MP Materials (MP) 10-Q 5 Aug 22 2022 Q2 Quarterly report Financial data

COVER

COVER - shares	6 Months Ended
	Jun. 30, 2022	Aug. 01, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2022
Document Transition Report	false
Entity File Number	001-39277
Entity Registrant Name	MP Materials Corp. / DE
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	84-4465489
Entity Address, Address Line One	6720 Via Austi Parkway, Suite 450
Entity Address, City or Town	Las Vegas
Entity Address, State or Province	NV
Entity Address, Postal Zip Code	89119
City Area Code	702
Local Phone Number	844-6111
Title of 12(b) Security	Common Stock, par value of $0.0001 per share
Trading Symbol	MP
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		177,534,132
Amendment Flag	false
Entity Central Index Key	0001801368
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 664,457	$ 1,179,297
Short-term investments	599,666	0
Total cash, cash equivalents and short-term investments	1,264,123	1,179,297
Accounts receivable (including related party), net of allowance for credit losses of $0 and $0, respectively	32,748	51,009
Inventories	42,244	38,692
Income taxes receivable	4,271	0
Prepaid expenses and other current assets	5,486	7,809
Total current assets	1,348,872	1,276,807
Non-current assets
Property, plant and equipment, net	749,848	610,612
Other non-current assets	2,519	2,247
Total non-current assets	752,367	612,859
Total assets	2,101,239	1,889,666
Current liabilities
Accounts payable and accrued liabilities	62,097	35,734
Income taxes payable	0	3,463
Current installments of long-term debt—related party	0	16,082
Other current liabilities	4,050	4,264
Total current liabilities	66,147	59,543
Non-current liabilities
Asset retirement obligations	18,162	17,615
Environmental obligations	16,589	16,598
Long-term debt, net of current portion	676,683	674,927
Deferred income taxes	146,606	104,500
Other non-current liabilities	6,315	7,751
Total non-current liabilities	864,355	821,391
Total liabilities	930,502	880,934
Commitments and contingencies
Stockholders’ equity:
Preferred stock ($0.0001 par value, 50,000,000 shares authorized, none issued and outstanding in either period)	0	0
Common stock ($0.0001 par value, 450,000,000 shares authorized, 177,534,132 and 177,816,554 shares issued and outstanding, as of June 30, 2022, and December 31, 2021, respectively)	18	18
Additional paid-in capital	939,900	936,299
Retained earnings	231,235	72,415
Accumulated other comprehensive loss	(416)	0
Total stockholders’ equity	1,170,737	1,008,732
Total liabilities and stockholders’ equity	$ 2,101,239	$ 1,889,666

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Allowance for credit losses	$ 0	$ 0
Preferred stock, par value (usd per share)	$ 0.0001	$ 0.0001
Preferred stock, authorized (shares)	50,000,000	50,000,000
Preferred stock, issued (shares)	0	0
Preferred shares, outstanding (shares)	0	0
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Common stock, authorized (shares)	450,000,000	450,000,000
Common stock, outstanding (shares)	177,534,132	177,816,554
Common stock, issued (shares)	177,534,132	177,816,554

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Statement [Abstract]
Product sales (including related party)	$ 139,183,000	$ 72,522,000	$ 300,938,000	$ 132,261,000
Other sales (including related party)	4,379,000	596,000	8,882,000	828,000
Total revenue	143,562,000	73,118,000	309,820,000	133,089,000
Operating costs and expenses:
Cost of sales (including related party)(excluding depreciation, depletion and amortization)	22,092,000	17,955,000	45,265,000	35,891,000
Selling, general and administrative	18,222,000	12,647,000	38,787,000	26,105,000
Advanced projects, development and other	1,668,000	984,000	3,486,000	1,109,000
Depreciation, depletion and amortization	5,407,000	6,666,000	10,667,000	12,816,000
Accretion of asset retirement and environmental obligations	419,000	592,000	837,000	1,185,000
Write-down of inventories	0	1,809,000	0	1,809,000
Total operating costs and expenses	47,808,000	40,653,000	99,042,000	78,915,000
Operating income	95,754,000	32,465,000	210,778,000	54,174,000
Interest expense, net	(1,326,000)	(2,639,000)	(3,231,000)	(3,793,000)
Other income	2,212,000	3,504,000	2,406,000	3,559,000
Income before income taxes	96,640,000	33,330,000	209,953,000	53,940,000
Income tax expense	(23,371,000)	(6,164,000)	(51,133,000)	(10,655,000)
Net income	$ 73,269,000	$ 27,166,000	$ 158,820,000	$ 43,285,000
Earnings per share:
Basic EPS (in USD per share)	$ 0.42	$ 0.16	$ 0.90	$ 0.25
Diluted EPS (in USD per share)	$ 0.38	$ 0.15	$ 0.83	$ 0.24
Weighted-average shares outstanding:
Weighted-average shares outstanding, basic (in shares)	176,527,570	172,677,923	176,442,043	170,810,353
Weighted-average shares outstanding, diluted (in shares)	193,414,563	193,145,644	193,452,921	186,282,857

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 73,269	$ 27,166	$ 158,820	$ 43,285
Other comprehensive loss, net of tax:
Net unrealized losses on available-for-sale securities	(416)	0	(416)	0
Total comprehensive income	$ 72,853	$ 27,166	$ 158,404	$ 43,285

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-in Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Loss
Beginning balance (shares) at Dec. 31, 2020		0	170,719,979
Beginning balance at Dec. 31, 2020	$ 853,877	$ 0	$ 17	$ 916,482	$ (62,622)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of Public Warrants (shares)			7,080,005
Redemption of Public Warrants	(1)		$ 1	(2)
Stock-based compensation (shares)			54,722
Stock-based compensation	10,171			10,171
Forfeiture of restricted stock (in shares)			(90,000)
Shares used to settle payroll tax withholding (shares)			(16,219)
Shares used to settle payroll tax withholding	(527)			(527)
Net income	43,285				43,285
Net unrealized losses on available-for-sale securities	0
Other	(180)			(180)
Ending balance (shares) at Jun. 30, 2021		0	177,748,487
Ending balance at Jun. 30, 2021	906,625	$ 0	$ 18	925,944	(19,337)	0
Beginning balance (shares) at Mar. 31, 2021		0	170,745,864
Beginning balance at Mar. 31, 2021	875,157	$ 0	$ 17	921,643	(46,503)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Redemption of Public Warrants (shares)			7,080,005
Redemption of Public Warrants	(1)		$ 1	(2)
Stock-based compensation (shares)			18,402
Stock-based compensation	4,498			4,498
Forfeiture of restricted stock (in shares)			(90,000)
Shares used to settle payroll tax withholding (shares)			(5,784)
Shares used to settle payroll tax withholding	(193)			(193)
Net income	27,166				27,166
Net unrealized losses on available-for-sale securities	0
Other	(2)			(2)
Ending balance (shares) at Jun. 30, 2021		0	177,748,487
Ending balance at Jun. 30, 2021	906,625	$ 0	$ 18	925,944	(19,337)	0
Beginning balance (shares) at Dec. 31, 2021		0	177,816,554
Beginning balance at Dec. 31, 2021	1,008,732	$ 0	$ 18	936,299	72,415	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (shares)			60,185
Stock-based compensation	17,897			17,897
Shares used to settle payroll tax withholding (shares)			(342,607)
Shares used to settle payroll tax withholding	(14,296)			(14,296)
Net income	158,820				158,820
Net unrealized losses on available-for-sale securities	(416)					(416)
Ending balance (shares) at Jun. 30, 2022		0	177,534,132
Ending balance at Jun. 30, 2022	1,170,737	$ 0	$ 18	939,900	231,235	(416)
Beginning balance (shares) at Mar. 31, 2022		0	177,526,007
Beginning balance at Mar. 31, 2022	1,090,368	$ 0	$ 18	932,384	157,966	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (shares)			13,303
Stock-based compensation	7,718			7,718
Shares used to settle payroll tax withholding (shares)			(5,178)
Shares used to settle payroll tax withholding	(202)			(202)
Net income	73,269				73,269
Net unrealized losses on available-for-sale securities	(416)					(416)
Ending balance (shares) at Jun. 30, 2022		0	177,534,132
Ending balance at Jun. 30, 2022	$ 1,170,737	$ 0	$ 18	$ 939,900	$ 231,235	$ (416)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating activities:
Net income	$ 73,269,000	$ 27,166,000	$ 158,820,000	$ 43,285,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	5,407,000	6,666,000	10,667,000	12,816,000
Accretion of asset retirement and environmental obligations	419,000	592,000	837,000	1,185,000
Accretion of discount on short-term investments			(1,008,000)	0
Gain on forgiveness of Paycheck Protection Loan			0	(3,401,000)
Loss on sale or disposal of long-lived assets, net			258,000	37,000
Stock-based compensation expense			17,213,000	10,171,000
Accretion of debt discount and amortization of debt issuance costs			2,274,000	3,287,000
Write-down of inventories	0	1,809,000	0	1,809,000
Revenue recognized in exchange for debt principal reduction			(13,566,000)	(22,901,000)
Deferred income taxes			42,106,000	8,105,000
Decrease (increase) in operating assets:
Accounts receivable (including related party)			18,261,000	(4,589,000)
Inventories			(3,552,000)	(5,038,000)
Income taxes receivable			(4,271,000)	0
Prepaid expenses, other current and non-current assets			1,437,000	(2,973,000)
Increase (decrease) in operating liabilities:
Accounts payable and accrued liabilities			(5,476,000)	4,236,000
Income taxes payable			(3,463,000)	2,451,000
Other current and non-current liabilities			(675,000)	(511,000)
Net cash provided by operating activities			219,862,000	47,969,000
Investing activities:
Additions to property, plant and equipment			(122,584,000)	(44,691,000)
Purchases of short-term investments			(599,195,000)	0
Proceeds from sale of property, plant and equipment			0	125,000
Proceeds from government awards used for construction			5,130,000	0
Net cash used in investing activities			(716,649,000)	(44,566,000)
Financing activities:
Proceeds from issuance of long-term debt			0	690,000,000
Principal payments on debt obligations and finance leases			(4,488,000)	(990,000)
Payment of debt issuance costs			0	(17,749,000)
Tax withholding on stock-based awards			(14,296,000)	(527,000)
Other			0	(244,000)
Net cash provided by (used in) financing activities			(18,784,000)	670,490,000
Net change in cash, cash equivalents and restricted cash			(515,571,000)	673,893,000
Cash, cash equivalents and restricted cash beginning balance			1,181,157,000	532,440,000
Cash, cash equivalents and restricted cash ending balance	665,586,000	1,206,333,000	665,586,000	1,206,333,000
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	664,457,000	1,196,875,000	664,457,000	1,196,875,000
Restricted cash, current	600,000	340,000	600,000	340,000
Restricted cash, non-current	529,000	9,118,000	529,000	9,118,000
Total cash, cash equivalents and restricted cash	$ 665,586,000	$ 1,206,333,000	$ 665,586,000	$ 1,206,333,000

