Sisecam Resources (SIRE) 10-Q 3 Aug 21 2021 Q2 Quarterly report Financial data

COVER

COVER - shares	6 Months Ended
	Jun. 30, 2021	Jul. 27, 2021
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	001-36062
Entity Registrant Name	CINER RESOURCES LP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-2613366
Entity Address, Address Line One	Five Concourse Parkway
Entity Address, Address Line Two	Suite 2500
Entity Address, City or Town	Atlanta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30328
City Area Code	770
Local Phone Number	375-2300
Title of 12(b) Security	Common units representing limited partnership interests
Trading Symbol	CINR
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Small Business Entity	false
Emerging Growth Company	false
Entity Shell Company	false
Entity Central Index Key	0001575051
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Amendment Flag	false
Common Unitholders
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		19,779,388
General Partner
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		399,000

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 2.5	$ 0.5
Accounts receivable—affiliates	49	86.5
Accounts receivable, net	96.2	40.6
Inventory	31.4	33.5
Other current assets	9.4	4.1
Total current assets	188.5	165.2
Property, plant and equipment, net	308.3	307.4
Other non-current assets	26.4	25.4
Total assets	523.2	498
Current liabilities:
Current portion of long-term debt	3	3
Accounts payable	21.9	16.4
Due to affiliates	2.1	2.9
Accrued expenses	34	33.6
Total current liabilities	61	55.9
Long-term debt	133	128.1
Other non-current liabilities	8.4	8.7
Total liabilities	202.4	192.7
Commitments and contingencies
Equity:
Common unitholders - Public and Ciner Wyoming Holding Co. (19.8 units issued and outstanding at June 30, 2021 and December 31, 2020)	175.5	170
General partner unitholders - Ciner Resource Partners LLC (0.4 units issued and outstanding at June 30, 2021 and December 31, 2020)	4.3	4.2
Accumulated other comprehensive income	3.4	0
Partners’ capital attributable to Ciner Resources LP	183.2	174.2
Noncontrolling interest	137.6	131.1
Total equity	320.8	305.3
Total liabilities and partners’ equity	$ 523.2	$ 498

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares	Jun. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Common units issued (in shares)	19.8	19.8
Common units outstanding (in shares)	19.8	19.8
General partner units issued (in shares)	0.4	0.4
General partner units outstanding (in shares)	0.4	0.4

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net Sales:
Sales—others	$ 120.7	$ 44.2	$ 248.5	$ 104.6
Sales—affiliates	0	32	0	86
Net sales	120.7	76.2	248.5	190.6
Operating costs and expenses:
Cost of products sold including freight costs (excludes depreciation, depletion and amortization expense set forth separately below)	99.1	67.7	205.7	154.3
Depreciation, depletion and amortization expense	7.7	6.5	16.4	13
Selling, general and administrative expenses—affiliates	4.2	4.4	7.8	8.5
Selling, general and administrative expenses—others	1.4	1.6	3.4	3.3
Total operating costs and expenses	112.4	80.2	233.3	179.1
Operating income (loss)	8.3	(4)	15.2	11.5
Other (expenses) income:
Interest income	0	0.1	0	0.1
Interest expense	(1.5)	(1.5)	(2.8)	(2.8)
Total other expense, net	(1.5)	(1.4)	(2.8)	(2.7)
Net income (loss)	6.8	(5.4)	12.4	8.8
Net income (loss) attributable to noncontrolling interest	3.9	(2.1)	7.1	5.4
Net income (loss) attributable to Ciner Resources LP	2.9	(3.3)	5.3	3.4
Other comprehensive income (loss):
Income on derivative financial instruments	5.1	2.8	6.6	0.7
Comprehensive income (loss)	11.9	(2.6)	19	9.5
Comprehensive income (loss) attributable to noncontrolling interest	6.4	(0.7)	10.3	5.7
Comprehensive income (loss) attributable to Ciner Resources LP	$ 5.5	$ (1.9)	$ 8.7	$ 3.8
Net income per limited partner unit:
Net income per limited partner unit - (basic) (in dollars per share)	$ 0.15	$ (0.17)	$ 0.27	$ 0.17
Net income per limited partner unit - (diluted) (in dollars per share)	$ 0.15	$ (0.17)	$ 0.27	$ 0.17
Limited partner units outstanding:
Weighted average limited partner units outstanding - (basic) (in shares)	19.8	19.7	19.8	19.7
Weighted average limited partner units outstanding - (diluted) (in shares)	19.8	19.7	19.8	19.7

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net income	$ 12.4	$ 8.8
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization expense	16.7	13
Equity-based compensation expenses	0.4	0.7
Other non-cash items	0.2	0.2
Changes in operating assets and liabilities:
Accounts receivable—affiliates	(4.4)	26.4
Accounts receivable, net	(13.7)	2.1
Inventory	2.3	(9.5)
Other current and non-current assets	(2)	(0.1)
Accounts payable	6.1	(4.2)
Due to affiliates	(0.7)	(0.2)
Accrued expenses and other liabilities	1.1	(6)
Net cash provided by operating activities	18.4	31.2
Cash flows from investing activities:
Capital expenditures	(17.1)	(20.3)
Net cash used in investing activities	(17.1)	(20.3)
Cash flows from financing activities:
Borrowings on Ciner Wyoming Equipment Financing Arrangement	0	30
Repayments on Ciner Wyoming Equipment Financing Arrangement	(1.5)	(0.7)
Other	(0.4)	(0.4)
Distributions to common unitholders, general partner, and noncontrolling interest	(3.9)	(27.9)
Net cash provided by (used in) financing activities	0.7	(8.5)
Net increase in cash and cash equivalents	2	2.4
Cash and cash equivalents at beginning of period	0.5	14.9
Cash and cash equivalents at end of period	2.5	17.3
Supplemental disclosure of cash flow information:
Interest paid during the period	2.3	2.7
Supplemental disclosure of non-cash investing activities:
Capital expenditures on account	1.4	7.9
Ciner Wyoming Credit Facility
Cash flows from financing activities:
Borrowings on Ciner Wyoming Credit Facility	57.5	121.5
Repayments on Ciner Wyoming Credit Facility	(50)	(131)
Ciner Resources Credit Facility
Cash flows from financing activities:
Borrowings on Ciner Wyoming Credit Facility	1	0
Repayments on Ciner Wyoming Credit Facility	$ (2)	$ 0

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Unaudited) - USD ($) $ in Millions	Total	Accumulated Other Comprehensive Income (Loss)	Partners’ Capital Attributable to Ciner Resources LP Equity	Noncontrolling Interest	Common UnitholdersPartnership units	General PartnerPartnership units
Beginning balance at Dec. 31, 2019	$ 299.9	$ (3)	$ 172.7	$ 127.2	$ 171.4	$ 4.3
Increase (decrease) in shareholders' equity
Net income	14.2		6.7	7.5	6.6	0.1
Other comprehensive (loss)/income	(2.1)	(1)	(1)	(1.1)
Equity-based compensation plan activity	0.1		0.1		0.1
Distributions	(13.9)		(6.8)	(7.1)	(6.7)	(0.1)
Ending balance at Mar. 31, 2020	298.2	(4)	171.7	126.5	171.4	4.3
Beginning balance at Dec. 31, 2019	299.9	(3)	172.7	127.2	171.4	4.3
Increase (decrease) in shareholders' equity
Net income	8.8
Ending balance at Jun. 30, 2020	281.9	(2.6)	163.2	118.7	161.7	4.1
Beginning balance at Mar. 31, 2020	298.2	(4)	171.7	126.5	171.4	4.3
Increase (decrease) in shareholders' equity
Net income	(5.4)		(3.3)	(2.1)	(3.3)
Other comprehensive (loss)/income	2.8	1.4	1.4	1.4
Equity-based compensation plan activity	0.3		0.3		0.3
Distributions	(14)		(6.9)	(7.1)	(6.7)	(0.2)
Ending balance at Jun. 30, 2020	281.9	(2.6)	163.2	118.7	161.7	4.1
Beginning balance at Dec. 31, 2020	305.3	0	174.2	131.1	170	4.2
Increase (decrease) in shareholders' equity
Net income	5.6		2.4	3.2	2.4
Other comprehensive (loss)/income	1.5	0.8	0.8	0.7
Distributions	(3.9)			(3.9)
Ending balance at Mar. 31, 2021	308.5	0.8	177.4	131.1	172.4	4.2
Beginning balance at Dec. 31, 2020	305.3	0	174.2	131.1	170	4.2
Increase (decrease) in shareholders' equity
Net income	12.4
Ending balance at Jun. 30, 2021	320.8	3.4	183.2	137.6	175.5	4.3
Beginning balance at Mar. 31, 2021	308.5	0.8	177.4	131.1	172.4	4.2
Increase (decrease) in shareholders' equity
Net income	6.8		2.9	3.9	2.8	0.1
Other comprehensive (loss)/income	5.2	2.6	2.6	2.6
Equity-based compensation plan activity	0.3		0.3		0.3
Ending balance at Jun. 30, 2021	$ 320.8	$ 3.4	$ 183.2	$ 137.6	$ 175.5	$ 4.3

CORPORATE STRUCTURE AND SUMMARY

CORPORATE STRUCTURE AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
CORPORATE STRUCTURE AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	CORPORATE STRUCTURE AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of Operations The unaudited condensed consolidated financial statements are composed of Ciner Resources LP (the “Partnership,” “CINR,” “Ciner Resources,” “we,” “us,” or “our”), a publicly traded Delaware limited partnership, and its consolidated subsidiary, Ciner Wyoming LLC (“Ciner Wyoming”), which is in the business of mining trona ore to produce soda ash. The Partnership’s operations consist solely of its investment in Ciner Wyoming. The Partnership was formed in April 2013 by Ciner Wyoming Holding Co. (“Ciner Holdings”), a wholly-owned subsidiary of Ciner Resources Corporation (“Ciner Corp”). Ciner Corp is a direct wholly-owned subsidiary of Ciner Enterprises Inc. (“Ciner Enterprises”), which is a direct wholly-owned subsidiary of WE Soda Ltd., a U.K. corporation (“WE Soda”). WE Soda is a direct wholly-owned subsidiary of KEW Soda Ltd., a U.K. corporation (“KEW Soda”), which is a direct wholly-owned subsidiary of Akkan Enerji ve Madencilik Anonim Şirketi (“Akkan”). Akkan is directly and wholly owned by Turgay Ciner, the Chairman of the Ciner Group (“Ciner Group”), a Turkish conglomerate of companies engaged in energy and mining (including soda ash mining), media and shipping markets. The Partnership owns a controlling interest comprised of 51.0% membership interest in Ciner Wyoming. All of our soda ash processed is sold to various domestic and international customers, including American Natural Soda Ash Corporation (“ANSAC”), which was an affiliate for export sales in 2020. As a result of terminating Ciner Corp’s membership in ANSAC effective as of the end of day on December 31, 2020, ANSAC is no longer an affiliate of the Partnership. All mining and processing activities of Ciner Wyoming take place in one facility located in the Green River Basin of Wyoming. Basis of Presentation and Significant Accounting Policies The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) applicable to interim period financial statements and reflect all adjustments, consisting of normal recurring accruals, which are necessary for fair presentation of the results of operations, financial position and cash flows for the periods presented. All intercompany transactions, balances, revenue and expenses have been eliminated in consolidation. The results of operations for the three and six month periods ended June 30, 2021 and 2020 are not necessarily indicative of the operating results for the full year. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes to audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2020 (the “2020 Annual Report”) filed with the United States Securities and Exchange Commission on March 16, 2021. There have been no material changes in the significant accounting policies followed by us during the six months ended June 30, 2021 from those disclosed in the 2020 Annual Report. Noncontrolling interests NRP Trona LLC, a wholly-owned subsidiary of Natural Resource Partners L.P. ("NRP"), currently owns a 49.0% membership interest in Ciner Wyoming. NRP’s membership interest in Ciner Wyoming is reflected as the noncontrolling interest in the Partnership’s financial results. Segment Reporting As the Partnership earns substantially all of its revenues through the sale of soda ash mined at a single location, we have concluded that we have one operating segment for reporting purposes. Use of Estimates The preparation of these unaudited condensed consolidated financial statements, in accordance with GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities at the dates of the unaudited condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Furthermore, we considered the impact of the COVID-19 pandemic on the use of estimates and assumptions used for financial reporting. While our production is recovering from the COVID-19 pandemic negative impact, as of June 30, 2021, as we cannot predict the duration or the scope of the COVID-19 pandemic and its impact on our operations, the potential negative financial impact to our results cannot be reasonably estimated but could be material. As a result of these uncertainties, actual results could differ from those estimates and assumptions. If the economy or markets in which we operate remain weaker than pre-COVID-19 levels, our business, financial condition and results of operations may be further materially and adversely impacted. Subsequent Events We have evaluated subsequent events through the filing date of this Quarterly Report on Form 10-Q. Recently Issued Accounting Pronouncements and Securities and Exchange Commission Rules Securities and Exchange Commission Rules On October 31, 2018, the SEC issued a final rule that amends the current disclosure regime for SEC registrants with material mining operations. Among the final rule’s amendments is the addition of Subpart 1300 to SEC Regulation S-K. The purpose of the amendments is to provide investors with more comprehensive information while aligning the SEC’s disclosure requirements with the global regulatory standards outlined by the Committee for Mineral Reserves International Reporting Standards, which is commonly referred to as “CRIRSCO.” When assessing the materiality of mining operations to determine whether disclosures are required, registrants must consider operations in the aggregate (including all mining properties irrespective of the current stage of development or operation) and evaluate both quantitative and qualitative factors. Registrants must comply with the revised requirements for their first fiscal year beginning on or after January 1, 2021. Further, the disclosures required under the final rule must be supported by the work of a qualified person, such as a mine engineer. When a registrant first reports mineral reserves or resources, or makes a material change to such disclosures, it must file a technical report summary supporting the disclosure. Developing this detailed disclosure information (e.g., by using an expert) and maintaining appropriate disclosure controls and procedures over it will require significant time, resources, and effort. The Partnership continues to evaluate the impact this guidance will have on its disclosures in the Annual Report on Form 10-K for the year ended December 31, 2021. Recent Accounting Guidance Not Yet Adopted In March 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ASU 2020-04”) providing temporary guidance to ease the potential burden in accounting for reference rate reform primarily resulting from the discontinuation of the London Inter-bank Offered Rate (“LIBOR,”), which is currently expected to occur on December 31, 2021. The amendments in ASU 2020-04 are elective and apply to all entities that have contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued. The new guidance provides the following optional expedients: (i) simplifies accounting analyses under current GAAP for contract modifications; (ii) simplifies the assessment of hedge effectiveness and allows hedging relationships affected by reference rate reform to continue; and (iii) allows a one-time election to sell or transfer debt securities classified as held to maturity that reference a rate affected by reference rate reform. An entity may elect to apply the amendments prospectively from March 12, 2020 through December 31, 2022 by accounting topic. The Partnership continues to evaluate ASU 2020-04 but does not expect a material impact to the Partnership’s consolidated financial statements.

