements with local individuals or groups; and governmental factors. The number, type and specific characteristics of the modifying factors applied will necessarily be a function of and depend upon the mineral, mine, property, or project. |
| net present value (NPV) | The present value of the difference between the future cash flows associated with a project and the investment required for acquiring the project. Aggregate of future net cash flows discounted back to a common base date, usually the present. NPV is an indicator of how much value an investment or project adds to a company. |
| net smelter return royalty (NSR) | A defined percentage of the gross revenue from a resource extraction operation, less a proportionate share of transportation, insurance, and processing costs. |
| open pit | A mine that is entirely on the surface. Also referred to as open-cut or open-cast mine. |
Term | Definition |
| open stope | In competent rock, it is possible to remove all of a moderate sized ore body, resulting in an opening of considerable size. Such large, irregularly-shaped openings are called stopes. The mining of large inclined ore bodies often requires leaving horizontal pillars across the stope at intervals in order to prevent collapse of the walls. |
| ounce (oz) (troy) | Used in imperial statistics. A kilogram is equal to 32.1507 ounces. A troy ounce is equal to 31.1035 grams. |
| plant | A group of buildings, and especially to their contained equipment, in which a process or function is carried out; on a mine it will include warehouses, hoisting equipment, compressors, repair shops, offices, mill or concentrator. |
| portal | The surface entrance to a tunnel or adit |
| preliminary feasibility study, pre-feasibility study | A preliminary feasibility study (prefeasibility study) is a comprehensive study of a range of options for the technical and economic viability of a mineral project that has advanced to a stage where a qualified person has determined (in the case of underground mining) a preferred mining method, or (in the case of surface mining) a pit configuration, and in all cases has determined an effective method of mineral processing and an effective plan to sell the product. A pre-feasibility study includes a financial analysis based on reasonable assumptions, based on appropriate testing, about the modifying factors and the evaluation of any other relevant factors that are sufficient for a qualified person to determine if all or part of the indicated and measured mineral resources may be converted to mineral reserves at the time of reporting. The financial analysis must have the level of detail necessary to demonstrate, at the time of reporting, that extraction is economically viable |
| probable mineral reserve | A probable mineral reserve is the economically mineable part of an indicated and, in some cases, a measured mineral resource. For a probable mineral reserve, the qualified person’s confidence in the results obtained from the application of the modifying factors and in the estimates of tonnage and grade or quality is lower than what is sufficient for a classification as a proven mineral reserve, but is still sufficient to demonstrate that, at the time of reporting, extraction of the mineral reserve is economically viable under reasonable investment and market assumptions. The lower level of confidence is due to higher geologic uncertainty when the qualified person converts an indicated mineral resource to a probable reserve or higher risk in the results of the application of modifying factors at the time when the qualified person converts a measured mineral resource to a probable mineral reserve. A qualified person must classify a measured mineral resource as a probable mineral reserve when his or her confidence in the results obtained from the application of the modifying factors to the measured mineral resource is lower than what is sufficient for a proven mineral reserve. |
| propylitic | Characteristic greenish color. Minerals include chlorite, actinolite and epidote. Typically contains the assemblage quartz–chlorite–carbonate |
| proven mineral reserve | A proven mineral reserve is the economically mineable part of a measured mineral resource. For a proven mineral reserve, the qualified person has a high degree of confidence in the results obtained from the application of the modifying factors and in the estimates of tonnage and grade or quality. A proven mineral reserve can only result from conversion of a measured mineral resource. |
Term | Definition |