DESCRIPTION OF BUSINESS AND BAS

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	6 Months Ended
	Jun. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION Description of Business: MP Materials is the largest producer of rare earth materials in the Western Hemisphere. We own and operate the Mountain Pass Rare Earth Mine and Processing Facility (“Mountain Pass”), the only rare earth mining and processing site of scale in North America. The Company is headquartered in Las Vegas, Nevada. References herein to the “Company,” “we,” “our,” and “us,” refer to MP Materials Corp. and its subsidiaries. We currently produce a rare earth concentrate that we sell pursuant to an offtake agreement to Shenghe Resources (Singapore) International Trading Pte. Ltd. (“Shenghe”), a majority-owned subsidiary of Leshan Shenghe Rare Earth Co., Ltd. (“Leshan Shenghe”) whose ultimate parent is Shenghe Resources Holding Co., Ltd., a leading global rare earth company listed on the Shanghai Stock Exchange. We are currently recommissioning, upgrading and enhancing the processing facility at Mountain Pass to provide for the separation of the individual rare earth elements contained in our concentrate (referred to as the “Stage II optimization project” or “Stage II”), that will allow us to sell separated rare earth oxides directly to end users. Additionally, in the first quarter of 2022, we began construction on our initial rare earth, metal, alloy and magnet manufacturing facility in Fort Worth, Texas (the “Fort Worth Facility”) as a part of our Stage III downstream expansion strategy (“Stage III”). For more information on our relationship and agreements with Shenghe, see Note 3, “Relationship and Agreements with Shenghe,” and Note 14, “Related-Party Transactions.” In April 2022, the Company entered into a definitive long-term supply agreement with General Motors Company (NYSE: GM) (“GM”) to supply U.S.-sourced and manufactured rare earth materials, alloy and finished magnets for the electric motors in more than a dozen models using GM’s Ultium Platform, with a gradual production ramp that is expected to begin in late 2023, starting with alloy. The definitive long-term supply agreement solidifies the terms of a binding agreement announced by the Company in December 2021. Operating segments are defined as components of an enterprise about which separate financial information is available and evaluated regularly by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker views the Company’s operations and manages the business as one reportable segment. The cash flows and profitability of the Company’s operations are significantly affected by the market price of rare earth products. The prices of rare earth products are affected by numerous factors beyond the Company’s control. The products of the Company are sold globally, with a primary focus in the Asian market due to the refining capabilities of the region. Rare earth products are critical inputs in hundreds of existing and emerging clean-tech applications including electric vehicles and wind turbines as well as drones and defense applications. Basis of Presentation: The unaudited Condensed Consolidated Financial Statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) for interim financial information and with the rules and regulations of the U.S. Securities and Exchange Commission. Accordingly, they do not include all of the information and notes required by GAAP for complete consolidated financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included. Results of operations and cash flows for the interim periods presented herein are not necessarily indicative of the results that would be achieved during a full year of operations or in future periods. These unaudited Condensed Consolidated Financial Statements and notes thereto should be read in conjunction with the Consolidated Financial Statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021.

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
SIGNIFICANT ACCOUNTING POLICIES	SIGNIFICANT ACCOUNTING POLICIES Principles of Consolidation: The unaudited Condensed Consolidated Financial Statements include the accounts of MP Materials Corp. and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. Use of Estimates : The preparation of the unaudited Condensed Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect (i) the reported amounts of assets and liabilities, (ii) the disclosure of contingent assets and liabilities at the date of the unaudited Condensed Consolidated Financial Statements, and (iii) the reported amounts of revenues and expenses during the reporting period. Accordingly, actual results may differ from those estimates. Concentration of Risk: Financial instruments that potentially subject the Company to credit risk consist principally of cash and cash equivalents, short-term investments and trade accounts receivable. The Company believes that its credit risk is limited because the Company’s current contracts are with companies with a reliable payment history. The Company does not believe that it is exposed to any significant risks related to its cash accounts, money market funds, or short-term investments. As of June 30, 2022, Shenghe, a related party of the Company and our principal customer, accounted for more than 90% of product sales. Furthermore, while revenue is generated in the United States, Shenghe conducts its primary operations in China and may transport and sell products in the Chinese market. Therefore, the Company’s revenue is affected by Shenghe’s ultimate realized prices in China. In addition, there is an ongoing economic conflict between China and the United States that has resulted in tariffs and trade barriers that may negatively affect the Company’s business and results of operations. See Note 3, “Relationship and Agreements with Shenghe,” for additional information. In December 2019, a novel strain of coronavirus (known as “COVID-19”) began to impact the population of China. In March 2020, the outbreak of COVID-19 was declared a global pandemic after growing both in the United States and globally. The responses by governments, societies, and private sector entities to the COVID-19 pandemic, which include temporary closures of businesses, social distancing, travel restrictions, “shelter in place,” and other governmental regulations and various economic stimulus programs, have significantly impacted market volatility and general global economic conditions, including significant business and supply chain disruption as well as broad-based changes in supply and demand. Since the onset of the COVID-19 pandemic, we have experienced, at times, significant shipping delays due to congestion and slowdowns at U.S. and international ports caused by shortages in vessels, containers, and truckers, also disrupting the global supply chain. Congestion and slowdowns have affected and may continue to affect the capacity at ports to receive deliveries of products or the loading of shipments onto vessels. Despite these factors, we have not experienced a reduction in production or sales due to the COVID-19 pandemic; however, the COVID-19 pandemic has contributed to certain cost and schedule pressures on the Stage II optimization project. The Company has worked proactively and diligently to adjust working schedules and hours to optimize logistics and shipping, which has thus far prevented a significant negative impact on our product sales and has mitigated certain impacts on Stage II construction and recommissioning progress. However, there can be no assurance that the ongoing COVID-19 pandemic will not have a negative impact on our production, sales, or growth projects in the future. As the situation continues to evolve, including as a result of new and potential future variants of COVID-19, the possibility of federal or state mandates on vaccinations, or other factors that may affect international shipping and logistics or involve responses to government actions such as strikes or other disruptions, it is impossible to predict the effect and ultimate impact of the COVID-19 pandemic on the Company’s business and results of operations. The extent and duration of any business disruptions, and related financial impact, cannot be estimated at this time. Cash, Cash Equivalents and Short-term Investments: Cash and cash equivalents consist of all cash balances and highly liquid investments, including U.S. treasury and agency securities, with a maturity of three months or less at the time of purchase. The Company’s short-term investments consist of U.S. treasury and agency securities that have original maturities greater than three months at the time of purchase. These investments have been classified and accounted for as available-for-sale securities and the Company reevaluates the classification each reporting period. The Company classifies its available-for-sale securities as either current or non-current based on each instrument’s underlying contractual maturity date and the Company’s expectations of sales and redemptions within the next twelve months. See Note 4, “Cash, Cash Equivalents and Investments,” for additional information. Available-for-sale securities are recorded at fair value each reporting period. For unrealized losses in securities that the Company intends to hold and will not more likely than not be required to sell before recovery, the Company further evaluates whether declines in fair value below amortized cost are due to credit or non-credit related factors. The Company considers credit related impairments to be changes in value that are driven by a change in the creditor’s ability to meet its payment obligations, and records an allowance and recognizes a corresponding loss when the impairment is incurred. Unrealized non-credit related losses and unrealized gains are reported, net of income taxes, in accumulated other comprehensive income or loss, a component of stockholders’ equity within the unaudited Condensed Consolidated Balance Sheets, until realized. Realized gains and losses are reported within our unaudited Condensed Consolidated Statements of Operations upon realization. Accrued interest receivable is included in “Accounts receivable (including related party)” within the Company’s unaudited Condensed Consolidated Balance Sheets. Recently Issued Accounting Pronouncements: There were no new accounting pronouncements recently issued or effective during the three and six months ended June 30, 2022, that had or would be expected to have a material impact on the Company’s unaudited Condensed Consolidated Financial Statements. Reclassifications: Certain amounts in prior periods have been reclassified to conform to the current year presentation.

RELATIONSHIP AND AGREEMENTS WIT

RELATIONSHIP AND AGREEMENTS WITH SHENGHE	6 Months Ended
	Jun. 30, 2022
Related Party Transactions [Abstract]
RELATIONSHIP AND AGREEMENTS WITH SHENGHE	RELATIONSHIP AND AGREEMENTS WITH SHENGHE Offtake Agreement In March 2022, the Company entered into an offtake agreement with Shenghe (the “Offtake Agreement”), which became effective upon the termination of the A&R Offtake Agreement (as discussed and defined below). The initial term of the Offtake Agreement is two years, with the option to extend the term at the Company’s discretion for an additional one-year period. Pursuant to the Offtake Agreement, and subject to certain exclusions, Shenghe shall purchase on a “take or pay” basis the rare earth concentrate produced by the Company as the exclusive distributor in China, with certain exceptions for the Company’s direct sales globally. In addition, at the discretion of the Company, Shenghe may be required to purchase on a “take or pay” basis certain non-concentrate rare earth products, although the Company may sell all non-concentrate rare earth products in its sole discretion to customers or end users in any jurisdiction. Under the Offtake Agreement, Shenghe will be paid a variable commission on net proceeds to the Company. Similar to the A&R Offtake Agreement, the sales price of rare earth concentrate sold to Shenghe is based on an agreed-upon price per metric ton, subject to certain quality adjustments depending on the measured characteristics of the product, with an adjustment for the ultimate market price of the product realized by Shenghe upon sales to their customers. The sales price and other terms applicable to a quantity of offtake products are set forth in monthly purchase agreements between the Company and Shenghe. Original Commercial Agreements In May 2017, the Company entered into a set of commercial arrangements with Shenghe, which included a technical services agreement (the “TSA”) and an offtake agreement (the “Original Offtake Agreement”). The Original Offtake Agreement required Shenghe to advance the Company an initial $50.0 million (the “Initial Prepayment Amount”) to fund the restart of operations at the mine and the TSA required Shenghe to fund any additional operating and capital expenditures required to bring Mountain Pass to full operability. Shenghe also agreed to provide additional funding of $30.0 million to the Company pursuant to a separate letter agreement dated June 20, 2017 (the “Letter Agreement”) (the “First Additional Advance”), in connection with our acquisition of Mountain Pass. In addition to the repayment of the First Additional Advance, pursuant to the Letter Agreement, the Initial Prepayment Amount increased by $30.0 million. We refer to the aggregate prepayments made by Shenghe pursuant to the Original Offtake Agreement and the Framework Agreement (defined below), as adjusted for Gross Profit Recoupment (defined below) amounts and any other qualifying repayments to Shenghe, inclusive of the $30.0 million increase to the Initial Prepayment Amount, as the “Prepaid Balance.” Under the Original Offtake Agreement, we sold to Shenghe, and Shenghe purchased on a firm “take or pay” basis, all of the rare earth products produced at Mountain Pass. Shenghe marketed and sold these products to customers, and retained the gross profits earned on subsequent sales. The gross profits were credited against the Prepaid Balance, and provided the means by which we repaid, and Shenghe recovered, such amounts (the “Gross Profit Recoupment”). Framework Agreement and Restructured Commercial Agreements In May 2020, the Company entered into a framework agreement and amendment (the “Framework Agreement”) with Shenghe and Leshan Shenghe that restructured the commercial arrangements and provided for, among other things, a revised funding amount and schedule to settle Shenghe’s prepayment obligations to the Company, as well as an amendment to the Original Offtake Agreement, as discussed below. Pursuant to the Framework Agreement, the Company entered into an amended and restated offtake agreement with Shenghe on May 19, 2020 (the “A&R Offtake Agreement”), which, upon effectiveness, superseded and replaced the Original Offtake Agreement. Pursuant to the Framework Agreement, Shenghe funded the remaining portion of the Initial Prepayment Amount and agreed to fund an additional $35.5 million advance (the “Second Additional Advance” and together with the Initial Prepayment Amount, inclusive of the $30.0 million increase pursuant to the Letter Agreement, the “Offtake Advances”), which amounts were fully funded in June 2020. The A&R Offtake Agreement maintained the key take-or-pay, amounts owed on actual and deemed advances from Shenghe, and other terms of the Original Offtake Agreement, with the following changes, among other items: (i) as to the offtake products subject to the A&R Offtake Agreement, provided that if we sold such offtake products to a third party, then, until the Prepaid Balance was reduced to zero, we would pay an agreed percentage of our revenue from such sales to Shenghe, to be credited against the amounts owed on Offtake Advances; (ii) provided that the sales price to be paid by Shenghe for our rare earth products (a portion of which reduces the Prepaid Balance rather than being paid in cash) would be based on market prices (net of taxes, tariffs and certain other agreed charges) less applicable discounts; and (iii) obliged us to pay Shenghe, on an annual basis, an amount equal to our annual net income, less any amounts recouped through the Gross Profit Recoupment mechanism over the course of the year, until the Prepaid Balance was reduced to zero. The sales price and other terms applicable to a quantity of offtake products were set forth in monthly purchase agreements between the Company and Shenghe. In March 2022, the Company made a $2.9 million payment to Shenghe pursuant to item (iii) discussed above. Upon payment by the Company, the Prepaid Balance was repaid in full, and the A&R Offtake Agreement was terminated. Product Sales and Cost of Sales: The Company and Shenghe enter into sales agreements in which Shenghe purchases the Company’s rare earth products at sale prices based on the ultimate market price of the product realized by Shenghe upon sales to their customers. Product sales from these agreements with Shenghe were $131.6 million and $286.6 million for the three and six months ended June 30, 2022, respectively, as compared to $72.2 million and $131.9 million for the three and six months ended June 30, 2021, respectively. Additionally, in March 2022, the Company entered into a sales agreement with Shenghe for certain stockpiles of rare earth fluoride (“REF”). Sales of REF, which are included in the unaudited Condensed Consolidated Statements of Operations in “Other sales (including related party),” were $4.4 million and $8.5 million for the three and six months ended June 30, 2022, respectively. Cost of sales, which includes shipping and freight, related to these agreements with Shenghe was $21.0 million and $43.6 million for the three and six months ended June 30, 2022, respectively, as compared to $17.9 million and $35.7 million for the three and six months ended June 30, 2021, respectively. Purchases: The Company purchases certain reagent products (produced by an unrelated third-party manufacturer) used in the flotation process from Shenghe. Total purchases were $1.4 million and $2.6 million for the three and six months ended June 30, 2022, respectively, as compared to $1.4 million and $2.1 million for the three and six months ended June 30, 2021, respectively. Accounts Receivable: As of June 30, 2022, and December 31, 2021, $29.6 million and $49.9 million of the accounts receivable, respectively, and as stated on the unaudited Condensed Consolidated Balance Sheets, were receivable from and pertained to sales made to Shenghe in the ordinary course of business. Indebtedness: The Company’s related-party debt is described in Note 7, “Debt Obligations.”

