Dual-listed Lithium Americas will rapidly develop its large-scale lithium project in northern Nevada, as it moves to become the leading source of lithium production in the US, the company said on Thursday, announcing the outcomes of a preliminary feasibility study (PFS) for the Thacker Pass project.

The PFS demonstrates that the project, which will be developed in two phases, could produce 60 000 t/y of battery-grade lithium carbonate (Li₂CO₃).

Phase 1 will require $581-million for a 30 000 t/y operation and at $12 000/t for battery grade Li₂O₃ is expected to generate sufficient cashflow to fully fund the $478-million required for Phase 2, Lithium Americas said in a statement.

“As a large US-based lithium project with strong economics, we expect Thacker Pass to attract significant strategic partnership opportunities to accelerate the path to production,” said Lithium Americas president of North American operations, Alexi Zawadzki.

Assuming a price of $12 000/t of battery-grade Li₂CO₃, the PFS delivered an after-tax internal rate of return of 29.3% and an after-tax net present value of $2.6-million at an 8% discount.

The PFS contemplates a Phase 1construction start date of 2020, with lithium production beginning in 2022. Phase 2 construction will start in 2025, with additional production entering the market by 2026.

Although not contemplated in the PFS, Lithium Americas said that Phase 2 could be redesigned to increase production capacity, based on market conditions.   

The project will be developed as an openpit mining operation with a 46 year mine life. The ore will be processed in a leaching circuit using sulphuric acid to liberate the lithium from the claystone. Following the leaching process, the lithium bearing solution will be purified using crystallisers and reagents to produce battery-grade Li₂CO₃.

Lithium Americas is proposing to build a 5 280 t/d conventional sulphuric acid plant on site.

The company said the onsite production of sulphuric acid is a major contributor to the positive economics of the PFS, as the plant will produce excess sulphuric acid that will be sold, as well as electricity from a “captive” cogeneration sulphur-burning acid plant. The 2 640 t/d acid plant proposed for Phase 1 will generate 35 MW of electricity.

The average life of mine operating costs are estimated at $2 570/t of Li₂CO₃, net credits from sulphuric acid and electricity sales. The average LoM all-in sustaining costs, including royalties and sustaining capital costs, are $3 043/t.

The PFS supports a proven and probable reserve estimate of 179.4-million tonnes of ore with an average grade of 3 283 parts per million lithium containing 3.1-million tonnes of lithium carbonate equivalent.

Lithium Americas has collaborated with Ganfeng Lithium to develop and test the process flowsheet.