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 prefeasibility study.

The US Department of Energy has said it will lend ioneer up to $700-million to develop the mine.

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

Latest Developments
US President Joe Biden has published a key environmental report for ioneer's Rhyolite Ridge lithium mine, the last step needed before approving what will become one of the largest US sources of the electric vehicle battery metal.

The move comes after a review process of more than six years and as part of Washington's ongoing efforts to boost domestic critical minerals production and offset China's market dominance. If approved, the mine would be the first lithium project permitted by Biden officials.

The final environmental-impact statement sets in motion a review period of at least 30 days before a record of decision can be issued. The US Bureau of Land Management (BLM) has  also published an opinion on how a rare flower – Tiehm's buckwheat flower – at the mine site can best be protected.

The flower is found nowhere else in the world and was declared an endangered species in 2022. The Center for Biological Diversity (CBD) and some other conservation groups thus oppose the project, making it an area of contention in the debate about whether biodiversity matters more than the fight against climate change.

The BLM has worked with the US Fish and Wildlife Service and the company to craft "significant protections for the plant", including changing mine design plans and propagation efforts that include construction of a greenhouse and hiring botanists.

The CBD has said it is disappointed that Washington "continues to subvert public engagement on this mine by . . . failing to back up any of its assertions."

The death of more than 17 000 flowers near the mine site in 2020 sparked allegations of a "premeditated" attack. Australia-based ioneer denied harming the flowers. The government later blamed thirsty squirrels.

South Africa's Sibanye-Stillwater agreed in 2021 to buy half of the project for $490-million, but only when permits are obtained.

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.