Can BCM’s ISR Success at Ema Disrupt Conventional Rare Earth Mining?

A Breakthrough in Rare Earth Extraction

Brazilian Critical Minerals Ltd (ASX – BCM) has announced a significant technical milestone at its Ema rare earths project in Brazil, successfully extracting and precipitating rare earth elements (REEs) using in-situ recovery (ISR) methods under real-world field conditions. This achievement confirms the commercial-scale viability of ISR, a process that leaches minerals directly from the deposit without traditional mining excavation.

ISR at Ema employs a low-concentration magnesium sulfate (MgSO₄) solution to mobilize rare earths from clay-rich horizons. The field trials demonstrated rapid pH adjustment and effective leaching, resulting in high-grade pregnant leach solutions (PLS) rich in key magnet rare earth oxides (MREO) such as neodymium, praseodymium, dysprosium, and terbium, which are critical for permanent magnets in clean energy technologies.

Environmental and Economic Advantages

The use of a mild, environmentally benign reagent aligns with BCM’s commitment to sustainable mining practices, offering a low-impact alternative to conventional rare earth extraction. The February 2025 scoping study highlighted the project’s exceptionally low capital expenditure (US$55 million) and operating costs (US$6.15 per kilogram of total rare earth oxides), underscoring ISR’s potential to transform the economics of rare earth production outside Southeast Asia.

Field data showed strong permeability and stable hydrological conditions, essential for ISR system design. The extracted solutions contained up to 41% magnet rare earth elements within total rare earth oxides, placing Ema among the highest-grade magnet rare earth projects globally. These promising early results pave the way for producing a mixed rare earth carbonate (MREC) product suitable for downstream processing and offtake agreements.

Looking Ahead – From Trial to Production

With the ISR pilot trial successfully validating the technology, BCM is advancing toward a bankable feasibility study, expected to commence shortly. Concurrently, the company is progressing environmental and mining permits, financing discussions, and offtake negotiations to secure the project’s commercial future.

Managing Director Andrew Reid emphasized the milestone’s significance, noting that ISR at Ema not only de-risks the project technically but also positions it as a transformative player in the global rare earth supply chain, delivering high environmental, social, and governance (ESG) standards.

While these initial extraction results are encouraging, they represent only the early phase of the field trial. Continued testing will focus on optimizing reagent use, reducing residual magnesium and sulfate levels, and scaling up production to meet market demand.