| qualified person | A qualified person is an individual who is a mineral industry professional with at least five years of relevant experience in the type of mineralization and type of deposit under consideration and in the specific type of activity that person is undertaking on behalf of the registrant; and an eligible member or licensee in good standing of a recognized professional organization at the time the technical report is prepared. For an organization to be a recognized professional organization, it must: (A) Be either: (1) An organization recognized within the mining industry as a reputable professional association, or (2) A board authorized by U.S. federal, state or foreign statute to regulate professionals in the mining, geoscience or related field; (B) Admit eligible members primarily on the basis of their academic qualifications and experience; (C) Establish and require compliance with professional standards of competence and ethics; (D) Require or encourage continuing professional development; (E) Have and apply disciplinary powers, including the power to suspend or expel a member regardless of where the member practices or resides; and; (F) Provide a public list of members in good standing. |
| raise | A vertical or inclined underground working that has been excavated from the bottom upward |
| reclamation | The restoration of a site after mining or exploration activity is completed. |
| refining | A high temperature process in which impure metal is reacted with flux to reduce the impurities. The metal is collected in a molten layer and the impurities in a slag layer. Refining results in the production of a marketable material. |
| rock quality designation (RQD) | A measure of the competency of a rock, determined by the number of fractures in a given length of drill core. For example, a friable ore will have many fractures and a low RQD. |
| royalty | An amount of money paid at regular intervals by the lessee or operator of an exploration or mining property to the owner of the ground. Generally based on a specific amount per tonne or a percentage of the total production or profits. Also, the fee paid for the right to use a patented process. |
| run-of-mine | A term used to describe ore of average grade for the deposit, typically used for the ore pile adjacent the process plant. |
| semi-autogenous grinding (SAG) | A method of grinding rock into fine powder whereby the grinding media consists of larger chunks of rocks and steel balls. |
| shaft | A vertical or inclined excavation for the purpose of opening and servicing a mine. It is usually equipped with a hoist at the top, which lowers and raises a conveyance for handling men and material |
| specific gravity | The weight of a substance compared with the weight of an equal volume of pure water at 4°C. |
| stope | An excavation in a mine, other than development workings, made for the purpose of extracting ore. |
| strike length | The horizontal distance along the long axis of a structural surface, rock unit, mineral deposit or geochemical anomaly. |
Term | Definition |
| sublevel stoping | A large-scale open stoping method. Access is provided to the ore body at various sub-intervals between the main haulage levels to drill and blast the intervening ore |
| tailings | Material rejected from a mill after the recoverable valuable minerals have been extracted. |
| uniaxial compressive strength | A measure of the strength of a rock, which can be determined through laboratory testing, and used both for predicting ground stability underground, and the relative difficulty of crushing. |
| 25.0 | RELIANCE ON INFORMATION PROVIDED BY THE REGISTRANT |
The QPs fully relied on the registrant for the guidance in the areas noted in the following sub-sections. As the operations have been in production for 11 years, the registrant has considerable experience in this area.
The QPs took undertook checks that the information provided by the registrant was suitable to be used in the Report.
| • | Information relating to inflation, interest rates, discount rates, taxes. |
This information is used in the economic analysis in Chapter 19. It supports the mineral resource estimate in Chapter 11, and the mineral reserve estimate in Chapter 12.
| • | Information relating to market studies/markets for product, market entry strategies, marketing and sales contracts, product valuation, product specifications, refining and treatment charges, transportation costs, agency relationships, material contracts (e.g. mining, concentrating, smelting, refining, transportation, handling, hedging arrangements, and forward sales contracts), and contract status (in place, renewals). |
This information is used when discussing the market, commodity price and contract information in Chapter 16, and in the economic analysis in Chapter 19. It supports the mineral resource estimate in Chapter 11, and the mineral reserve estimate in Chapter 12.
| • | Information relating to the corporate ownership interest, the mineral tenure (concessions, payments to retain, obligation to meet expenditure/reporting of work conducted), surface rights, water rights (water take allowances), royalties, encumbrances, easements and rights-of-way, violations and fines, permitting requirements, ability to maintain and renew permits |
This information is used in support of the property ownership information in Chapter 3, the permitting and closure discussions in Chapter 17, and the economic analysis in Chapter 19. It supports the mineral resource estimate in Chapter 11, and the mineral reserve estimate in Chapter 12.