NET INCOME PER UNIT AND CASH DI

NET INCOME PER UNIT AND CASH DISTRIBUTION	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
NET INCOME PER UNIT AND CASH DISTRIBUTION	NET INCOME PER UNIT AND CASH DISTRIBUTION Allocation of Net Income Net income per unit applicable to limited partners is computed by dividing limited partners’ interest in net income attributable to Ciner Corp, after deducting the general partner’s interest and any incentive distributions, by the weighted average number of outstanding common units. Our net income is allocated to the general partner and limited partners in accordance with their respective partnership percentages, after giving effect to priority income allocations for incentive distributions, if any, to our general partner, pursuant to our partnership agreement. Earnings in excess of distributions are allocated to the general partner and limited partners based on their respective ownership interests. Payments made to our unitholders are determined in relation to actual distributions declared and are not based on the net income allocations used in the calculation of net income per unit. In addition to the common units, we have also identified the general partner interest and incentive distribution rights (“IDRs”) as participating securities and use the two-class method when calculating the net income per unit applicable to limited partners, which is based on the weighted-average number of common units outstanding during the period. Anti-dilutive units outstanding were immaterial for both the three and six months ended June 30, 2021 and 2020. The net income attributable to limited partner unitholders and the weighted average units for calculating basic and diluted net income per limited partner units were as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions, except per unit data) 2021 2020 2021 2020 Numerator: Net income (loss) attributable to Ciner Resources LP $ 2.9 $ (3.3) $ 5.3 $ 3.4 Less: General partner’s interest in net income — — 0.1 0.1 Total limited partners’ interest in net income (loss) $ 2.9 $ (3.3) $ 5.2 $ 3.3 Denominator: Weighted average limited partner units outstanding: Weighted average limited partner units outstanding (basic) 19.8 19.7 19.8 19.7 Weighted average limited partner units outstanding (diluted) 19.8 19.7 19.8 19.7 Net income (loss) per limited partner unit: Net income (loss) per limited partner unit (basic) $ 0.15 $ (0.17) $ 0.27 $ 0.17 Net income (loss) per limited partner unit (diluted) $ 0.15 $ (0.17) $ 0.27 $ 0.17 The calculation of limited partners’ interest in net income (loss) is as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Net income attributable to common unitholders: Distributions (1) $ — $ — $ — $ 6.7 Undistributed earnings (loss) (Distributions) in excess of net income (loss) 2.9 (3.3) 5.2 (3.4) Common unitholders’ interest in net income (loss) $ 2.9 $ (3.3) $ 5.2 $ 3.3 (1) Distributions declared per limited partner unit for the period $ — $ — $ — $ 0.340 Quarterly Distribution Our general partner has considerable discretion in determining the amount of available cash, the amount of distributions and the decision to make any distribution. Although our partnership agreement requires that we distribute all of our available cash quarterly, there is no guarantee that we will make quarterly cash distributions to our unitholders, and we have no legal obligation to do so. In an effort to achieve greater financial and liquidity flexibility during the COVID-19 pandemic, on August 3, 2020, each of the members of the board of managers of Ciner Wyoming approved a suspension of quarterly distributions to its members. In addition, effective August 3, 2020, in connection with the quarterly distribution for the quarter ended June 30, 2020, each of the members of the board of directors of our general partner approved a suspension of quarterly distributions to our unitholders. Each of the board of managers of Ciner Wyoming and the board of directors of our general partner has approved the continuation of the suspension of quarterly distributions to the members of Ciner Wyoming and our unitholders, as applicable, for each of the quarters ended September 30, 2020, December 31, 2020, March 31, 2021 and June 30, 2021 in a continued effort to achieve greater financial and liquidity flexibility during the COVID-19 pandemic. In March 2021, the board of managers of Ciner Wyoming approved a special $8.0 million distribution to, amongst other things, provide the Partnership with funds to retire the Ciner Resources Credit Facility. Management and the board of directors of our general partner will continue to evaluate, on a quarterly basis, whether it is appropriate to reinstate a distribution to our unitholders, which will be dependent in part on our cash reserves, liquidity, total debt levels and anticipated capital expenditures. General Partner Interest and Incentive Distribution Rights Our partnership agreement provides that our general partner initially will be entitled to 2.0% of all distributions that we make prior to our liquidation. Our general partner has the right, but not the obligation, to contribute up to a proportionate amount of capital to us in order to maintain its 2.0% general partner interest if we issue additional units. Our general partner’s approximate 2.0% interest, and the percentage of our cash distributions to which our general partner is entitled from such approximate 2.0% interest, will be proportionately reduced if we issue additional units in the future (other than the issuance of common units upon a reset of the IDRs), and our general partner does not contribute a proportionate amount of capital to us in order to maintain its approximate 2.0% general partner interest. Our partnership agreement does not require that our general partner fund its capital contribution with cash. It may, instead, fund its capital contribution by contributing to us common units or other property. IDRs represent the right to receive increasing percentages (13.0%, 23.0% and 48.0%) of quarterly distributions from operating surplus after we have achieved the minimum quarterly distribution and the target distribution levels. Our general partner currently holds the IDRs, but may transfer these rights separately from its general partner interest, subject to certain restrictions in our partnership agreement. Percentage Allocations of Distributions from Operating Surplus The following table illustrates the percentage allocations of distributions from operating surplus between the unitholders and our general partner based on the specified target distribution levels. The amounts set forth under the column heading "Marginal Percentage Interest in Distributions" are the percentage interests of our general partner and the unitholders in any distributions from operating surplus we distribute up to and including the corresponding amount in the column "Total Quarterly Distribution per Unit Target Amount." The percentage interests shown for our unitholders and our general partner for the minimum quarterly distribution also apply to quarterly distribution amounts that are less than the minimum quarterly distribution. Under our partnership agreement, our general partner has considerable discretion to determine the amount of available cash (as defined therein) for distribution each quarter to the Partnership’s unitholders, including discretion to establish cash reserves that would limit the amount of available cash eligible for distribution to the Partnership’s unitholders for any quarter. The Partnership does not guarantee that it will pay the target amount of the minimum quarterly distribution listed below (or any distributions) on its units in any quarter. The percentage interests set forth below for our general partner (1) include a 2.0% general partner interest, (2) assume that our general partner has contributed any additional capital necessary to maintain its 2.0% general partner interest, (3) assume that our general partner has not transferred its IDRs and (4) assume that we do not issue additional classes of equity securities. Marginal Percentage Total Quarterly Unitholders General Partner Minimum Quarterly Distribution $0.5000 98.0 % 2.0 % First Target Distribution above $0.5000 up to $0.5750 98.0 % 2.0 % Second Target Distribution above $0.5750 up to $0.6250 85.0 % 15.0 % Third Target Distribution above $0.6250 up to $0.7500 75.0 % 25.0 % Thereafter above $0.7500 50.0 % 50.0 %

INVENTORY

INVENTORY	6 Months Ended
	Jun. 30, 2021
Inventory Disclosure [Abstract]
INVENTORY	INVENTORY Inventory consisted of the following: As of (In millions) June 30, 2021 December 31, 2020 Raw materials $ 10.5 $ 9.9 Finished goods 9.7 13.4 Stores inventory 11.2 10.2 Total $ 31.4 $ 33.5

