The mineral resource estimate at Lithium Americas Corp.’s Thacker Pass lithium project in Humboldt County, Nevada, has increased to 13.7 million metric tons (mt) of lithium carbonate equivalent (LCE) grading 2,231 parts per million lithium (ppm Li) of measured and indicated and 4.4 million mt of LCE grading 2,112 ppm Li of inferred resources.

“The world needs more large-scale and environmentally responsible lithium projects to enable the clean energy transition,” President and CEO Jonathan Evans said.

The bulk of the increase in the mineral resource tonnage is primarily due to change in cut-off grade, a decision the company said was driven by market demands and supported by changes made to the process flowsheet, and to comply with updated Canadian Institute of Mining and Metallurgy (CIM 2019) best practice guidelines.

The company said the updated mineral resource estimate does not constitute a material change and does not affect the integrity of the resources and reserves used in the preliminary feasibility study for Thacker Pass.

Lithium Americas continues to advance the ongoing feasibility study targeting an increased initial production capacity to 40,000 mt/y of lithium carbonate (Phase 1) from the previously announced 30,000 to 35,000 mt/y. The increased target capacity reflects optimizations to the mine plan and leaching efficiencies, maintaining the same proposed 3,000-mt/d sulfuric acid plant and water usage. The company is continuing to optimize engineering to complete the capital cost estimate and incorporate the impact of inflationary pressure, permit requirements and an increase in processing equipment.

In addition, the company plans to include an expansion scenario to target total capacity of 80,000 mt/y of lithium carbonate. The 40,000-mt/y expansion (Phase 2) is designed to demonstrate Thacker Pass’ ability to scale production and align with potential customers’ and partners’ longer-term demands. The Phase 2 expansion scenario would entail additional time required to amend and meet permitting requirements beyond Phase 1.

To meet potential customer and partner needs, the company continues to also advance engineering to consider an option for a 20,000-mt/y lithium hydroxide chemical conversion plant.