Brazilian Critical Minerals Launches Key ISR Trial at Ema Rare Earths Project

A New Chapter for Ema Rare Earths

Brazilian Critical Minerals Ltd (ASX: BCM) has taken a significant step forward in developing its Ema Rare Earths Project in Brazil by commencing an in-situ recovery (ISR) field trial. This trial, launched in May 2025, is designed to test the unique geological and hydrogeological properties of the deposit using magnesium sulphate as a lixiviant, a method that promises lower capital intensity and environmental impact compared to traditional mining.

The Ema deposit, discovered just two years ago, has already demonstrated impressive potential with a maiden mineral resource estimate of nearly one billion tonnes and a scoping study projecting a net present value (NPV) of US$355 million. The ISR trial aims to validate key parameters such as hydraulic conductivity and clay permeability, which are critical for the success of the ISR mining method.

Trial Objectives and Industry Collaboration

The field trial is being conducted by WSP Brazil, a global leader in ISR mining, with environmental oversight from CERN. It builds on successful laboratory testwork performed at ANSTO, which indicated that the soft, quartz-rich nature of the Ema mineralisation allows for high recoveries of magnet rare earth elements over short leaching periods. This characteristic could translate into highly favourable operating costs for the project.

Over the next three months, the trial will involve multiple injection and pumping scenarios to assess the movement and permeability of the magnesium sulphate solution through the clay horizon. The company will also conduct water washing and clay rehabilitation tests to ensure environmental sustainability. Extracted solutions rich in rare earth elements will be processed to produce a Mixed Rare Earth Carbonate (MREC), which will be supplied to strategic partners for quality control and to advance offtake agreements.

Strategic Implications and Next Steps

Managing Director Andrew Reid highlighted the rapid progress since the deposit's discovery, emphasizing the trial's role in confirming the deposit's suitability for commercial ISR mining. The relatively low capital expenditure of US$55 million, combined with the promising metallurgical results, positions Ema as one of the most cost-effective rare earth projects outside China.

As the trial progresses, the data collected will be crucial for refining the project’s development plan and attracting further investment. The successful demonstration of ISR at Ema could set a precedent for similar deposits globally, particularly those with ion-adsorption clays where conventional mining is less viable.

Investors and industry watchers will be keenly awaiting updates on the trial’s outcomes, the quality of the MREC product, and the advancement of strategic partnerships that could underpin the project’s commercialisation.