DEBT

DEBT	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
DEBT	DEBT Long-term debt, net of debt issuance costs, consisted of the following: As of (In millions) June 30, 2021 December 31, 2020 Ciner Wyoming Credit Facility, secured principal expiring on August 1, 2022, variable interest rate as a weighted average rate of 2.75% and 2.25% as of June 30, 2021 and December 31, 2020, respectively $ 110.0 $ 102.5 Ciner Wyoming Equipment Financing Arrangement with maturity date of March 26, 2028, fixed interest rate of 2.479% 26.0 27.6 Ciner Resources Credit Facility, secured principal expiring on August 1, 2022, variable interest rate as a weighted average rate of 2.25% as of December 31, 2020 — 1.0 Total debt 136.0 131.1 Current portion of long-term debt 3.0 3.0 Total long-term debt $ 133.0 $ 128.1 Aggregate maturities required on long-term debt as of June 30, 2021 are due in future years as follows: (In millions) Amount 2021 $ 1.5 2022 113.1 2023 3.2 2024 3.3 2025 3.3 Thereafter 11.8 Total $ 136.2 Ciner Wyoming Equipment Financing Arrangement On March 26, 2020, Ciner Wyoming and Banc of America Leasing & Capital, LLC, as lender (the “Equipment Financing Lender”), entered into an equipment financing arrangement (the “Ciner Wyoming Equipment Financing Arrangement”) including a Master Loan and Security Agreement, dated as of March 25, 2020 (as amended, the “Master Agreement”) and an Equipment Security Note Number 001, dated as of March 25, 2020 (the “Initial Secured Note”), which provides the terms and conditions for the debt financing of certain equipment related to Ciner Wyoming’s new natural gas-fired turbine co-generation facility that became operational in March 2020. Each equipment financing under the Ciner Wyoming Equipment Financing Arrangement will be evidenced by the execution of one or more equipment notes (including the Initial Secured Note) that incorporate the terms and conditions of the Master Agreement (each, an “Equipment Note”). In order to secure the payment and performance of Ciner Wyoming’s obligations under the Ciner Wyoming Equipment Financing Arrangement and other debt obligations owed by Ciner Wyoming to the Equipment Financing Lender, Ciner Wyoming granted to the Equipment Financing Lender a continuing security interest in all of Ciner Wyoming’s right, title and interest in and to the Equipment (as defined in the Master Agreement) and certain related collateral. The Ciner Wyoming Equipment Financing Arrangement (1) incorporates all covenants in the Ciner Wyoming Credit Facility (as defined below), now or hereinafter existing, or in any applicable replacement credit facility accepted in writing by the Equipment Financing Lender, that are based upon a specified level or ratio relating to assets, liabilities, indebtedness, rentals, net worth, cash flow, earnings, profitability, or any other accounting-based measurement or test, and (2) includes customary events of default subject to applicable grace periods, including, among others, (i) payment defaults, (ii) certain mergers or changes in control of Ciner Wyoming, (iii) cross defaults with certain other indebtedness (a) to which the Equipment Financing Lender is a party or (b) to third parties in excess of $10 million, and (iv) the commencement of certain insolvency proceedings or related events identified in the Master Agreement. Upon the occurrence of an event of default, in its discretion, the Equipment Financing Lender may exercise certain remedies, including, among others, the ability to accelerate the maturity of any Equipment Note such that all amounts thereunder will become immediately due and payable, to take possession of the Equipment identified in any Equipment Note, and to charge Ciner Wyoming a default rate of interest on all then outstanding or thereafter incurred obligations under the Ciner Wyoming Equipment Financing Arrangement. Among other things, the Initial Secured Note: • has a principal amount of $30,000,000; • has a maturity date of March 26, 2028; • shall be payable by Ciner Wyoming to the Equipment Financing Lender in 96 consecutive monthly installments of principal and interest commencing on April 26, 2020 and continuing thereafter until the maturity date of the Initial Secured Note, which shall be in the amount of approximately $307,000 for the first 95 monthly installments and approximately $4,307,000 for the final monthly installment; and • entitles Ciner Wyoming to prepay all (but not less than all) of the outstanding principal balance of the Initial Secured Note (together with all accrued interest and other charges and amounts owed thereunder) at any time after one (1) year from the date of the Initial Secured Note, subject to Ciner Wyoming paying to the Equipment Financing Lender an additional prepayment amount determined by the amount of principal balance prepaid and the date such prepayment is made. In connection with the Second Ciner Wyoming Amendment (as defined below), the Master Agreement was amended to incorporate, among other things, the modified covenants set forth in the Second Ciner Wyoming Amendment related to consolidated leverage ratios of Ciner Wyoming. Ciner Wyoming’s balance under the Ciner Wyoming Equipment Financing Arrangement as of June 30, 2021 was $26.2 million ($26.0 million net of financing costs). In connection with the event of default (the “Facilities Agreement Default”) under the Facilities Agreement (as defined below) that arose in February 2021 (as defined and described below in the WE Soda and Ciner Enterprises Facilities Agreement section), Ciner Wyoming entered into a second amendment to the Master Agreement (the “Second Amendment to the Master Agreement”) on March 5, 2021. Such amendment modified the definition of change of control under the Master Agreement in order to prevent an event of default thereunder that could have otherwise resulted from the Facilities Agreement lenders foreclosing on certain equity interests in Ciner Holdings (the “Equity Default Remedy”) as a remedy for the Facilities Agreement Default, or as a remedy for future events of default under the Facilities Agreement. Management is not aware of any current circumstances that would result in an event of default under the Ciner Wyoming Equipment Financing Arrangement in the next twelve months. As of June 30, 2021, Ciner Wyoming was in compliance with all financial covenants of the Ciner Wyoming Equipment Financing Arrangement, as amended. Ciner Wyoming Credit Facility On August 1, 2017, Ciner Wyoming entered into a Credit Agreement (as amended, the “Ciner Wyoming Credit Facility ” and together with the Ciner Wyoming Equipment Financing Arrangement, the “Ciner Wyoming Debt Agreements”) with each of the lenders listed on the respective signature pages thereof and PNC Bank, National Association (“PNC Bank”), as administrative agent, swing line lender and a Letter of Credit (“L/C”) issuer. The Ciner Wyoming Credit Facility is a $225.0 million senior secured revolving credit facility with a syndicate of lenders, which will mature on the fifth anniversary of the closing date of such credit facility. The Ciner Wyoming Credit Facility provides for revolving loans to fund working capital requirements, and capital expenditures, to consummate permitted acquisitions and for all other lawful partnership purposes. The Ciner Wyoming Credit Facility has an accordion feature that allows Ciner Wyoming to increase the available revolving borrowings under the facility by up to an additional $75.0 million, subject to Ciner Wyoming receiving increased commitments from existing lenders or new commitments from new lenders and the satisfaction of certain other conditions. In addition, the Ciner Wyoming Credit Facility includes a sublimit up to $20.0 million for same-day swing line advances and a sublimit up to $40.0 million for letters of credit. In addition, the Ciner Wyoming Credit Facility contains various covenants and restrictive provisions that limit (subject to certain exceptions) Ciner Wyoming’s ability to: • make distributions on or redeem or repurchase units; • incur or guarantee additional debt; • make certain investments and acquisitions; • incur certain liens or permit them to exist; • enter into certain types of transactions with affiliates of Ciner Wyoming; • merge or consolidate with another company; and • transfer, sell or otherwise dispose of assets. The Ciner Wyoming Credit Facility contains events of default customary for transactions of this nature, including (i) failure to make payments required under the Ciner Wyoming Credit Facility, (ii) failure to comply with covenants and financial ratios in the Ciner Wyoming Credit Facility, (iii) the occurrence of a change of control, (iv) the institution of insolvency or similar proceedings against Ciner Wyoming and (v) the occurrence of a default under any other material indebtedness Ciner Wyoming may have. Upon the occurrence and during the continuation of an event of default, subject to the terms and conditions of the Ciner Wyoming Credit Facility, the administrative agent shall, at the request of the Required Lenders (as defined in the Ciner Wyoming Credit Facility), or may, with the consent of the Required Lenders, terminate all outstanding commitments under the Ciner Wyoming Credit Facility and may declare any outstanding principal of the Ciner Wyoming Credit Facility debt, together with accrued and unpaid interest, to be immediately due and payable. Under the Ciner Wyoming Credit Facility, a change of control is triggered if Ciner Corp and its wholly-owned subsidiaries, directly or indirectly, cease to own all of the equity interests, or cease to have the ability to elect a majority of the board of directors (or similar governing body) of our general partner (or any entity that performs the functions of the Partnership’s general partner). In addition, a change of control would be triggered if the Partnership ceases to own at least 50.1% of the economic interests in Ciner Wyoming or ceases to have the ability to elect a majority of the members of Ciner Wyoming’s board of managers. Loans under the Ciner Wyoming Credit Facility bear interest at Ciner Wyoming’s option at either: • a Base Rate, which equals the highest of (i) the federal funds rate in effect on such day plus 0.50%, (ii) the administrative agent’s prime rate in effect on such day or (iii) one-month LIBOR plus 1.0%, in each case, plus an applicable margin; or • the Eurodollar Rate plus an applicable margin; provided , that with respect to an applicable loan, if the Eurodollar Rate has ceased or will cease to be provided, if the regulatory supervisor for the administrator of the Eurodollar Rate or a governmental authority having jurisdiction over the administrative agent determine that the Eurodollar Rate is no longer representative or if the administrative agent determines that similar U.S. dollar-denominated credit facilities are being executed or modified to incorporate or adopt a new benchmark interest rate to replace the Eurodollar Rate, the administrative agent and Ciner Wyoming may establish an alternative interest rate for the applicable loan. The Ciner Wyoming Credit Facility has an interest rate floor of 0.50%. The unused portion of the Ciner Wyoming Credit Facility is subject to a per annum commitment fee and the applicable margin of the interest rate under the Ciner Wyoming Credit Facility will be determined as follows: Pricing Tier Leverage Ratio Eurodollar Rate Loans Base Rate Commitment 1 < 1.25:1.0 1.500% 0.500% 0.250% 2 ≥ 1.25:1.0 but < 1.75:1.0 1.750% 0.750% 0.275% 3 ≥ 1.75:1.0 but < 2.25:1.0 2.000% 1.000% 0.300% 4 ≥ 2.25:1.0 but < 3.00:1.0 2.250% 1.250% 0.375% 5 ≥ 3.00:1.0 but < 3.50:1.0 2.500% 1.500% 0.375% 6 ≥ 3.50:1.0 but < 4.00:1.0 2.750% 1.750% 0.425% 7 ≥ 4.00:1.0 3.000% 2.000% 0.475% In connection with the Facilities Agreement Default, Ciner Wyoming entered into a Third Amendment to the Ciner Wyoming Credit Facility (the “Third Amendment”) in order to prevent an event of default thereunder that could have otherwise resulted from the Facilities Agreement lenders exercising the Equity Default Remedy as a remedy for the Facilities Agreement Default, or a future event of default under the Facilities Agreement. Such amendment (i) modified the definition of change of control to exclude any change in control that could arise from lender actions under the Facilities Agreement relating to any events of default under the Facilities Agreement; (ii) reduced the leverage ratio to 3.00 to 1.00 for the quarter ended June 30, 2021 and each fiscal quarter thereafter (from amendments prior to the Third Amendment, a leverage ratio of 4.50 to 1.0 or lower was required for the quarter ended March 31, 2021 and an interest coverage ratio of not less than 3.00 to 1.0 is required); and (iii) added a covenant that any borrowings under the Wyoming Credit Facility are secured by substantially all of Ciner Wyoming’s personal property, subject to certain exclusions. Management is not aware of any current circumstances that would result in an event of default under the Ciner Wyoming Credit Facility in the next twelve months. As of June 30, 2021, Ciner Wyoming was in compliance with all financial covenants of the Ciner Wyoming Credit Facility. Ciner Resources Credit Facility On August 1, 2017, the Partnership entered into a Credit Agreement (as amended, the “Ciner Resources Credit Facility”) with each of the lenders listed on the respective signature pages thereof and PNC Bank, as administrative agent, swing line lender and an L/C issuer. The Ciner Resources Credit Facility was a $10.0 million senior secured revolving credit facility with a syndicate of lenders, that would have matured on the fifth anniversary of the closing date of such credit facility. The Ciner Resources Credit Facility provided for revolving loans to be available to fund distributions on the Partnership’s units and working capital requirements and capital expenditures, to consummate permitted acquisitions and for all other lawful partnership purposes. The Partnership’s obligations under the Ciner Resources Credit Facility were guaranteed by each of the Partnership’s material domestic subsidiaries other than Ciner Wyoming. In addition, the Partnership’s obligations under the Ciner Resources Credit Facility were secured by a pledge of substantially all of the Partnership’s assets (subject to certain exceptions), including the membership interests held in Ciner Wyoming by the Partnership. On March 8, 2021, the Partnership terminated the Ciner Resources Credit Facility; the Partnership repaid in full its obligations thereunder. WE Soda and Ciner Enterprises Facilities Agreement Ciner Enterprises, the entity that indirectly owns and controls the Partnership, has a credit agreement and certain related finance documents, to which WE Soda and Ciner Enterprises (as borrowers), and KEW Soda, WE Soda, WE Soda Kimya Yatırımları Anonim Şirketi, Ciner Kimya Yatırımları Sanayi ve Ticaret Anonim Şirketi, Ciner Enterprises, Ciner Holdings and Ciner Corp (as original guarantors and together with the borrowers, the “Ciner Obligors”), are parties (as amended and restated or otherwise modified, the “Facilities Agreement”). The Facilities Agreement expires on August 1, 2025. Even though neither we nor Ciner Wyoming are a party or a guarantor under the Facilities Agreement while any amounts are outstanding under the Facilities Agreement we will be indirectly affected by certain affirmative and restrictive covenants that apply to WE Soda and its subsidiaries (which include us). Besides the customary covenants and restrictions, the Facilities Agreement includes provisions that, without a waiver or amendment approved by lenders, whose commitments are more than 66-2/3% of the total commitments under the Facilities Agreement to undertake such action, would (i) prevent certain transactions (including loans) with our affiliates, including such transactions that could reasonably be expected to materially and adversely affect the interests of certain finance parties, (ii) restrict the ability to amend our limited partnership agreement or the general partner’s limited liability company agreement or our other constituency documents if such amendment could reasonably be expected to materially and adversely affect the interests of the lenders to the Facilities Agreement, (iii) restrict the amount of our capital expenditures if certain ratios are not achieved by the Ciner Obligors thereunder and (iv) prevent actions that enable certain restrictions or prohibitions on our ability to upstream cash (including via distributions) to the borrowers under the Facilities Agreement. Based on the Ciner Obligors’ applicable ratios currently, the Partnership’s expansion capital expenditures are prohibited until the Ciner Obligors’ applicable ratios are at specified levels pursuant to the Facilities Agreement. In addition, Ciner Enterprises’ ownership in Ciner Holdings is subject to a lien under the Facilities Agreement, which enables the lenders under the Facilities Agreement to foreclose on such collateral and take control of Ciner Holdings, which controls the general partner of the Partnership, if any of the borrowers or guarantors under the Facilities Agreement are unable to satisfy its respective obligations under the Facilities Agreement.

