OD6 Metals (ASX:OD6) has confirmed the validity of its ‘heap leaching process’ for rare earth material sourced from the group’s Splinter Rock Rare Earth Project in Esperance, Western Australia.
CPC Engineering has been working toward the completion of an optioneering assessment with the Australian Nuclear Science and Technology Organisation (ANSTO), which returned a lower-cost, higher-recovery of material, in comparison to an agitated tank leach.
The company notes that a heap leaching process only requires a “modular, scalable construction”, eliminating the need for large leach tanks, clay-washing, and detailed separation circuits.
In five years, the company anticipates to produce a minimum of 6,000 tonnes of rare earth oxide per year from the project, either as mixed rare earth carbonate (MREC) or mixed rare earth hydroxide (MREH).
The Inside Centre deposit currently holds an indicated resource of 119 million tonnes @ 1,632 parts per million (ppm) total rare earth oxide.
Managing Director Brett Hazelden describes the company’s downstream steps as the “most capital-efficient and operationally simple route” to advance the value output of Splinter Rock.
“Importantly, when benchmarked against other peers in the industry, it suggests a lower CAPEX profile is possible after removing the complex and expensive solid-liquid separation steps in an agitated tanks leach process,” Hazelden says.
“Notably, integration of our impurity removal steps and a Chlor-Alkali Facility (CAF) suggest a lower capital cost outcome and supports production of a high-value MREC product.”
Comparing primary leach options to other large-scale operations, the study investigated categories including rare earth recovery, circuit complexity, capital cost, expandability, product quality and payability, operating cost, technical and commercial risk, and robustness to variability.
The company is continuing its partnership with both CPC Engineering and ANSTO, pushing the optioneering study towards an optimal development pathway.
OD6 will be looking to produce samples for offtake discussions shortly, while preparing to undergo a drilling campaign at the original six holes with twin hold diamond core material.
ANSTO will upscale heap leach and impurity removal testwork by bulk testing 1 tonne of rare earth element-bearing material to produce around 1kg of MREC.
Write to Maddison Elliott at Mining.com.au
Images: OD6 Metals
