Brazilian Critical Minerals (ASX:BCM) demonstrates high-purity rare earth separation at Ema

Brazilian Critical Minerals has reported a technically significant milestone in the downstream development of its Ema Ionic Adsorbed Clay rare earth project in Brazil, with bench scale testwork confirming that rare earth elements can be upgraded and separated into individual high-purity oxides using commercially proven, environmentally responsible processing technology.

The work was undertaken with Rare Earth Technologies Inc in Cincinnati and represents a key validation step in demonstrating the ability to convert in situ leach solutions into marketable rare earth products.

Highlights

• Pregnant liquor solution from Ema was upgraded 200 times from 930 ppm to 186,000 ppm total rare earth oxides excluding cerium

• Near total recovery of rare earths was achieved with no material losses during concentration

• Individual rare earth oxides were separated in a single automated process, each achieving a minimum purity of 99.9%

• The separation system is already in commercial operation in Europe and uses non-toxic solvents and low chemical consumption

• Results support progression toward pilot scale testing and downstream processing pathways for the Ema project

The test program involved processing a 20 L sample of pregnant liquor solution generated from Ema through RETi’s proprietary solid phase extraction and high-performance liquid chromatography system.

The solution, which averaged 930 ppm total rare earth oxides, was first subjected to a cerium depletion step that removed 99.4% of cerium, followed by selective enrichment of the remaining rare earth elements into a small acid volume.

This produced a 200 fold concentration to 18.6% TREO excluding cerium, while maintaining near total recovery and rejecting non-rare earth impurities such as magnesium.

Chromatographic separation then generated cleanly separated individual rare earth oxides within a 24 minute cycle time, each achieving minimum 99.9% purity, with the process capable of reaching up to approximately 99.999% purity based on column chemistry and operating conditions.

The technology integrates solid phase extraction for group recovery and enrichment, followed by liquid chromatography separation using mineral acid eluents rather than organic solvents, delivering both environmental and safety advantages.

Brazilian Critical Minerals Managing Director Andrew Reid said the results confirmed the capability of the technology to upgrade and purify rare earths in a single processing route, stating that

“the RETi bench scale test indicated the technology is capable of achieving up to a 200× upgrade from feed to product, delivering cleanly separated rare earth oxides with minimal impurity carryover in a single processing route.”

He added that the use of non-toxic solvents and high selectivity further strengthened the environmental credentials of the Ema in situ recovery development pathway.

From a strategic perspective, the outcome directly supports the development of BCM’s Ema project, which hosts a JORC compliant Indicated and Inferred Mineral Resource of 943 Mt at a 500 ppm TREO cut off, with average metallurgical recoveries of 68% and a high proportion of magnetic rare earth oxides including NdPr and DyTb.

The company has commenced a bankable feasibility study targeted for completion in Q1 2026 and is advancing permitting and resource extension drilling to underpin economic evaluation.

The successful upgrading and separation of rare earths into high-purity individual oxides using commercially proven technology represents a critical step in de-risking the downstream processing route for Ema.

It provides practical evidence that the project’s in situ leach solutions can be converted into saleable products with high recoveries, high purity and strong environmental performance, positioning BCM to progress toward pilot scale testing and future commercial development as part of its broader rare earths value chain strategy.

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