お知らせ • Mar 12
Lithium Argentina AG Announces Updated Mineral Resource and Reserve Estimate for Cauchari-Olaroz Brine Operation
Lithium Argentina AG announced an updated mineral resource and reserve estimate on the Cauchari-Olaroz brine operation in Jujuy Province, Argentina. The Updated Estimate was completed by Aquatec and Groundwater Insight Inc. with an effective date of December 31, 2025, focused on expanding the resource footprint, incorporating production data and utilizing a basin-wide hydrological model designed to support the Cauchari-Olaroz Stage 2 development plans. Expanding on the Stage 1 operating capacity of 40,000 tonnes per annum of lithium carbonate equivalent, Stage 2 targets an additional 45,000 tonnes per annum of lithium carbonate equivalent. The Company plans to file a technical report including the Updated Estimate during March 2026. Increased Measured and Indicated resource estimate by 42% to 28.1 million tonnes of lithium carbonate equivalent. Updated Measured and Indicated resource with an average grade of 562 mg/L lithium (up from 19.9 million tonnes lithium carbonate equivalent at 592 mg/L previously). Inferred resource increased to 9.6 million tonnes lithium carbonate equivalent at an average grade of 567 mg/L lithium (up from 4.7 million tonnes lithium carbonate equivalent at 592 mg/L previously). Updated Estimate incorporates additional drilling and basin wide hydrological model. Expanded resource footprint with new drilling, extending the resource area by approximately 20 km south of previous resource footprint. Incorporates production well sampling data and results of a basin-wide hydrological model to support the Stage 2 development plan. Reserve model aligns with Stage 1 production and reaffirms project life. Reserves updated to align with Stage 1 production of 40,000 tonnes per annum over a 35-year operating period (2026–2060), consistent with the original 40-year project life after accounting for brine inventory and production to date. Advancing Stage 2 development plan targeting additional capacity of 45,000 tonnes per annum lithium carbonate equivalent. The Incentive Regime for Large Investments application for Stage 2 and environmental permits to support additional production capacity were both filed in December 2025. Results of an updated Stage 2 development plan are expected in mid-2026. The Updated Estimate supports Cauchari-Olaroz’ large-scale and high-quality lithium brine resource. Total Measured and Indicated resources increased lithium carbonate equivalent estimates by 42% compared to the 2019 estimate, including a significant increase in Measured resources reflecting additional drilling, incorporation of operating data, increased resource area and basin-wide hydrogeological modeling. The improved geological and aquifer understanding strengthens confidence in the resource base and supports the ongoing development planning for Stage 2. The Updated 2026 Mineral Resource and the 2019 Mineral Resource for Cauchari-Olaroz, on a 100% basis, are summarized in the table below. Category Cauchari-Olaroz 2019 Cauchari-Olaroz 2026 Change Li (mg/L) LCE (Mt) Li (mg/L) LCE (Mt) LCE (%) Measured 591 3.6 557 16.8 367% Indicated 592 16.3 571 11.3 -31% Total Measured and Indicated 592 19.9 562 28.1 42% Inferred 592 4.7 567 9.6 104%. A lithium grade cutoff of 300 mg/L is used to define the Mineral Resource Estimates in both 2019 and 2026. Mineral Resources are also expressed in the industry standard Lithium Carbonate Equivalent (LCE = Lithium × 5.323). The mass of lithium produced from 2018–2025 period (52,786 tonnes = 280,982 tonnes lithium carbonate equivalent) has been removed from the 2026 Mineral Resource Estimate. The Mineral Resource Estimate is not a Mineral Reserve Estimate and does not have demonstrated economic viability. There is no certainty that all or any part of the Mineral Resources will be converted to Mineral Reserves. Long-term lithium carbonate price assumed for the evaluation of the Mineral Resources is $18,000/tonne. Calculated brine volumes only include Measured, Indicated and Inferred Mineral Resource volumes above cut-off grade. The Mineral Resource Estimate has been classified in accordance with CIM Mineral Resources definitions and best practice guidelines (2012 and 2014). Comparisons of value may not add due to rounding of numbers and the differences caused by use of averaging methods. The mineral resources are presented on a 100% basis. The Technical Report includes an updated Mineral Reserve estimate of 1.4 million tonnes of lithium carbonate equivalent reflecting the existing Stage 1 operation plan with a capacity of 40,000 tonnes per annum. The project life supports an additional 35-year operating period using the existing production wells from 2026 through 2060 consistent with the previous 40-year project life after incorporating past brine production and existing brine inventory. The estimate incorporates updated hydrogeological modeling and brine production data since 2018, further strengthening confidence in the long-term performance of the basin and supporting continued development. Proven reserves in the 2026 estimate increased by approximately 45% compared to the 2019 estimate, primarily due to a longer period assigned to proven production, based on improved geological and hydrogeological understanding of the Cauchari-Olaroz system. Total Proven and Probable reserves decreased by approximately 28%, as the updated estimate reflects only the brine required to support the Stage 1 operation of 40,000 tonnes per year of lithium carbonate equivalent over a 40-year mine life. The 2019 Reserve estimate assumed a higher production capacity of 48,800 tonnes per year of lithium carbonate equivalent, a larger wellfield, and the full 40-Year production period (part of which has now passed) resulting in a larger reserve base at that time. The 2026 Reserve estimate excludes any production associated with a potential Stage 2 expansion or production capacity beyond Stage 1. Results from the basin-wide hydrological model and the updated Mineral Resource estimate will be incorporated into the Stage 2 development plan, with an update targeted for mid-2026. The updated Mineral Reserve for Cauchari-Olaroz, on a 100% basis, is summarized in the table below. Category Cauchari-Olaroz 2026 Production Period (Yr) Brine Pumped (m3) Average Li Concentration (mg/L) Lithium Metal (tonnes) LCE (Mt) Proven 0 through 10 227,782,565 588 75,315 0.4 Probable 11 through 35 526,320,091 572 190,463 1.0 Total Proven and Probable 35 754,102,655 580 265,779 1.4. The 2026 Mineral Reserve Estimate has an effective date of January 1, 2026. The 2026 Mineral Reserves were estimated using 63.0% of process efficiency. Long-term lithium carbonate price assumed for the evaluation of the 2026 Mineral Reserves is $18,000/tonne. Operating costs are estimated at $5,411/tonne. LCE is calculated using mass of LCE = 5.322785 multiplied by the mass of Lithium Metal.