ANSTO has started production of ABx Group’s (ASX:ABX) first mixed rare earth carbonate (MREC) product using 50kg of a 100kg bulk sample, with completion expected before the end of November 2025.
The sample will be distributed to potential customers and offtake partners for evaluation.
ABx has been running a program to produce a saleable MREC product from its Deep Leads ionic adsorption clay rare earth project in northern Tasmania to be used in downstream refining to produce separated rare earth oxides, rare earth metals, and magnets essential for electric vehicle motors, guidance systems, wind turbines, and other clean-energy technologies.
In partnership with external engineering experts, ABx conducted a formal processing options analysis. ABx notes that a key conclusion was that column leach tests should be conducted to confirm that the high extractions obtained in diagnostic leach tests in tanks are also observed in a column leach arrangement.
The company engaged ANSTO to conduct initial column leach tests. These are planned to begin in November, with results available by early 2026.
In this latest testwork, ANSTO conducted two impurity removal (IR) trials on rare earth-enriched leach solutions produced from a 1.2kg sub-sample of the 100kg bulk sample, taken from trial pit DLP002 within the Deep Leads resource area.
At near-optimum conditions (pH 5.9 and 6.2), ABx says the key impurity, aluminium, was almost completely removed, while more than 98% of rare earth elements remained in solution.
A critical metric for MREC product quality is the ratio of aluminium to total rare earths (Al:TREE ratio) in the solution following impurity removal.
In these two tests, the Al:TREE ratio was less than 0.005, which is likely to be maintained in the final MREC product. The company notes this is a very low level of aluminium and is likely to be appealing to customers.
ABx CEO Dr Mark Cooksey says these latest results are “extraordinarily good”.
Cooksey adds that these results provides further evidence that the Deep Leads resource represents the prized combination of high dysprosium (Dy) and terbium (Tb) grade, high rare earth recovery using low-cost conditions and low impurities that is conducive to producing a high value MREC product at low cost.
“Because of the very high DyTb content, high extractions, low impurities and a significant resource, ABx Group continues to receive strong interest from potential customers,” he continues.
The source of the material for these tests is a 100kg bulk sample from trial pit DLP002 from the Deep Leads resource. Leaching Performance ABx has previously reported ‘excellent’ leach test results, involving 300g samples, achieving 62-66% extractions of dysprosium and terbium at 25 wt% solids loading.
ABx says these results were achieved using “exceptionally benign conditions” (pH 4.5, ambient temperatures and pressure), which is anticipated to significantly reduce rare earth extraction costs. In this work, a 1.2kg sub-sample was leached using identical conditions, producing similarly strong results – 62% extraction for Dy and 63% for Tb.
Magnet rare earth prices remain high, with Benchmark reporting Dy oxide (DDP China) at over US$200/kg and Tb oxide (DDP China) at almost US$1,000/kg.
Furthermore, CIF Europe prices for Dy and Tb are over three times higher than Chinese domestic prices, illustrating the potential premium for non-China sources of rare earths.
ABx has previously executed a memorandum of understanding with Ucore Rare Metals (TSX-V:UCU), which is focused on rare earth processing facilities in North America.
The Deep Leads – Rubble Mound and Wind Break discoveries contain a resource estimate of 89 million tonnes averaging 844ppm total rare earth oxides (TREO).
The resource contains 36ppm Dy+Tb (Dy+Tb is 4.4% of TREO), which is touted as the highest of any ionic clay deposit in Australia and among the highest globally.
This resource estimate has been defined from only 29% of the project’s mineralised outline.
Write to Adam Orlando at Mining.com.au
Images: ABx
