Axel REE Advances ISR Milestone with Woolrich Leach Breakthrough

Column Leach Breakthrough Validates ISR Pathway

Axel REE Limited (ASX:AXL) has crossed a significant technical threshold in its rare earth element (REE) extraction efforts at the Woolrich deposit, part of its Caladão Project in Brazil. The company’s recent column leach tests at Core Resources’ Brisbane laboratory have successfully achieved pregnant liquor solution (PLS) breakthrough in two initial test columns, validating the hydraulic behaviour of Woolrich’s ionic clay material under conditions analogous to in situ recovery (ISR) mining.

This breakthrough confirms that the deposit’s 128 million tonnes of REE-bearing material responds well to low-impact magnesium sulphate leaching, a key pillar of Axel’s modular, low-capital ISR development strategy. The soluble total rare earth oxide (TREO) concentrations recorded range from 443ppm to 546ppm, aligning closely with soluble grades reported from operating ISR REE systems in Asia, such as the Gerik mine in Malaysia.

Optimising Leach Conditions and Kinetics

Diagnostic leach testing has refined the optimal operating window to low acidity conditions (pH 4.0) with magnesium sulphate concentrations around 0.25M. Notably, soluble TREO results showed relative insensitivity to reagent concentration across the tested range, but a strong dependence on pH control, underscoring the importance of acidity management in rare earth mobilisation.

Early kinetic data from the columns reveal that lower reagent concentrations facilitate faster percolation without compromising extraction performance, informing the design of subsequent column tests and future field trials. Moisture content and flow rates have been tightly controlled, providing valuable engineering data to support wellfield layout and ISR trial planning.

Resource Scale and Strategic Critical Minerals Position

The Woolrich deposit is a substantial component of Axel’s broader Caladão resource, which totals 572 million tonnes at 1,506ppm TREO and includes a significant gallium inventory of 439 million tonnes at 38ppm. Gallium, a critical metal for semiconductors and defence electronics, has been subject to Chinese export restrictions since 2023, highlighting Caladão’s potential as a strategic non-Chinese supply source.

Core Resources has commenced gallium leach testwork, with initial acid leach tests underway to build extraction data for this valuable byproduct. This dual focus on rare earths and gallium positions Axel uniquely in the critical minerals space, offering diversified supply optionality.

Pathway to Field Trials and Modular Production

With the column leach milestone achieved, Axel is advancing toward field-scale ISR trials at Woolrich, having selected the trial area and assembled a multidisciplinary team for wellfield design and in-ground testing. This follows the company’s recent announcement of a fully funded pilot ISR wellfield trial at Woolrich, which aims to validate low-cost extraction and downstream processing of mixed rare earth carbonate products.

These developments build on Axel’s modular ISR approach, which seeks to minimise surface disturbance and capital intensity by deploying hydrometallurgical plants within wellfields. The incremental testing strategy, including planned additional column leach tests and metallurgical programs for scandium and gallium, aims to de-risk the pathway from pilot to production scale.

The company’s progress is notable given the Caladão Project’s status as one of the largest primary gallium resources globally and its substantial rare earth inventory. As Axel moves closer to field trials, the market will be watching how these technical milestones translate into operational and commercial outcomes, particularly in the context of global critical minerals supply chain diversification.

This announcement follows Axel’s recent updates on pilot ISR wellfield trial funding and project advancement, underscoring a steady build-up of technical confidence in its ISR development model.