CASH, CASH EQUIVALENTS AND INVE

CASH, CASH EQUIVALENTS AND INVESTMENTS	6 Months Ended
	Jun. 30, 2022
Investments, Debt and Equity Securities [Abstract]
CASH, CASH EQUIVALENTS AND INVESTMENTS	CASH, CASH EQUIVALENTS AND INVESTMENTS The following table presents the Company’s cash, cash equivalents and short-term investments: June 30, 2022 December 31, 2021 (in thousands) Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value Cash: Demand deposits $ 29,668 $ — $ — $ 29,668 $ 26,536 $ — $ — $ 26,536 Cash equivalents: Money market funds 439,933 — — 439,933 1,152,761 — — 1,152,761 U.S. agency securities 194,875 — (19) 194,856 — — — — Total cash equivalents 634,808 — (19) 634,789 1,152,761 — — 1,152,761 Total cash and equivalents 664,476 — (19) 664,457 1,179,297 — — 1,179,297 Short-term investments: U.S. agency securities 207,764 — (141) 207,623 — — — — U.S. Treasury securities 392,439 — (396) 392,043 — — — — Total short-term investments 600,203 — (537) 599,666 — — — — Total cash, cash equivalents and short-term investments $ 1,264,679 $ — $ (556) $ 1,264,123 $ 1,179,297 $ — $ — $ 1,179,297 The Company does not intend to sell, nor is it more likely than not that the Company will be required to sell, any investments in unrealized loss positions before recovery of their amortized cost basis. We did not recognize any credit losses related to our available-for-sale investments during the three and six months ended June 30, 2022. The unrealized losses on our available-for-sale investments were primarily due to unfavorable changes in interest rates subsequent to initial purchase. None of the available-for-sale investments held as of June 30, 2022, were in a continuous unrealized loss position for greater than 12 months and the unrealized losses and the related risk of expected credit losses were not material. There were no realized gains or losses recognized for the three and six months ended June 30, 2022. As of June 30, 2022, all outstanding available-for-sale securities were due within one year.

INVENTORIES

INVENTORIES	6 Months Ended
	Jun. 30, 2022
Inventory Disclosure [Abstract]
INVENTORIES	INVENTORIES The Company’s inventories consisted of the following: June 30, 2022 December 31, 2021 (in thousands) Materials and supplies $ 12,186 $ 10,711 In-process 28,455 25,574 Finished goods 1,603 2,407 Total inventory $ 42,244 $ 38,692 During the second quarter of 2021, the Company recognized a non-cash write-down of a portion of its legacy low-grade stockpile inventory of $1.8 million, after determining that it contained a significant amount of alluvial material that did not meet

PROPERTY, PLANT AND EQUIPMENT

PROPERTY, PLANT AND EQUIPMENT	6 Months Ended
	Jun. 30, 2022
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT AND EQUIPMENT	PROPERTY, PLANT AND EQUIPMENT The Company’s property, plant and equipment consisted of the following: June 30, 2022 December 31, 2021 (in thousands) Land and land improvements $ 15,765 $ 7,925 Buildings and building improvements 8,950 8,791 Machinery and equipment 64,148 61,822 Assets under construction 271,054 134,327 Mineral rights 438,719 437,376 Property, plant and equipment, gross 798,636 650,241 Less: Accumulated depreciation and depletion (48,788) (39,629) Property, plant and equipment, net $ 749,848 $ 610,612 Additions to Property, Plant and Equipment: The Company capitalized expenditures related to property, plant and equipment of $154.4 million and $62.1 million for the six months ended June 30, 2022 and 2021, respectively, including amounts not yet paid (see Note 15, “Supplemental Cash Flow Information” ). The capitalized expenditures for the six months ended June 30, 2022, related to assets under construction to support the Company’s Stage II optimization project and its rare earth metal, alloy and magnet manufacturing facility as a part of Stage III, including the purchase of approximately 18 acres of land in Fort Worth, Texas, in February 2022 . The capitalized expenditures for the six months ended June 30, 2021, mostly related to vehicles, machinery, equipment, and assets under construction to support the Stage II optimization project and other capital projects at Mountain Pass. Government Awards: In November 2020, the Company was awarded a Defense Production Act Title III technology investment agreement (“TIA”) from the Department of Defense (“DOD”) to establish domestic processing for separated light rare earth elements in the amount of $9.6 million. During the six months ended June 30, 2022, pursuant to the TIA, the Company has received $5.1 million in reimbursements from the DOD. The funds received reduced the carrying amount of certain fixed assets associated with the Company’s Stage II optimization project, which are currently included in “Assets under construction.” As of June 30, 2022, the Company is entitled to receive an additional $0.1 million from the DOD under the TIA. In February 2022, the Company was awarded a $35.0 million contract by the DOD’s Office of Industrial Base Analysis and Sustainment Program to design and build a facility to process heavy rare earth elements (“HREE”) at Mountain Pass (the “HREE Production Project Agreement”). The Company must utilize the funds to acquire property and equipment that will contribute to commercial-scale production of separated HREE at Mountain Pass. The Company will be paid fixed amounts upon the completion of certain project milestones. In exchange for these funds, the DOD will have certain rights to technical data following the completion of the project. The funds received pursuant to the HREE Production Project Agreement will reduce the carrying amount of the fixed assets associated with the Company’s HREE separations facility, which will tie into the Company’s other Stage II facilities. The Company’s depreciation and depletion expense were as follows: For the three months ended June 30, For the six months ended June 30, (in thousands) 2022 2021 2022 2021 Depreciation expense $ 2,257 $ 1,890 $ 4,358 $ 3,419 Depletion expense $ 3,075 $ 4,686 $ 6,144 $ 9,217 There were no impairments recognized for the three and six months ended June 30, 2022 and 2021.

