Brazilian Critical Minerals (ASX:BCM) has reported strong magnesium sulphate leach results from its 2025 drilling campaign at the Ema Ionic Clay Rare Earth Project in Brazil’s Apuí region.
The company completed leaching tests across 56 holes and 262 samples, returning 58 intercepts within the mineralised horizon, with average recoveries of 48% total rare earth oxide (TREO) and 62% magnetic rare earth oxide (MREO).
“These … results continue to strengthen our confidence in Ema as a globally significant ionic clay rare earth project with strong potential for low-cost ISR development,” Managing Director Andrew Reid says.
“What is particularly encouraging is … the consistently high proportions of magnetic rare earths being returned under mild magnesium sulphate leaching conditions.”
Key results from the leaching program include EMA-TR-465 with 9m at 780 parts per million (ppm) leached TREO containing 271ppm leached MREO, representing a 35% MREO:TREO ratio.
EMA-TR-456 returned 9m at 606ppm leached TREO, with 277ppm leached MREO for a 46% MREO:TREO ratio.
The company says the ratio averaged 39% across all results, positioning Ema among higher-grade magnetic rare earth peer groups. The results match overall recoveries utilised for the February 2025 Scoping Study.
Brazilian Critical Minerals notes that the strongest soluble TREO and MREO values consistently occur within the lower saprolite horizon immediately above fresh bedrock, supporting the ISR development strategy.
Geological model and project scale
The enrichment zone typically measures around 10m in thickness, indicating a continuous mineralised horizon across the project area.
Several drill holes returned peak one-metre soluble TREO values exceeding 1,000ppm within the lower saprolite horizon, including 1,074ppm soluble TREO in EMA-TR-465 and 1,693ppm soluble TREO in EMA-TR-492.
The company says EMA-TR-492 highlighted ‘high-grade’ heavy rare earths near the fresh rock interface with a peak one-metre interval of 1,693ppm leached TREO containing 502ppm neodymium-praseodymium and 66ppm dysprosium-terbium.
Reid says the vertical enrichment profile observed at Ema, with increasing soluble TREO and MREO values toward the lower saprolite horizon, is highly comparable to ionic clay ISR deposits currently exploited in southern China.
“These results represent another important step toward further de-risking the project as we … [position] Ema as a future strategic supplier of rare earth materials to western supply chains,” Reid says.
Brazilian Critical Minerals has defined a total Mineral Resource Estimate of 1,071 million tonnes of rare earth elements, with 392 million tonnes at the indicated category.
The company says its Bankable Feasibility Study, utilising the updated mineral resource estimate, ANSTO metallurgical test results, and WSP groundwater modelling data, is nearing completion and due for release in June 2026.
Write to JC Villarba at Mining.com.au
Images: Unsplash