OTHER NON-CURRENT LIABILITIES

OTHER NON-CURRENT LIABILITIES	6 Months Ended
	Jun. 30, 2021
Asset Retirement Obligation Disclosure [Abstract]
OTHER NON-CURRENT LIABILITIES	OTHER NON-CURRENT LIABILITIES Other non-current liabilities consisted of the following: As of (In millions) June 30, 2021 December 31, 2020 Reclamation reserve $ 7.5 $ 7.3 Derivative instruments and hedges, fair value liabilities and other 0.9 1.4 Total $ 8.4 $ 8.7 A reconciliation of the Partnership’s reclamation reserve liability is as follows: For the period ended (In millions) June 30, 2021 December 31, 2020 Beginning reclamation reserve balance $ 7.3 $ 5.7 Accretion expense 0.2 0.3 Reclamation adjustments (1) — 1.3 Ending reclamation reserve balance $ 7.5 $ 7.3 (1) The reclamation costs are periodically evaluated for adjustments by the Wyoming Department of Environmental Quality. See Note 9 “Commitments and Contingencies,” “ Off-Balance Sheet Arrangements ” for additional information on our reclamation reserve, including recent changes to the underlying reclamation obligation that has resulted in the asset retirement obligation reclamation adjustment.

EMPLOYEE COMPENSATION

EMPLOYEE COMPENSATION	6 Months Ended
	Jun. 30, 2021
Retirement Benefits [Abstract]
EMPLOYEE COMPENSATION	EMPLOYEE COMPENSATION The Partnership participates in various benefit plans offered and administered by Ciner Corp and is allocated its portions of the annual costs related thereto. The specific plans are as follows: Retirement Plans - Benefits provided under the Pension Plan (the “Retirement Plan”) are based upon years of service and average compensation for the highest 60 consecutive months of the employee’s last 120 months of service, as defined. The Retirement Plan covers substantially all full-time employees hired before May 1, 2001. Ciner Corp’s Retirement Plan had a net liability balance of $52.6 million and $55.1 million as of June 30, 2021 and December 31, 2020, respectively. Ciner Corp’s current funding policy is to contribute an amount within the range of the minimum required and the maximum tax-deductible contribution. The Partnership’s allocated portions of the Retirement Plan’s net periodic pension benefit were $0.6 million and $0.3 million for the three months ended June 30, 2021 and 2020, respectively, and were $1.4 million and $0.7 million for the six months ended June 30, 2021 and 2020, respectively. The increase in the amount of benefit recognized during the six months ended June 30, 2021 was driven by asset changes from the prior period. Savings Plan - The 401(k) retirement plan (the “401(k) Plan”) covers all eligible hourly and salaried employees. Eligibility is limited to all domestic residents and any foreign expatriates who are in the United States indefinitely. The 401(k) Plan permits employees to contribute specified percentages of their compensation, while the Partnership makes contributions based upon specified percentages of employee contributions. Participants hired on or subsequent to May 1, 2001, will receive an additional contribution from the Partnership based on a percentage of the participant’s base pay. Contributions made to the 401(k) Plan were $0.7 million for each of the three months ended June 30, 2021 and 2020 and were $2.3 million for each of the six months ended June 30, 2021 and 2020. Postretirement Benefits - Most of the Partnership’s employees hired prior to May 1, 2017 are eligible for postretirement benefits other than pensions if they reach retirement age while still employed. The postretirement benefits are accounted for by Ciner Corp on an accrual basis over an employee’s period of service. The postretirement plan, excluding pensions, are not funded, and Ciner Corp has the right to modify or terminate the plan. The Ciner Corp post-retirement plan had a net unfunded liability of $13.1 million as of June 30, 2021 and December 31, 2020.

EQUITY - BASED COMPENSATION

EQUITY - BASED COMPENSATION	6 Months Ended
	Jun. 30, 2021
Share-based Payment Arrangement [Abstract]
EQUITY - BASED COMPENSATION	EQUITY - BASED COMPENSATION In July 2013, our general partner established the Ciner Resource Partners LLC 2013 Long-Term Incentive Plan (as amended to date, the “Plan” or “LTIP”). Historically, the Plan was intended to provide incentives that will attract and retain valued employees, officers, consultants and non-employee directors by offering them a greater stake in our success and a closer identity with us, and to encourage ownership of our common units by such individuals. The Plan provides for awards in the form of common units, phantom units, distribution equivalent rights (“DERs”), cash awards and other unit-based awards. All employees, officers, consultants and non-employee directors of us and our parents and subsidiaries are eligible to be selected to participate in the Plan. As of June 30, 2021, subject to further adjustment as provided in the Plan, a total of 0.7 million common units were available for awards under the Plan. Any common units tendered by a participant in payment of the tax liability with respect to an award, including common units withheld from any such award, will not be available for future awards under the Plan. Common units awarded under the Plan may be reserved or made available from our authorized and unissued common units or from common units reacquired (through open market transactions or otherwise). Any common units issued under the Plan through the assumption or substitution of outstanding grants from an acquired company will not reduce the number of common units available for awards under the Plan. If any common units subject to an award under the Plan are forfeited, any common units counted against the number of common units available for issuance pursuant to the Plan with respect to such award will again be available for awards under the Plan. The Partnership has made a policy election to recognize forfeitures as they occur in lieu of estimating future forfeiture activity under the Plan. Non-employee Director Awards During the six months ended June 30, 2021, a total of 17,511 common units were granted and fully vested to non-employee directors compared to 21,720 common units were granted during the six months ended June 30, 2020. The grant date average fair value per unit of these awards was $13.20 and $9.88 for the six months ended June 30, 2021 and 2020, respectively. The total fair value of these awards was approximately $0.2 million during each of the six months ended June 30, 2021 and 2020. Time Restricted Unit Awards We grant restricted unit awards in the form of common units to certain employees that vest over a specified period of time, usually between one The following table presents a summary of activity on the Time Restricted Unit Awards: Six Months Ended Six Months Ended (Units in whole numbers) Number of Common Units Grant-Date Average Fair Value per Unit (1) Number of Common Units Grant-Date Average Fair Value per Unit (1) Unvested at the beginning of period 21,937 $ 17.57 55,454 $ 20.33 Vested (12,247) 18.46 (27,802) 22.94 Unvested at the end of the period 9,690 $ 16.45 27,652 $ 17.71 (1) Determined by dividing the aggregate grant date fair value of awards by the number of common units. Total Return Performance Unit Awards Historically, we have granted TR Performance Unit Awards to certain employees. The TR Performance Unit Awards represent the right to receive a number of common units at a future date based on the achievement of market-based performance requirements in accordance with the TR Unit Performance Award agreement, and also include Distribution Equivalent Rights (“DERs”). DERs are the right to receive an amount equal to the accumulated cash distributions made during the period with respect to each common unit issued upon vesting. The TR Performance Unit Awards vest at the end of the performance period, usually between two We utilized a Monte Carlo simulation model to estimate the grant date fair value of TR Performance Unit Awards granted to employees, adjusted for market conditions. This type of award requires the input of highly subjective assumptions, including expected volatility and expected distribution yield. Historical and implied volatilities were used in estimating the fair value of these awards. The following table presents a summary of activity on the TR Performance Unit Awards: Six Months Ended Six Months Ended (Units in whole numbers) Number of Common Units Grant-Date Average Fair Value per Unit (1) Number of Common Units Grant-Date Average Fair Value per Unit (1) Unvested at the beginning of period 7,678 $ 41.53 20,173 $ 41.79 Vested (7,678) 41.53 (9,058) 42.21 Unvested at the end of the period — $ — 11,115 $ 41.59 (1) Determined by dividing the aggregate grant date fair value of awards by the number of common units. 2019 Performance Unit Awards On September 23, 2019, the board of directors of our general partner approved a new form of performance unit award to be granted based upon the achievement of certain financial, operating and safety-related performance metrics (“2019 Performance Unit Awards”) pursuant to our LTIP, and the vesting of the 2019 Performance Unit Awards is linked to a weighted average consisting of internal performance metrics defined in the 2019 Performance Unit Award agreement (the “Performance Metrics”) during a three-year performance period (the “Measurement Period”). The vesting of the 2019 Performance Unit Awards, and number of common units of the Partnership distributable pursuant to such vesting, is dependent on our performance relative to a pre-established budget over the Measurement Period; provided, that the awardee remains continuously employed with our general partner or its affiliates or satisfies other service-related criteria through the end of the Measurement Period, except in certain cases of Changes in Control (as defined in our LTIP) or the awardee’s death or disability. Vested 2019 Performance Unit Awards will be settled in our common units, with the number of such common units payable under the award for a given year in the Measurement Period to be calculated by multiplying the target number provided in the corresponding 2019 Performance Unit Award agreement by a payout multiplier, which may range from 0%-200% in each case, as determined by aggregating the corresponding weighted average assigned to the Performance Metrics. The 2019 Performance Unit Awards also contain DERs and entitle the recipient the right to receive an amount equal to the accumulated cash distributions made during the period with respect to each common unit issued. Upon vesting of the 2019 Performance Unit Awards, the award recipient is entitled to receive a cash payment equal to the sum of the distribution equivalents accumulated with respect to vested 2019 Performance Unit Awards during the period beginning on January 1, 2019 and ending on the applicable vesting date. The 2019 Performance Unit Awards granted to award recipients during 2019 have a performance cycle that began on January 1, 2019 and will end on December 31, 2021. The following table presents a summary of activity on the 2019 Performance Unit Awards for the period: Six Months Ended Six Months Ended (Units in whole numbers) Number of Common Units Grant-Date Average Fair Value per Unit (1) Number of Common Units Grant-Date Average Fair Value per Unit (1) Unvested at the beginning of period 29,057 $ 16.45 35,908 $ 16.45 Unvested at the end of the period 29,057 $ 16.45 35,908 $ 16.45 (1) Determined by dividing the weighted average price per common unit on the date of grant. Unrecognized Compensation Expense A summary of the Partnership’s unrecognized compensation expense for its unvested restricted time and performance-based units, and the weighted-average periods over which the compensation expense is expected to be recognized are as follows: Six Months Ended Six Months Ended Unrecognized Compensation Expense Weighted Average to be Recognized Unrecognized Compensation Expense Weighted Average to be Recognized Time Restricted Unit Awards $ 0.1 0.71 $ 0.4 1.54 TR Performance Unit Awards — — 0.1 0.59 2019 Performance Unit Awards — 0.59 0.2 1.59 Total $ 0.1 $ 0.7

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS)	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
ACCUMULATED OTHER COMPREHENSIVE LOSS	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) Accumulated Other Comprehensive Income (Loss) Accumulated other comprehensive income, attributable to Ciner Resources, includes unrealized gains and losses on derivative financial instruments. Amounts recorded in accumulated other comprehensive income as of June 30, 2021 and December 31, 2020, and changes within the period, consisted of the following: (In millions) Gains and (Losses) on Cash Flow Hedges Balance at December 31, 2020 — Other comprehensive income before reclassification 3.7 Amounts reclassified from accumulated other comprehensive loss (0.3) Net current period other comprehensive income 3.4 Balance at June 30, 2021 $ 3.4 Other Comprehensive Income (Loss) Other comprehensive income/(loss), including the portion attributable to noncontrolling interest, is derived from adjustments to reflect the unrealized gains (loss) on derivative financial instruments. The components of other comprehensive income (loss) consisted of the following: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Unrealized gain/(loss) on derivatives: Mark to market adjustment on interest rate swap contracts $ 0.1 $ 0.1 $ 0.4 $ (0.9) Mark to market adjustment on natural gas forward contracts 5.0 2.7 6.2 1.6 Gain on derivative financial instruments $ 5.1 $ 2.8 $ 6.6 $ 0.7 Reclassifications for the period The components of other comprehensive (loss) income, attributable to Ciner Resources LP, that have been reclassified consisted of the following: Three Months Ended June 30, Six Months Ended June 30, Affected Line Items on the Unaudited Condensed Consolidated Statements of Operations and Comprehensive (Loss) income (In millions) 2021 2020 2021 2020 Details about other comprehensive (loss) income components: Gains and losses on cash flow hedges: Interest rate swap contracts $ 0.1 $ 0.2 $ 0.2 $ 0.2 Interest expense Natural gas forward contracts (0.3) 0.6 (0.5) 1.0 Cost of products sold Total reclassifications for the period $ (0.2) $ 0.8 $ (0.3) $ 1.2

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	6 Months Ended
	Jun. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES From time to time we are party to various claims and legal proceedings related to our business. Although the outcome of these proceedings cannot be predicted with certainty, management does not currently expect any of the legal proceedings we are involved in to have a material effect on our business, financial condition and results of operations. We cannot predict the nature of any future claims or proceedings, nor the ultimate size or outcome of such proceedings and whether any damages resulting from them will be covered by insurance. Off-Balance Sheet Arrangements We have historically been subject to a self-bond agreement (the “Self-Bond Agreement”) with the Wyoming Department of Environmental Quality (“WDEQ”) under which we committed to pay directly for reclamation costs. In May 2019, the State of Wyoming enacted legislation that limits our and other mine operators’ ability to self-bond and required us to seek other acceptable financial instruments to provide alternate assurances for our reclamation obligations by November 2020. We provided such alternate assurances by timely securing a third-party surety bond effective October 15, 2020 (the “Surety Bond”) for the then-applicable full self-bond amount $36.2 million, which was also the amount of our obligation as of December 31, 2020. After we secured the Surety Bond, the previous Self-Bond Agreement was terminated. As of the date of this Report, the impact on our net income and liquidity due to securing the Surety Bond has been immaterial and we anticipate that to continue to be the case. The amount of such assurances that we are required to provide is subject to change upon periodic re-evaluation by the WDEQ’s Land Quality Division. As a result of the most recent such periodic re-evaluation, the Surety Bond amount was increased to $41.8 million effective March 1, 2021.

