Key Highlights

•  The first mixed rare earth carbonate from Woolrich testwork graded 54.4 per cent total rare earth oxides in dried form.

•  The testwork was conducted in Australia by Core Resources and designed to simulate in situ recovery, the extraction method Axel is pursuing.

•  The result is a laboratory step from leaching studies towards a saleable intermediate product, and the company says important questions remain.

Axel REE (ASX:AXL) has produced its first mixed rare earth carbonate (MREC) from laboratory testwork on material from the Woolrich ionic clay deposit, part of its Caladão rare earths project in Brazil. The company reported the result on 27 October 2026, describing the dried product as grading 54.4% total rare earth oxides (TREO).

The work was conducted in Australia by Core Resources and was designed to simulate in situ recovery (ISR), the extraction method Axel is pursuing at Woolrich. It represents a step from leaching studies towards demonstrating a saleable intermediate product, although the company has been clear that important questions remain unanswered.

What the testwork produced

The test produced 15.11 grams of dried MREC. Roughly 97% of the TREO and 99% of the mixed rare earth oxides (MREO) contained in the pregnant leach solution were precipitated, and this was achieved without a dedicated impurity removal stage.

Magnet rare earths featured prominently in the product. MREO made up 35.9% of the TREO content, neodymium-praseodymium (NdPr) accounted for 34.1%, and dysprosium-terbium represented 1.75%. Radioactive elements were very low, with uranium reported at 0.78 parts per million and thorium at 0.10 ppm. Aluminium and iron were described as low, though no figures were published for them.

Using October spot prices, the company estimated a gross contained rare earth oxide basket value of US$42.72 per kilogram, with NdPr and dysprosium-terbium contributing about 92.8% of that figure. This is a theoretical value based on contained oxides and should not be read as a realised sale price.

How the flowsheet works

The process began with column leaching of Woolrich regolith using magnesium sulphate, which generated the leach solution. That solution was blended with filtrate from an earlier precipitation test and then treated with magnesium bicarbonate to precipitate the carbonate, which was subsequently dried.

Axel said the magnesium-based reagents allow a flowsheet with fewer treatment stages than many conventional rare earth circuits. The company also believes it is the first operator in Minas Gerais to develop an ISR process for ionic adsorption clays.

Managing director Dr Patience Mpofu described the outcome as encouraging, pointing to "excellent precipitation performance" and the absence of a separate impurity removal step. She linked the low uranium and thorium levels to what she called the "naturally buffered mineralised regolith", which she said limited the mobilisation of impurities during leaching.

Why it matters

Ionic clay deposits have attracted attention because rare earths in these materials can, in principle, be recovered with relatively mild reagents rather than the intensive cracking and roasting needed for hard-rock ores. ISR goes further by leaching the ore in place rather than mining and moving it, which may reduce disturbance and operating costs if it proves effective at scale.

Axel intends to move Woolrich towards field-scale ISR testing, so a laboratory carbonate with a high share of magnet metals and low radioactive content gives it a benchmark for that work.

Limitations and next steps

The results come from laboratory work on a blended feed solution and may not reflect performance in the field. Overall recovery from ore to product has not yet been reported, and the company said further testing is needed to establish it. Process consistency and commercial product specifications are also yet to be defined, so the flowsheet is not ready to support commercial-scale design.

Axel said additional metallurgical work will examine feed solution consistency, precipitation performance and product quality across representative conditions. That programme is intended to establish recoveries and product specifications before the company advances to field-scale testing and, eventually, engineering for a larger operation. Basket values will also move with rare earth prices, which have been volatile and remain hard to forecast.