Mount Ridley's Selectro process delivers strong critical-mineral recoveries

Mount Ridley Mines Limited (ASX: MRD) has released initial metallurgical testwork results from historical drill samples taken from the Grass Patch Complex. The work used the company’s wholly owned Selectro™ leach process. The ASX announcement is dated 12 August 2026.

The testwork was unoptimised and bench-scale. Selectro was applied to unbeneficiated composite material and compared with a hydrochloric-acid baseline. This setup is important because the reported results come before the process and material preparation steps that Mount Ridley says are planned for further work.

The announcement presents the results as an initial comparison between Selectro and the HCl baseline. It does not describe a completed flowsheet or an optimised commercial process. Instead, it provides an early indication of how the wholly owned process performed against the selected historical material under the test conditions.

Heavy rare earth recoveries came in at 77–83%, including terbium, dysprosium and yttrium. Light rare earth recoveries were 70–77%, including neodymium and praseodymium. Scandium recovery was 80%. Gallium averaged 56%, compared with zero recovery from the HCl baseline under the same test conditions.

The reported results cover heavy rare earths, light rare earths, scandium and gallium. The rare-earth results are shown as ranges, while scandium is reported as a single recovery and gallium as an average recovery. This presentation gives investors several separate points of comparison rather than one combined recovery figure.

The gallium result is particularly distinct within the supplied data because the Selectro result is set against zero recovery from the comparative HCl baseline under the same test conditions. The rare-earth and scandium results also show that the process recovered material across the mineral categories included in the testwork.

Mount Ridley said Selectro delivered more than double the average recovery of the comparative HCl leach across its rare earth, scandium and gallium basket. That is the central comparative message in the announcement. The company is presenting Selectro not only as a process that produced recoveries, but as one that outperformed the selected baseline across the reported basket.

The comparison should still be read alongside the testwork conditions. The material was unbeneficiated, the work was unoptimised and the results were generated at bench scale. The announcement therefore frames the outcome as an early-stage result rather than a final statement on process performance.

The company describes Selectro as a closed-loop system designed to lower reagent costs and improve environmental performance relative to conventional hydrometallurgical approaches. Those are the stated design objectives of the process. The supplied recovery results, however, are initial metallurgical outcomes and do not by themselves establish whether those objectives have been achieved at a later development stage.

The source explicitly says the results were achieved before beneficiation, reagent optimisation or process optimisation. That qualification is central to interpreting the reported percentages. It means the announcement is providing an early testwork signal from unbeneficiated material, while leaving several development steps still to be addressed.

For retail investors, the distinction between a promising initial result and a developed process is important. The reported recoveries provide the core evidence in this update, while the absence of beneficiation and optimisation means the announcement is best understood in the context of ongoing technical work rather than as a completed project outcome.

Further programs are planned around beneficiation, recycling reagents and downstream product development. Mount Ridley is also assessing potential third-party licensing pathways. These workstreams extend beyond the initial recovery comparison and indicate the areas in which the company intends to develop the process further.

Beneficiation and reagent recycling are specifically identified as future work areas, while downstream product development points to activity after the initial leach stage. The potential licensing pathway adds a separate commercial-development angle, although the supplied announcement does not provide an outcome for that assessment.

Taken on its own terms, the market insight is about the strength of an early Selectro test on historical Grass Patch material. The process produced the reported heavy rare earth, light rare earth, scandium and gallium recoveries before beneficiation or optimisation, and Mount Ridley said the comparative result was more than double the average recovery of the HCl leach across the basket.

The balance of the announcement is its early-stage qualification. Further work on beneficiation, reagent recycling, process optimisation and downstream product development will determine how the initial bench-scale results develop, while the company continues to assess potential third-party licensing pathways.