Brazil’s 1.1-bn-ton rare earth project hits peak 95% terbium recovery

Rare earths are increasingly becoming a supply-chain issue rather than simply a mining story, particularly for elements such as terbium and dysprosium that are used to improve the performance of permanent magnets at high temperatures. 

Brazilian company IMC Rare Earths says laboratory testing at its Itarantim project has produced terbium recoveries of up to 95.2%, alongside the successful production of a mixed rare earth carbonate. The results could strengthen the case for developing the project as another source of magnet materials outside China, although the work remains at the laboratory testing stage. 

Itarantim is an ionic adsorption clay deposit spanning Bahia and Minas Gerais and is estimated to contain about 1.1 billion tonnes of inferred mineral resources. The company says the resource contains neodymium, praseodymium, dysprosium and terbium.

Combining high terbium recovery with rare earth carbonate production

The latest results came from metallurgical testwork conducted with the Instituto Federal do Rio Grande do Norte and its EMBRAPII-affiliated CT Mineral laboratory. In the best-performing composite, known as COMP C2, terbium recovery averaged 81.1% and reached a maximum of 95.2%.

Recovery, rather than simply the concentration of an element in the ground, is an important indicator of whether a deposit could eventually be processed economically. For ionic adsorption clay deposits, rare earth elements are loosely attached to clay minerals and can be released through leaching.

IMC says material from a 105.8 million tonne inferred domain at Itarantim contains an average of 8 parts per million terbium. The company also reported strong leach recoveries for other magnet rare earth elements, including dysprosium. “Terbium and dysprosium are among the scarcest and most highly sought-after elements,” the company said in a statement, pointing to their use in permanent magnets for EVs, wind turbines, robotics, electronics and defense systems. 

Brazil aims for a bigger role in rare earth supply

The strategic importance of the project comes from the concentration of rare earth processing and refining capacity in China. While rare earth elements are found in multiple countries, building alternative supply chains requires deposits with suitable geology, extraction characteristics and processing economics.

That has turned projects in countries such as Brazil, Australia, the US and Canada into potential components of a more diversified supply chain. Brazil is already one of the world’s major mineral producers, while its rare earth sector has attracted growing interest as governments and companies look for alternatives to Chinese supply.

“We are very encouraged by these results, which mark an important step forward in our project. There has been an awakening around the world that we need greater supplies of rare earths from diverse areas,” said Frank Scolaro, CEO and chair of IMC Rare Earths.

While the scale of the resource is notable, the project still needs additional technical work before its commercial potential can be established. IMC has now brought in ANSTO Minerals for additional quantitative metallurgical testing, and the next phase is expected to provide more detailed data on recovery rates and the properties of the mixed rare earth carbonate produced from Itarantim material.