BCM’s REE heap leach test opens door to lower-cost options for Ema

Brazilian Critical Minerals’ successful column testing offers potential for low-capex heap leaching for its Ema project
Leaching successfully achieves 63% recovery of MREOs after only 18 days using magnesium sulphate
Company now considering in-situ leaching of Ema mineralisation

Special Report: Successful column leaching has raised the likelihood that Brazilian Critical Minerals will be able to construct a rare earths processing flow sheet that will allow development of its Ema project with fewer steps and lower risks.

Testing by the Australian Nuclear Science & Technology Organisation on a 50kg composite of 62 samples collected from 12 holes achieved 63% recovery of valuable magnet rare earth oxides (MREO) after just 18 days of heap leaching using magnesium sulphate.

Importantly for Brazilian Critical Minerals (ASX:BCM), the results provide the option for a low-capex REE heap leach operation for its Ema project in Brazil.

As such, the company is now planning to go a step further and fully explore the possibilities of in-situ leaching of Ema mineralisation, which will involve even fewer steps from mine to final product than is involved in heap leaching.

“These results are quite stunning in their simplicity, to be able to desorb the rare earths so quickly at a high rate of recovery is quite remarkable,” managing director Andrew Reid said.

“The physical and chemical characteristics of the mineralisation at Ema have now been thoroughly tested giving similar results for both slurry (tank leaching) and now heap leaching.

“These heap leach results have now validated a much lower capex path to production when compared to tank leaching. The company now intends to extend its testing regime towards in-situ leaching, where we are confident of high recoveries being achieved, with the only unknown element of clay permeability to be determined.

“Field and lab work to demonstrate the permeability of the Ema mineralisation to in-situ leaching is now being planned.

“Not only is the company heading towards a low capex and low opex project setup, but the ability to get high recoveries utilising magnesium sulfate as opposed to ammonium sulfate means the Ema project could be one of the greenest and environmentally friendliest mines ever constructed.”

Lower-cost processing

The column testing was carried out as a key part of the company’s strategy to grow and progress the current Ema resource of 1.02Bt at 793 parts per million (ppm) total rare earth oxide (TREO) towards development.

Notably, the final calculated leach liquor and residue recovery of 63% is materially in line with previously announced slurry recovery results and demonstrate clear potential to achieve lower processing costs through simpler and scalable treatment options.

Lower processing costs also make it viable to treat lower-grade material, which will help secure economies of scale.

It also gives the company confidence that in-situ leaching is possible as the clay hosting Ema mineralisation is comprised of almost 50% quartz, which could enable economic rates of fluid flow.

This article was developed in collaboration with Brazilian Critical Minerals, a Stockhead advertiser at the time of publishing.

This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.