OD6 Metals Ltd (ASX:OD6) has achieved high metallurgical recoveries in multiple prospect areas at its Grass Patch Project, north of Esperance in Western Australia, from samples tested at the Australian Nuclear Science Organisation (ANSTO).
The “excellent” metallurgical recoveries, of up to 86% magnet rare earth elements (MREE) in multiple prospect areas, were achieved across 11 new samples.
These 11 samples were selected from three of the Grass Patch prospect areas identified during the first pass reconnaissance drill program completed last year.
Recoveries averaged 69% MREE recovery at 25g/l HCl. At Belgian Prospect, MREE recovery ranged from 47% to 86% (average 68.5%); at Circle Valley Prospects from 76% and 82% recovery of MREE (average 78%); and 48% recovery of MREE from a single sample at Scaddan Prospect.
Importantly recoveries for all magnet rare earth oxides (MREO) — including neodymium. praseodymium, dysprosium and terbium — are similar. The company highlights that “this is the key to overall project economics for any clay-hosted rare earth project”.
Further targeted drilling
OD6 says that when combined with the first-pass reconnaissance drill program assays, these initial metallurgical results confirm further targeted drilling should occur at the Belgian, Circle Valley and Scaddan prospects.
OD6 Metals managing director Brett Hazelden said: “Whilst our focus over the last 12 months has been firmly on our world-class Splinter Rock Project, we have continued to leverage that work and apply it at Grass Patch.
“It is pleasing to report that all 11 metallurgical samples sent to ANSTO have surprised us on the upside of our expected metallurgical leach recoveries, with each of the 15 rare earth elements also being broadly equally recovered which is one of our key tests for clay projects to be potentially successful.
"The results confirm further targeted drilling should occur primarily at the Belgian, Circle Valley and Scaddan prospects.
“We have utilised our new bottle roll technique, developed in conjunction with ANSTO, designed and calibrated to reflect an equivalent six-hour stirred reactor leach. With reference to the low slurry density used, it is important to highlight this is the standard slurry density used by ANSTO for all clay-hosted rare earth projects inclusive of acid soluble and ionic diagnostic leach tests.
“As we progress further bench scale testing, it is anticipated that a slurry density of between 25% and 30% is likely to be optimal, as recorded on a number of other projects, with little to no decrease in leach recoveries.”
Grass Patch Project Prospect Areas and drill locations showing significant intersections >300ppm TREO