DEBT OBLIGATIONS

DEBT OBLIGATIONS	6 Months Ended
	Jun. 30, 2022
Debt Disclosure [Abstract]
DEBT OBLIGATIONS	DEBT OBLIGATIONS The Company’s current and non-current portions of long-term debt were as follows: June 30, 2022 December 31, 2021 (in thousands) Long-term debt Convertible Notes due 2026 $ 690,000 $ 690,000 Less: Unamortized debt issuance costs (13,317) (15,073) Net carrying amount 676,683 674,927 Less: Current installments of long-term debt — — Long-term debt, net of current portion $ 676,683 $ 674,927 Long-term debt to related party Offtake Advances $ — $ 16,599 Less: Unamortized debt discount — (517) Net carrying amount — 16,082 Less: Current installments of long-term debt to related party — (16,082) Long-term debt to related party, net of current portion $ — $ — Convertible Notes In March 2021, the Company issued $690.0 million aggregate principal amount of 0.25% unsecured green convertible senior notes that mature, unless earlier converted, redeemed or repurchased, on April 1, 2026 (the “Convertible Notes”), at a price of par. Interest on the Convertible Notes is payable on April 1 st and October 1 st of each year, beginning on October 1, 2021. The Convertible Notes may, at the Company’s election, be settled in cash, shares of common stock of the Company, or a combination thereof. The Company has the option to redeem the Convertible Notes, in whole or in part, beginning on April 5, 2024. The Convertible Notes are convertible into shares of the Company’s common stock at an initial conversion price of $44.28 per share, or 22.5861 shares, per $1,000 principal amount of notes, subject to adjustment upon the occurrence of certain corporate events. However, in no event will the conversion price exceed 28.5714 shares of common stock per $1,000 principal amount of notes. As of June 30, 2022, based on the conversion price, the maximum number of shares that could be issued to satisfy the conversion feature of the Convertible Notes was 19,714,266. The Convertible Notes’ if-converted value did not exceed its principal amount as of June 30, 2022. Interest expense related to the Convertible Notes was as follows: For the three months ended June 30, For the six months ended June 30, (in thousands) 2022 2021 2022 2021 Coupon interest $ 431 $ 431 $ 862 $ 455 Amortization of debt issuance costs 879 875 1,756 923 Convertible Notes interest expense $ 1,310 $ 1,306 $ 2,618 $ 1,378 The debt issuance costs are being amortized to interest expense over the term of the Convertible Notes at an effective interest rate of 0.51%. The remaining term of the Convertible Notes was 3.8 years as of June 30, 2022. Offtake Advances Under the A&R Offtake Agreement, a portion of the sales prices of products sold to Shenghe was paid in the form of debt reduction, rather than cash. In addition, the Company had to pay the following amounts to Shenghe in cash to reduce the debt obligation until repaid in full: (i) an agreed-upon percentage of sales of products to parties other than Shenghe under the A&R Offtake Agreement; (ii) 100% of net profits from asset sales; and (iii) 100% of net income determined under GAAP, less the tax-effected amount of total non-cash recoupment from sales of products to Shenghe. For the three and six months ended June 30, 2022, zero and $14.2 million, respectively, of the sales prices of products sold to Shenghe was paid in the form of debt reduction (see Note 15, “Supplemental Cash Flow Information” ), as compared to $11.7 million and $20.9 million, for the three and six months ended June 30, 2021, respectively. During the three and six months ended June 30, 2022, the Company made payments to Shenghe of zero and $0.2 million, respectively, based on sales to other parties, as compared to $0.1 million for the three and six months ended June 30, 2021. No amounts were required to be paid based on asset sales. The A&R Offtake Agreement did not have a stated rate (and was non-interest-bearing), and repayment was contingent on a number of factors, including market prices realized by Shenghe, the Company’s sales to other parties, asset sales, and the Company’s annual net income. The imputed interest rate was a function of this discount taken together with our expectations about the timing of the anticipated reductions of the principal balance. The Company had determined that it would recognize adjustments from these estimates following a prospective method where the Company updated its estimate of the effective interest rate in future periods based on revised estimates of the timing of remaining principal reductions at that time. The effective rate applicable from the June 5, 2020, inception to full repayment, was between 4.41% and 24.75%. As discussed in Note 3, “Relationship and Agreements with Shenghe,” the Company made a $2.9 million payment to Shenghe in March 2022. Upon payment by the Company, the Prepaid Balance was repaid in full, and the A&R Offtake Agreement was terminated. Paycheck Protection Loan In April 2020, the Company obtained a loan of $3.4 million pursuant to the Paycheck Protection Program under the CARES Act, (the “Paycheck Protection Loan”). In June 2021, the Company received notification from the Small Business Administration that the Paycheck Protection Loan and related accrued interest was forgiven. Consequently, during the three and six months ended June 30, 2021, the Company recorded a gain on forgiveness of the Paycheck Protection Loan in the amount of $3.4 million, which is included in “Other income” within our unaudited Condensed Consolidated Statements of Operations. Tariff-Related Rebates In May 2020, the government of the People’s Republic of China suspended certain tariffs that had been charged to consignees of our product on imports, and provided such relief retroactive to March 2020. In addition, Shenghe began negotiating for tariff rebates from sales prior to March 2020, which affected Shenghe’s realized prices, and thus the Prepaid Balance. These, in turn, affected the Company’s realized prices on prior sales. While additional tariff rebates were possible, the Company did not have insight into Shenghe’s negotiations or their probability of success, and such negotiations were outside of the Company’s control. Thus, the Company fully constrained estimates of any future tariff rebates that may have been realized at that time. In January 2021, the Company received information from Shenghe regarding its successful negotiation of additional tariff rebates. Consequently, the Company revised its estimates of variable consideration and recognized $2.0 million of revenue for the six months ended June 30, 2021. Additionally, for the six months ended June 30, 2021, the Company recorded a reduction in the principal balance of the debt obligation and the corresponding debt discount of $2.2 million and $0.2 million, respectively. Equipment Notes The Company has entered into several financing agreements for the purchase of equipment, including trucks, tractors, loaders, graders, and various other machinery. The Company’s equipment notes, which are secured by the purchased equipment, have terms of between 4 to 5 years and interest rates of between 0.0% and 6.5% per annum. The current and non-current portions of the equipment notes, which are included within the unaudited Condensed Consolidated Balance Sheets in “Other current liabilities” and “Other non-current liabilities,” respectively, were as follows: June 30, 2022 December 31, 2021 (in thousands) Equipment notes Current $ 2,439 $ 2,566 Non-current 5,930 7,095 $ 8,369 $ 9,661 As of June 30, 2022, none of the agreements or indentures governing our indebtedness contain financial covenants.

ASSET RETIREMENT AND ENVIRONMEN

ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS	6 Months Ended
	Jun. 30, 2022
Asset Retirement Obligation And Environmental Remediation Obligations [Abstract]
ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS	ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS Asset Retirement Obligations The Company estimates asset retirement obligations based on the requirements to reclaim its mine pit and related processing and separations facilities at Mountain Pass. Minor reclamation activities related to discrete portions of the Company’s operations are ongoing. As of June 30, 2022, the Company estimated a significant portion of the cash outflows for the major reclamation and the retirement of Mountain Pass will be incurred beginning in 2057. In June 2021, San Bernardino County approved the Company’s re-zoning request for certain of its properties such that certain of the Company’s processing facilities would be zoned for industrial end uses as opposed to the prior “resource conservation” designation, which may obviate the Company’s current requirement to demolish and reclaim the impacted areas. In March 2022, based on the Company’s preliminary evaluation of the impact of the re-zoning, the Company submitted a revised reclamation plan to San Bernardino County for review. After acceptance of the reclamation plan by San Bernardino County and final approval by the State of California, which have not yet occurred as of June 30, 2022, the Company will update the estimated cash flows underlying its asset retirement obligations, as the Company’s existing reclamation obligations will not be legally reduced until such approval is obtained. As of June 30, 2022, the credit-adjusted risk-free rate ranged between 6.5% and 8.2% depending on the timing of expected settlement and when the layer or increment was recognized. There were no significant increments or decrements for the three and six months ended June 30, 2022 and 2021. The balance as of June 30, 2022, and December 31, 2021, included current portions of $0.1 million. The total estimated future undiscounted cash flows required to satisfy the asset retirement obligations were $167.2 million and $167.3 million as of June 30, 2022, and December 31, 2021, respectively. The Company is required to provide the applicable government agencies with financial assurances relating to the closure and reclamation obligations. As of June 30, 2022, and December 31, 2021, the Company had financial assurance requirements of $42.3 million and $39.0 million, respectively, which were satisfied with surety bonds placed with the California state and regional agencies. Environmental Obligations The Company assumed certain environmental remediation liabilities related to the monitoring of groundwater contamination. The Company engaged an environmental consultant to develop a remediation plan and remediation cost projections based upon that plan. Utilizing the remediation plan developed by the environmental consultant, management developed an estimate of future cash payments for the remediation plan. As of June 30, 2022, management estimated the cash outflows related to these environmental activities will be incurred annually over the next 26 years. The Company’s environmental remediation liabilities are measured at the expected value of future cash outflows discounted to their present value using a discount rate of 2.93%. There were no significant changes in the estimated remaining remediation costs for the three and six months ended June 30, 2022 and 2021. The total estimated aggregate undiscounted cost of $27.4 million and $27.7 million as of June 30, 2022, and December 31, 2021, respectively, was principally related to water monitoring and treatment activities required by state and local agencies. Based on management’s best estimate of the cost and timing and the assumption that payments are considered to be fixed and reliably determinable, the Company has discounted the liability. The balance as of June 30, 2022, and December 31, 2021, included current portions of $0.5 million.

INCOME TAXES

INCOME TAXES	6 Months Ended
	Jun. 30, 2022
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXESThe Company calculates the provision for income taxes during interim reporting periods by applying an estimate of the annual effective tax rate to its year-to-date pretax book income or loss. The tax effects of discrete items, including but not limited to, excess tax benefits associated with stock-based compensation, valuation allowance adjustments based on new evidence and enactment of tax laws, are reported in the interim period in which they occur. The effective tax rate (income taxes as a percentage of income or loss before income taxes) including discrete items was 24.2% and 24.4% for the three and six months ended June 30, 2022, respectively, as compared to 18.5% and 19.8% for the three and six months ended June 30, 2021, respectively. Our effective income tax rate can vary from period to period depending on, among other factors, percentage depletion, executive compensation deduction limitations, other permanent book/tax items, and changes to our valuation allowance, if any. Certain of these and other factors, including our history and projections of pretax earnings, are considered in assessing our ability to realize our net deferred tax assets.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	6 Months Ended
	Jun. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Litigation: The Company may become party to lawsuits, administrative proceedings and government investigations, including environmental, regulatory, and other matters, in the ordinary course of business. Large, and sometimes unspecified, damages or penalties may be sought in some matters, and certain matters may require years to resolve. In January 2019, a former employee filed a complaint with the California Labor & Workforce Development Agency alleging numerous violations of California labor law, and subsequently filed a representative action against the Company. In October 2021, we entered into a memorandum of understanding to settle the lawsuit in the amount of $1.0 million, including legal fees, subject to the court’s approval of the class settlement.

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	6 Months Ended
	Jun. 30, 2022
Share-Based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION 2020 Incentive Plan: In November 2020, the Company’s stockholders approved the MP Materials Corp. 2020 Stock Incentive Plan (the “2020 Incentive Plan”), which permits the Company to issue stock options (incentive and/or non-qualified); stock appreciation rights; restricted stock, restricted stock units, and other stock awards; and performance awards. As of June 30, 2022, there were 6,578,290 shares available for future grants under the 2020 Incentive Plan. Stock-Based Compensation: During the three and six months ended June 30, 2022, the Company recognized $7.4 million and $17.2 million, respectively, of stock-based compensation expense, as compared to $4.5 million and $10.2 million for the three and six months ended June 30, 2021, respectively, which is principally included in the unaudited Condensed Consolidated Statements of Operations in “Selling, general and administrative.” Additionally, during the three and six months ended June 30, 2022, the Company capitalized $0.3 million and $0.7 million, respectively, of stock-based compensation to “Property, plant and equipment, net.” No stock-based compensation was capitalized to “Property, plant and equipment, net” during the three and six months ended June 30, 2021.

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS ASC Topic 820, “Fair Value Measurements and Disclosures” (“ASC 820”), establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described below: Level 1 Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities; Level 2 Quoted prices in markets that are not active, quoted prices for similar assets or liabilities in active markets, quoted prices or inputs that are observable, either directly or indirectly, for substantially the full term of the asset or liability and model-based valuation techniques (e.g., the Black-Scholes model) for which all significant inputs are observable in active markets. Level 3 Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (supported by little or no market activity). The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of assets and liabilities and their placement within the fair value hierarchy. The following methods and assumptions are used to estimate the fair value of each class of financial instruments for which it is practicable to estimate. The fair value of the Company’s accounts receivable, accounts payable, short-term debt and accrued liabilities approximates the carrying amounts because of the immediate or short-term maturity of these financial instruments. Cash, Cash Equivalents and Restricted Cash The Company’s cash, cash equivalents and restricted cash are classified within Level 1 of the fair value hierarchy. The carrying amounts reported in the unaudited Condensed Consolidated Balance Sheets approximate the fair value of cash, cash equivalents and restricted cash due to the short-term nature of these assets. Short-term Investments The fair value of the Company’s short-term investments, which are classified as available-for-sale securities, is estimated based on quoted prices in active markets and is classified as a Level 1 measurement. Convertible Notes The fair value of the Company’s Convertible Notes is estimated based on quoted prices in active markets and is classified as a Level 1 measurement. Offtake Advances The Company’s Offtake Advances were classified within Level 3 of the fair value hierarchy as of December 31, 2021, because there were unobservable inputs that followed an imputed interest rate model to calculate the amortization of the embedded debt discount, which was recognized as non-cash interest expense, by estimating the timing of anticipated payments and reductions of the debt principal balance. This model-based valuation technique, for which there were unobservable inputs, was used to estimate the fair value of the liability classified within Level 3 of the fair value hierarchy as of December 31, 2021. Equipment Notes The Company’s equipment notes are classified within Level 2 of the fair value hierarchy because there are inputs that are directly observable for substantially the full term of the liability. Model-based valuation techniques for which all significant inputs are observable in active markets were used to calculate the fair values of liabilities classified within Level 2 of the fair value hierarchy. Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The carrying amounts and estimated fair values by input level of the Company’s financial instruments were as follows: June 30, 2022 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 664,457 $ 664,457 $ 664,457 $ — $ — Short-term investments $ 599,666 $ 599,666 $ 599,666 $ — $ — Restricted cash $ 1,129 $ 1,129 $ 1,129 $ — $ — Financial liabilities: Convertible Notes $ 676,683 $ 681,120 $ 681,120 $ — $ — Equipment notes $ 8,369 $ 7,871 $ — $ 7,871 $ — December 31, 2021 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 1,179,297 $ 1,179,297 $ 1,179,297 $ — $ — Restricted cash $ 1,860 $ 1,860 $ 1,860 $ — $ — Financial liabilities: Convertible Notes $ 674,927 $ 880,026 $ 880,026 $ — $ — Offtake Advances $ 16,082 $ 16,501 $ — $ — $ 16,501 Equipment notes $ 9,661 $ 9,737 $ — $ 9,737 $ —