| 25.5 | Environmental Matters |
| • | Information relating to baseline and supporting studies for environmental permitting, environmental permitting and monitoring requirements, ability to maintain and renew permits, emissions controls, closure planning, closure and reclamation bonding and bonding requirements, sustainability accommodations, and monitoring for and compliance with requirements relating to protected areas and protected species. |
This information is used when discussing property ownership information in Chapter 3, the permitting and closure discussions in Chapter 17, and the economic analysis in Chapter 19. It supports the mineral resource estimate in Chapter 11, and the mineral reserve estimate in Chapter 12.
| 25.6 | Stakeholder Accommodations |
| • | Information relating to social and stakeholder baseline and supporting studies, hiring and training policies for workforce from local communities, partnerships with stakeholders (including national, regional, and state mining associations; trade organizations; fishing organizations; state and local chambers of commerce; economic development organizations; non-government organizations; and, state and federal governments), and the community relations plan. |
This information is used in the social and community discussions in Chapter 17, and the economic analysis in Chapter 19. It supports the mineral resource estimate in Chapter 11, and the mineral reserve estimate in Chapter 12.
| • | Information relating to taxation and royalty considerations at the Project level, monitoring requirements and monitoring frequency, and bonding requirements. |
This information is used in the economic analysis in Chapter 19. It supports the mineral resource estimate in Chapter 11, and the mineral reserve estimate in Chapter 12.
| 25.8.1 | Exploration and Drilling |
Internal controls are discussed where required in the relevant chapters of the technical report summary. The following sub-sections summarize the types of procedures, protocols, guidance and controls that Coeur has in place for its exploration and mineral resource and reserve estimation efforts, and the type of risk assessments that are undertaken.
Coeur has the following internal controls protocols in place for exploration data:
| • | Written procedures and guidelines to support preferred sampling methods and approaches; periodic compliance reviews of adherence to such written procedures and guidelines; |
| • | Maintenance of a complete chain-of-custody, ensuring the traceability and integrity of the samples at all handling stages from collection, transportation, sample preparation and analysis to long-term sample storage; |
| • | Geological logs are checked and verified, and there is a physical sign-off to attest to the validation protocol required; |
| • | Quality control checks on collar and downhole survey data for errors or significant deviations; |
| • | Appropriate types of quality control samples are inserted into the sample stream at appropriate frequencies to assess analytical data quality; |
| • | Third-party fully certified labs are used for assays used in public disclosure or resource models |
| • | Regular inspection of analytical and sample preparation facilities by appropriately experienced Coeur personnel; |
| • | QA/QC data are regularly verified to ensure that outliers sample mix-ups, contamination, or laboratory biases during the sample preparation and analysis steps are correctly identified, mitigated or remediated. Changes to database entries are required be documented; |
| • | Database upload and verification procedures to ensure the accuracy and integrity of the data being entered into the Project database(s). These are typically performed using software data-checking routines. Changes to database entries are required to be documented. Data are subject to regular backups. |
| 25.8.2 | Mineral Resource and Mineral Reserve Estimates |
Coeur has the following internal controls protocols in place for mineral resource and mineral reserve estimation:
| • | Prior to use in mineral resource or mineral reserve estimation, the selected data to support estimation are downloaded from the database into a project file and reviewed for improbable entries and high values; |
| • | Written procedures and guidelines are used to support estimation methods and approaches; |
| • | Completion of annual technical statements on each mineral resource and mineral reserve estimate by qualified persons. These technical statements include evaluation of modifying and technical factors, incorporate available reconciliation data, and are based on a cashflow analysis; |
| • | Internal reviews of block models, mineral resources and mineral reserves using a “layered responsibility” approach with Qualified Person involvement at the site and corporate levels; |
Coeur has established mine risk registers that are regularly reviewed and maintained. The registers record the risk type, the nature of the impact if the risk occurred, the frequency or probability of the risk occurrence, planned mitigation measures, and record of progress of the mitigation undertaken. Risks are removed from the registers if mitigation measures are successful or added to the registers as a new risk is recognized.
