MP Materials Corp DE

Introduction

Mineral resources and mineral reserves were estimated by SRK Consulting (U.S.) Inc. (“SRK”) for inclusion in this Annual Report. Pursuant to the requirements of Regulation S-K Subpart 1300 (“S-K 1300”), SRK prepared a pre-feasibility level Technical Report Summary for Mountain Pass with an effective date of October 1, 2023 (the “2023 TRS”) (refer to Exhibit 96.1 to this Annual Report). The mineral resource and mineral reserve estimated in the 2023 TRS were subsequently depleted by SRK to present an estimate of our resources and reserves as of December 31, 2023. The depletion removed by SRK represents resources and reserves that were extracted from the Mountain Pass open pit from October 1, 2023, through December 31, 2023.

Mineral Resource and Mineral Reserve Definitions

Item 1300 of S-K 1300 defines a “mineral resource” as a concentration or occurrence of material of economic interest in or on the Earth’s crust in such form, grade or quality, and quantity that there are reasonable prospects for economic extraction. A mineral resource is a reasonable estimate of mineralization, taking into account relevant factors such as cut-off grade (“COG”), likely mining dimensions, location or continuity, that, with the assumed and justifiable technical and economic conditions, is likely to, in whole or in part, become economically extractable. It is not merely an inventory of all mineralization drilled or sampled.

A “measured mineral resource” is that part of a mineral resource for which quantity and grade or quality are estimated on the basis of conclusive geological evidence and sampling. The level of geological certainty associated with a measured mineral resource is sufficient to allow a qualified person to apply modifying factors, as defined in this section, in sufficient detail to support detailed mine planning and final evaluation of the economic viability of the deposit. Because a measured mineral resource has a higher level of confidence than the level of confidence of either an indicated mineral resource or an inferred mineral resource, a measured mineral resource may be converted to a proven mineral reserve or to a probable mineral reserve.

An “indicated mineral resource” is that part of a mineral resource for which quantity and grade or quality are estimated on the basis of adequate geological evidence and sampling. The level of geological certainty associated with an indicated mineral resource is sufficient to allow a qualified person to apply modifying factors in sufficient detail to support mine planning and evaluation of the economic viability of the deposit. Because an indicated mineral resource has a lower level of confidence than the level of confidence of a measured mineral resource, an indicated mineral resource may only be converted to a probable mineral reserve.

An “inferred mineral resource” is that part of a mineral resource for which quantity and grade or quality are estimated on the basis of limited geological evidence and sampling. The level of geological uncertainty associated with an inferred mineral resource is too high to apply relevant technical and economic factors likely to influence the prospects of economic extraction in a manner useful for evaluation of economic viability. Because an inferred mineral resource has the lowest level of geological confidence of all mineral resources, which prevents the application of the modifying factors in a manner useful for evaluation of economic viability, an inferred mineral resource may not be considered when assessing the economic viability of a mining project and may not be converted to a mineral reserve.

Item 1300 of S-K 1300 defines a “mineral reserve” as an estimate of tonnage and grade or quality of indicated and measured mineral resources that, in the opinion of the qualified person, can be the basis of an economically viable project. More specifically, it is the economically mineable part of a measured or indicated mineral resource, which includes diluting materials and allowances for losses that may occur when the material is mined or extracted. A “proven mineral reserve” is the economically mineable part of a measured mineral resource and can only result from conversion of a measured mineral resource. A “probable mineral reserve” is the economically mineable part of an indicated and, in some cases, a measured mineral resource.

Estimation Methodology

The mineral resource estimate has been constrained by a geological model considering relevant rock types, structure, and mineralization envelopes as defined by TREO content within relevant geological features. This geological model is informed principally by diamond core drilling and multiple phases of geological mapping. Sectional interpretation based on the combination of these data were used to influence implicit modeling of the geological data with manual controls where appropriate. Data has been composited to reasonable lengths based on the original sample lengths and expected mining unit scale, and outliers have been addressed during estimation using restrictions on influence.

