Mount Ridley Mines Achieves 91.8% Scandium Recovery in Selectro Test 3

Mount Ridley Mines (ASX: MRD) achieved a scandium recovery rate of 91.8% in the final phase of its Selectro™ testing program at the Grass Patch project in Western Australia. This result was obtained using only half the reagent dose applied in previous trials, marking a significant improvement in process efficiency. The company notes that this performance exceeds the 88% recovery assumption cited by Sunrise Energy Metals and the 70-80% range disclosed by Scandium International.

The trial utilized unbeneficiated ore under atmospheric pressure and low-temperature conditions, reaching maximum recovery in under four hours. Heavy rare earths averaged 84% recovery, while light rare earths reached 77%. According to Cashu Research, a division of Cashu Group, this is the highest published scandium leach recovery from a listed developer, offering a lower-cost alternative to the high-pressure acid leaching methods typically employed in the sector.

Grass Patch Resource Scale and Location

The Grass Patch deposit contains 47,357 tonnes of scandium within a 946-megatonne resource at a grade of 50.1 parts per million. This volume represents the largest reported scandium resource under the JORC Code. The site also contains gallium and heavy rare earths, minerals designated as critical by the United States due to supply chain concentration in China.

Located approximately 25 kilometers from the port of Esperance, the project benefits from direct logistical access to export infrastructure. The proximity reduces transport costs and supply chain complexity compared to inland deposits, a factor that enhances the commercial viability of processing lower-grade feedstocks that might not justify the capital expenditure of traditional autoclave systems.

Validation Steps and Patent Status

The Selectro™ technology is wholly owned by Mount Ridley Mines and currently holds patent-pending status. The company has identified validation using third-party feed materials as the immediate next step in its development roadmap. This phase aims to confirm that the high recovery rates observed at Grass Patch are reproducible across different ore compositions, a critical requirement for securing offtake agreements and financing.

The research note highlights that such efficiency gains could make processing economically feasible for ore streams previously deemed too low-grade for standard high-pressure methods. By reducing reagent costs and eliminating the need for high-temperature autoclaves, the process lowers the operational barrier to entry for scandium production. Mount Ridley Mines continues to advance the project, with the next phase focused on demonstrating consistent performance across varied geological inputs.