ioneer Quadruples Rhyolite Ridge Reserves, Secures US$996M DOE Loan

A Major Reserve Upgrade

ioneer Ltd has announced a significant milestone for its Rhyolite Ridge lithium-boron project in Nevada, USA, with ore reserves more than quadrupling from 60 million tonnes to 247 million tonnes. This substantial increase underpins a projected mine life of 95 years, positioning Rhyolite Ridge as one of the longest-life lithium projects globally. The updated reserve figures reflect the company’s ongoing exploration success and resource definition efforts, reinforcing the project's strategic importance in the U.S. critical minerals landscape.

Robust Economics Amid Market Challenges

Despite prevailing weak lithium prices, ioneer’s updated economic assessment confirms the project's resilience. The unlevered net present value (NPV) stands at US$1.37 billion with an internal rate of return (IRR) of 14.5%, signaling strong financial viability. Average annual EBITDA is forecast at US$406 million, supported by diversified revenue streams from both lithium and boric acid production. Notably, the project’s all-in sustaining cash costs place it in the bottom quartile of the global lithium cost curve, enhancing its competitiveness even in challenging market conditions.

Fully Permitted and De-Risked

Rhyolite Ridge is fully permitted and shovel ready, having received the final federal permit and a positive Record of Decision from the Bureau of Land Management in late 2024. The project benefits from a US$996 million low-cost loan from the U.S. Department of Energy, providing critical financial backing to accelerate development. Offtake agreements are in place with major partners including Ford, EcoPro, PPES, and Dragonfly, securing future sales of lithium and boron products. Engineering design is approximately 70% complete, with Fluor engaged as the EPCM contractor.

Strategic Partnering and Next Steps

To complement the DOE debt, ioneer has engaged Goldman Sachs to lead a strategic partnering process aimed at securing equity financing. This process, expected to take at least four months, seeks a partner to help bring the project into production. The company plans to make a final investment decision once equity and debt financing are secured, with construction anticipated to take around 36 months thereafter. First production is targeted approximately three years post-FID, marking a significant step toward establishing a domestic U.S. lithium and boron supply chain.

A Unique Lithium-Boron Asset

Rhyolite Ridge’s unique sedimentary lithium-boron deposit offers integrated mining and chemical processing with high recoveries and low energy input. The project’s dual revenue streams from lithium carbonate and boric acid provide a natural hedge against commodity price volatility, enhancing economic stability. With a large and expandable resource base exceeding 510 million tonnes, the project holds substantial potential for future growth beyond the initial stage production of 2.6 million tonnes per annum.