Brazilian Critical Minerals (ASX:BCM) recorded the tracer reagent magnesium sulfate in multiple extraction holes over field trial areas undergoing injection at the Ema rare earths project in Brazil, according to a Friday Australian bourse filing

The chemical changes in the solution show that magnesium sulfate migrated from the injection holes to the extraction holes in the field trial locations.

The pH levels reduced significantly in the extraction solution with the addition of low concentration magnesium sulfate and are now at or below pH of 4, which is the level required to leach rare earths into solution via in-situ recovery.

The solutions potentially containing rare earths were extracted from the monitoring holes and are en route to the laboratory for analysis.