AGREEMENTS AND TRANSACTIONS WIT

AGREEMENTS AND TRANSACTIONS WITH AFFILIATES	6 Months Ended
	Jun. 30, 2021
Related Party Transactions [Abstract]
AGREEMENTS AND TRANSACTIONS WITH AFFILIATES	AGREEMENTS AND TRANSACTIONS WITH AFFILIATES Agreements and transactions with affiliates collectively have a significant impact on the Partnership’s financial statements because the Partnership is a subsidiary in a global group structure. Agreements directly between the Partnership and other affiliates, or indirectly between affiliates that the Partnership does not control, can have a significant impact on recorded amounts or disclosures in the Partnership's financial statements, including any commitments and contingencies between the Partnership and affiliates, or potentially, third parties. Ciner Corp was the exclusive sales agent for the Partnership and through its membership in ANSAC, through December 31, 2020, Ciner Corp has responsibility for promoting and increasing the use and sale of soda ash and other refined or processed sodium products produced. Through December 31, 2020, ANSAC served as the primary international distribution channel for the Partnership and two other U.S. manufacturers of trona-based soda ash. ANSAC operated on a cooperative service-at-cost basis to its members such that typically any annual profit or loss is passed through to the members. As previously disclosed as part of its strategic initiative to gain better direct access and control of international customers and logistics and the ability to leverage the expertise of Ciner Group, the world’s largest natural soda ash producer, effective as of the end of day on December 31, 2020, Ciner Corp exited ANSAC (the “ANSAC termination date”). In connection with the exit settlement agreement with ANSAC (the “ANSAC Early Exit Agreement”), among other things, there are sales commitments to ANSAC in 2021 and 2022 where Ciner Corp continues to sell, at substantially lower volumes, product to ANSAC for export sales purposes, with a fixed rate per ton selling, general and administrative expense, and also purchases a limited amount of export logistics services in 2021. Through in part the Partnership’s affiliates, the Partnership has amongst other things: (i) obtained its own international customer sales arrangements for 2021, (ii) obtained third-party export port services, and (iii) chartered and executed its own international product delivery. For the three months and six months ended June 30, 2021, the total logistic services, which are included in cost of products sold, from other Ciner affiliates were approximately $0.7 million and $2.2 million, respectively. Historically, by design and prior to Ciner Corp’s exit from ANSAC, ANSAC managed most of our international sales, marketing and logistics, and as a result, was our largest customer for the year ended December 31, 2020, accounting for 45.4%, of our net sales. Although ANSAC has historically been our largest customer, the impact of Ciner Corp’s exit from ANSAC on our net sales, net income and liquidity was limited. We made this determination primarily based upon the belief that we would continue to be one of the lowest cost producers of soda ash in the global market. With a low-cost position combined with better direct access and control of our customers and logistics and the ability to leverage Ciner Group’s expertise in these areas, through a combination of ANSAC sales and commitments for 2021 and 2022 as part of the transition from ANSAC and new customers, we have been able to adequately replace these net sales made under the former agreement with ANSAC. Since January 1, 2021, Ciner Corp has been managing the Partnership’s sales and marketing activities for exports. Ciner Corp has leveraged the distributor network established by Ciner Group and independent third-party distribution partners to optimize our reach into each market. In accordance with the ANSAC Early Exit Agreement, Ciner Corp began marketing soda ash on our behalf directly into international markets and building its international sales, marketing and supply chain infrastructure. We now have access to utilize the distribution network that has already been established by the Ciner Group. We believe that by having the option of combining our volumes with Ciner Group’s soda ash exports from Turkey, Ciner Corp’s strategic exit from ANSAC has helped us leverage Ciner Group’s, the world’s largest natural soda ash producer, soda ash operations which we expect will improve our ability to optimize our market share both domestically and internationally. Being able to work with the Ciner Group provides us with the opportunity to better attract and more efficiently serve larger global customers. In addition, the Partnership is working to enhance its international logistics infrastructure that includes, among other things, a domestic port for export capabilities. These export capabilities are being developed by an affiliated company and options being evaluated range from continued outsourcing in the near term to developing its own port capabilities in the longer term. Selling, general and administrative expenses also include amounts charged to the Partnership by its affiliates principally consisting of salaries, benefits, office supplies, professional fees, travel, rent and other costs of certain assets used by the Partnership. On October 23, 2015, the Partnership entered into a Services Agreement (the “Services Agreement”) with our general partner and Ciner Corp. Pursuant to the Services Agreement, Ciner Corp has agreed to provide the Partnership with certain corporate, selling, marketing, and general and administrative services, in return for which the Partnership has agreed to pay Ciner Corp an annual management fee and reimburse Ciner Corp for certain third-party costs incurred in connection with providing such services. In addition, under the limited liability company agreement governing Ciner Wyoming, Ciner Wyoming reimburses us for employees who operate our assets and for support provided to Ciner Wyoming. These transactions do not necessarily represent arm's length transactions and may not represent all costs if Ciner Wyoming operated on a standalone basis. As a result of terminating Ciner Corp’s membership in ANSAC, ANSAC is no longer an affiliate of the Partnership as of the ANSAC termination date. The following tables include transactions with ANSAC as an affiliate prior to the ANSAC termination date on December 31, 2020. The transactions with ANSAC as of and for the three and six months ended June 30, 2021 are reported as non-affiliate transactions. The total selling, general and administrative costs charged to the Partnership by affiliates were as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Ciner Corp $ 4.2 $ 4.0 $ 7.8 $ 7.5 ANSAC (1) N/A 0.4 N/A 1.0 Total selling, general and administrative expenses - affiliates $ 4.2 $ 4.4 $ 7.8 $ 8.5 (1) ANSAC allocated its expenses to its members using a pro-rata calculation based on sales. Net sales to affiliates were as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 ANSAC N/A $ 32.0 N/A $ 86.0 Total N/A $ 32.0 N/A $ 86.0 The Partnership had accounts receivable from affiliates and due to affiliates as follows: As of June 30, December 31, June 30, December 31, (In millions) Accounts receivable from affiliates Due to affiliates ANSAC N/A $ 41.9 N/A $ 0.2 Ciner Corp 47.3 44.6 2.1 2.6 Other 1.7 — — 0.1 Total $ 49.0 $ 86.5 $ 2.1 $ 2.9

Revenue

Revenue	6 Months Ended
	Jun. 30, 2021
Segment Reporting [Abstract]
Revenue	REVENUE We have one major international customer which accounts for over 10% of total net sales for both the quarter ended and six months ended June 30, 2021 and 2020. Revenues from this international customer were approximately $27.1 million and $32.0 million for the three months ended June 30, 2021 and 2020, respectively, and were $54.6 million and $86.0 million for the six months ended June 30, 2021 and 2020, respectively. The net sales by geographic area are as follows: The net sales by geographic area are as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Domestic $ 70.5 $ 44.2 $ 136.8 $ 99.4 International 50.2 32.0 111.7 91.2 Total net sales $ 120.7 $ 76.2 $ 248.5 $ 190.6

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS Financial instruments consist primarily of cash and cash equivalents, accounts receivable, accounts payable, accrued expenses, derivative financial instruments and long-term debt. The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable and accrued expenses approximate their fair values because of the nature of such instruments. Our long-term debt and derivative financial instruments are measured at their fair value based on quoted market values for similar but not identical financial instruments. Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis Derivative Financial Instruments We have interest rate swap contracts, designated as cash flow hedges, to mitigate our exposure to possible increases in interest rates. The swap contracts had an aggregate notional value of $50.0 million and $37.5 million at June 30, 2021 and December 31, 2020, respectively. The swaps have various maturities through 2024. We enter into natural gas forward contracts, designated as cash flow hedges, to mitigate volatility in the price of natural gas related to a portion of the natural gas we consume. These contracts generally have various maturities through 2023. These contracts had an aggregate notional value of $22.8 million and $25.9 million at June 30, 2021 and December 31, 2020, respectively. The following table presents the fair value of derivative assets and derivative liabilities and the respective locations as of June 30, 2021 and December 31, 2020: Assets Liabilities June 30, December 31, June 30, December 31, (In millions) Balance Sheet Location Fair Value Fair Value Balance Sheet Location Fair Value Fair Value Derivatives designated as hedges: Interest rate swap contracts - current $ — $ — Accrued Expenses $ 0.1 $ 0.2 Natural gas forward contracts - current Other current assets 5.7 1.4 Accrued Expenses 0.1 0.7 Interest rate swap contracts - non-current — — Other non-current liabilities 0.8 1.1 Natural gas forward contracts - non-current Other non-current assets 2.0 0.9 Other non-current liabilities — 0.2 Total fair value of derivatives designated as hedging instruments $ 7.7 $ 2.3 $ 1.0 $ 2.2 Financial Assets and Liabilities not Measured at Fair Value The carrying value of our long-term debt materially reflects the fair value of our long-term debt as its key terms are similar to indebtedness with similar amounts, durations and credit risks. See Note 4 “Debt” for additional information on our debt arrangements.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	6 Months Ended
	Jun. 30, 2021
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS Suspension of Distributions Effective August 2, 2021, the board of Ciner Wyoming unanimously approved a continuation of the suspension of quarterly distributions to the members of Ciner Wyoming. Effective August 2, 2021, in connection with the quarterly distribution for the quarter ended June 30, 2021, each of the members of the board of directors of our general partner approved a continuation of the suspension of quarterly distributions to unitholders in order to increase financial and liquidity flexibility as the COVID-19 pandemic continues. The boards of directors of Ciner Wyoming and our general partner will continue to evaluate, on a quarterly basis, whether it is appropriate to reinstate the distribution to the member and unitholders, respectively, which will be dependent in part on our cash reserves, liquidity, total debt levels and anticipated capital expenditures.