EARNINGS PER SHARE

EARNINGS PER SHARE	6 Months Ended
	Jun. 30, 2022
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHAREBasic earnings per share (“EPS”) is computed by dividing net income by the weighted-average number of common shares outstanding during the period. Diluted EPS is computed by dividing net income by the weighted-average number of common shares outstanding plus the effect of dilutive potential common shares outstanding during the period using the treasury stock method or the if-converted method, as applicable. The following table reconciles the weighted-average common shares outstanding used in the calculation of basic EPS to the weighted-average common shares outstanding used in the calculation of diluted EPS: For the three months ended June 30, For the six months ended June 30, 2022 2021 2022 2021 Weighted-average shares outstanding, basic 176,527,570 172,677,923 176,442,043 170,810,353 Assumed conversion of public warrants (1) — 3,440,138 — 5,681,248 Assumed conversion of Convertible Notes 15,584,409 15,584,409 15,584,409 8,351,866 Assumed conversion of restricted stock 845,450 1,183,720 996,994 1,179,927 Assumed conversion of restricted stock units 457,134 259,454 429,475 259,463 Weighted-average shares outstanding, diluted 193,414,563 193,145,644 193,452,921 186,282,857 (1) Warrants to purchase 11,499,968 shares of the Company’s common stock at $11.50 per share were issued in connection with Fortress Value Acquisition Corp.’s initial public offering pursuant to a warrant agreement, dated April 29, 2020, by and between the Company and Continental Stock Transfer & Trust Company, as warrant agent. The warrants were redeemed through a cashless exercise in the second quarter of 2021. The following table presents the calculation of basic and diluted EPS for the Company’s common stock: For the three months ended June 30, For the six months ended June 30, (in thousands, except share and per share data) 2022 2021 2022 2021 Calculation of basic EPS: Net income $ 73,269 $ 27,166 $ 158,820 $ 43,285 Weighted-average shares outstanding, basic 176,527,570 172,677,923 176,442,043 170,810,353 Basic EPS $ 0.42 $ 0.16 $ 0.90 $ 0.25 Calculation of diluted EPS: Net income $ 73,269 $ 27,166 $ 158,820 $ 43,285 Interest expense, net of tax (1) : Convertible Notes 993 1,064 1,981 1,106 Diluted income $ 74,262 $ 28,230 $ 160,801 $ 44,391 Weighted-average shares outstanding, diluted 193,414,563 193,145,644 193,452,921 186,282,857 Diluted EPS $ 0.38 $ 0.15 $ 0.83 $ 0.24 (1) The three and six months ended June 30, 2022 and 2021, were tax-effected at a rate of 24.2%, 24.4%, 18.5% and 19.8%, respectively.

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	6 Months Ended
	Jun. 30, 2022
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATIONSHIP AND AGREEMENTS WITH SHENGHE Offtake Agreement In March 2022, the Company entered into an offtake agreement with Shenghe (the “Offtake Agreement”), which became effective upon the termination of the A&R Offtake Agreement (as discussed and defined below). The initial term of the Offtake Agreement is two years, with the option to extend the term at the Company’s discretion for an additional one-year period. Pursuant to the Offtake Agreement, and subject to certain exclusions, Shenghe shall purchase on a “take or pay” basis the rare earth concentrate produced by the Company as the exclusive distributor in China, with certain exceptions for the Company’s direct sales globally. In addition, at the discretion of the Company, Shenghe may be required to purchase on a “take or pay” basis certain non-concentrate rare earth products, although the Company may sell all non-concentrate rare earth products in its sole discretion to customers or end users in any jurisdiction. Under the Offtake Agreement, Shenghe will be paid a variable commission on net proceeds to the Company. Similar to the A&R Offtake Agreement, the sales price of rare earth concentrate sold to Shenghe is based on an agreed-upon price per metric ton, subject to certain quality adjustments depending on the measured characteristics of the product, with an adjustment for the ultimate market price of the product realized by Shenghe upon sales to their customers. The sales price and other terms applicable to a quantity of offtake products are set forth in monthly purchase agreements between the Company and Shenghe. Original Commercial Agreements In May 2017, the Company entered into a set of commercial arrangements with Shenghe, which included a technical services agreement (the “TSA”) and an offtake agreement (the “Original Offtake Agreement”). The Original Offtake Agreement required Shenghe to advance the Company an initial $50.0 million (the “Initial Prepayment Amount”) to fund the restart of operations at the mine and the TSA required Shenghe to fund any additional operating and capital expenditures required to bring Mountain Pass to full operability. Shenghe also agreed to provide additional funding of $30.0 million to the Company pursuant to a separate letter agreement dated June 20, 2017 (the “Letter Agreement”) (the “First Additional Advance”), in connection with our acquisition of Mountain Pass. In addition to the repayment of the First Additional Advance, pursuant to the Letter Agreement, the Initial Prepayment Amount increased by $30.0 million. We refer to the aggregate prepayments made by Shenghe pursuant to the Original Offtake Agreement and the Framework Agreement (defined below), as adjusted for Gross Profit Recoupment (defined below) amounts and any other qualifying repayments to Shenghe, inclusive of the $30.0 million increase to the Initial Prepayment Amount, as the “Prepaid Balance.” Under the Original Offtake Agreement, we sold to Shenghe, and Shenghe purchased on a firm “take or pay” basis, all of the rare earth products produced at Mountain Pass. Shenghe marketed and sold these products to customers, and retained the gross profits earned on subsequent sales. The gross profits were credited against the Prepaid Balance, and provided the means by which we repaid, and Shenghe recovered, such amounts (the “Gross Profit Recoupment”). Framework Agreement and Restructured Commercial Agreements In May 2020, the Company entered into a framework agreement and amendment (the “Framework Agreement”) with Shenghe and Leshan Shenghe that restructured the commercial arrangements and provided for, among other things, a revised funding amount and schedule to settle Shenghe’s prepayment obligations to the Company, as well as an amendment to the Original Offtake Agreement, as discussed below. Pursuant to the Framework Agreement, the Company entered into an amended and restated offtake agreement with Shenghe on May 19, 2020 (the “A&R Offtake Agreement”), which, upon effectiveness, superseded and replaced the Original Offtake Agreement. Pursuant to the Framework Agreement, Shenghe funded the remaining portion of the Initial Prepayment Amount and agreed to fund an additional $35.5 million advance (the “Second Additional Advance” and together with the Initial Prepayment Amount, inclusive of the $30.0 million increase pursuant to the Letter Agreement, the “Offtake Advances”), which amounts were fully funded in June 2020. The A&R Offtake Agreement maintained the key take-or-pay, amounts owed on actual and deemed advances from Shenghe, and other terms of the Original Offtake Agreement, with the following changes, among other items: (i) as to the offtake products subject to the A&R Offtake Agreement, provided that if we sold such offtake products to a third party, then, until the Prepaid Balance was reduced to zero, we would pay an agreed percentage of our revenue from such sales to Shenghe, to be credited against the amounts owed on Offtake Advances; (ii) provided that the sales price to be paid by Shenghe for our rare earth products (a portion of which reduces the Prepaid Balance rather than being paid in cash) would be based on market prices (net of taxes, tariffs and certain other agreed charges) less applicable discounts; and (iii) obliged us to pay Shenghe, on an annual basis, an amount equal to our annual net income, less any amounts recouped through the Gross Profit Recoupment mechanism over the course of the year, until the Prepaid Balance was reduced to zero. The sales price and other terms applicable to a quantity of offtake products were set forth in monthly purchase agreements between the Company and Shenghe. In March 2022, the Company made a $2.9 million payment to Shenghe pursuant to item (iii) discussed above. Upon payment by the Company, the Prepaid Balance was repaid in full, and the A&R Offtake Agreement was terminated. Product Sales and Cost of Sales: The Company and Shenghe enter into sales agreements in which Shenghe purchases the Company’s rare earth products at sale prices based on the ultimate market price of the product realized by Shenghe upon sales to their customers. Product sales from these agreements with Shenghe were $131.6 million and $286.6 million for the three and six months ended June 30, 2022, respectively, as compared to $72.2 million and $131.9 million for the three and six months ended June 30, 2021, respectively. Additionally, in March 2022, the Company entered into a sales agreement with Shenghe for certain stockpiles of rare earth fluoride (“REF”). Sales of REF, which are included in the unaudited Condensed Consolidated Statements of Operations in “Other sales (including related party),” were $4.4 million and $8.5 million for the three and six months ended June 30, 2022, respectively. Cost of sales, which includes shipping and freight, related to these agreements with Shenghe was $21.0 million and $43.6 million for the three and six months ended June 30, 2022, respectively, as compared to $17.9 million and $35.7 million for the three and six months ended June 30, 2021, respectively. Purchases: The Company purchases certain reagent products (produced by an unrelated third-party manufacturer) used in the flotation process from Shenghe. Total purchases were $1.4 million and $2.6 million for the three and six months ended June 30, 2022, respectively, as compared to $1.4 million and $2.1 million for the three and six months ended June 30, 2021, respectively. Accounts Receivable: As of June 30, 2022, and December 31, 2021, $29.6 million and $49.9 million of the accounts receivable, respectively, and as stated on the unaudited Condensed Consolidated Balance Sheets, were receivable from and pertained to sales made to Shenghe in the ordinary course of business. Indebtedness: The Company’s related-party debt is described in Note 7, “Debt Obligations.”

SUPPLEMENTAL CASH FLOW INFORMAT

SUPPLEMENTAL CASH FLOW INFORMATION	6 Months Ended
	Jun. 30, 2022
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract]
SUPPLEMENTAL CASH FLOW INFORMATION	SUPPLEMENTAL CASH FLOW INFORMATION Supplemental cash flow information and non-cash investing and financing activities were as follows: For the six months ended June 30, (in thousands) 2022 2021 Supplemental cash flow information: Cash paid for interest $ 1,040 $ 134 Cash payments related to income taxes $ 16,621 $ 2 Supplemental non-cash investing and financing activities: Property, plant and equipment acquired with seller-financed equipment notes $ — $ 9,407 Property, plant and equipment purchased but not yet paid $ 31,839 $ 17,372 Revenue recognized in exchange for debt principal reduction $ 13,566 $ 22,901 Paycheck Protection Loan forgiveness (1) $ — $ 3,401 (1) As discussed in Note 7, “Debt Obligations.”

