Ioneer Ltd reveals promising Falcon gravity concentration testwork results that enhance lithium grade and yield at its Rhyolite Ridge project, underpinning future expansion potential.
- Falcon gravity concentration testwork increases lithium grade by 1.4-2 times
- Mass reductions of 39-72% achieved, improving processing efficiency
- Lithium yield improvements between 45-125% demonstrated
- New mine plan prioritizes high-boron lithium ore with Streams 2 and 3 stockpiled
- Project benefits from substantial boric acid co-product and secured US$996 million DOE loan
Rhyolite Ridge’s Unique Mineralogy and Growth Potential
Ioneer Ltd (ASX:INR, Nasdaq: IONR) has delivered a significant update on its flagship Rhyolite Ridge Lithium-Boron Project in Nevada, highlighting encouraging metallurgical testwork results that could unlock future production growth beyond the initial phase. Central to this progress is the application of Falcon gravity concentration technology on the project’s low-boron lithium mineralisation streams, which has demonstrated substantial improvements in lithium grade, mass reduction, and lithium yield.
Rhyolite Ridge stands out globally not only for its sizeable lithium resource, over 3.97 million tonnes of lithium carbonate equivalent, but also for its substantial boric acid co-product, a rare combination that enhances the project’s economic profile. Ioneer’s Managing Director Bernard Rowe emphasised the deposit’s flexibility and growth optionality, signaling the company’s intent to attract new equity partners as it advances development.
Testwork Highlights and Processing Strategy
The recent testwork focused on Streams 2 and 3, which represent low-boron lithium mineralisation that is currently excluded from the primary vat leach processing plant designed for high-boron ore (Stream 1). Using Sepro’s Falcon gravity concentrator, Ioneer achieved lithium grade increases ranging from 1.4 to 2 times, while reducing the mass of material requiring processing by 39-72%. This beneficiation step not only concentrates lithium but also significantly reduces acid consumption, a key driver of operating costs.
In addition, lithium yield improvements of 45-125% were recorded, indicating more efficient lithium recovery per unit of acid used. These results are preliminary and have not yet been optimized, with further enhancements expected through additional testwork, including a two-step Falcon process to recover lithium from middling tails.
Mine Planning and Economic Implications
Ioneer is finalizing a new mine plan that prioritizes the high-boron Stream 1 ore due to its higher metal value and superior economics. Streams 2 and 3 will be stockpiled within the permitted project boundary, providing optionality for future expansions. The current processing plant is designed for 2.5 million tonnes per annum of high-boron ore but can accommodate some Stream 2 and minor Stream 3 feed.
This strategic stockpiling, combined with the promising beneficiation results, positions Rhyolite Ridge for scalable growth. The project’s recent US$996 million loan from the U.S. Department of Energy and final federal permitting clearance further de-risk the development pathway. Offtake agreements with major automakers and battery suppliers underscore the market’s confidence in the project’s long-term potential.
Looking Ahead
While the testwork results are encouraging, they remain early-stage and require further validation and optimization. The company’s next steps include releasing the updated mine plan and revised project economics, which will incorporate capital and operating cost estimates reflecting these metallurgical advances. Investors will be watching closely for how these developments translate into improved project valuation and financing terms.
Bottom Line?
Ioneer’s metallurgical advances at Rhyolite Ridge set the stage for potential lithium production growth, but execution and optimization remain key.
Questions in the middle?
- How will the updated mine plan balance processing of high- and low-boron ores?
- What timeline does Ioneer envision for deploying expanded processing facilities for Streams 2 and 3?
- How might these testwork results influence negotiations with potential equity partners?