CORPORATE STRUCTURE AND SUMMA_2

CORPORATE STRUCTURE AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Jun. 30, 2021
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations The unaudited condensed consolidated financial statements are composed of Ciner Resources LP (the “Partnership,” “CINR,” “Ciner Resources,” “we,” “us,” or “our”), a publicly traded Delaware limited partnership, and its consolidated subsidiary, Ciner Wyoming LLC (“Ciner Wyoming”), which is in the business of mining trona ore to produce soda ash. The Partnership’s operations consist solely of its investment in Ciner Wyoming. The Partnership was formed in April 2013 by Ciner Wyoming Holding Co. (“Ciner Holdings”), a wholly-owned subsidiary of Ciner Resources Corporation (“Ciner Corp”). Ciner Corp is a direct wholly-owned subsidiary of Ciner Enterprises Inc. (“Ciner Enterprises”), which is a direct wholly-owned subsidiary of WE Soda Ltd., a U.K. corporation (“WE Soda”). WE Soda is a direct wholly-owned subsidiary of KEW Soda Ltd., a U.K. corporation (“KEW Soda”), which is a direct wholly-owned subsidiary of Akkan Enerji ve Madencilik Anonim Şirketi (“Akkan”). Akkan is directly and wholly owned by Turgay Ciner, the Chairman of the Ciner Group (“Ciner Group”), a Turkish conglomerate of companies engaged in energy and mining (including soda ash mining), media and shipping markets. The Partnership owns a controlling interest comprised of 51.0% membership interest in Ciner Wyoming. All of our soda ash processed is sold to various domestic and international customers, including American Natural Soda Ash Corporation (“ANSAC”), which was an affiliate for export sales in 2020. As a result of terminating Ciner Corp’s membership in ANSAC effective as of the end of day on December 31, 2020, ANSAC is no longer an affiliate of the Partnership. All mining and processing activities of Ciner Wyoming take place in one facility located in the Green River Basin of Wyoming.
Basis of Presentation and Significant Accounting Policies	Basis of Presentation and Significant Accounting Policies The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“GAAP”) applicable to interim period financial statements and reflect all adjustments, consisting of normal recurring accruals, which are necessary for fair presentation of the results of operations, financial position and cash flows for the periods presented. All intercompany transactions, balances, revenue and expenses have been eliminated in consolidation. The results of operations for the three and six month periods ended June 30, 2021 and 2020 are not necessarily indicative of the operating results for the full year. These unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and notes to audited consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2020 (the “2020 Annual Report”) filed with the United States Securities and Exchange Commission on March 16, 2021. There have been no material changes in the significant accounting policies followed by us during the six months ended June 30, 2021 from those disclosed in the 2020 Annual Report.
Segment Reporting	Segment ReportingAs the Partnership earns substantially all of its revenues through the sale of soda ash mined at a single location, we have concluded that we have one operating segment for reporting purposes.
Use of Estimates	Use of Estimates The preparation of these unaudited condensed consolidated financial statements, in accordance with GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, and disclosure of contingent assets and liabilities at the dates of the unaudited condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements and Securities and Exchange Commission Rules Securities and Exchange Commission Rules On October 31, 2018, the SEC issued a final rule that amends the current disclosure regime for SEC registrants with material mining operations. Among the final rule’s amendments is the addition of Subpart 1300 to SEC Regulation S-K. The purpose of the amendments is to provide investors with more comprehensive information while aligning the SEC’s disclosure requirements with the global regulatory standards outlined by the Committee for Mineral Reserves International Reporting Standards, which is commonly referred to as “CRIRSCO.” When assessing the materiality of mining operations to determine whether disclosures are required, registrants must consider operations in the aggregate (including all mining properties irrespective of the current stage of development or operation) and evaluate both quantitative and qualitative factors. Registrants must comply with the revised requirements for their first fiscal year beginning on or after January 1, 2021. Further, the disclosures required under the final rule must be supported by the work of a qualified person, such as a mine engineer. When a registrant first reports mineral reserves or resources, or makes a material change to such disclosures, it must file a technical report summary supporting the disclosure. Developing this detailed disclosure information (e.g., by using an expert) and maintaining appropriate disclosure controls and procedures over it will require significant time, resources, and effort. The Partnership continues to evaluate the impact this guidance will have on its disclosures in the Annual Report on Form 10-K for the year ended December 31, 2021. Recent Accounting Guidance Not Yet Adopted In March 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting (“ASU 2020-04”) providing temporary guidance to ease the potential burden in accounting for reference rate reform primarily resulting from the discontinuation of the London Inter-bank Offered Rate (“LIBOR,”), which is currently expected to occur on December 31, 2021. The amendments in ASU 2020-04 are elective and apply to all entities that have contracts, hedging relationships, and other transactions that reference LIBOR or another reference rate expected to be discontinued. The new guidance provides the following optional expedients: (i) simplifies accounting analyses under current GAAP for contract modifications; (ii) simplifies the assessment of hedge effectiveness and allows hedging relationships affected by reference rate reform to continue; and (iii) allows a one-time election to sell or transfer debt securities classified as held to maturity that reference a rate affected by reference rate reform. An entity may elect to apply the amendments prospectively from March 12, 2020 through December 31, 2022 by accounting topic. The Partnership continues to evaluate ASU 2020-04 but does not expect a material impact to the Partnership’s consolidated financial statements.

NET INCOME PER UNIT AND CASH _2

NET INCOME PER UNIT AND CASH DISTRIBUTION (Tables)	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Calculation of Net Income Per Unit	The net income attributable to limited partner unitholders and the weighted average units for calculating basic and diluted net income per limited partner units were as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions, except per unit data) 2021 2020 2021 2020 Numerator: Net income (loss) attributable to Ciner Resources LP $ 2.9 $ (3.3) $ 5.3 $ 3.4 Less: General partner’s interest in net income — — 0.1 0.1 Total limited partners’ interest in net income (loss) $ 2.9 $ (3.3) $ 5.2 $ 3.3 Denominator: Weighted average limited partner units outstanding: Weighted average limited partner units outstanding (basic) 19.8 19.7 19.8 19.7 Weighted average limited partner units outstanding (diluted) 19.8 19.7 19.8 19.7 Net income (loss) per limited partner unit: Net income (loss) per limited partner unit (basic) $ 0.15 $ (0.17) $ 0.27 $ 0.17 Net income (loss) per limited partner unit (diluted) $ 0.15 $ (0.17) $ 0.27 $ 0.17
Calculation of Limited Partners' Interest in Net Income	The calculation of limited partners’ interest in net income (loss) is as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Net income attributable to common unitholders: Distributions (1) $ — $ — $ — $ 6.7 Undistributed earnings (loss) (Distributions) in excess of net income (loss) 2.9 (3.3) 5.2 (3.4) Common unitholders’ interest in net income (loss) $ 2.9 $ (3.3) $ 5.2 $ 3.3 (1) Distributions declared per limited partner unit for the period $ — $ — $ — $ 0.340
Percentage Allocations of Distributions From Operating Surplus	Marginal Percentage Total Quarterly Unitholders General Partner Minimum Quarterly Distribution $0.5000 98.0 % 2.0 % First Target Distribution above $0.5000 up to $0.5750 98.0 % 2.0 % Second Target Distribution above $0.5750 up to $0.6250 85.0 % 15.0 % Third Target Distribution above $0.6250 up to $0.7500 75.0 % 25.0 % Thereafter above $0.7500 50.0 % 50.0 %

INVENTORY (Tables)

INVENTORY (Tables)	6 Months Ended
	Jun. 30, 2021
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory consisted of the following: As of (In millions) June 30, 2021 December 31, 2020 Raw materials $ 10.5 $ 9.9 Finished goods 9.7 13.4 Stores inventory 11.2 10.2 Total $ 31.4 $ 33.5

DEBT (Tables)

DEBT (Tables)	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Components of Long-term Debt	Long-term debt, net of debt issuance costs, consisted of the following: As of (In millions) June 30, 2021 December 31, 2020 Ciner Wyoming Credit Facility, secured principal expiring on August 1, 2022, variable interest rate as a weighted average rate of 2.75% and 2.25% as of June 30, 2021 and December 31, 2020, respectively $ 110.0 $ 102.5 Ciner Wyoming Equipment Financing Arrangement with maturity date of March 26, 2028, fixed interest rate of 2.479% 26.0 27.6 Ciner Resources Credit Facility, secured principal expiring on August 1, 2022, variable interest rate as a weighted average rate of 2.25% as of December 31, 2020 — 1.0 Total debt 136.0 131.1 Current portion of long-term debt 3.0 3.0 Total long-term debt $ 133.0 $ 128.1
Aggregate Maturities on Long-term Debt	Aggregate maturities required on long-term debt as of June 30, 2021 are due in future years as follows: (In millions) Amount 2021 $ 1.5 2022 113.1 2023 3.2 2024 3.3 2025 3.3 Thereafter 11.8 Total $ 136.2
Schedule of Debt Covenants	The unused portion of the Ciner Wyoming Credit Facility is subject to a per annum commitment fee and the applicable margin of the interest rate under the Ciner Wyoming Credit Facility will be determined as follows: Pricing Tier Leverage Ratio Eurodollar Rate Loans Base Rate Commitment 1 < 1.25:1.0 1.500% 0.500% 0.250% 2 ≥ 1.25:1.0 but < 1.75:1.0 1.750% 0.750% 0.275% 3 ≥ 1.75:1.0 but < 2.25:1.0 2.000% 1.000% 0.300% 4 ≥ 2.25:1.0 but < 3.00:1.0 2.250% 1.250% 0.375% 5 ≥ 3.00:1.0 but < 3.50:1.0 2.500% 1.500% 0.375% 6 ≥ 3.50:1.0 but < 4.00:1.0 2.750% 1.750% 0.425% 7 ≥ 4.00:1.0 3.000% 2.000% 0.475%

OTHER NON-CURRENT LIABILITIES (

OTHER NON-CURRENT LIABILITIES (Tables)	6 Months Ended
	Jun. 30, 2021
Asset Retirement Obligation Disclosure [Abstract]
Schedule of Other Non-current Liabilities	Other non-current liabilities consisted of the following: As of (In millions) June 30, 2021 December 31, 2020 Reclamation reserve $ 7.5 $ 7.3 Derivative instruments and hedges, fair value liabilities and other 0.9 1.4 Total $ 8.4 $ 8.7
Reconciliation of Partnership's Reclamation Reserve Liability	A reconciliation of the Partnership’s reclamation reserve liability is as follows: For the period ended (In millions) June 30, 2021 December 31, 2020 Beginning reclamation reserve balance $ 7.3 $ 5.7 Accretion expense 0.2 0.3 Reclamation adjustments (1) — 1.3 Ending reclamation reserve balance $ 7.5 $ 7.3 (1) The reclamation costs are periodically evaluated for adjustments by the Wyoming Department of Environmental Quality. See Note 9 “Commitments and Contingencies,” “ Off-Balance Sheet Arrangements ” for additional information on our reclamation reserve, including recent changes to the underlying reclamation obligation that has resulted in the asset retirement obligation reclamation adjustment.

EQUITY - BASED COMPENSATION (Ta

EQUITY - BASED COMPENSATION (Tables)	6 Months Ended
	Jun. 30, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Time Restricted Unit Award Activity	The following table presents a summary of activity on the Time Restricted Unit Awards: Six Months Ended Six Months Ended (Units in whole numbers) Number of Common Units Grant-Date Average Fair Value per Unit (1) Number of Common Units Grant-Date Average Fair Value per Unit (1) Unvested at the beginning of period 21,937 $ 17.57 55,454 $ 20.33 Vested (12,247) 18.46 (27,802) 22.94 Unvested at the end of the period 9,690 $ 16.45 27,652 $ 17.71
Schedule of Time Restricted Performance Unit Award Activity	The following table presents a summary of activity on the TR Performance Unit Awards: Six Months Ended Six Months Ended (Units in whole numbers) Number of Common Units Grant-Date Average Fair Value per Unit (1) Number of Common Units Grant-Date Average Fair Value per Unit (1) Unvested at the beginning of period 7,678 $ 41.53 20,173 $ 41.79 Vested (7,678) 41.53 (9,058) 42.21 Unvested at the end of the period — $ — 11,115 $ 41.59 (1) Determined by dividing the aggregate grant date fair value of awards by the number of common units.
Schedule of Performance Unit Awards	The following table presents a summary of activity on the 2019 Performance Unit Awards for the period: Six Months Ended Six Months Ended (Units in whole numbers) Number of Common Units Grant-Date Average Fair Value per Unit (1) Number of Common Units Grant-Date Average Fair Value per Unit (1) Unvested at the beginning of period 29,057 $ 16.45 35,908 $ 16.45 Unvested at the end of the period 29,057 $ 16.45 35,908 $ 16.45 (1) Determined by dividing the weighted average price per common unit on the date of grant.
Schedule of Unrecognized Compensation Expense	A summary of the Partnership’s unrecognized compensation expense for its unvested restricted time and performance-based units, and the weighted-average periods over which the compensation expense is expected to be recognized are as follows: Six Months Ended Six Months Ended Unrecognized Compensation Expense Weighted Average to be Recognized Unrecognized Compensation Expense Weighted Average to be Recognized Time Restricted Unit Awards $ 0.1 0.71 $ 0.4 1.54 TR Performance Unit Awards — — 0.1 0.59 2019 Performance Unit Awards — 0.59 0.2 1.59 Total $ 0.1 $ 0.7