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	6 Months Ended
	Jun. 30, 2022
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS

SIGNIFICANT ACCOUNTING POLICI_2

SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Jun. 30, 2022
Accounting Policies [Abstract]
Basis of Presentation	The unaudited Condensed Consolidated Financial Statements of the Company have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) for interim financial information and with the rules and regulations of the U.S. Securities and Exchange Commission. Accordingly, they do not include all of the information and notes required by GAAP for complete consolidated financial statements. In the opinion of management, all adjustments (consisting of normal recurring accruals) considered necessary for a fair presentation have been included.Results of operations and cash flows for the interim periods presented herein are not necessarily indicative of the results that would be achieved during a full year of operations or in future periods. These unaudited Condensed Consolidated Financial Statements and notes thereto should be read in conjunction with the Consolidated Financial Statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021.
Principles of Consolidation	The unaudited Condensed Consolidated Financial Statements include the accounts of MP Materials Corp. and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	The preparation of the unaudited Condensed Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect (i) the reported amounts of assets and liabilities, (ii) the disclosure of contingent assets and liabilities at the date of the unaudited Condensed Consolidated Financial Statements, and (iii) the reported amounts of revenues and expenses during the reporting period. Accordingly, actual results may differ from those estimates.
Concentration of Risk	Financial instruments that potentially subject the Company to credit risk consist principally of cash and cash equivalents, short-term investments and trade accounts receivable. The Company believes that its credit risk is limited because the Company’s current contracts are with companies with a reliable payment history. The Company does not believe that it is exposed to any significant risks related to its cash accounts, money market funds, or short-term investments. As of June 30, 2022, Shenghe, a related party of the Company and our principal customer, accounted for more than 90% of product sales. Furthermore, while revenue is generated in the United States, Shenghe conducts its primary operations in China and may transport and sell products in the Chinese market. Therefore, the Company’s revenue is affected by Shenghe’s ultimate realized prices in China. In addition, there is an ongoing economic conflict between China and the United States that has resulted in tariffs and trade barriers that may negatively affect the Company’s business and results of operations. See Note 3, “Relationship and Agreements with Shenghe,” for additional information. In December 2019, a novel strain of coronavirus (known as “COVID-19”) began to impact the population of China. In March 2020, the outbreak of COVID-19 was declared a global pandemic after growing both in the United States and globally. The responses by governments, societies, and private sector entities to the COVID-19 pandemic, which include temporary closures of businesses, social distancing, travel restrictions, “shelter in place,” and other governmental regulations and various economic stimulus programs, have significantly impacted market volatility and general global economic conditions, including significant business and supply chain disruption as well as broad-based changes in supply and demand. Since the onset of the COVID-19 pandemic, we have experienced, at times, significant shipping delays due to congestion and slowdowns at U.S. and international ports caused by shortages in vessels, containers, and truckers, also disrupting the global supply chain. Congestion and slowdowns have affected and may continue to affect the capacity at ports to receive deliveries of products or the loading of shipments onto vessels. Despite these factors, we have not experienced a reduction in production or sales due to the COVID-19 pandemic; however, the COVID-19 pandemic has contributed to certain cost and schedule pressures on the Stage II optimization project. The Company has worked proactively and diligently to adjust working schedules and hours to optimize logistics and shipping, which has thus far prevented a significant negative impact on our product sales and has mitigated certain impacts on Stage II construction and recommissioning progress. However, there can be no assurance that the ongoing COVID-19 pandemic will not have a negative impact on our production, sales, or growth projects in the future. As the situation continues to evolve, including as a result of new and potential future variants of COVID-19, the possibility of federal or state mandates on vaccinations, or other factors that may affect international shipping and logistics or involve responses to government actions such as strikes or other disruptions, it is impossible to predict the effect and ultimate impact of the COVID-19 pandemic on the Company’s business and results of operations. The extent and duration of any business disruptions, and related financial impact, cannot be estimated at this time.
Cash and Cash Equivalents	Cash and cash equivalents consist of all cash balances and highly liquid investments, including U.S. treasury and agency securities, with a maturity of three months or less at the time of purchase.
Short-term Investments	The Company’s short-term investments consist of U.S. treasury and agency securities that have original maturities greater than three months at the time of purchase. These investments have been classified and accounted for as available-for-sale securities and the Company reevaluates the classification each reporting period. The Company classifies its available-for-sale securities as either current or non-current based on each instrument’s underlying contractual maturity date and the Company’s expectations of sales and redemptions within the next twelve months. See Note 4, “Cash, Cash Equivalents and Investments,” for additional information. Available-for-sale securities are recorded at fair value each reporting period. For unrealized losses in securities that the Company intends to hold and will not more likely than not be required to sell before recovery, the Company further evaluates whether declines in fair value below amortized cost are due to credit or non-credit related factors. The Company considers credit related impairments to be changes in value that are driven by a change in the creditor’s ability to meet its payment obligations, and records an allowance and recognizes a corresponding loss when the impairment is incurred. Unrealized non-credit related losses and unrealized gains are reported, net of income taxes, in accumulated other comprehensive income or loss, a component of stockholders’ equity within the unaudited Condensed Consolidated Balance Sheets, until realized. Realized gains and losses are reported within our unaudited Condensed Consolidated Statements of Operations upon realization. Accrued interest receivable is included in “Accounts receivable (including related party)” within the Company’s unaudited Condensed Consolidated Balance Sheets.
Recently Issued Accounting Pronouncements	There were no new accounting pronouncements recently issued or effective during the three and six months ended June 30, 2022, that had or would be expected to have a material impact on the Company’s unaudited Condensed Consolidated Financial Statements.
Reclassifications	Certain amounts in prior periods have been reclassified to conform to the current year presentation.

CASH, CASH EQUIVALENTS AND IN_2

CASH, CASH EQUIVALENTS AND INVESTMENTS (Tables)	6 Months Ended
	Jun. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Debt Securities, Available-for-Sale	The following table presents the Company’s cash, cash equivalents and short-term investments: June 30, 2022 December 31, 2021 (in thousands) Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value Cash: Demand deposits $ 29,668 $ — $ — $ 29,668 $ 26,536 $ — $ — $ 26,536 Cash equivalents: Money market funds 439,933 — — 439,933 1,152,761 — — 1,152,761 U.S. agency securities 194,875 — (19) 194,856 — — — — Total cash equivalents 634,808 — (19) 634,789 1,152,761 — — 1,152,761 Total cash and equivalents 664,476 — (19) 664,457 1,179,297 — — 1,179,297 Short-term investments: U.S. agency securities 207,764 — (141) 207,623 — — — — U.S. Treasury securities 392,439 — (396) 392,043 — — — — Total short-term investments 600,203 — (537) 599,666 — — — — Total cash, cash equivalents and short-term investments $ 1,264,679 $ — $ (556) $ 1,264,123 $ 1,179,297 $ — $ — $ 1,179,297
Schedule of Cash and Cash Equivalents	The following table presents the Company’s cash, cash equivalents and short-term investments: June 30, 2022 December 31, 2021 (in thousands) Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value Amortized Cost Basis Unrealized Gains Unrealized Losses Estimated Fair Value Cash: Demand deposits $ 29,668 $ — $ — $ 29,668 $ 26,536 $ — $ — $ 26,536 Cash equivalents: Money market funds 439,933 — — 439,933 1,152,761 — — 1,152,761 U.S. agency securities 194,875 — (19) 194,856 — — — — Total cash equivalents 634,808 — (19) 634,789 1,152,761 — — 1,152,761 Total cash and equivalents 664,476 — (19) 664,457 1,179,297 — — 1,179,297 Short-term investments: U.S. agency securities 207,764 — (141) 207,623 — — — — U.S. Treasury securities 392,439 — (396) 392,043 — — — — Total short-term investments 600,203 — (537) 599,666 — — — — Total cash, cash equivalents and short-term investments $ 1,264,679 $ — $ (556) $ 1,264,123 $ 1,179,297 $ — $ — $ 1,179,297

INVENTORIES (Tables)

INVENTORIES (Tables)	6 Months Ended
	Jun. 30, 2022
Inventory Disclosure [Abstract]
Inventories	The Company’s inventories consisted of the following: June 30, 2022 December 31, 2021 (in thousands) Materials and supplies $ 12,186 $ 10,711 In-process 28,455 25,574 Finished goods 1,603 2,407 Total inventory $ 42,244 $ 38,692

PROPERTY, PLANT AND EQUIPMENT (

PROPERTY, PLANT AND EQUIPMENT (Tables)	6 Months Ended
	Jun. 30, 2022
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment and Depreciation and Depletion Expense	The Company’s property, plant and equipment consisted of the following: June 30, 2022 December 31, 2021 (in thousands) Land and land improvements $ 15,765 $ 7,925 Buildings and building improvements 8,950 8,791 Machinery and equipment 64,148 61,822 Assets under construction 271,054 134,327 Mineral rights 438,719 437,376 Property, plant and equipment, gross 798,636 650,241 Less: Accumulated depreciation and depletion (48,788) (39,629) Property, plant and equipment, net $ 749,848 $ 610,612 The Company’s depreciation and depletion expense were as follows: For the three months ended June 30, For the six months ended June 30, (in thousands) 2022 2021 2022 2021 Depreciation expense $ 2,257 $ 1,890 $ 4,358 $ 3,419 Depletion expense $ 3,075 $ 4,686 $ 6,144 $ 9,217

DEBT OBLIGATIONS (Tables)

DEBT OBLIGATIONS (Tables)	6 Months Ended
	Jun. 30, 2022
Debt Disclosure [Abstract]
Schedule of debt obligations	The Company’s current and non-current portions of long-term debt were as follows: June 30, 2022 December 31, 2021 (in thousands) Long-term debt Convertible Notes due 2026 $ 690,000 $ 690,000 Less: Unamortized debt issuance costs (13,317) (15,073) Net carrying amount 676,683 674,927 Less: Current installments of long-term debt — — Long-term debt, net of current portion $ 676,683 $ 674,927 Long-term debt to related party Offtake Advances $ — $ 16,599 Less: Unamortized debt discount — (517) Net carrying amount — 16,082 Less: Current installments of long-term debt to related party — (16,082) Long-term debt to related party, net of current portion $ — $ — The current and non-current portions of the equipment notes, which are included within the unaudited Condensed Consolidated Balance Sheets in “Other current liabilities” and “Other non-current liabilities,” respectively, were as follows: June 30, 2022 December 31, 2021 (in thousands) Equipment notes Current $ 2,439 $ 2,566 Non-current 5,930 7,095 $ 8,369 $ 9,661
Interest expense, net	Interest expense related to the Convertible Notes was as follows: For the three months ended June 30, For the six months ended June 30, (in thousands) 2022 2021 2022 2021 Coupon interest $ 431 $ 431 $ 862 $ 455 Amortization of debt issuance costs 879 875 1,756 923 Convertible Notes interest expense $ 1,310 $ 1,306 $ 2,618 $ 1,378

