Ioneer Lifts Rhyolite Ridge NPV 38% to $1.9 Billion with Higher Lithium Production

Optimizing Throughput Without Extra Cost

Ioneer Ltd has unveiled a material improvement in the economics of its 100%-owned Rhyolite Ridge Lithium-Boron Project, located in Nevada, USA. The key driver behind this upgrade is a reduction in the leach retention time from three days to two, enabling the processing of 25% more ore annually without any additional capital expenditure or changes to the plant design.

Bernard Rowe, Managing Director of Ioneer, highlighted that this optimization leverages a more efficient use of sulphuric acid in the vat leaching process, allowing for increased production volumes of both lithium hydroxide and boric acid chemicals. This operational refinement has resulted in a 38% increase in the unlevered life of mine net present value (NPV) to US$1.888 billion and a 16.8% internal rate of return (IRR), underscoring the project's enhanced financial robustness.

Production and Cost Metrics

The updated mine plan supports an average annual lithium hydroxide production of 25,500 tonnes from year three onwards, a 20% increase over previous estimates. Boric acid production is also set to rise by 9% to 126,700 tonnes annually. Importantly, these gains come with an all-in sustaining cash cost estimated at US$5,626 per metric tonne lithium carbonate equivalent, positioning Rhyolite Ridge in the lowest cost quartile globally for lithium producers.

The project benefits from its unique mineralogy, being the only known lithium deposit worldwide amenable to vat and heap leaching, which facilitates on-site production of high-purity lithium and boron chemicals. The stable revenue stream from boron, a commodity with historically low price volatility, adds resilience to the project's financial profile amid fluctuating lithium markets.

Resource and Reserve Confirmation

Independent Mining Consultants, Inc. (IMC) updated the Mineral Resource and Ore Reserve estimates to reflect the new processing parameters. The overall tonnage and grade remain largely consistent with prior announcements, with a modest 2% increase in proven and probable ore reserves. The project’s mine life is projected at 82 years, supported by a substantial reserve base of 260 million tonnes within a total mineral resource of 539 million tonnes.

The project is fully permitted, having secured all critical federal and state approvals, including the Bureau of Land Management’s Record of Decision in October 2024. Additionally, Ioneer closed a US$996 million loan with the U.S. Department of Energy Loan Programs Office, providing a strong financial foundation as the company advances toward a final investment decision and construction phase.

Strategic Importance and Market Outlook

Rhyolite Ridge is strategically positioned to supply the rapidly growing US demand for lithium and boron, critical materials for electric vehicle batteries and various industrial applications. The project has secured offtake agreements with major industry players including Ford Motor Company, Toyota’s Prime Planet Energy & Solutions, and Korea’s EcoPro Innovation.

Market forecasts anticipate lithium demand to grow by more than 15% annually, with battery-grade lithium hydroxide expected to see the most significant growth. Boron demand remains stable and uncorrelated with lithium price cycles, providing a valuable hedge against market volatility. Ioneer’s dual-product strategy enhances the project’s resilience and long-term viability.