ACCUMULATED OTHER COMPREHENSI_2

ACCUMULATED OTHER COMPREHENSIVE LOSS (Tables)	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Loss	Amounts recorded in accumulated other comprehensive income as of June 30, 2021 and December 31, 2020, and changes within the period, consisted of the following: (In millions) Gains and (Losses) on Cash Flow Hedges Balance at December 31, 2020 — Other comprehensive income before reclassification 3.7 Amounts reclassified from accumulated other comprehensive loss (0.3) Net current period other comprehensive income 3.4 Balance at June 30, 2021 $ 3.4
Components of Other Comprehensive Income/(Loss)	The components of other comprehensive income (loss) consisted of the following: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Unrealized gain/(loss) on derivatives: Mark to market adjustment on interest rate swap contracts $ 0.1 $ 0.1 $ 0.4 $ (0.9) Mark to market adjustment on natural gas forward contracts 5.0 2.7 6.2 1.6 Gain on derivative financial instruments $ 5.1 $ 2.8 $ 6.6 $ 0.7
Schedule of Reclassifications Out of Other Comprehensive Loss, Attributable to Ciner Resources	The components of other comprehensive (loss) income, attributable to Ciner Resources LP, that have been reclassified consisted of the following: Three Months Ended June 30, Six Months Ended June 30, Affected Line Items on the Unaudited Condensed Consolidated Statements of Operations and Comprehensive (Loss) income (In millions) 2021 2020 2021 2020 Details about other comprehensive (loss) income components: Gains and losses on cash flow hedges: Interest rate swap contracts $ 0.1 $ 0.2 $ 0.2 $ 0.2 Interest expense Natural gas forward contracts (0.3) 0.6 (0.5) 1.0 Cost of products sold Total reclassifications for the period $ (0.2) $ 0.8 $ (0.3) $ 1.2

AGREEMENTS AND TRANSACTIONS W_2

AGREEMENTS AND TRANSACTIONS WITH AFFILIATES (Tables)	6 Months Ended
	Jun. 30, 2021
Related Party Transactions [Abstract]
Schedule of Transactions with Affiliates	The total selling, general and administrative costs charged to the Partnership by affiliates were as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Ciner Corp $ 4.2 $ 4.0 $ 7.8 $ 7.5 ANSAC (1) N/A 0.4 N/A 1.0 Total selling, general and administrative expenses - affiliates $ 4.2 $ 4.4 $ 7.8 $ 8.5 (1) ANSAC allocated its expenses to its members using a pro-rata calculation based on sales. Net sales to affiliates were as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 ANSAC N/A $ 32.0 N/A $ 86.0 Total N/A $ 32.0 N/A $ 86.0 The Partnership had accounts receivable from affiliates and due to affiliates as follows: As of June 30, December 31, June 30, December 31, (In millions) Accounts receivable from affiliates Due to affiliates ANSAC N/A $ 41.9 N/A $ 0.2 Ciner Corp 47.3 44.6 2.1 2.6 Other 1.7 — — 0.1 Total $ 49.0 $ 86.5 $ 2.1 $ 2.9

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 30, 2021
Segment Reporting [Abstract]
Schedule of Net Sales By Geographic Area	The net sales by geographic area are as follows: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2021 2020 2021 2020 Domestic $ 70.5 $ 44.2 $ 136.8 $ 99.4 International 50.2 32.0 111.7 91.2 Total net sales $ 120.7 $ 76.2 $ 248.5 $ 190.6

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Derivative Assets and Liabilities	The following table presents the fair value of derivative assets and derivative liabilities and the respective locations as of June 30, 2021 and December 31, 2020: Assets Liabilities June 30, December 31, June 30, December 31, (In millions) Balance Sheet Location Fair Value Fair Value Balance Sheet Location Fair Value Fair Value Derivatives designated as hedges: Interest rate swap contracts - current $ — $ — Accrued Expenses $ 0.1 $ 0.2 Natural gas forward contracts - current Other current assets 5.7 1.4 Accrued Expenses 0.1 0.7 Interest rate swap contracts - non-current — — Other non-current liabilities 0.8 1.1 Natural gas forward contracts - non-current Other non-current assets 2.0 0.9 Other non-current liabilities — 0.2 Total fair value of derivatives designated as hedging instruments $ 7.7 $ 2.3 $ 1.0 $ 2.2

CORPORATE STRUCTURE AND SUMMA_3

CORPORATE STRUCTURE AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	6 Months Ended
	Jun. 30, 2021segment
Noncontrolling Interest [Line Items]
Number of operating segments	1
Ciner Wyoming
Noncontrolling Interest [Line Items]
Membership interest	51.00%
Membership interest attributable to noncontrolling interest	49.00%

NET INCOME PER UNIT AND CASH _3

NET INCOME PER UNIT AND CASH DISTRIBUTION - Calculation of net income per unit (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Net income (loss) attributable to Ciner Resources LP	$ 2.9	$ (3.3)	$ 5.3	$ 3.4
Less: General partner’s interest in net income	0	0	0.1	0.1
Total limited partners’ interest in net income (loss)	$ 2.9	$ (3.3)	$ 5.2	$ 3.3
Weighted average limited partner units outstanding:
Weighted average common units outstanding (basic) (in shares)	19.8	19.7	19.8	19.7
Weighted average common units outstanding (diluted) (in shares)	19.8	19.7	19.8	19.7
Net income (loss) per limited partner unit:
Net income per limited partner unit (basic) (in dollars per share)	$ 0.15	$ (0.17)	$ 0.27	$ 0.17
Net income per limited partner units (diluted) (in dollars per share)	$ 0.15	$ (0.17)	$ 0.27	$ 0.17
Distributions	$ 0	$ 0	$ 0	$ 6.7
Undistributed earnings (loss) (Distributions) in excess of net income (loss)	2.9	(3.3)	5.2	(3.4)
Common unitholders’ interest in net income (loss)	$ 2.9	$ (3.3)	$ 5.2	$ 3.3
Distributions declared per common unit for the period (in dollars per share)	$ 0	$ 0	$ 0	$ 0.340

NET INCOME PER UNIT AND CASH _4

NET INCOME PER UNIT AND CASH DISTRIBUTION - Narrative (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	0	0	0	0
Revolving credit facility | Ciner Resources Credit Facility | Line of Credit
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Repayments of debt	$ 8
Second Target Distribution | General Partner
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Increasing percentage allocation of operating surplus			13.00%
Third Target Distribution | General Partner
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Increasing percentage allocation of operating surplus			23.00%
Thereafter | General Partner
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Increasing percentage allocation of operating surplus			48.00%
Ciner Resource Partners LLC | General Partner
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Percentage of general partner ownership interest held			2.00%

NET INCOME PER UNIT AND CASH _5

NET INCOME PER UNIT AND CASH DISTRIBUTION - Target distributions and marginal percentage interests (Details)	6 Months Ended
	Jun. 30, 2021$ / shares
Minimum Quarterly Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Minimum quarterly distribution target levels (in dollars per share)	$ 0.5000
First Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Minimum quarterly distribution target levels (in dollars per share)	0.5000
Maximum quarterly distribution target levels (in dollars per share)	0.5750
Second Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Minimum quarterly distribution target levels (in dollars per share)	0.5750
Maximum quarterly distribution target levels (in dollars per share)	0.6250
Third Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Minimum quarterly distribution target levels (in dollars per share)	0.6250
Maximum quarterly distribution target levels (in dollars per share)	0.7500
Thereafter
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Minimum quarterly distribution target levels (in dollars per share)	$ 0.7500
Unitholders | Minimum Quarterly Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	98.00%
Unitholders | First Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	98.00%
Unitholders | Second Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	85.00%
Unitholders | Third Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	75.00%
Unitholders | Thereafter
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	50.00%
General Partner | Minimum Quarterly Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	2.00%
General Partner | First Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	2.00%
General Partner | Second Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	15.00%
General Partner | Third Target Distribution
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	25.00%
General Partner | Thereafter
Schedule of Percentage Allocation of Distributions From Operating Surplus [Line Items]
Marginal interest in distribution, percentage	50.00%

INVENTORY (Details)

INVENTORY (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Raw materials	$ 10.5	$ 9.9
Finished goods	9.7	13.4
Stores inventory	11.2	10.2
Total	$ 31.4	$ 33.5

DEBT - Components of long-term

DEBT - Components of long-term debt (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total debt	$ 136	$ 131.1
Current portion of long-term debt	3	3
Total long-term debt	$ 133	$ 128.1
Ciner Wyoming Credit Facility | Revolving credit facility | Line of Credit
Debt Instrument [Line Items]
Interest rate	2.75%	2.25%
Total debt	$ 110	$ 102.5
Ciner Wyoming Equipment Financing Arrangement | Secured Debt
Debt Instrument [Line Items]
Stated interest rate	2.479%
Total debt	$ 26	$ 27.6
Ciner Resources Credit Facility | Revolving credit facility | Line of Credit
Debt Instrument [Line Items]
Interest rate		2.25%
Total debt	$ 0	$ 1

DEBT - Maturities of long-term

DEBT - Maturities of long-term debt (Details) $ in Millions	Jun. 30, 2021USD ($)
Debt Disclosure [Abstract]
2021	$ 1.5
2022	113.1
2023	3.2
2024	3.3
2025	3.3
Thereafter	11.8
Total	$ 136.2

DEBT - Ciner Wyoming Equipment

DEBT - Ciner Wyoming Equipment Financing Arrangement (Details)	6 Months Ended
	Jun. 30, 2021USD ($)installment	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
Long-term debt, gross	$ 136,200,000
Long-term debt	136,000,000	$ 131,100,000
Secured Debt | Ciner Wyoming Equipment Financing Arrangement
Debt Instrument [Line Items]
Face amount	$ 30,000,000
Number of installments | installment	96
Periodic payment	$ 307,000
Number of monthly installments | installment	95
Periodic payment terms, balloon payment to be paid	$ 4,307,000
Long-term debt, gross	26,200,000
Long-term debt	26,000,000	$ 27,600,000
Secured Debt | Ciner Wyoming Equipment Financing Arrangement | Minimum
Debt Instrument [Line Items]
Third party indebtedness	$ 10,000,000

DEBT DEBT - Ciner Wyoming Credi

DEBT DEBT - Ciner Wyoming Credit Facility (Details) - Ciner Wyoming Credit Facility	6 Months Ended
	Jun. 30, 2021USD ($)	Mar. 31, 2021
Revolving credit facility
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 225,000,000
Accordion feature, increase limit	$ 75,000,000
Revolving credit facility | Line of Credit
Debt Instrument [Line Items]
Change of control percentage threshold	50.10%
Interest coverage ratio, minimum		3
Consolidated leverage ratio	3	4.50
Debt instrument, term	5 years
Revolving credit facility | Line of Credit | Minimum
Debt Instrument [Line Items]
Interest rate floor	0.50%
Revolving credit facility | Line of Credit | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
Revolving credit facility | Line of Credit | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%
Swing Line Advances
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 20,000,000
Letter of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 40,000,000

DEBT DEBT - Schedule of Debt Co

DEBT DEBT - Schedule of Debt Covenants (Details) - Revolving credit facility - Line of Credit - Ciner Wyoming Credit Facility	6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021
Debt Instrument [Line Items]
Consolidated leverage ratio	3	4.50
Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
Pricing Tier 1
Debt Instrument [Line Items]
Commitment Fee	0.25%
Pricing Tier 1 | Maximum
Debt Instrument [Line Items]
Consolidated leverage ratio	1.25
Pricing Tier 1 | Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Pricing Tier 1 | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.50%
Pricing Tier 2
Debt Instrument [Line Items]
Commitment Fee	0.275%
Pricing Tier 2 | Maximum
Debt Instrument [Line Items]
Consolidated leverage ratio	1.75
Pricing Tier 2 | Minimum
Debt Instrument [Line Items]
Consolidated leverage ratio	1.25
Pricing Tier 2 | Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
Pricing Tier 2 | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate	0.75%
Pricing Tier 3
Debt Instrument [Line Items]
Commitment Fee	0.30%
Pricing Tier 3 | Maximum
Debt Instrument [Line Items]
Consolidated leverage ratio	2.25
Pricing Tier 3 | Minimum
Debt Instrument [Line Items]
Consolidated leverage ratio	1.75
Pricing Tier 3 | Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate	2.00%
Pricing Tier 3 | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%
Pricing Tier 4
Debt Instrument [Line Items]
Commitment Fee	0.375%
Pricing Tier 4 | Maximum
Debt Instrument [Line Items]
Consolidated leverage ratio	3
Pricing Tier 4 | Minimum
Debt Instrument [Line Items]
Consolidated leverage ratio	2.25
Pricing Tier 4 | Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate	2.25%
Pricing Tier 4 | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate	1.25%
Pricing Tier 5
Debt Instrument [Line Items]
Commitment Fee	0.375%
Pricing Tier 5 | Maximum
Debt Instrument [Line Items]
Consolidated leverage ratio	3.50
Pricing Tier 5 | Minimum
Debt Instrument [Line Items]
Consolidated leverage ratio	3
Pricing Tier 5 | Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate	2.50%
Pricing Tier 5 | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
Pricing Tier 6
Debt Instrument [Line Items]
Commitment Fee	0.425%
Pricing Tier 6 | Maximum
Debt Instrument [Line Items]
Consolidated leverage ratio	4
Pricing Tier 6 | Minimum
Debt Instrument [Line Items]
Consolidated leverage ratio	3.50
Pricing Tier 6 | Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate	2.75%
Pricing Tier 6 | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate	1.75%
Pricing Tier 7
Debt Instrument [Line Items]
Commitment Fee	0.475%
Pricing Tier 7 | Minimum
Debt Instrument [Line Items]
Consolidated leverage ratio	4
Pricing Tier 7 | Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate	3.00%
Pricing Tier 7 | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate	2.00%

