How Did Brazilian Critical Minerals Achieve 14x Rare Earth Grades in ISR Trials?

Breakthrough in Rare Earth Extraction

Brazilian Critical Minerals Ltd (ASX, BCM) has announced a significant technical milestone in its quest to develop the Ema rare earth elements (REE) project in Brazil’s Apuí region. The company’s in-situ recovery (ISR) field trials have successfully demonstrated the extraction of rare earth elements directly from the deposit using a low-impact leaching method. This approach bypasses traditional open-pit mining, offering a more environmentally sustainable path to rare earth production.

The field trials, initiated in late May 2025, involved injecting a magnesium sulfate solution into the mineralised clay horizon. The solution effectively leached rare earths into a pregnant leach solution (PLS), which was then extracted and analysed. Remarkably, the PLS grades reached up to 7,800 parts per million (ppm) total rare earth oxides (TREO), more than 14 times higher than the in-situ mineralised grades, underscoring the efficiency of the ISR method.

Exceptional Grade and Composition

What sets the Ema project apart is the exceptionally high proportion of magnet rare earth elements (MREO) within the total rare earth oxides. The MREO content averaged between 40% and 44% across all extraction holes, positioning Ema as one of the richest deposits globally in these critical elements. These magnet elements, including neodymium, praseodymium, dysprosium, and terbium, are essential for manufacturing high-performance magnets used in electric vehicles, wind turbines, and defense technologies.

Additionally, the presence of heavy rare earths such as dysprosium and terbium exceeding 100 ppm, and samarium concentrations averaging over 5% of TREO, highlight the strategic value of the deposit. Samarium-cobalt magnets, for instance, are widely used in aerospace and defense applications, adding a premium dimension to the project’s product basket.

Strong Government Engagement and ESG Credentials

Beyond the technical success, BCM has secured robust support from local and state authorities. Meetings with Amazonas state officials, including Governor Wilson Lima, and Apui’s Mayor and Vice Mayor, have reinforced a collaborative approach to project development. The company emphasised the ISR method’s environmental benefits, notably zero additional deforestation and no tailings dams, aligning with stringent Brazilian environmental regulations.

This strong social license is reflected in 100% positive community survey responses, a critical factor for advancing permitting and construction. The state and municipality have expressed eagerness to accelerate project construction once all permits are in place, signalling a favourable regulatory environment.

Advancing Toward Feasibility and Production

To capitalise on these promising results, BCM has appointed Altris Engineering as the lead consultant for the bankable feasibility study (BFS), expected to conclude in the first quarter of 2026. Altris brings extensive experience in critical minerals projects, focusing on cost-effective, operable designs that minimise capital expenditure.

Complementary technical work is underway with ANSTO conducting advanced process optimisation on the extracted PLS, and WSP performing detailed hydrogeological modelling to refine ISR system design. These efforts aim to validate the commercial viability of the ISR approach at scale.

Financially, BCM reported cash reserves of A$2.46 million as of 30 September 2025, supporting ongoing development activities. The company continues to hold 100% ownership of multiple exploration tenements covering over 60,000 hectares in the Apuí region, underpinning its resource base.

Looking Ahead

Brazilian Critical Minerals’ successful ISR field trials mark a pivotal step in unlocking a world-class rare earth deposit with a low environmental footprint. The combination of high-grade rare earth recovery, strong government backing, and advancing feasibility studies positions the Ema project as a potential future supplier of critical materials essential for the global clean energy transition.