Axel REE (ASX: AXL) is advancing its Caladão rare earth element and gallium project in Brazil toward field-scale in-situ recovery (ISR) validation after rapidly expanding the project’s mineral resource estimate during 2025.
The company’s December 2025 mineral resource estimate stands at 572 million tonnes at 1,506 parts per million total rare earth oxide, containing 861,000 tonnes of total rare earth oxide.
Caladão also hosts a gallium resource of 439Mt at 38ppm gallium, containing 16,700t of gallium metal.
Axel held $6.6 million in cash at 31 March and is funded to complete the planned ISR field trial validation program throughout 2026.
Caladão Resource Expands Rapidly
The Caladão resource increased from an initial August 2025 estimate of 233Mt of rare earth element mineralisation to 572Mt in December 2025.
Contained total rare earth oxide increased from 499,000t to 861,000t over the same period.
The gallium resource also expanded from 100Mt to 439Mt, lifting contained gallium metal from 4,200t to 16,700t.
The project area includes key deposits and targets such as Woolrich, Paraíso, Marambaia, Tiger Creek, and Bengo Creek within Brazil’s Lithium Valley region.
ISR Driving Development Strategy
Axel is targeting rare earth recovery from ionic clays using ISR, which circulates reagents through modular wellfields before recovering solutions at surface.
The process is designed to recover rare earths without conventional open pit mining, crushing or large fixed infrastructure.
Axel’s proposed process uses magnesium sulphate lixiviant to recover rare earths from ionic clay mineralisation and produce mixed rare earth carbonate.
The company is pursuing the approach because it offers a potential low-capital, low-operating-cost and modular development pathway with a small surface footprint.
Woolrich Field Trial Planned
Axel has selected the Woolrich deposit as the first targeted wellfield for field-scale validation of the Caladão in-situ recovery concept.
The Woolrich deposit has a 2,000-hectare mineralised footprint with potential wellfields already identified.
Leaching tests have returned up to 464ppm soluble total rare earth oxide and a magnet-rich rare earth assemblage of about 42% magnet rare earth oxide, including neodymium-praseodymium and dysprosium-terbium.
The planned validation work will assess orebody modelling, injection well drilling, chemistry, permeability, flow rates, pregnant leach solution specifications, and customer testing.
Paraíso Adds Expansion Inventory
The Paraíso deposit has also emerged as a potential in-situ recovery wellfield area, with Axel identifying nine possible wellfields across about 1,000ha.
Paraíso has returned grade-thickness values of up to 13,705 gram-metres total rare earth oxide, indicating stacked and laterally coherent mineralised clay horizons.
Soluble magnet rare earth oxide averages about 41% to 42% of soluble total rare earth oxide, while neodymium-praseodymium averages about 39% to 40%.
The Paraíso and Tiger Creek areas provide further expansion inventory beyond the first Woolrich field trial.
Gallium Provides Further Upside
Caladão hosts what Axel describes as Brazil’s only defined primary gallium resource and one of the largest gallium resources globally.
Gallium is a critical technology metal used in defence, solar energy, EVs, and next-generation semiconductors for AI data centres.
The company sees gallium as a separate development pathway alongside its core rare earth element in-situ recovery strategy.
Axel is positioning the project as a potential non-Chinese source of gallium and magnet rare earths for Western critical minerals supply chains.
Metallurgy Supports Optionality
Independent metallurgical test work led by the Australian Nuclear Science and Technology Organisation (ANSTO) has confirmed a pathway to recover gallium and co-recover scandium from Caladão mineralisation.
The test work has demonstrated encouraging gallium recoveries, with further optimisation underway.
Axel is continuing metallurgical work to optimise recoveries and assess downstream product strategy.
The gallium and scandium potential adds optionality to partnership discussions and supports the broader case for a multi-commodity critical minerals development at Caladão.