Other risk controls include aspects such as:
| • | Active monitoring programs such as mill performance, geotechnical networks, water sampling, waste management; |
| • | Regular review of markets, commodity and price forecasts by internal specialists; reviews of competitor activities; |
| • | Regular reviews of stakeholder concerns, accommodations to stakeholder concerns and ongoing community consultation; |
| • | Monitoring of key permits and obligations such as tenures, surface rights, mine environmental and operating permits, agreements and regulatory changes to ensure all reporting and payment obligations have been met to keep those items in good standing. |
| No. | Title No. | Concession Name | Owner/Parties | Type | Expiry Date | Hectares | Acres | Annual Holding Costs | Royalty | Group |
| 1 | 164465 | Palmarejo | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2029-05-08 | 52.0755 | 128.681 | $18,320.00 | N/A | Huruapa |
| 2 | 167281 | Nueva Patria | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-10-29 | 11.0000 | 27.181 | $3,870.00 | N/A | Huruapa |
| 3 | 167282 | Maclovia | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-10-29 | 6.0000 | 14.826 | $2,110.00 | N/A | Huruapa |
| 4 | 167322 | San Juan de Dios | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-11-02 | 23.0000 | 56.834 | $8,092.00 | N/A | Huruapa |
| 5 | 167323 | Patria Vieja | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-11-02 | 4.0000 | 9.884 | $1,408.00 | N/A | Huruapa |
| 6 | 170588 | Unificación Guerra al Tirano | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2032-06-01 | 27.4471 | 67.823 | $9,656.00 | 2%NSR | Huruapa |
| 7 | 185236 | El Rosario | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2039-12-13 | 10.9568 | 27.075 | $3,854.00 | N/A | Huruapa |
| 8 | 186009 | Los Tajos | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2039-12-13 | 2.7043 | 6.682 | $952.00 | N/A | Huruapa |
| 9 | 187906 | Tres de Mayo | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2040-11-21 | 39.8582 | 98.491 | $14,022.00 | 2%NSR | Huruapa |
| 10 | 188817 | San Carlos | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2040-11-28 | 160.0000 | 395.367 | $56,288.00 | N/A | Huruapa |
| 11 | 188820 | La Buena Fe | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2040-11-28 | 60.0000 | 148.263 | $21,108.00 | N/A | Huruapa |
| 12 | 189692 | La Estrella | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2040-12-04 | 59.5863 | 147.240 | $20,962.00 | N/A | Huruapa |
| 13 | 191332 | Sulema No. 2 | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2041-12-18 | 15.8280 | 39.112 | $5,568.00 | N/A | Huruapa |
| 14 | 194678 | Santo Domingo | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2042-05-06 | 15.3737 | 37.989 | $5,408.00 | N/A | Huruapa |
| 15 | 195487 | Unificación Huruapa | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2039-09-13 | 213.7755 | 528.249 | $75,206.00 | N/A | Huruapa |
| 16 | 198543 | Reyna de Oro | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2043-11-29 | 27.1791 | 67.161 | $9,562.00 | 2%NSR | Huruapa |
| 17 | 209541 | La Aurelia | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2049-08-02 | 10.0000 | 24.710 | $3,518.00 | N/A | Huruapa |
| 18 | 209648 | Ampliación La Buena Fe | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2049-08-02 | 40.8701 | 100.992 | $14,378.00 | N/A | Huruapa |
| 19 | 209975 | Caballero Azteca | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2049-08-30 | 5.0510 | 12.481 | $1,776.00 | N/A | Huruapa |
| 20 | 209976 | Carmelita | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2049-08-30 | 5.3430 | 13.203 | $1,880.00 | N/A | Huruapa |
| 21 | 210163 | El Risco | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2049-09-09 | 24.0000 | 59.305 | $8,444.00 | N/A | Huruapa |
