Rimfire’s Murga Deposit Shows Potential for Low-Cost Scandium Extraction

Encouraging Early Metallurgical Results from Murga

Rimfire Pacific Mining (ASX:RIM) has unveiled promising early results from its metallurgical study on the Murga Scandium Deposit, located in the Fifield District of New South Wales. The initial 14-day bottle roll tests suggest scandium recoveries between 60% and 90% could be achievable at atmospheric pressures, a significant technical milestone given the deposit’s low iron content.

These tests, the first of their kind on Murga’s mineralised material, involved leaching laterite and saprolite samples at ambient temperature and pressure. The relatively constant rate of scandium extraction during the test, coupled with low iron dissolution, a major acid consumer, indicates that atmospheric heap leaching could be a viable and less capital-intensive alternative to the high pressure acid leaching (HPAL) methods typically required for high iron scandium deposits.

Building on a Potentially Game-Changing Extraction Method

Murga’s inferred mineral resource estimate stands at 11,900 tonnes of scandium oxide, contributing to Rimfire’s total Fifield scandium inventory of over 16,000 tonnes. The low iron grade, approximately 16% Fe compared to over 30% Fe at nearby deposits like Rio Tinto’s Burra, positions Murga uniquely within the region, potentially enabling simpler processing.

Following the encouraging initial results, Rimfire has commenced two extended bottle roll tests running for 160 to 180 days. These longer-term tests aim to generate more comprehensive data on scandium recovery kinetics and acid consumption, essential for confirming the feasibility of atmospheric leaching on a commercial scale.

Under the guidance of metallurgical consultant Boyd Willis, who brings over four decades of experience in hydrometallurgical processes including scandium and nickel laterite ore processing, the study will also explore column (vat) leach tests and agitated tank leach tests. These will simulate full-scale heap leach operations and alternative atmospheric leaching techniques at elevated temperatures, respectively, to further refine extraction strategies.

Strategic Implications for Rimfire and the Fifield Scandium Hub

Rimfire’s Managing Director David Hutton emphasised the significance of these findings, noting that Murga’s low iron scandium could represent a "technically commercial breakthrough". The potential to extract scandium at atmospheric pressures could reduce capital expenditure and operational complexity compared to HPAL, which is being considered by nearby projects such as Sunrise Energy Metals’ Syerston and Australian Mines’ Flemington deposits.

This development aligns with Rimfire’s broader strategy to build a globally significant scandium resource inventory within the Fifield District, Australia’s emerging scandium epicentre. The company’s focus on advancing metallurgical studies complements recent expansions of its resource base and joint venture arrangements, reinforcing its position in the sector.

While the initial results are encouraging, they remain indicative rather than definitive. The extended bottle roll tests underway will be critical in validating recovery rates and operational parameters. Investors and market watchers will be keen to see how these metallurgical outcomes influence Rimfire’s project economics and development timelines in the coming months.