A number of internal controls have been applied over the history of the Mountain Pass deposit to demonstrate the consistency and reliability of historical analytical data supporting mineral resource estimation. Almost all data supporting the mineral resource has been generated by an iteration of a site-based laboratory at the Mountain Pass mine. The Mountain Pass laboratory uses various quality assurance and quality control (“QA/QC”) measures to calibrate modern equipment and ensure analytical precision and accuracy. QA/QC generated by previous laboratories has undergone check assays at independent third-party laboratories, and generally demonstrate no consistent bias. The quality analytical database is also supported by a limited amount of blind quality control samples inserted during a re-assay program, including site-specific standards of known TREO content, a variety of duplicate samples, and blank samples. The implementation and results of these various QA/QC programs have not been fully aligned with current industry standards and are not comprehensive but are considered satisfactory for use in mineral resource estimation.

Estimates have been validated to the input data using statistical and visual comparisons, localized swath plot comparisons of mean grades, and review of the limited mine production reconciliation data to the model. In general, estimates of grade quality are shown to align closely with the input exploration data, but have been demonstrated to be under-reporting relative to the grade control drilling. SRK has categorized uncertainty and risk at Mountain Pass by classifying the contained mineral resource by varying degrees of confidence in the estimate. The mineral resources at the Mountain Pass deposit have been classified in accordance with S-K 1300 definitions. The classification parameters are defined by the distance to composited data, the number of drillholes used to inform estimated block grades and a geostatistical indicator of relative estimation quality (kriging efficiency). As an overall modifier to classification, SRK considered the results from the QA/QC noted above and the observed variability in production reconciliation in the mineral resource classification as well, both of which preclude the assignment of measured resources, as defined by the SEC. Bulk density is based on average density measurements collected from the various rock types over the years, and carbonatite density in particular is supported by extensive mining and processing experience with the materials.

An economic COG of 2.18% TREO has been developed to ensure that material reported as a mineral resource can satisfy the definition of having reasonable prospects for economic extraction as required for the SEC definition. Mineral resources have been constrained within an optimized economic pit shell based on reserve input parameters, with the exception of the assumed equivalent concentrate price ($12,461 per dry short ton (“ST”) of 60% TREO concentrate), which is set 15% higher than the reserves price. The equivalent concentrate price used for pit optimization reflects the gross contained value realized from sales of the four individual REO products (see below) produced from the onsite separations facility. The equivalent concentrate price is calculated based on (i) the expected percentage distribution of the REO products in the bastnaesite concentrate, (ii) the expected metallurgical recoveries for the separations facility and (iii) the expected sales prices for the REO products. For purposes of calculating the end-of-year (“EOY”) 2022 mineral resources, the equivalent concentrate price was reflected net of the operating costs of the separations facility, while the equivalent concentrate price for EOY 2023 mineral resources is reflected gross of these costs, with the operating costs instead included along with the other estimated operating costs (mining; processing; selling, general and administrative (“SG&A”); etc.) that were used in the pit optimization.

For mineral resources, a revenue factor of 1.0 is selected which corresponds to a break-even pit shell volume. SRK notes that the pit selected for mineral resources has been influenced by setbacks relative to critical infrastructure such as the tailing storage and the mill and flotation facilities.

A description of the methodology used to calculate mineral resources is provided in Exhibit 96.1 to this Annual Report.

SRK developed a life-of-mine (“LoM”) plan for the Mountain Pass operation in support of mineral reserves. During 2023 the Company completed construction of a separations facility at Mountain Pass that allows the Company to separate bastnaesite concentrate into four individual REO products for sale. The separations facility is currently ramping up and the Company expects the plant to operate at full design capacity by the end of 2024. For economic modeling of the mineral reserves, SRK assumed that 2024 production will be a combination of bastnaesite concentrate sales and sales of four individual REO products: neodymium and praseodymium (previously defined as “NdPr”) oxide; samarium, europium, and gadolinium (“SEG+”) oxalate; lanthanum carbonate; and cerium chloride. Forecast economic parameters are based on historical cost performance for process, transportation, and administrative costs, as well as a first principles estimation of future mining costs. Forecast revenue from concentrate sales and individual separated product sales is based on a preliminary market study commissioned by the Company.

From this evaluation, pit optimization was performed based on an equivalent concentrate price of $10,836 per dry ST of 60% TREO concentrate. The equivalent concentrate price reflects the gross contained value realized from sales of the four individual REO products produced from the onsite separations facility. The equivalent concentrate price is calculated based on (i) the expected percentage distribution of the REO products in the bastnaesite concentrate, (ii) the expected metallurgical recoveries for the separations facility and (iii) the expected sales prices for the REO products. For purposes of calculating the EOY 2022 mineral reserves, the equivalent concentrate price was reflected net of the operating costs of the separations facility, while the equivalent concentrate price for EOY 2023 mineral reserves is reflected gross of these costs, with the operating costs instead included along with the other estimated operating costs (mining, processing, SG&A, etc.) that were used in the pit optimization.

