ABx Group Achieves Outstanding Rare Earth Extractions in Larger-Scale Slurry Leach Testing

ABx Group (ASX: ABX) has reported exceptional extraction results from larger-scale slurry leach tests on bulk samples from its Deep Leads ionic adsorption clay project in northern Tasmania.

The tests, which ANSTO conducted on 300-gram sub-samples, reproduced the high extraction rates achieved in smaller-scale trials under benign conditions.

Management said the results confirm the project’s potential to deliver a low-cost, low-impurity mixed rare earth carbonate (MREC) product with high proportions of dysprosium and terbium.

Larger-Scale Tests Validate Process

The latest program used a 100-kilogram bulk sample from Deep Leads, where rare earth element (REE) mineralisation occurs in shallow clay layers.

ANSTO tested two slurry configurations at pH 4.5 and ambient temperature and pressure, recording 60–66% extraction for dysprosium, 55–62% for terbium, 65–72% for neodymium, and 63–70% for praseodymium.

These results closely tracked earlier diagnostic leach tests on 80-gram samples, demonstrating that high recoveries can be achieved at larger scale under commercial conditions.

The leach solutions contained extremely low levels of aluminium and iron, impurities that typically cause rare earth losses during processing, suggesting MREC from Deep Leads would maintain high recoveries through refining to deliver a high-purity product.

Because the extractions occurred without higher temperatures, pressures or aggressive acids, the process offers potential for lower operating costs compared with other clay-hosted deposits worldwide.

Strategic Importance of HRE

Deep Leads is particularly enriched in heavy rare earths (HRE), with dysprosium and terbium accounting for more than 4% of the resource—the highest proportion for any ionic clay deposit in Australia.

These elements – critical for permanent magnets in EVs, wind turbines and defence technologies – carry some of the highest supply risk across the rare earth sector.

Benchmark pricing data shows terbium oxide at nearly US$1,000 per kilogram, while non-Chinese supply of HRE can command premiums of more than three times Chinese domestic prices.

ANSTO will now move to the next stage of testing, focused on impurity removal using ammonium bicarbonate, before producing a MREC sample in the December quarter of 2025.

ABx has already signed a memorandum of understanding with Ucore Rare Metals for potential processing in North America and is in discussions with additional partners.

Commercial Development Pathway

Chief executive officer Mark Cooksey said the results build further confidence in the commercial development pathway for ABx.

“We are eagerly looking forward to the production of the MREC sample—because of high dysprosium-terbium content, high extractions, low impurities, and a significant resource, ABx Group continues to receive strong interest from potential customers.”

With a resource base of 89 million tonnes defined across Deep Leads, Rubble Mound, and Wind Break, and only 29% of the mineralised outline drilled, ABx says Tasmania’s rare earth resource could rival global peers in scale and value.

“ABx has high-grade REE discoveries 52km east of Deep Leads, confirming that Tasmania’s REE deposits are extensive and can be an important source of dysprosium and terbium, potentially rivalling production from southern China,” Mr Cooksley added.