| 22 | 210320 | Victoria | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2049-09-23 | 76.0883 | 188.018 | $26,768.00 | N/A | Huruapa |
| 23 | 210479 | Lezcura | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2049-10-07 | 14.5465 | 35.945 | $5,118.00 | N/A | Huruapa |
| 24 | 212281 | La Mexicana | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2050-09-28 | 142.1410 | 351.237 | $50,006.00 | N/A | Huruapa |
| 25 | 214101 | Virginia | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2051-08-09 | 12.0906 | 29.876 | $4,254.00 | N/A | Huruapa |
| 26 | 221490 | Trogan | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2054-02-18 | 3,844.5413 | 9,500.031 | $1,352,510.00 | N/A | Huruapa |
| 27 | 221491 | Trogan Fracción | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2054-02-18 | 7.9682 | 19.690 | $2,804.00 | N/A | Huruapa |
| 28 | 222319 | La Curra | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2054-06-24 | 37.6593 | 93.058 | $13,248.00 | N/A | Huruapa |
| 29 | 223292 | La Currita | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2054-11-24 | 13.6805 | 33.805 | $4,812.00 | N/A | Huruapa |
No. | Title No. | Concession Name | Owner/Parties | Type | Expiry Date | Hectares | Acres | Annual Holding Costs | Royalty | Group |
| 30 | 224118 | Ampliación Trogan | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2055-04-07 | 703.2318 | 1,737.717 | $247,396.00 | N/A | Huruapa |
| 31 | 225223 | Ampl. Trogan Oeste | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2055-08-04 | 1,699.9939 | 4,200.760 | $598,058.00 | N/A | Huruapa |
| 32 | 225278 | Trogan Norte 1 | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2055-08-11 | 1,024.0000 | 2,530.349 | $360,244.00 | N/A | Huruapa |
| 33 | 225279 | Trogan Norte 2 | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2055-08-11 | 1,019.2222 | 2,518.543 | $358,562.00 | N/A | Huruapa |
| 34 | 225308 | Trogan Oeste | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2055-08-15 | 2,699.0748 | 6,669.533 | $949,534.00 | N/A | Huruapa |
| 35 | 225574 | La Moderna | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2055-09-22 | 75.8635 | 187.462 | $26,688.00 | N/A | Huruapa |
| 36 | 226201 | La Buena Fe Norte | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2055-11-28 | 98.0878 | 242.379 | $34,508.00 | N/A | Huruapa |
| 37 | 166401 | San Miguel | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-06-03 | 12.9458 | 31.990 | $4,554.00 | N/A | None |
| 38 | 166402 | San Juan | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-06-03 | 3.0000 | 7.413 | $1,056.00 | N/A | None |
| 39 | 166422 | San Luis | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-06-03 | 4.0000 | 9.884 | $1,408.00 | N/A | None |
| 40 | 166423 | Empalme | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-06-03 | 6.0000 | 14.826 | $2,110.00 | N/A | None |
| 41 | 166424 | Sangre De Cristo | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-06-03 | 41.0000 | 101.313 | $14,424.00 | N/A | None |
| 42 | 166425 | Santa Clara | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-06-03 | 15.0000 | 37.066 | $5,278.00 | N/A | None |
| 43 | 166426 | El Carmen | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-06-03 | 59.0864 | 146.005 | $20,786.00 | N/A | None |
| 44 | 166427 | Las Tres B.B.B. | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-06-03 | 23.0010 | 56.836 | $8,092.00 | N/A | None |
| 45 | 166428 | Swanwick | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-06-03 | 70.1316 | 173.298 | $24,672.00 | N/A | None |
| 46 | 166429 | Las Tres S.S.S. | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-06-03 | 19.1908 | 47.421 | $6,752.00 | N/A | None |