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	6 Months Ended
	Jun. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Disclosure of Asset and Liability Not Measured at Fair Value	The carrying amounts and estimated fair values by input level of the Company’s financial instruments were as follows: June 30, 2022 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 664,457 $ 664,457 $ 664,457 $ — $ — Short-term investments $ 599,666 $ 599,666 $ 599,666 $ — $ — Restricted cash $ 1,129 $ 1,129 $ 1,129 $ — $ — Financial liabilities: Convertible Notes $ 676,683 $ 681,120 $ 681,120 $ — $ — Equipment notes $ 8,369 $ 7,871 $ — $ 7,871 $ — December 31, 2021 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 1,179,297 $ 1,179,297 $ 1,179,297 $ — $ — Restricted cash $ 1,860 $ 1,860 $ 1,860 $ — $ — Financial liabilities: Convertible Notes $ 674,927 $ 880,026 $ 880,026 $ — $ — Offtake Advances $ 16,082 $ 16,501 $ — $ — $ 16,501 Equipment notes $ 9,661 $ 9,737 $ — $ 9,737 $ —
Fair Value, Assets Measured on Recurring Basis	The carrying amounts and estimated fair values by input level of the Company’s financial instruments were as follows: June 30, 2022 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 664,457 $ 664,457 $ 664,457 $ — $ — Short-term investments $ 599,666 $ 599,666 $ 599,666 $ — $ — Restricted cash $ 1,129 $ 1,129 $ 1,129 $ — $ — Financial liabilities: Convertible Notes $ 676,683 $ 681,120 $ 681,120 $ — $ — Equipment notes $ 8,369 $ 7,871 $ — $ 7,871 $ — December 31, 2021 (in thousands) Carrying Amount Fair Value Level 1 Level 2 Level 3 Financial assets: Cash and cash equivalents $ 1,179,297 $ 1,179,297 $ 1,179,297 $ — $ — Restricted cash $ 1,860 $ 1,860 $ 1,860 $ — $ — Financial liabilities: Convertible Notes $ 674,927 $ 880,026 $ 880,026 $ — $ — Offtake Advances $ 16,082 $ 16,501 $ — $ — $ 16,501 Equipment notes $ 9,661 $ 9,737 $ — $ 9,737 $ —

EARNINGS PER SHARE (Tables)

EARNINGS PER SHARE (Tables)	6 Months Ended
	Jun. 30, 2022
Earnings Per Share [Abstract]
Schedule of weighted-average common shares outstanding used in the calculation of basic earnings per share to the weighted-average common shares outstanding used in the calculation of diluted earnings per share	The following table reconciles the weighted-average common shares outstanding used in the calculation of basic EPS to the weighted-average common shares outstanding used in the calculation of diluted EPS: For the three months ended June 30, For the six months ended June 30, 2022 2021 2022 2021 Weighted-average shares outstanding, basic 176,527,570 172,677,923 176,442,043 170,810,353 Assumed conversion of public warrants (1) — 3,440,138 — 5,681,248 Assumed conversion of Convertible Notes 15,584,409 15,584,409 15,584,409 8,351,866 Assumed conversion of restricted stock 845,450 1,183,720 996,994 1,179,927 Assumed conversion of restricted stock units 457,134 259,454 429,475 259,463 Weighted-average shares outstanding, diluted 193,414,563 193,145,644 193,452,921 186,282,857 (1) Warrants to purchase 11,499,968 shares of the Company’s common stock at $11.50 per share were issued in connection with Fortress Value Acquisition Corp.’s initial public offering pursuant to a warrant agreement, dated April 29, 2020, by and between the Company and Continental Stock Transfer & Trust Company, as warrant agent. The warrants were redeemed through a cashless exercise in the second quarter of 2021.
Schedule of the calculation of basic and diluted earnings per share	The following table presents the calculation of basic and diluted EPS for the Company’s common stock: For the three months ended June 30, For the six months ended June 30, (in thousands, except share and per share data) 2022 2021 2022 2021 Calculation of basic EPS: Net income $ 73,269 $ 27,166 $ 158,820 $ 43,285 Weighted-average shares outstanding, basic 176,527,570 172,677,923 176,442,043 170,810,353 Basic EPS $ 0.42 $ 0.16 $ 0.90 $ 0.25 Calculation of diluted EPS: Net income $ 73,269 $ 27,166 $ 158,820 $ 43,285 Interest expense, net of tax (1) : Convertible Notes 993 1,064 1,981 1,106 Diluted income $ 74,262 $ 28,230 $ 160,801 $ 44,391 Weighted-average shares outstanding, diluted 193,414,563 193,145,644 193,452,921 186,282,857 Diluted EPS $ 0.38 $ 0.15 $ 0.83 $ 0.24 (1) The three and six months ended June 30, 2022 and 2021, were tax-effected at a rate of 24.2%, 24.4%, 18.5% and 19.8%, respectively.

SUPPLEMENTAL CASH FLOW INFORM_2

SUPPLEMENTAL CASH FLOW INFORMATION (Tables)	6 Months Ended
	Jun. 30, 2022
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract]
Schedule of Cash Flow, Supplemental Disclosures	Supplemental cash flow information and non-cash investing and financing activities were as follows: For the six months ended June 30, (in thousands) 2022 2021 Supplemental cash flow information: Cash paid for interest $ 1,040 $ 134 Cash payments related to income taxes $ 16,621 $ 2 Supplemental non-cash investing and financing activities: Property, plant and equipment acquired with seller-financed equipment notes $ — $ 9,407 Property, plant and equipment purchased but not yet paid $ 31,839 $ 17,372 Revenue recognized in exchange for debt principal reduction $ 13,566 $ 22,901 Paycheck Protection Loan forgiveness (1) $ — $ 3,401 (1) As discussed in Note 7, “Debt Obligations.”

DESCRIPTION OF BUSINESS AND B_2

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (Details)	6 Months Ended
	Jun. 30, 2022 segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	1

SIGNIFICANT ACCOUNTING POLICI_3

SIGNIFICANT ACCOUNTING POLICIES (Details)	6 Months Ended
	Jun. 30, 2022
Shenghe | Product sales | Customer concentration risk | Shenghe
Concentration Risk [Line Items]
Concentration risk percentage	90%

RELATIONSHIP AND AGREEMENTS W_2

RELATIONSHIP AND AGREEMENTS WITH SHENGHE - Offtake and Original Commercial Agreements (Details) - Affiliated Entity - USD ($) $ in Millions		1 Months Ended
	Jun. 20, 2017	Mar. 31, 2022	May 31, 2017
Offtake Agreement
Related Party Transaction [Line Items]
Initial term		2 years
Extension period		1 year
Initial Prepayment Amount
Related Party Transaction [Line Items]
Advances			$ 50
Increase in advances	$ 30
First Additional Advance
Related Party Transaction [Line Items]
Advances	$ 30

RELATIONSHIP AND AGREEMENTS W_3

RELATIONSHIP AND AGREEMENTS WITH SHENGHE - Framework Agreement and Restructured Commercial Arrangements (Details) - USD ($) $ in Thousands			1 Months Ended		6 Months Ended
	May 19, 2020	Jun. 20, 2017	Mar. 31, 2022	May 31, 2017	Jun. 30, 2022	Jun. 30, 2021
Related Party Transaction [Line Items]
Principal payments on debt obligations and finance leases					$ 4,488	$ 990
Affiliated Entity | Shenghe
Related Party Transaction [Line Items]
Principal payments on debt obligations and finance leases			$ 2,900
Original Offtake Agreement, Second Additional Advance | Affiliated Entity | Shenghe
Related Party Transaction [Line Items]
Advances	$ 35,500
Initial Prepayment Amount | Affiliated Entity
Related Party Transaction [Line Items]
Advances				$ 50,000
Increase in advances		$ 30,000
Initial Prepayment Amount | Affiliated Entity | Shenghe
Related Party Transaction [Line Items]
Increase in advances	$ 30,000

CASH, CASH EQUIVALENTS AND IN_3

CASH, CASH EQUIVALENTS AND INVESTMENTS - Amortized Costs, Unrealized Gains and Losses, and Estimated Fair Value (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Total cash and equivalents
Amortized Cost Basis	$ 664,457	$ 664,457	$ 1,179,297	$ 1,196,875
Short-term investments:
Amortized Cost Basis	600,203	600,203	0
Unrealized Gains	0	0	0
Unrealized Losses	(537)	(537)	0
Short-term investments	599,666	599,666	0
Amortized Cost Basis	1,264,679	1,264,679	1,179,297
Unrealized Gains	0	0	0
Unrealized Losses	(556)	(556)	0
Total cash, cash equivalents and short-term investments	1,264,123	1,264,123	1,179,297
Debt securities, available-for-sale, realized gain (loss)	0	0
U.S. agency securities
Short-term investments:
Amortized Cost Basis	207,764	207,764	0
Unrealized Gains	0	0	0
Unrealized Losses	(141)	(141)	0
Short-term investments	207,623	207,623	0
U.S. Treasury securities
Short-term investments:
Amortized Cost Basis	392,439	392,439	0
Unrealized Gains	0	0	0
Unrealized Losses	(396)	(396)	0
Short-term investments	392,043	392,043	0
Total cash and equivalents
Total cash and equivalents
Amortized Cost Basis	664,476	664,476	1,179,297
Unrealized Gains	0	0	0
Unrealized Losses	(19)	(19)	0
Estimated Fair Value	664,457	664,457	1,179,297
Demand deposits
Total cash and equivalents
Amortized Cost Basis	29,668	29,668	26,536
Estimated Fair Value	29,668	29,668	26,536
Total cash equivalents
Total cash and equivalents
Amortized Cost Basis	634,808	634,808	1,152,761
Unrealized Gains	0	0	0
Unrealized Losses	(19)	(19)	0
Estimated Fair Value	634,789	634,789	1,152,761
Money market funds
Total cash and equivalents
Amortized Cost Basis	439,933	439,933	1,152,761
Unrealized Gains	0	0	0
Unrealized Losses	0	0	0
Estimated Fair Value	439,933	439,933	1,152,761
U.S. agency securities
Total cash and equivalents
Amortized Cost Basis	194,875	194,875	0
Unrealized Gains	0	0	0
Unrealized Losses	(19)	(19)	0
Estimated Fair Value	$ 194,856	$ 194,856	$ 0

INVENTORIES (Details)

INVENTORIES (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Inventory Disclosure [Abstract]
Materials and supplies	$ 12,186	$ 10,711
In-process	28,455	25,574
Finished goods	1,603	2,407
Total inventory	$ 42,244	$ 38,692

INVENTORIES - Narrative (Detail

INVENTORIES - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Inventory Disclosure [Abstract]
Write-down of inventories	$ 0	$ 1,809,000	$ 0	$ 1,809,000

PROPERTY, PLANT AND EQUIPMENT -

PROPERTY, PLANT AND EQUIPMENT - Schedule (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 798,636	$ 650,241
Less: Accumulated depreciation and depletion	(48,788)	(39,629)
Property, plant and equipment, net	749,848	610,612
Land and land improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	15,765	7,925
Buildings and building improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	8,950	8,791
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	64,148	61,822
Assets under construction
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	271,054	134,327
Mineral rights
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 438,719	$ 437,376

PROPERTY, PLANT AND EQUIPMENT_2

PROPERTY, PLANT AND EQUIPMENT - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Feb. 28, 2022	Nov. 30, 2020
Property, Plant and Equipment [Abstract]
Capitalized expenditures			$ 154,400,000	$ 62,100,000
Technology investment agreement, stage II optimization contribution	$ 100,000		100,000			$ 9,600,000
Proceeds from technology investment agreement, stage II optimization contribution			5,100,000
Asset impairment charges	$ 0	$ 0	$ 0	$ 0
HREE Production Project Agreement, Stage II Optimization Contribution					$ 35,000,000

PROPERTY, PLANT AND EQUIPENT -

PROPERTY, PLANT AND EQUIPENT - Depreciation and Depletion Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Property, Plant and Equipment [Abstract]
Depreciation expense	$ 2,257	$ 1,890	$ 4,358	$ 3,419
Depletion expense	$ 3,075	$ 4,686	$ 6,144	$ 9,217

