This report is based on public company disclosures, filings and announcements reviewed by GSN; figures are as stated by the company and have not been independently verified.

The headline of a mining announcement is usually a promise of scale. The footnote is where the promise meets the rock. Rimfire Pacific Mining (ASX: RIM) has released data on scandium recovery from its Murga deposit in central New South Wales, and the numbers on the surface look encouraging. The fine print, however, reveals a process that is still in its infancy, relying on a fifteen-week test to project results over a full year. The company is betting that patience in the lab can translate into lower capital costs in the field, but the gap between a bottle roll and a commercial heap is wide.

Rimfire Pacific Mining said it is making progress with Stage 2 (long-term) bottle roll testing on low-iron host rock samples from Murga. The work used simple leaching at atmospheric pressures and ambient temperatures, a method the company describes as cost-effective. The tests were run on a 0.74 kilogram sample of saprolite-hosted scandium material and a 1 kilogram sample of laterite-hosted material. At the end of fifteen weeks, the company reported scandium recoveries of 22.7 percent from the saprolite and 15.2 percent from the laterite.

The company’s projection, which is the part of the document that carries the most weight, suggests these recoveries could rise to at least 60 percent for saprolite and 30 percent for laterite if the extraction rate holds over a longer, more commercially realistic timeframe such as 365 days. The filing notes that heap leaching of deposits with similar mineralogy typically takes between 100 and 400 days. Rimfire Pacific Mining also highlighted that acid consumption was low, at 0.34 tonnes per tonne of saprolite and 0.23 tonnes per tonne of laterite. The pregnant leach solution from the saprolite showed a high scandium-to-iron ratio of 2.24 milligrams of scandium per gram of iron, which the company says could ease downstream separation.

This announcement is a step in Rimfire Pacific Mining’s effort to assess the viability of extracting scandium from the Murga deposit. The company is testing whether scandium can be recovered from these rocks using less complex and less capital-intensive atmospheric leaching technologies. The company describes the work as part of a metallurgical study it calls key to unlocking value from Murga, and suggests that the low-iron host rocks at Murga are a potential differentiator compared to other deposits in the area. The company’s executive chair, Bronwyn Barnes, said the data demonstrated that scandium is continuing to be successfully recovered via bottle roll leaching at atmospheric pressures. She called the deposit’s low-iron host rocks a potential gamechanger.

The thread connecting this announcement to the company’s broader story is the search for a low-capital processing route. Scandium is a critical mineral, and demand is accelerating across advanced manufacturing, AI data centres, defence, and aerospace, according to the company. Rimfire Pacific Mining believes it is well positioned to capitalise on this opportunity. The current work is designed to determine if atmospheric leaching can unlock value from Murga without the complexity of more intensive processing technologies.

If the fifteen-week recovery rate remains linear over a full year, the case for a lower-capital processing route would be stronger. This could allow Rimfire Pacific Mining to pursue a simpler processing circuit, reducing the capital intensity of the project. If the acid consumption remains low and the scandium-to-iron ratio holds, downstream separation might be easier, potentially improving the purity of the final product. The signpost to watch is further testing, where the company will need to demonstrate that the linear extrapolation holds true at a larger scale.

This desk’s reading is that the data is promising but preliminary. The projection of 60 percent recovery is based on maintaining the rate observed in fifteen weeks over a full year. The document does not provide data on what happens after the first year, or how the rate might change as the ore is depleted. The disclosure does not describe any testing beyond the bottle roll samples. The company is relying on extrapolation to bridge the gap between the lab and the mine. To our eye, the low acid consumption and high scandium-to-iron ratio are the most interesting parts of the disclosure, as they point to potential operational efficiencies. The headline recovery numbers are secondary to the processing economics.

What to watch includes whether longer leaching bears out the 365-day projection and whether any larger-scale testing follows. The company will need to demonstrate that the linear response observed in the bottle roll tests holds at a larger scale. A larger leach test would be one way to confirm the recovery rates and acid consumption. The company will also need to address the lower recovery in laterite, which it attributes to other minerals consuming more acid. How far Murga advances will depend on the results of this longer-term work.

Sources