Brazilian Critical Minerals Ltd (ASX:BCM) has produced one of the world's largest tonnage mineral resource estimates (MRE) for fully ionic clay rare earth deposits at the Ema Rare Earths Element (REE) Project in Brazil.
The JORC-compliant resource estimate weighs in at 1.02 billion tonnes at 793 parts per million (ppm) total rare earth oxides (TREO), with a higher-grade portion of 221 million tonnes at 977 ppm TREO.
Critically, high-value magnet rare earths including neodymium, praseodymium, dysprosium and terbium make up about 27% to 31% of the TREO at Ema, positioning it as one of Brazil’s most enriched magnet rare earth oxide (MREO) deposits.
Magnet rare earths are in high demand due to their applications in clean energy technology, including wind turbines, electric vehicle batteries and high-end computer hardware, including medical equipment.
Becoming global REE leader
“Today’s announcement is very important for the company and our shareholders as it now sets us on a path towards development,” Brazilian Critical Minerals managing director Andrew Reid said.
“This result places Ema as one of the largest ionic rare earths deposits in the world. The team has done a tremendous job in getting such a large MRE defined in less than one year, which now confirms the immense potential of the Ema project in Brazil.
“Not only do we have a massive mineral resource of more than 1 billion tonnes but also significantly, we have more than 300 million tonnes at grades close to 1,000ppm which will assist in generating positive financial cash flow models.
“Opportunities to increase both grade and tonnage remain high due to the extremely conservative global specific gravity (SG) of 1.34 which was applied to the estimated volumes.
“Additional deeper, less weathered samples from the higher-grade horizon is expected to result in significantly higher SGs.
“With only 46% of the total area drilled, the team is confident of increasing not only tonnages but believes the opportunities to also increase the grade are well founded and will be tested through the next round of drilling commencing over the coming months.
“BCM is now well on its way to establishing the company as a global rare earths leader.”
BCM says the mineralisation included in its MRE is close to surface and amenable to low-cost open put mining methods – the deposit is also open to the east and west as well as at depth for further exploration.
The company is now focused on converting the MRE from the inferred category to the higher-confidence indicated and measured categories with the current drilling program.
Metallurgical chops
The project has also demonstrated strong metallurgical results thus far, being a fully ionic clay deposit requiring zero drilling into fresh rock.
Tests have also revealed the mineralisation at Ema is amenable to lost-cost REE recovery processes, using limited reagents while achieving high purities in the final product.
BCM leveraged a standard weak ammonium sulphate leaching solution, pH 4, at ambient temperatures over low leach times of only 30 minutes duration, producing MREO recoveries of:
- 10 metres at 76% neodymium, 74% praseodymium, 47% dysprosium and 54% terbium from 10 metres;
- 6 metres at 66% neodymium, 61% praseodymium, 56% dysprosium and 83% terbium from 10 metres;
- 13 metres at 71% neodymium, 62% praseodymium, 45% dysprosium and 52% terbium from 5 metres;
- 5 metres at 66% neodymium, 66% praseodymium, 52% dysprosium and 55% terbium from 12 metres; and,
- 10 metres at 65% neodymium, 61% praseodymium, 43% dysprosium and 50% terbium from 10 metres.
BCM says these results indicate the mineralisation at Ema is suited to low-cost processing through conventional processing facilities commonly used in China.