Can BCM Sustain Exceptional ISR Grades as Ema Moves Toward Production?

Breakthrough ISR Leaching Performance

Brazilian Critical Minerals Limited (ASX, BCM) has unveiled outstanding results from its in-situ recovery (ISR) pilot field trials at the Ema rare earth project in Brazil. The company reported pregnant leach solution (PLS) grades reaching as high as 7,800 parts per million (ppm) total rare earth oxides (TREO), a remarkable uplift of more than 14 times the in-situ mineralised grades averaging around 534 ppm. This leap in grade concentration through ISR leaching is being hailed as world-class and positions the Ema project on a fast track towards production.

The ISR process involves injecting a low concentration magnesium sulphate solution into the mineralised clay horizon, which then leaches rare earth elements into solution. The trials demonstrated excellent permeability and leaching efficiency, with magnet rare earth oxides (MREO), critical for high-performance magnets, consistently comprising 42 to 45% of the TREO. Notably, super high-grade MREO concentrations peaked above 3,500 ppm, underscoring the economic potential of the deposit.

Strategic Importance of Heavy Rare Earths

Among the rare earth elements extracted, critical heavy rare earths such as dysprosium and terbium exceeded 100 ppm in some locations, while samarium concentrations reached up to 397 ppm, representing over 5% of TREO. This is significant given samarium-cobalt magnets’ widespread use in defense and aerospace sectors, highlighting the strategic value of the Ema resource beyond traditional rare earth markets.

Managing Director Andrew Reid emphasized the unexpected scale of the results, noting that the ability to upgrade grades by 14 times through ISR leaching is unprecedented. He highlighted that the strength of the magnet rare earth oxides fraction could propel the project to the forefront of the rare earths sector, especially as MREO is expected to represent approximately 90% of future project revenue.

Advancing Towards Commercial Production

The company is progressing multiple fronts to advance the Ema project. A feasibility study is underway, environmental permitting is progressing, extensional resource drilling is 25% complete, and hydrogeological modelling has commenced. Over 2,600 litres of high-grade PLS have been extracted from the field trials, with approximately 1,000 litres dispatched to ANSTO facilities in Sydney for processing and further optimisation.

BCM plans to refine impurity removal and rare earth precipitation processes as part of the bankable feasibility study, aiming to produce a final mixed rare earth carbonate product. Early interest from potential offtakers has been reported, indicating strong market appetite for the project’s output.

Context Within the Rare Earths Market

The Ema project’s ionic adsorbed clay deposit is one of the largest globally, with a combined indicated and inferred mineral resource estimate of 943 million tonnes at 716 ppm TREO. The high metallurgical recoveries averaging 68% for magnet rare earth oxides further enhance the project’s attractiveness. The ISR method offers a lower environmental footprint compared to traditional mining, aligning with growing demand for sustainable rare earth supply chains critical to green technologies and defense applications.

While the results are promising, commercial scale-up and processing optimisation remain key next steps. The company’s ability to maintain high-grade leaching at scale and secure environmental approvals will be crucial to translating these pilot successes into production.