The results of pit optimization guided the design and scheduling of the ultimate pit. SRK generated a cash flow model which indicated positive economics for the LoM plan, which provides the basis for the reserves. Reserves within the new ultimate pit are sequenced for the remaining 33-year LoM (2024 through 2056).

The costs used for pit optimization include estimated mining, processing, sustaining capital, transportation, and administrative costs, including an allocation of corporate costs. Processing and SG&A costs used for pit optimization were based on historical actual costs.

Processing recovery for concentrate is variable based on a mathematical relationship to estimate overall TREO recovery versus ore grade. The calculated COG for the reserves is 2.43% TREO, which was applied to indicated blocks contained within an ultimate pit, the design of which was guided by economic pit optimization.

The optimized pit shell selected to guide final pit design was based on a combination of the revenue factor (“RF”) 0.70 pit (used on the north half of the deposit) and the RF 1.00 pit shell (used on the south half of the deposit). The inter-ramp pit slopes used for the mineral reserves pit design are based on geotechnical studies and range from 44° to 47°.

Measured resources in stockpiles were converted to proven reserves. Indicated pit resources were converted to probable reserves by applying the appropriate modifying factors to potential mining pit shapes created during the mine design process. Inferred resources present within the LoM pit are treated as waste. Internal controls to demonstrate the consistency and reliability of the historic analytical data supporting the mineral resource estimate (which forms the basis for the mineral reserve estimate) are discussed above.

A description of the methodology used to calculate mineral reserves is provided in Exhibit 96.1 to this Annual Report.

Results

As of December 31, 2023, SRK estimates total indicated resources of 1.45 million STs with an average grade of 2.75% TREO and 9.09 million STs of inferred resources with an average grade of 5.05% TREO. Mineral resources are reported exclusive of mineral reserves. The reference point for mineral resources is in situ material.

(1)TREO% represents the total of individually assayed light rare earth oxides on a 99.7% basis of total contained TREO, based on the historical site analyses.

(2)Percentage of individual light rare earth oxides are based on the average ratios; La 2 O 3 is calculated at a ratio of 32.6% grade of TREO% equivalent estimated grade, CeO 2 is calculated at a ratio of 49.9% of TREO% equivalent estimated grade, Pr 6 O 11 is calculated at a ratio of 4.3% of TREO% equivalent estimated grade, Nd 2 O 3 is calculated at a ratio of 12.1% of TREO% equivalent estimated grade, and Sm 2 O 3 is calculated at a ratio of 0.9% of TREO% equivalent estimated grade. The sum of light rare earths averages 99.7%; the additional 0.3% cannot be accounted for based on the analyses available to date and has been discounted from this resource statement.

General Notes:

•Mineral resources are reported exclusive of mineral reserves.

•Mineral resources are not mineral reserves and do not have demonstrated economic viability. There is no certainty that all or any part of the mineral resources estimated will be converted into the mineral reserves estimate.

•Mineral resource tonnage and contained metal have been rounded to reflect the accuracy of the estimate, any apparent rounding errors are considered insignificant.

•Mineral resource tonnage and grade are reported as diluted.

•The mineral resource model has been depleted for historical mining based on the December 31, 2023, pit topography.

•Pit optimization is based on an average TREO% equivalent concentrate price of $12,461 per dry ST of 60% TREO concentrate, average mining cost at the pit exit of $1.70 per dry ST mined plus $0.068 per dry ST mined for each 15 feet bench above or below the pit exit, combined milling and SG&A costs of $78.94 per dry ST ore milled, separations facility costs of $1,551 per dry ST of 60% TREO concentrate treated, freight of $163 per ST of dry product shipped, sustaining capital costs of $30.48 per dry ST of ore mined, and overall pit slope angles of 39° to 45° including ramps.

•The mineral resource statement reported herein only includes the REE cerium, lanthanum, neodymium, praseodymium, and samarium (often referred to as LREE). While other REE, often referred to as HREE, are present in the deposit, they are not accounted for in this estimate due to historic data limitations.

The following table is provided to show the change in mineral resources from December 31, 2022, to December 31, 2023:

(1)Percentages do not recompute as presented due to rounding.