| 47 | 166430 | El Rosario | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2030-06-03 | 14.0000 | 34.595 | $4,926.00 | N/A | None |
| 48 | 172225 | Guadalupe De Los Reyes | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2033-10-26 | 8.0000 | 19.768 | $2,814.00 | N/A | None |
| 49 | 179842 | Elyca | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2036-12-16 | 10.0924 | 24.939 | $3,550.00 | N/A | None |
| 50 | 186960 | Santa Cruz | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2040-05-16 | 10.0000 | 24.710 | $3,518.00 | 3%NSR | None |
| 51 | 199402 | Constituyentes 1917 | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2044-04-18 | 66.2411 | 163.685 | $23,304.00 | 1%NSR | None |
| 52 | 213579 | Montecristo | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2051-05-17 | 38.0560 | 94.038 | $13,388.00 | 1%NSR | None |
| 53 | 213580 | Montecristo Fraccion | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2051-05-17 | 0.2813 | 0.695 | $98.00 | 1%NSR | None |
| 54 | 226590 | Montecristo II | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2056-02-01 | 27.1426 | 67.071 | $9,548.00 | 1%NSR | None |
| 55 | 191486 | San Francisco | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2041-12-18 | 38.1598 | 94.295 | $13,424.00 | 2%NSR | None |
| 56 | 196127 | Ampl. San Antonio | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2042-09-22 | 20.9174 | 51.688 | $7,358.00 | 2%NSR | None |
| 57 | 204385 | San Antonio | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2047-02-12 | 14.8932 | 36.802 | $5,240.00 | 2%NSR | None |
| 58 | 209497 | Guazapares | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2049-08-02 | 30.9111 | 76.383 | $10,874.00 | 2%NSR | None |
| 59 | 211040 | Guazapares 3 | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2050-03-23 | 250.0000 | 617.761 | $87,950.00 | 2%NSR | None |
| 60 | 212890 | Guazapares 1 | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2051-02-12 | 451.9655 | 1,116.827 | $159,002.00 | 2%NSR | None |
| 61 | 213572 | Guazapares 5 | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2051-05-17 | 88.8744 | 219.613 | $31,266.00 | 2%NSR | None |
No. | Title No. | Concession Name | Owner/Parties | Type | Expiry Date | Hectares | Acres | Annual Holding Costs | Royalty | Group |
| 62 | 220788 | Cantilito | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2053-10-06 | 37.0350 | 91.515 | $13,028.00 | 2%NSR | None |
| 63 | 222869 | San Antonio | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2054-09-13 | 105.1116 | 259.735 | $36,978.00 | 2%NSR | None |
| 64 | 223664 | Guazapares 4 | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2055-02-01 | 63.9713 | 158.076 | $22,506.00 | 2%NSR | None |
| 65 | 226217 | Guazapares 2 | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2055-12-01 | 404.0016 | 998.306 | $142,128.00 | 2%NSR | None |
| 66 | 226884 | Vinorama | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2056-03-16 | 474.2220 | 1,171.823 | $166,832.00 | 2%NSR | None |
| 67 | 229553 | Temoris Fracción 4 | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2057-05-17 | 18.6567 | 46.102 | $6,564.00 | N/A | None |
| 68 | 232082 | Guazapares | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2057-05-17 | 4,242.1190 | 10,482.463 | $1,492,378.00 | N/A | None |
| 69 | 243762 | Temoris Centro Fracc. 1 | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2057-05-17 | 4,940.1997 | 12,207.451 | $1,737,962.00 | N/A | None |
| 70 | 243763 | Temoris Centro Fracc. 2 | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2057-05-17 | 2,380.0000 | 5,881.085 | $837,284.00 | N/A | None |
| 71 | 243767 | Temoris Centro Fracc. 6 R1A | Coeur Mexicana, S.A. de C.V. | Concesión Minera | 2057-05-17 | 956.2010 | 2,362.815 | $336,392.00 | N/A | None |
| | Totals | | | | | 27,226.6466 | 67,278.24 | $9,578,336.00 | | |
