ASX Announcement — 12 August 2026
Mount Ridley Mines Limited (ASX: MRD) has released initial results from metallurgical testwork on historical drill samples from the Grass Patch Complex, using its wholly owned Selectro™ leach process.
The unoptimised bench-scale work applied Selectro to unbeneficiated composite material and compared the results with a hydrochloric-acid baseline.
Initial recovery results
- Heavy rare earths: recoveries of 77–83%, including terbium, dysprosium and yttrium.
- Light rare earths: recoveries of 70–77%, including neodymium and praseodymium.
- Scandium: recovery of 80%.
- Gallium: average recovery of 56%, compared with zero recovery from the HCl baseline under the same test conditions.
Mount Ridley said Selectro delivered more than double the average recovery of the comparative HCl leach across its rare earth, scandium and gallium basket. The company describes the process as a closed-loop system designed to lower reagent costs and improve environmental performance relative to conventional hydrometallurgical approaches.
The results are early-stage and were achieved before beneficiation, reagent optimisation or process optimisation. Further programs are planned around beneficiation, recycling reagents and downstream product development, while the company also assesses potential third-party licensing pathways.