Rimfire Advances Murga Scandium Extraction with Atmospheric Leach Testing

Testing a Cheaper Route for Scandium Recovery

Rimfire Pacific Mining (ASX:RIM) has kicked off a metallurgical study focused on unlocking the economic potential of its Murga Scandium Deposit by testing whether low iron scandium mineralisation can be extracted using atmospheric pressure leaching. This approach, if successful, could sidestep the more capital intensive and complex high pressure acid leaching (HPAL) methods currently considered for other Fifield district deposits.

The study, conducted by Perth-based Simulus Laboratories under metallurgical consultant Boyd Willis, commenced with bottle roll leach testing on representative samples from Murga. These tests simulate leaching kinetics and reagent consumption at atmospheric pressure, providing early insight into recovery feasibility. Rimfire expects initial results by late June 2026, which will guide further optimisation work planned for the September quarter.

Murga’s Low Iron Advantage in a Crowded Scandium Field

Murga stands out in the Fifield Scandium District for its relatively low iron content, around 16% Fe compared to deposits like Rio Tinto’s Burra with roughly double that iron grade. This compositional difference matters because high iron levels complicate extraction and drive up costs. Rimfire’s Managing Director David Hutton highlighted that Murga’s low iron scandium represents a potential technical breakthrough, offering a pathway to less costly atmospheric tank or vat leaching techniques.

With an inferred mineral resource of 56.1 million tonnes at 138ppm scandium (equivalent to 11,900 tonnes of scandium oxide), Murga significantly bolsters Rimfire’s global scandium inventory, which now totals 16.2 kilotonnes of scandium oxide across its Fifield assets. This scale positions Rimfire among the district’s leading scandium players, alongside neighbours such as Sunrise Energy Metals and Australian Mines.

Regional Growth and Resource Expansion Prospects

Rimfire’s recent resource upgrade at Murga, which tripled its size to 56.1Mt, forms the foundation for this metallurgical push, building on the company’s strategy to expand its scandium footprint. The company also owns the Rabbit Trap Project about 40 kilometres north, where the Malamute Scandium Prospect offers further upside potential. Recent drilling and acquisition moves have consolidated Rimfire’s position in the region, with the Malamute prospect showing promising mineralisation over a sizable area.

These developments follow Rimfire’s acquisition of Rabbit Trap and the validation of historic mineralisation at Broken Hill, reflecting a broader push to build a diversified scandium and base metals portfolio. The metallurgical study at Murga is a key step in realising value from these resources by potentially lowering capital requirements through simpler extraction methods.

Next Steps and Market Implications

Following the initial bottle roll tests, Rimfire plans a second stage involving further atmospheric leaching experiments such as agitated or vat leach techniques, depending on particle size and initial results. The company aims to complete this phase by late September 2026, with the goal of establishing whether Murga’s low iron scandium can be economically recovered without resorting to HPAL.

This metallurgical work could materially affect project economics and investor sentiment, given the potential cost savings and reduced technical complexity. However, results remain preliminary, and economic viability is not yet confirmed. The study’s progress will be closely watched as it could reshape the competitive landscape of scandium supply in Australia.

Rimfire’s efforts to grow its scandium inventory and refine extraction methods come amid a rising global interest in scandium for advanced alloys and clean energy technologies. How the company navigates these metallurgical challenges will be critical to its ambitions and market positioning over the coming months.

Rimfire’s metallurgical testing builds on its recent tripled Murga scandium resource and consolidates its foothold with the Rabbit Trap project acquisition, setting the stage for a potentially transformative phase in its scandium development strategy.