Axel REE Limited reports breakthrough metallurgical test results from its Caladão Project in Brazil, achieving over 96% recovery of magnetic rare earth oxides using hydrochloric acid leaching. This milestone supports a dual-path development strategy combining low-cost in situ recovery with a longer-term acid leach option.
- Over 96% recovery of magnetic rare earth oxides (MREO) via hydrochloric acid leaching
- Testwork on composites from two drill holes 2km apart confirms repeatability
- Dual development pathway, modular in situ recovery (ISR) and acid leach processing
- Gallium recovery improved to ~30%, with potential up to 50% using oxalic acid
- Caladão Project hosts inferred resources of 572Mt rare earth oxides and 439Mt gallium
Breakthrough in Rare Earth Recovery
Axel REE Limited (ASX – AXL) has announced a significant advancement in the metallurgical processing of its Caladão Rare Earth Elements (REE) Project in Minas Gerais, Brazil. Recent testwork conducted by the Australian Nuclear Science and Technology Organisation (ANSTO) demonstrated exceptional recovery rates exceeding 96% for magnetic rare earth oxides (MREO) using hydrochloric acid (HCl) leaching on composite samples from two diamond drill holes spaced approximately two kilometres apart.
This result marks a substantial improvement over previous acid leach tests, which had achieved only up to 28% recovery. The repeatability of these outcomes across multiple locations within Area A of the project underscores the robustness of the leaching process under controlled laboratory conditions.
Dual-Pathway Development Strategy
The testwork supports Axel’s innovative two-pathway development concept for Caladão. The near-term focus remains on modular in situ recovery (ISR) targeting ionic adsorption clay zones using magnesium sulphate (MgSO₄). This approach aims to deploy scalable, low-cost hydrometallurgical plants within wellfields such as Paraíso (Area A) and Woolrich (Area B), minimising surface disturbance and capital expenditure.
Concurrently, the acid leach pathway offers longer-term optionality to extract magnetic rare earths and gallium from non-ionic clay mineralisation zones that are less responsive to mild salt leaching. This dual approach could maximise overall rare earth recovery across different mineralisation styles, enhancing project flexibility and value.
Gallium Recovery and Resource Scale
Alongside rare earths, gallium recovery has also improved, reaching approximately 30% in these latest tests. Previous ANSTO work using oxalic acid has shown gallium recoveries up to 50%, highlighting potential for further optimisation. Gallium is a critical metal with growing demand in electronics and renewable energy sectors, adding strategic importance to the Caladão Project.
The project’s inferred mineral resources are substantial, with 572 million tonnes of rare earth oxides at Area A and B combined, and 439 million tonnes of gallium-bearing material. These figures position Caladão as one of the largest rare earth and gallium projects outside China, a key consideration amid global supply chain diversification efforts.
Technical and Economic Considerations
Hydrochloric acid leaching is a well-established method in rare earth processing, commonly used to produce rare-earth chloride solutions for downstream purification. Axel’s results confirm that certain weathered profiles at Caladão are highly amenable to this technique, although project economics will depend on factors such as acid consumption, impurity management, and materials handling.
While no further acid leach testing is planned in the immediate term, the company retains this pathway as a viable option to revisit as the project advances. The current priority remains on scaling up ISR operations, which promise a modular, repeatable, and environmentally considerate extraction method.
Looking Ahead
Non-Executive Chairman Paul Dickson emphasised the strategic advantage of Caladão’s dual-pathway approach, stating that the combination of low-cost ISR and high-recovery acid leach options enhances the project’s potential to become a major rare earth and gallium producer. As global demand for critical minerals intensifies, Axel’s progress at Caladão will be closely watched by investors and industry stakeholders alike.
Bottom Line?
Axel’s metallurgical breakthrough at Caladão sets the stage for scalable rare earth production with flexible processing options.
Questions in the middle?
- How will Axel balance investment between ISR scale-up and acid leach pathway development?
- What are the projected capital and operating costs associated with the hydrochloric acid leach process at scale?
- How might evolving global rare earth demand and supply dynamics impact Axel’s project timelines and partnerships?