DEBT OBLIGATIONS - Schedule of

DEBT OBLIGATIONS - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Less: Unamortized debt issuance costs	$ (13,317)	$ (15,073)
Net carrying amount	676,683	674,927
Less: Current installments of long-term debt	0	0
Less: Current installments of long-term debt to related party	0	(16,082)
Long-term debt, net of current portion	676,683	674,927
Convertible Notes Due 2026 | Convertible Debt
Debt Instrument [Line Items]
Outstanding balance, gross	690,000	690,000
Related Party Debt
Debt Instrument [Line Items]
Less: Unamortized debt discount	0	(517)
Net carrying amount	0	16,082
Less: Current installments of long-term debt to related party	0	(16,082)
Long-term debt, net of current portion	0	0
Related Party Debt | Offtake Advances
Debt Instrument [Line Items]
Outstanding balance, gross	$ 0	$ 16,599

DEBT OBLIGATIONS - Convertible

DEBT OBLIGATIONS - Convertible Notes (Details) - Convertible Debt - Convertible Notes Due 2026 $ / shares in Units, $ in Millions	1 Months Ended	6 Months Ended
	Mar. 31, 2021 USD ($) $ / shares	Jun. 30, 2022 shares
Debt Instrument [Line Items]
Advance funded | $	$ 690
Interest rate	0.25%
Debt instrument, convertible, conversion price (in dollars per share) | $ / shares	$ 44.28
Debt instrument, convertible, conversion ratio	0.0225861
Debt instrument, convertible, number of equity instruments (in shares) | shares		19,714,266
Maximum
Debt Instrument [Line Items]
Debt instrument, convertible, conversion ratio	0.0285714

DEBT OBLIGATIONS - Interest Exp

DEBT OBLIGATIONS - Interest Expense, Net (Details) - Convertible Debt - Convertible Notes Due 2026 - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Debt Instrument [Line Items]
Coupon interest	$ 431	$ 431	$ 862	$ 455
Amortization of debt issuance costs	879	875	1,756	923
Convertible Notes interest expense	$ 1,310	$ 1,306	$ 2,618	$ 1,378
Debt instrument, interest rate, effective percentage	0.51%		0.51%
Debt term			3 years 9 months 18 days

DEBT OBLIGATIONS - Offtake Adva

DEBT OBLIGATIONS - Offtake Advances (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended
	Mar. 31, 2022	Jun. 30, 2020	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Debt Instrument [Line Items]
Principal payments on debt obligations and finance leases					$ 4,488	$ 990
Affiliated Entity
Debt Instrument [Line Items]
Revenue from related parties			$ 131,600	$ 72,200	286,600	131,900
Shenghe | Affiliated Entity
Debt Instrument [Line Items]
Principal payments on debt obligations and finance leases	$ 2,900
Related Party Debt | Offtake Advances
Debt Instrument [Line Items]
Required payments, percent of net profits from sales of assets		100%
Required payments, percent of net income		100%
Reduction in debt as a result of sales			0	11,700	14,200	20,900
Repayments of related party debt			$ 0	$ 100	$ 200	100
Related Party Debt | Offtake Advances | Minimum
Debt Instrument [Line Items]
Debt instrument, interest rate, effective percentage			4.41%		4.41%
Related Party Debt | Offtake Advances | Maximum
Debt Instrument [Line Items]
Debt instrument, interest rate, effective percentage			24.75%		24.75%
Related Party Debt | Tariff-Related Rebate
Debt Instrument [Line Items]
Revenue from related parties						2,000
Reduction in the principal balance of the debt obligation						2,200
Reduction in debt discount						$ 200

DEBT OBLIGATIONS - Paycheck Pro

DEBT OBLIGATIONS - Paycheck Protection Loan (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended
	Apr. 30, 2020	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Debt Instrument [Line Items]
Gain on extinguishment of debt			$ 0	$ 3,401
Paycheck Protection Loan | Paycheck Protection Program Loan
Debt Instrument [Line Items]
Proceeds from debt issuance	$ 3,400
Gain on extinguishment of debt		$ 3,400		$ 3,400

DEBT OBLIGATIONS - Equipment No

DEBT OBLIGATIONS - Equipment Notes (Details) - Equipment notes - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Equipment notes
Current	$ 2,439	$ 2,566
Non-current	5,930	7,095
Notes payable	$ 8,369	$ 9,661
Minimum
Debt Instrument [Line Items]
Debt term	4 years
Debt instrument, interest rate, stated percentage	0%
Maximum
Debt Instrument [Line Items]
Debt term	5 years
Debt instrument, interest rate, stated percentage	6.50%

ASSET RETIREMENT AND ENVIRONM_2

ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS - Additional Information (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Unusual Risk or Uncertainty [Line Items]
Asset retirement obligation, current	$ 0.1	$ 0.1
Estimated undiscounted cash flows, to satisfy obligation	167.2	167.3
Closure and reclamation obligations, financial assurances	$ 42.3	39
Remediation term	26 years
Discount rate	2.93%
Environmental obligations, undiscounted cost	$ 27.4	27.7
Environmental obligations, current	$ 0.5	$ 0.5
Minimum
Unusual Risk or Uncertainty [Line Items]
Asset retirement obligations, credit-adjusted risk free rate	6.50%
Maximum
Unusual Risk or Uncertainty [Line Items]
Asset retirement obligations, credit-adjusted risk free rate	8.20%

INCOME TAXES - Additional Infor

INCOME TAXES - Additional Information (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Income Tax Disclosure [Abstract]
Effective tax rate	24.20%	18.50%	24.40%	19.80%

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) $ in Millions	1 Months Ended
	Oct. 31, 2021 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Settlement charge	$ 1

STOCK-BASED COMPENSATION - Addi

STOCK-BASED COMPENSATION - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 7,400,000	$ 4,500,000	$ 17,200,000	$ 10,200,000
Stock-based compensation expense, amount capitalized	$ 300,000	$ 0	$ 700,000	$ 0
2020 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future grants (in shares)	6,578,290		6,578,290

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Level 1
Financial assets:
Cash and cash equivalents	$ 664,457	$ 1,179,297
Short-term investments	599,666
Restricted cash	1,129	1,860
Level 2
Financial assets:
Cash and cash equivalents	0	0
Short-term investments	0
Restricted cash	0	0
Level 3
Financial assets:
Cash and cash equivalents	0	0
Short-term investments	0
Restricted cash	0	0
Convertible Notes | Level 1
Financial liabilities:
Debt fair value	681,120	880,026
Convertible Notes | Level 2
Financial liabilities:
Debt fair value	0	0
Convertible Notes | Level 3
Financial liabilities:
Debt fair value	0	0
Offtake Advances | Level 1
Financial liabilities:
Debt fair value		0
Offtake Advances | Level 2
Financial liabilities:
Debt fair value		0
Offtake Advances | Level 3
Financial liabilities:
Debt fair value		16,501
Equipment notes | Level 1
Financial liabilities:
Debt fair value	0	0
Equipment notes | Level 2
Financial liabilities:
Debt fair value	7,871	9,737
Equipment notes | Level 3
Financial liabilities:
Debt fair value	0	0
Carrying Amount
Financial assets:
Cash and cash equivalents	664,457	1,179,297
Short-term investments	599,666
Restricted cash	1,129	1,860
Carrying Amount | Convertible Notes
Financial liabilities:
Debt fair value	676,683	674,927
Carrying Amount | Offtake Advances
Financial liabilities:
Debt fair value		16,082
Carrying Amount | Equipment notes
Financial liabilities:
Debt fair value	8,369	9,661
Fair Value
Financial assets:
Cash and cash equivalents	664,457	1,179,297
Short-term investments	599,666
Restricted cash	1,129	1,860
Fair Value | Convertible Notes
Financial liabilities:
Debt fair value	681,120	880,026
Fair Value | Offtake Advances
Financial liabilities:
Debt fair value		16,501
Fair Value | Equipment notes
Financial liabilities:
Debt fair value	$ 7,871	$ 9,737

EARNINGS PER SHARE - Schedule o

EARNINGS PER SHARE - Schedule of Weighted Average Number of Shares (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Apr. 29, 2020
Class of Warrant or Right [Line Items]
Weighted-average shares outstanding, basic (in shares)	176,527,570	172,677,923	176,442,043	170,810,353
Assumed conversion of Public Warrants (in shares)	0	3,440,138	0	5,681,248
Assumed conversion of Convertible Notes (in shares)	15,584,409	15,584,409	15,584,409	8,351,866
Weighted-average shares outstanding, diluted (in shares)	193,414,563	193,145,644	193,452,921	186,282,857
Public Warrant
Class of Warrant or Right [Line Items]
Number of securities called by warrants (in shares)					11,499,968
Exercise price of warrants (usd per share)					$ 11.50
Restricted Stock
Class of Warrant or Right [Line Items]
Assumed conversion of restricted stock awards (in shares)	845,450	1,183,720	996,994	1,179,927
Restricted Stock Units (RSUs)
Class of Warrant or Right [Line Items]
Assumed conversion of restricted stock awards (in shares)	457,134	259,454	429,475	259,463

EARNINGS PER SHARE - Calculatio

EARNINGS PER SHARE - Calculation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Calculation of basic EPS:
Net income	$ 73,269	$ 27,166	$ 158,820	$ 43,285
Weighted-average shares outstanding, basic (in shares)	176,527,570	172,677,923	176,442,043	170,810,353
Basic EPS (in USD per share)	$ 0.42	$ 0.16	$ 0.90	$ 0.25
Calculation of diluted EPS:
Interest expense on convertible debt, net of tax	$ 993	$ 1,064	$ 1,981	$ 1,106
Diluted income	$ 74,262	$ 28,230	$ 160,801	$ 44,391
Weighted-average shares outstanding, diluted (in shares)	193,414,563	193,145,644	193,452,921	186,282,857
Diluted EPS (in USD per share)	$ 0.38	$ 0.15	$ 0.83	$ 0.24
Effective tax rate	24.20%	18.50%	24.40%	19.80%

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Related Party Transaction [Line Items]
Cost of sales (including related party)(excluding depreciation, depletion and amortization)	$ 22,092	$ 17,955	$ 45,265	$ 35,891
Accounts receivable (including related party), net of allowance for credit losses of $0 and $0, respectively	32,748		32,748		$ 51,009
Affiliated Entity
Related Party Transaction [Line Items]
Revenue from related parties	131,600	72,200	286,600	131,900
Purchases from related party	1,400	1,400	2,600	2,100
Accounts receivable (including related party), net of allowance for credit losses of $0 and $0, respectively	29,600		29,600		$ 49,900
Affiliated Entity | Rare Earth Fluoride
Related Party Transaction [Line Items]
Revenue from related parties	4,400		8,500
Affiliated Entity | Shipping And Freight Related Agreements With Shenghe
Related Party Transaction [Line Items]
Expenses from transactions with related party	$ 21,000	$ 17,900	$ 43,600	$ 35,700

SUPPLEMENTAL CASH FLOW INFORM_3

SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Supplemental cash flow information:
Cash paid for interest	$ 1,040	$ 134
Cash payments related to income taxes	16,621	2
Supplemental non-cash investing and financing activities:
Property, plant and equipment acquired with seller-financed equipment notes	0	9,407
Property, plant and equipment purchased but not yet paid	31,839	17,372
Revenue recognized in exchange for debt principal reduction	13,566	22,901
Paycheck Protection Loan forgiveness	$ 0	$ 3,401