OD6 Metals Ltd (ASX:OD6) has lauded very high-grade rare earth recoveries at its Splinter Rock Project near Esperance in WA with shares soaring by 51.22% to $0.31.
The company returned up to 96% magnetic rare earths during hydrochloric acid leach tests across four of Splinter Rock’s prospects.
Metallurgical results show that roughly 80-90% of magnet rare earth oxides are located in the fine clay hosted size fraction, while removing the coarse-grained clays can lead to a 30-50% reduction in the material to be leached.
Overall, OD6 says the findings boost its confidence in Splinter Rock and serve as the impetus for further optimisation test-work, with infill drilling in the pipeline for all four rare earth prospects.
Potential for process optimisation
OD6 Metals managing director Brett Hazelden said the metallurgical findings, undertaken by a specialist team at the Australian Nuclear Science Organisation (ANSTO), represented a watershed moment for OD6.
“Results provide comfort that high recoveries can be achieved utilising a simple hydrochloric acid leach,” Hazelden explained.
“Testing has spotlighted the potential for additional process optimisation through lowering acid strengths, increasing leach times and removal of coarse grain clay material.
Samples pave the way
OD6 cherrypicked 25 samples from Splinter Rock’s four key prospects - Prop, Centre, Scrum and Flanker.
ANSTO set out to determine the leachability of these rare earths and metallurgical recoveries from each prospect are:
- Prop: 44% to 96% recovery of magnetic rare earths, averaging 71%;
- Centre: 54% to 78% recovery, averaging 62%; and
- Scrum & Flanker: 64% and 76% respective recoveries.
“It is becoming clear that the areas within the clay basins at distance from the source granites provide the best target zones.”
The MD went on to say the results underscored the importance of OD6’s electromagnetic survey results, which proved invaluable in targeting highly weathered clays.
Next up
OD6 plans to accelerate metallurgical test-work at Splinter Rock, drawing samples from a recently completed phase two drill program.
The campaign’s key objectives include expanding the number of acid leach conditions and investigating what impact lower acid dosages could have on leach duration.
Further drill assays are expected this month, while final airborne and 3D modelling data are expected in Q2. Step-out drilling is planned through May and June.
“Our immediate focus is to conduct targeted infill drilling in these clay basins and proceed with further optimisation test-work, bringing us closer to our near-term goal of declaring a significant, high-quality maiden JORC mineral resource estimate,” Hazelden concluded.