The difference as compared to the previous year is due to inferred resources located within the mineral reserve pit that were mined and processed during 2023, and a change in the mineral resource COG due to updated project economics.

As of December 31, 2023, SRK estimates total proven reserves of 0.64 million STs of ore with an average grade of 4.28% TREO and 27.82 million STs of probable reserves with an average ore grade of 6.25%. The Company’s total proven and probable reserves are estimated as 28.46 million STs with an average grade of 6.20%. The reference point for the mineral reserves is material delivered to the Mountain Pass mill and flotation facilities.

Based on these estimated reserves, the Company’s expected remaining mine life is approximately 33 years (2024 through 2056) to complete the processing of stockpiles and separations.

The following table states the amount of the Company’s proven and probable mineral reserves as of December 31, 2023.

General Notes:

•Reserves stated as contained within an economically mineable open pit design stated above a 2.43% TREO COG.

•Mineral reserves tonnage and contained metal have been rounded to reflect the accuracy of the estimate, and numbers may not add due to rounding.

•MY% (mass yield) calculation is based on 60% concentrate grade of the product and the ore grade dependent metallurgical recovery. MY% = (TREO% * Met recovery)/60% concentrate TREO grade.

•Indicated mineral resources have been converted to probable reserves. Measured mineral resources have been converted to proven reserves.

•Reserves are diluted at the contact of the 2% TREO geological model triangulation (further to dilution inherent to the resource model and assume selective mining unit of 15 feet x 15 feet x 30 feet).

•Mineral reserves tonnage and grade are reported as diluted.

•Pit optimization is based on an average TREO% equivalent concentrate price of $10,836 per dry ST of 60% TREO concentrate, average mining cost at the pit exit of $1.70 per dry ST mined plus $0.068 per dry ST mined for each 15 feet bench above or below the pit exit, combined milling and SG&A costs of $78.94 per dry ST ore milled, separations facility costs of $1,551 per dry ST of 60% TREO concentrate treated, freight of $163 per ST of dry product shipped, sustaining capital costs of $30.48 per dry ST of ore mined, and overall pit slope angles of 39° to 45° including ramps.

•Reserves contain material inside and outside permitted mining but within mineral lease.

•Reserves assume 100% mining recovery.

•The strip ratio for the remaining reserves is 6.3 to 1 (waste to ore ratio).

•The mineral reserves were estimated by SRK.

The following table is provided to show the change in reserves from December 31, 2022, to December 31, 2023:

The reason for the differences between the two estimates is due to reserves that were mined and processed during 2023. It is noted that reserves depletion due to mining and processing during 2023 was partially offset by additional above COG material that was identified by closely spaced blasthole sampling. This above COG material was not included in the previous reserves estimate because the material had not been identified by the wider spaced resource drilling that informed the resource block model utilized for the 2023 TRS.

Factors and Assumptions Affecting Mineral Resource and Mineral Reserve Estimates

There are numerous uncertainties inherent in estimating quantities and qualities of REO reserves and costs to mine recoverable reserves, including many factors beyond our control. We will regularly evaluate our REO reserve estimates. This may be done in conjunction with additional exploration drilling programs. The estimates of REO reserves as to both quantity and quality will also be updated to reflect new drilling or other data received. Estimates of economically recoverable REO reserves, however, necessarily depend upon a number of variable factors and assumptions, all of which may vary considerably from actual results, such as:

•geological, mining and processing conditions and/or effects from prior mining that may not be fully identified by available data or that may differ from experience;

•the strategic approach to mining and processing the deposit may change depending upon market demand, corporate strategy and other prevailing economic conditions;

•assumptions concerning future prices of rare earth products, foreign exchange rates, process recovery rates, transportation costs, operating costs, capital costs, and reclamation costs; and

•assumptions concerning future effects of regulation, including the issuance of required permits and taxes by governmental agencies and foreign government policy relating to import or export of rare earth products.

Actual REO tonnage recovered from identified REO reserves and revenues and expenditures with respect to the same may vary materially from estimates. Further, period-to-period, our future estimates of REO reserves may fluctuate significantly as macroeconomic conditions and our level of understanding with respect to the deposit change. These estimates may not accurately reflect our actual REO reserves. Any inaccuracy in our estimates related to our REO reserves could result in lower-than-expected revenues and higher-than-expected costs.