Name of the Project
Rhyolite Ridge lithium/boron project.

Location
Nevada, US.

Project Owner/s
In September 2021, Sibanye-Stillwater entered into an agreement with ioneer to establish a joint venture (JV) company with respect to Rhyolite Ridge. Following the satisfaction or waiver of all conditions precedent, Sibanye-Stillwater will acquire a 50% interest in the JV, with ioneer maintaining a 50% interest and retaining the operational management responsibility for the JV.

Project Description
A definitive feasibility study (DFS), completed in April 2020, has placed Rhyolite Ridge as the single-most attractive project for the production of lithium carbonate, lithium hydroxide and boric acid globally.

The lithium and boron mineral resource is estimated at 146.5-million metric tonnes, including an ore reserve of 60-million metric tonnes, an increase in the reserve from the previous estimate of 280% over the 26-year life-of-mine (LoM).

The mine plan comprises almost entirely reserve material, with nearly 50% of that being proven ore reserves.

The resource remains open in three directions, allowing for a potential extension to the LoM.

The project will mine 2.5-million metric tons a year of ore over the LoM to produce about 20 600 t/y of lithium carbonate, or about 22 000 t/y of lithium hydroxide and 174 400 t/y of boric acid, on average.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
The project has an after-tax net present value, at an 8% real discount rate, of $1.265-billion and an unlevered internal rate of return of 20.8%, with a payback of 5.2 years from the start of first production.

Capital Expenditure
The DFS estimates that the total capital expenditure to complete the project will be $785-million, including an 8% contingency.

This represents an increase of $186-million from the PFS.

Planned Start/End Date
ioneer expects to start production in 2025 to support urgent requirements for battery materials in the US.

Latest Developments
The Bureau of Land Management (BLM) has issued a trespass notice to Australia-based ioneer for the unauthorised use of certain Tiehm’s buckwheat habitat at the Rhyolite Ridge lithium project.

The areas were being used as a laydown area for geotechnical drilling operations associated with collection of subsurface data.

BLM says its November 2022 approval of ioneer’s application for the drilling operations directed that all disturbance pertaining to drilling activities be conducted outside of areas identified as critical habitat for Tiehm’s buckwheat – a plant listed as endangered by the US Fish and Wildlife Service.

ioneer confirmed the permit breach and said the placement and storage equipment along Cave Springs road was not authorised under the permit issued by the BLM.

The company emphasised that it was a violation of BLM regulatory requirements, but that no Tiehm’s buckwheat was disturbed.

“We take full responsibility for the breach and sincerely regret the inadvertent noncompliance with the permit. Since day one, ioneer has instructed our staff and contractors about the need to observe all permit conditions. We are investigating exactly how this failure occurred, and we will take action to assure total compliance in the future,” MD Bernard Rowe has said.

Key Contracts, Suppliers and Consultants
Fluor (DFS).

Contact Details for Project Information
ioneer, tel +61 2 9922 5800.
Sibanye-Stillwater, tel +27 11 278 9600 or email ir@sibanyestillwater.com.