Name of the Project
Rhyolite Ridge lithium/boron project.

Location
Nevada, in the US.

Client
Global Geoscience.

Project Description
Rhyolite Ridge is a hard-rock lithium and boron project with a high-grade lithium/boron resource of 121.4-million tonnes.

The results of a prefeasibility study (PFS) have confirmed the project’s scale, competitive forecast cash operating costs, robust operating margins, long life and exceptional economics.

The PFS is based on an openpit mining operation, with the ore being processed by vat acid leaching, evaporation and crystallisation to produce boric acid and lithium carbonate.

Owner mining is then planned to be undertaken using a mine equipment fleet comprising twenty-one 90 t haul trucks, two excavators, two drills and associated support equipment. The project is expected to produce 20 200 t/y of lithium carbonate and 173 000 t/y of boric acid. The PFS envisages processing lithium/boron (searlesite) mineralisation and stockpiling the lithium-only (clay) mineralisation.

As part of the PFS, two cases were selected for detailed assessment: a 3 500 t/d sulphuric acid plant, with a nominal processing throughput of 2.7-million tonnes a year; and a 4 500 t/d sulphuric acid plant, with a nominal processing throughput of 3.6-million tonnes a year. The 3 500 t/d sulphuric acid plant has been selected as the base case scenario for the PFS. The plant will provide acid for leaching, steam for evaporation and 47 MW of power, which meet the operation’s operational requirements and allow for excess power to be sold.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
The project has a pretax net present value at a 7% discount rate, of $2.22-billion and an internal rate of return of 29.8%, with a payback of four years from the start of operations.

Value
Initial capital expenditure is estimated at $426-million, including indirect costs and contingency, plus $173-million for a lump sum turnkey sulphuric acid plant.

Duration
Subject to all approvals being acquired, construction could start in the third quarter of 2019, with first ore to be processed in the third quarter of 2021.

Latest Developments
Over the next few months Global Geoscience will appoint an engineering firm for the definitive feasibility, which is expected to be completed in the third quarter of 2019.

Key Contracts and Suppliers
Amec Foster Wheeler (PFS).

On Budget and on Time?
Too early to state.

Contact Details for Project Information
Global Geoscience, tel +61 2 9922 5800.