ABx Group’s ANSTO tests show high heavy rare earth recoveries

Key highlights

• ANSTO diagnostic leach tests on a 100 kg Deep Leads bulk sample confirm >70% extractions for dysprosium (Dy) and terbium (Tb)—the most sought-after heavy rare earths. 
• Effective leaching demonstrated at pH ≥4.0–4.7, implying lower impurities and potentially lower reagent costs versus more acidic regimes. 
• Mixed rare earth carbonate (MREC) sample on track for Q4 2025; prospective customers are awaiting compositions and samples.
• Resource snapshot (Deep Leads–Rubble Mound–Wind Break): 89 Mt @ 844 ppm TREO, with 36 ppm Dy+Tb (4.4% of TREO)—described by ABx as the highest ionic proportion among Australian clay-hosted REE resources. 
• Commercial pathway: MREC focus, Ucore MoU for North American processing, and wider offtake discussions underway. 
• Market check (1:12pm AEST, 3 Sep 2025): ABX A$0.099 (Cboe live); A$0.058, +141.46% (ASX delayed); 1-yr +135.71%; 26.83m shares traded; Mkt Cap ~A$24.94m; OS: 251.88m. (Session snapshot provided by user.)
  
   

ABx Group (ASX: ABX) has reported strong confirmation from ANSTO on leach performance at its Deep Leads ionic adsorption clay (IAC) rare earths project in northern Tasmania. Diagnostic leach tests on sub-samples of a 100 kg bulk sample achieved greater than 70% extractions of Dy and Tb at near-neutral leach conditions (pH 4.0–4.7)—outcomes that align with, and in cases surpass, the company’s in-house test work. For investors tracking heavy rare earth supply chains, the test conditions matter as much as the headline percentages: higher pH can reduce impurity pickup (e.g., aluminium, iron) and, by extension, lower operating complexity and reagent bills.

What the testing showed—and why pH matters

ABx says ANSTO’s program ran at ambient temperature and pressure with ammonium sulfate lixiviant across pH 4.0, 4.5 and 4.7. The extraction responses for key magnet rare earths—Pr, Nd, Dy, Tb—were high and broadly consistent across the pH window, with only a modest drop-off at pH 4.7. The company highlights that maintaining performance above pH 4 is operationally meaningful: it supports benign chemistry, lower impurity mobilization, and a cleaner pathway to an MREC intermediate—without stepping into more aggressive acid regimes that can complicate waste handling and capex/opex. 

ABx also notes that previous ANSTO work indicated Deep Leads delivered the highest near-neutral leach extractions reported across Australian clay-hosted resources, pointing to a high ionic proportion of REEs in this system—an attribute that can make ammonium exchange leaching more efficient. While all clay systems vary, high ionic character is often associated with short, low-energy leach times and simpler impurity rejection, desirable traits when designing flowsheets for consistent MREC specifications. 

Management’s view: validation and pace to samples

Managing Director & CEO Dr Mark Cooksey called ANSTO’s confirmation “an important milestone,” 

Source: ABX ASX Announcement 

Scale, grade and the Dy/Tb mix: what’s in the ground

ABx pegs the Deep Leads–Rubble Mound–Wind Break resource at 89 Mt averaging 844 ppm TREO, including 36 ppm Dy+Tb (4.4% of TREO). Within the IAC peer set, ABx characterizes this Dy/Tb proportion as the highest for an Australian clay resource and among the highest globally—noteworthy because Dy and Tb command strategic pricing and face acute supply risk in permanent-magnet value chains (EVs, wind turbines, defense). If that heavier mix translates into the MREC basket, product value could skew favorably versus peers—provided extraction selectivity and impurity control hold as the flowsheet scales. 

From bench to buyers: the MREC milestone and offtake angle

ABx’s near-term slurry tests will test leach performance at higher solids loading—a step toward operating parameters that better resemble plant conditions. The goal is to produce a high-purity MREC (with a higher Dy/Tb proportion) at ambient temperature and pressure in short leach times, then deliver samples and data to potential customers in Q4 2025. The company already has a Memorandum of Understanding with Ucore Rare Metals for North American processing, while additional offtake discussions are underway—signaling market pull if product specs land as expected. 

In market terms, an MREC with elevated Dy/Tb content is particularly attractive to refineries targeting magnet-grade feedstock. If ABx can validate repeatable quality and low impurity levels at commercially relevant solids loadings, the value proposition strengthens: lower acid consumption, a cleaner impurity profile, and competitive recoveries together influence total cost per kilogram of separated REOs—a metric buyers scrutinize during qualification. 

How this fits the broader ABx portfolio

ABx positions itself as a multi-pronged materials company: (1) Heavy rare earths in Tasmania; (2) ALCORE clean-fluorine chemical production from aluminium smelter waste; and (3) near-term bauxite production for industrial markets. The REE program is the present catalyst, but the portfolio approach helps diversify funding and strategic options as REE flowsheet work progresses. 

 

What the market is pricing—and what to watch next

At 1:12pm AEST, ABX shares were trading at A$0.058 on the ASX (delayed), +141.46% on the day, with 26.83 million shares traded and a market cap near A$24.94m. The 12-month return sits around +135.71%—reminding investors that execution milestones (and any slippage) can be amplified in smaller caps. 

Catalysts over the next 3–6 months:

• Slurry/leach optimization at higher solids and impurity control results. 
• Q4 MREC production, composition analysis and customer feedback. 
• Further offtake and processing agreements, including updates related to the Ucore MoU. 
• Resource growth and/or updates across broader Deep Leads–Rubble Mound–Wind Break areas (the current resource covers ~29% of the mineralised outline). 
  
   

Risks and balance of probabilities (the drawdown lens)

As in any early-stage flowsheet, scaling risk is material: bench-scale extractions can compress when solids loading, residence time, rheology and impurity deportment change at pilot scale. Capex/opex estimates remain sensitive to reagent intensity and tailings management stances. Qualification risk also looms: MREC spec variability—especially for Dy/Tb proportions and trace contaminants—can stretch negotiation timelines. ABx’s benign-pH performance is encouraging, but plant-relevant testing and buyer validation will ultimately settle the probability distribution around commercial outcomes.