The Thacker Cross lithium challenge is an open-pit mine being developed in Humboldt County, Nevada, US, by Lithium Americas, a Canada-based lithium growth firm. It’s claimed to be the biggest recognized lithium useful resource within the US.
It is going to have a manufacturing capability of 40,000 tonnes every year (tpa) in Section I and a manufacturing capability of 80,000tpa within the second part.
The ultimate environmental impression assertion (EIS) for the challenge was filed in December 2020 whereas a report of resolution (ROD) from the US Bureau of Land Administration was obtained in January 2021.
The feasibility examine (FS) for the challenge was accomplished in November 2022. It confirmed a two-phase growth with a mine lifetime of 40 years.
The development works of the challenge commenced in March 2023. Section I of the challenge is estimated to contain a capital funding of $2.93bn, with manufacturing anticipated to start in 2027.
Thacker Cross lithium challenge location
The Thacker Cross lithium challenge is positioned roughly 100km north-northwest of Winnemucca and 33km west-northwest of Orovada, Nevada.
The mine spans an space of roughly 4,236ha.
Geology and mineralisation particulars of Thacker Cross challenge
The mine is positioned throughout the extinct, 30km × 45km McDermitt Caldera supervolcano. This volcanic subject is a part of a southeastward-propagating volcanic pattern that extends from Steens Mountain into north-central Nevada.
Alluvium with a median thickness of roughly 5m caps the lithium-rich clays throughout the deposit. The underlying sedimentation is an intra-caldera rhyolite tuff whereas basaltic lavas and ash layers are intercalated with the lacustrine sediments at irregular intervals.
The mineralisation on the higher clay horizons is majorly composed of smectite-type clay whereas illite-type clay dominates the deeper horizons.
Reserves at Thacker Cross
The Thacker Cross challenge is estimated to include confirmed and possible mineral reserves of roughly 217.3 million tonnes (mt) of lithium carbonate equal (LCE) grading 3,160 components per million (ppm) of lithium, as of November 2022.
Mining strategies at Thacker Cross lithium challenge
The Thacker Cross operations will make use of open-pit mining utilizing a modified panel mining technique with excavators and floor miners.
The pit design includes a shallow pit with a most pit depth of 120m, which can be mined in blocks with 5m-long benches at a strip ratio of 1.6:1. Mining can be carried out in a sequential method with one block mined at a time whereas the beforehand mined space can be backfilled. It is going to have a bench width of 50m and a peak of 5m.
The mining fleet consisting of 91t class finish dump vans loaded by two 18t class hydraulic excavators in 5 passes was chosen.
Ore processing particulars at Thacker Cross challenge
The run-of-mine (ROM) ore can be transferred to a toothed roll crusher and blended with filter wash resolution in attrition scrubbers to take away clay. The ore slurry can be transferred to the leaching circuit the place stirred reactors will leach the slurry to provide a lithium brine by filtration.
The processing plant will separate lithium from the remaining salts akin to magnesium, potassium and sodium within the brine. The lithium brine will bear crystallisation of magnesium sulphate, adopted by the elimination of residual magnesium by including quicklime.
Lithium from the brine can be precipitated as a carbonate stable with the addition of soda ash. Magnesium sulphate is faraway from the lithium brine by a magnesium sulphate evaporator and crystalliser.
The purified lithium brine can be transferred to a lithium carbonate precipitation circuit to provide lithium carbonate solids, which can be filtered and washed with water. The ensuing purified lithium carbonate can be dried earlier than it’s packaged for cargo to prospects.
Website infrastructure at Thacker Cross website
The Thacker Cross lithium challenge is linked to State Route (SR) 293 freeway by way of an asphalt paved entry street.
The uncooked water provide can be from a sequence of wells within the Quinn River Valley utilizing electrical submersible effectively pumps to pump water to a floor pump station. Two booster pump stations will pump the water to the processing facility by means of a 12km-long pipeline. The uncooked water may also be handled to provide potable water that can be saved on-site.
The ability provide required for the operations is envisaged to be equipped from the Harney Electrical grid utilizing a 115kV transmission line that runs instantly by means of the positioning.
Mission financing particulars
Lithium Americas obtained a conditional dedication from the US Division of Power (DOE) for a mortgage of $2.26bn beneath the Superior Expertise Automobiles Manufacturing (ATVM) Mortgage Program in March 2024.
The mortgage, along with a strategic funding from Common Motors Holdings (GM), is predicted to supply a lot of the capital required to fund Section I.
Contractors concerned
The PFS was ready by Advisian Americas, a division of Australian engineering firm Worley. Advisian supplied the design of the mine, processing plant, and challenge infrastructure.
Market professional World Lithium was chosen to conduct a market examine and worth projection for lithium carbonate for the challenge. Chemetics supplied the design of the sulphuric acid plant and the related infrastructure. Different contractors that supported the PFS embrace Nice Basin Environmental Companies and Mining-Plus.
Sawtooth Mining, a subsidiary of mining and pure sources firm The North American Coal, was appointed as contract miner for the Thacker Cross challenge in September 2019. The corporate is liable for mine engineering, building, operation, and reclamation companies in addition to the provision of sure gear.
US-based building companies firm The Industrial Firm (TIC) was awarded the design and construct contract. It’s liable for the general value estimate within the definitive feasibility examine, in addition to the engineering design of the plant, water provide and electrical infrastructure, and normal website works.