Australian Strategic Materials (ASM) has generated positive recovery results from heap leach metallurgical testing conducted at its Dubbo rare earths project in New South Wales.
As part of a rare earth options assessment (REOA), ASM has been evaluating lower capital and shorter implementation options to recover light rare earths such as neodymium (Nd) and praseodymium (Pr) and heavy rare earths like dysprosium (Dy) and terbium (Tb) from Dubbo.
“In the current rare earth market, it is essential that we explore more cost-effective and faster pathways to deliver the Dubbo project and ensure strong project economics,” ASM managing director and chief executive officer Rowena Smith said.
One identified pathway from the REOA was heap leaching methods, which would allow ASM to develop and construct Dubbo via a phased approach, eliminating the need for a capital and energy-intensive roaster and associated infrastructure in the first phase’s process flowsheet.
The first phase of construction would focus on separated rare earth oxide production. Early revenue would be expected to fund the second phase’s development, which would incorporate additional processing steps required to recover other critical minerals at Dubbo, including zirconium, niobium, hafnium, samarium and gadolinium.
As part of the REOA, ASM has undertaken various scoping variability tank leach and bottle roll tests on select drill core intervals from Dubbo to assess different leaching techniques and reagent types and regimes.
The results indicated an assortment of light and heavy rare earth recoveries across the ore deposit, with potential for further optimisation.
Following this success, ASM conducted a metallurgical test program over bottle roll leach tests on drilled core intervals and three large mining zone composites across the the Toongi deposit using hydrochloric acid.
One of the three composites – HLC-West – yielded strong rare earth recoveries, including:
- Nd recoveries up to 80 per cent
- Pr recoveries up to 85 per cent
- Tb recoveries up to 44 per cent
- Dy recoveries up to 38 per cent.
“The initial results are very encouraging for both light and heavy rare earth elements, showing potential to simplify the flowsheet by removing capital-intensive processing steps, which could significantly reduce both capital and operating costs and deliver strong project economics,” Smith said.
“Based on these findings, we are now fast-tracking a heap leach scoping study to rapidly assess the economic viability of developing the Dubbo project in phases – with the first phase focused on the production of light and heavy rare earth oxides.”
The scoping study is expected to be completed in the third quarter of 2025, which will underpin further column leaching testwork set to commence in late June.
Dubbo is projected to deliver up to 1000 local jobs during the construction phase and about 270 jobs during the operational phase, with a final investment decision targeted for the first half of 2026.
Materials produced from Dubbo will be refined into critical metals at ASM’s proposed metals plants, one of which is in South Korea.
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