Name of the Project
Rhyolite Ridge lithium/boron project.

Location
Nevada, in the US.

Project Owner/s
ioneer, formerly 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.

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

Planned Start/End Date
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
Battery-grade lithium hydroxide has been successfully produced from the Rhyolite Ridge project using standard commercial processes.

The testwork, undertaken by lithium processing technology group Veolia Water Technologies, confirmed the key flowsheet parameters for the project and completed the key steps of the definitive feasibility study (DFS).

The testwork has confirmed that Rhyolite Ridge will be able to produce a range of products at the mine site, including boric acid, lithium carbonate and lithium hydroxide, ioneer MD Bernard Rowe has said.

The DFS is evaluating the range of potential Rhyolite Ridge lithium products to determine which provides the most commercial benefits. The study will be completed in the third quarter.

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.