DEBT DEBT - Ciner Resources Cre

DEBT DEBT - Ciner Resources Credit Facility (Details) - Revolving credit facility - Line of Credit - Ciner Resources Credit Facility	6 Months Ended
	Jun. 30, 2021USD ($)
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 10,000,000
Debt instrument, term	5 years

DEBT DEBT - WE Soda and Ciner E

DEBT DEBT - WE Soda and Ciner Enterprises Facilities Agreement (Details)	Jun. 30, 2021
WE Soda and Ciner Enterprises Facilities Agreement
Debt Instrument [Line Items]
Commitment percentage threshold	66.67%

OTHER NON-CURRENT LIABILITIES_2

OTHER NON-CURRENT LIABILITIES (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Asset Retirement Obligation Disclosure [Abstract]
Reclamation reserve	$ 7.5	$ 7.3
Derivative instruments and hedges, fair value liabilities and other	0.9	1.4
Total	8.4	8.7
Reclamation reserve
Beginning reclamation reserve balance	7.3	5.7
Accretion expense	0.2	0.3
Reclamation adjustments	0	1.3
Ending reclamation reserve balance	$ 7.5	$ 7.3

EMPLOYEE COMPENSATION (Details)

EMPLOYEE COMPENSATION (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Average compensation period			60 months
Period of last service			120 months
Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Net unfunded liability	$ 52.6		$ 52.6		$ 55.1
Net periodic pension cost (credit)	(0.6)	$ (0.3)	(1.4)	$ (0.7)
Savings Plan
Defined Benefit Plan Disclosure [Line Items]
Contributions made by employer	0.7	0.7	2.3	2.3
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net unfunded liability	13.1		13.1		$ 13.1
Net periodic pension cost (credit)	$ 0.3	$ 0.3	$ 0.5	$ 0.5

EQUITY - BASED COMPENSATION - N

EQUITY - BASED COMPENSATION - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of common units available under plan (shares)	700,000
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common units vested (in shares)	12,247	27,802
Common units grant date average fair value (in dollars per share)	$ 18.46	$ 22.94
Restricted Stock Units (RSUs) | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	1 year
Restricted Stock Units (RSUs) | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Performance-Based Units | Total Return Performance Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common units vested (in shares)	7,678	9,058
Common units grant date average fair value (in dollars per share)	$ 41.53	$ 42.21
Performance-Based Units | Minimum | Total Return Performance Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	2 years
Payout range	0.00%
Performance-Based Units | Minimum | 2019 Performance Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payout range	0.00%
Performance-Based Units | Maximum | Total Return Performance Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Payout range	200.00%
Performance-Based Units | Maximum | 2019 Performance Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payout range	200.00%
Director - non employee | Common units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common units granted (in shares)	17,511	21,720
Common units vested (in shares)	17,511
Common units grant date average fair value (in dollars per share)	$ 13.20	$ 9.88
Fair value of common units granted and vested	$ 0.2	$ 0.2

EQUITY - BASED COMPENSATION - S

EQUITY - BASED COMPENSATION - Schedule of Restricted Unit Award Activity (Details) - Restricted Stock Units (RSUs) - $ / shares	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Number of Common Units
Unvested at the beginning of period (in shares)	21,937	55,454
Vested (in shares)	(12,247)	(27,802)
Unvested at the end of the period (in shares)	9,690	27,652
Grant-Date Average Fair Value per Unit
Unvested at the beginning of period (in dollars per share)	$ 17.57	$ 20.33
Vested (in dollars per share)	18.46	22.94
Unvested at the end of the period (in dollars per share)	$ 16.45	$ 17.71

EQUITY - BASED COMPENSATION -_2

EQUITY - BASED COMPENSATION - Schedule of Total Return Performance Unit Award Activity (Details) - Total Return Performance Unit Awards - Performance-Based Units - $ / shares	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Number of Common Units
Unvested at the beginning of period (in shares)	7,678	20,173
Vested (in shares)	(7,678)	(9,058)
Unvested at the end of the period (in shares)	0	11,115
Grant-Date Average Fair Value per Unit
Unvested at the beginning of period (in dollars per share)	$ 41.53	$ 41.79
Vested (in dollars per share)	41.53	42.21
Unvested at the end of the period (in dollars per share)	$ 0	$ 41.59

EQUITY - BASED COMPENSATION EQU

EQUITY - BASED COMPENSATION EQUITY - BASED COMPENSATION - Performance Unit Awards (Details) - 2019 Performance Unit Awards - Performance-Based Units - $ / shares	Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020
Number of Common Units
Unvested at the beginning of period (in shares)	29,057	35,908	35,908
Unvested at the end of the period (in shares)	29,057	29,057	35,908
Grant-Date Average Fair Value per Unit
Unvested at the beginning of period (in dollars per share)	$ 16.45	$ 16.45	$ 16.45
Unvested at the end of the period (in dollars per share)	$ 16.45	$ 16.45	$ 16.45

EQUITY - BASED COMPENSATION - U

EQUITY - BASED COMPENSATION - Unrecognized Compensation Expense (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation expense	$ 0.1	$ 0.7
Time Restricted Unit Awards
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation expense	$ 0.1	$ 0.4
Weighted average to be recognized (in years)	8 months 15 days	1 year 6 months 14 days
Total Return Performance Unit Awards | Performance-Based Units
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation expense	$ 0	$ 0.1
Weighted average to be recognized (in years)	0 days	7 months 2 days
2019 Performance Unit Awards | Performance-Based Units
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unrecognized compensation expense	$ 0	$ 0.2
Weighted average to be recognized (in years)	7 months 2 days	1 year 7 months 2 days

ACCUMULATED OTHER COMPREHENSI_3

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 308.5	$ 305.3	$ 298.2	$ 299.9	$ 305.3
Net current period other comprehensive income	5.2	1.5	2.8	(2.1)
Ending balance	320.8	308.5	$ 281.9	$ 298.2	320.8
Gains and (Losses) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		$ 0			0
Other comprehensive income before reclassification					3.7
Amounts reclassified from accumulated other comprehensive loss					(0.3)
Net current period other comprehensive income					3.4
Ending balance	$ 3.4				$ 3.4

ACCUMULATED OTHER COMPREHENSI_4

ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Components of Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized loss (gain) on derivative financial instruments	$ 5.1	$ 2.8	$ 6.6	$ 0.7
Interest rate swap contracts
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized loss (gain) on derivative financial instruments	0.1	0.1	0.4	(0.9)
Natural gas forward contracts
Accumulated Other Comprehensive Income (Loss) [Line Items]
Unrealized loss (gain) on derivative financial instruments	$ 5	$ 2.7	$ 6.2	$ 1.6

ACCUMULATED OTHER COMPREHENSI_5

ACCUMULATED OTHER COMPREHENSIVE LOSS - Schedule of Reclassifications out of Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Interest expense	$ 1.5		$ 1.5		$ 2.8	$ 2.8
Cost of products sold	99.1		67.7		205.7	154.3
Net income	6.8	$ 5.6	(5.4)	$ 14.2	12.4	8.8
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Net income	(0.2)		0.8		(0.3)	1.2
Gains and (Losses) on Cash Flow Hedges | Interest rate swap contracts | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Interest expense	0.1		0.2		0.2	0.2
Gains and (Losses) on Cash Flow Hedges | Natural gas forward contracts | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Cost of products sold	$ (0.3)		$ 0.6		$ (0.5)	$ 1

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Narrative (Details) - USD ($) $ in Millions	Mar. 01, 2021	Oct. 15, 2020
Self-bond agreement for reclamation costs
Other Commitments [Line Items]
Off balance sheet commitment	$ 41.8	$ 36.2

AGREEMENTS AND TRANSACTIONS W_3

AGREEMENTS AND TRANSACTIONS WITH AFFILIATES - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Total charges for services obtained from affiliates	$ 0.7	$ 2.2
Revenue from Contract with Customer Benchmark | Customer Concentration Risk | ANSAC
Related Party Transaction [Line Items]
Concentration risk, percentage			45.40%

AGREEMENTS AND TRANSACTIONS W_4

AGREEMENTS AND TRANSACTIONS WITH AFFILIATES - Costs charged by affiliates (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Related Party Transaction [Line Items]
Total selling, general and administrative expenses - affiliates	$ 4.2	$ 4.4	$ 7.8	$ 8.5
Ciner Corp
Related Party Transaction [Line Items]
Total selling, general and administrative expenses - affiliates	$ 4.2	4	$ 7.8	7.5
ANSAC
Related Party Transaction [Line Items]
Total selling, general and administrative expenses - affiliates		$ 0.4		$ 1

AGREEMENTS AND TRANSACTIONS W_5

AGREEMENTS AND TRANSACTIONS WITH AFFILIATES - Net sales to affiliates (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Related Party Transaction [Line Items]
Net sales to affiliates	$ 0	$ 32	$ 0	$ 86
ANSAC
Related Party Transaction [Line Items]
Net sales to affiliates		$ 32		$ 86

AGREEMENTS AND TRANSACTIONS W_6

AGREEMENTS AND TRANSACTIONS WITH AFFILIATES - Receivables from or payables to affiliates (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Accounts receivable from affiliates	$ 49	$ 86.5
Due to affiliates	2.1	2.9
ANSAC
Related Party Transaction [Line Items]
Accounts receivable from affiliates		41.9
Due to affiliates		0.2
Ciner Corp
Related Party Transaction [Line Items]
Accounts receivable from affiliates	47.3	44.6
Due to affiliates	2.1	2.6
Other
Related Party Transaction [Line Items]
Accounts receivable from affiliates	1.7	0
Due to affiliates	$ 0	$ 0.1

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue from External Customer [Line Items]
Revenue from international customer	$ 120.7	$ 76.2	$ 248.5	$ 190.6
International
Revenue from External Customer [Line Items]
Revenue from international customer	50.2	32	111.7	91.2
ANSAC | International
Revenue from External Customer [Line Items]
Revenue from international customer	$ 27.1	$ 32	$ 54.6	$ 86

Revenue - Sales by geographic a

Revenue - Sales by geographic area (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Sales by geographical area
Revenue by major product line	$ 120.7	$ 76.2	$ 248.5	$ 190.6
Domestic
Sales by geographical area
Revenue by major product line	70.5	44.2	136.8	99.4
International
Sales by geographical area
Revenue by major product line	$ 50.2	$ 32	$ 111.7	$ 91.2

FAIR VALUE MEASUREMENTS - Narra

FAIR VALUE MEASUREMENTS - Narrative (Details) - Recurring fair value measurements - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Natural gas forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount	$ 22,800,000	$ 25,900,000
Designated as Hedging Instrument | Cash Flow Hedging | Interest rate swap contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notional amount	$ 50,000,000	$ 37,500,000

FAIR VALUE MEASUREMENTS - Sched

FAIR VALUE MEASUREMENTS - Schedule of Fair Value of Derivative Assets and Liability (Details) - Recurring fair value measurements - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Assets
Total fair value of derivatives designated as hedging instruments	$ 7.7	$ 2.3
Liabilities
Total fair value of derivatives designated as hedging instruments	1	2.2
Other current assets | Interest rate swap contracts
Assets
Derivative asset, current	0	0
Other current assets | Natural gas forward contracts
Assets
Derivative asset, current	5.7	1.4
Other non-current assets | Interest rate swap contracts
Assets
Derivative asset, noncurrent	0	0
Other non-current assets | Natural gas forward contracts
Assets
Derivative asset, noncurrent	2	0.9
Accrued Expenses | Interest rate swap contracts
Liabilities
Derivative liability, current	0.1	0.2
Accrued Expenses | Natural gas forward contracts
Liabilities
Derivative liability, current	0.1	0.7
Other non-current liabilities | Interest rate swap contracts
Liabilities
Derivative liability, noncurrent	0.8	1.1
Other non-current liabilities | Natural gas forward contracts
Liabilities
Derivative liability, noncurrent	$ 0	$ 0.2