Dubbo Project Heap Leach Yields Up to 85% Recovery for Key Rare Earths
Australian Strategic Materials reports promising heap leach test results at its Dubbo Project, showing strong recoveries of key rare earth elements and enabling a simpler, phased development approach.
- Heap leach testwork yields up to 85% recovery for neodymium and praseodymium
- Optimal crush size reduces processing complexity and costs
- Heap leach process could bypass capital-intensive roasting stage
- Phased project development to focus initially on separated rare earth oxides
- Upcoming scoping study and column leach tests to validate economic viability
Encouraging Metallurgical Advances
Australian Strategic Materials Limited (ASM) has unveiled highly promising results from its heap leach metallurgical testwork at the Dubbo Project in New South Wales. The testwork, part of ASM’s Rare Earth Options Assessment, focused on recovering critical rare earth elements such as neodymium (Nd), praseodymium (Pr), terbium (Tb), and dysprosium (Dy) using hydrochloric acid leaching on ore composites from the Toongi deposit.
Notably, the HLC-West composite, representing the initial 8-10 years of mining, demonstrated recoveries of up to 85% for Pr, 80% for Nd, 44% for Tb, and 38% for Dy. These figures are significant given the strategic importance of these elements in high-tech and clean energy applications, especially amid supply constraints influenced by Chinese export controls.
Simplifying the Processing Flowsheet
The testwork results suggest that heap leaching at crush sizes between 12.5 mm and 25 mm optimizes recovery while reducing the need for extensive crushing. This simplification could eliminate several capital-intensive steps traditionally required in rare earth processing, such as roasting and complex flotation circuits. ASM’s Managing Director, Rowena Smith, highlighted that this approach could significantly lower both capital expenditure and operating costs, improving the project’s economic profile and accelerating its path to production.
By focusing initially on separated rare earth oxide production through a heap leach process, ASM aims to implement a phased development strategy. The first phase would generate early revenue streams and simplify offtake agreements, easing funding challenges. Subsequent phases would target additional critical minerals like zirconium, niobium, and hafnium, leveraging the project's full resource potential.
Next Steps and Market Implications
Building on these encouraging findings, ASM is fast-tracking a Heap Leach Scoping Study expected in early Q3 2025. This study will provide a high-level economic assessment of the heap leach-first approach. Concurrently, column leach testwork is scheduled to commence, aiming to refine heap leach parameters over a longer duration and under more representative conditions.
The heap leach option aligns well with global efforts to diversify rare earth supply chains and reduce reliance on dominant producers. ASM’s progress could position the Dubbo Project as a competitive, lower-cost supplier of critical rare earth oxides, supporting emerging technologies and national security interests.
While the results are promising, the full economic viability depends on upcoming studies and scale-up testwork. Investors and industry watchers will be keen to see how ASM balances technical optimization with market dynamics in the months ahead.
Bottom Line?
ASM’s heap leach advances could reshape Dubbo’s development timeline and cost structure, setting the stage for a new rare earth supply contender.
Questions in the middle?
- How will the upcoming Heap Leach Scoping Study quantify the economic benefits of the simplified flowsheet?
- What are the potential challenges in scaling heap leach from testwork to commercial production?
- How might ASM’s phased approach influence funding strategies and offtake negotiations?
