OD6 Metals (ASX:OD6) is pursuing additional phase two reconnaissance drilling at the Belgian, Circle Valley, and Scaddan prospects.
The $9.22 million market capitalisation company is also conducting additional sighter bottle roll tests using selected phase two drill samples.
The company today (6 March 2024) reports it has achieved ‘excellent’ metallurgical recoveries up to 86% magnet rare earth elements (MagREE) in multiple prospect areas as part of the Grass Patch Project in Western Australia.
The company collected 11 samples from 3 prospects, namely Belgian, Circle Valley, and Scaddan, which achieved an average 69% MagREE recovery.
At Belgian, metallurgical recoveries returned an average of 68.5%, while at Circle Valley, metallurgical recoveries returned an average of 78%.
OD6 reports most importantly, recoveries for all magnet rare earth oxides (MagREO) inclusive of neodymium, praseodymium, dysprosium, and terbium are all similar.
The company notes that this is key to overall project economics for any clay-hosted rare earths project.
Managing Director Brett Hazelden says the company has continued to leverage the work conducted at Splinter Rock, and apply it at Grass Patch, with the results confirming 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 6 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.”
The Grass Patch clay-hosted prospect areas are characterised by a combination of ionically adsorbed, acid soluble and refractory REEs.
OD6’s chosen assay method (4-acid digestion) does not report the refractory rare earth component, aiming to eliminate the variable grade proportion of the refractory material, which could introduce modelling errors in the future.
Work conducted by OD6 continues to demonstrate that utilising the alternative Lithium Borate Fusion Digest method can increase the head grade by up to 30% compared to the 4-acid assay method.
However, the company says it is important to note that this extra grade is highly unlikely to be recoverable in any proposed clay hosted rare earth process flowsheet.
All assays are based on the 4-acid soluble digestion method, rather than the ALS Lithium Borate Fusion Digest method, aligning with OD6’s reporting of geological drill assays and the Mineral Resource Estimate.
Future potential commercial production of REE is ‘significantly’ improved through successful leaching of both ionic and acid-soluble REEs, the company says.
OD6 Metals is an Australian explorer and developer focused on critical minerals. The Grass Patch Project lies in the Esperance-Goldfields region of Western Australia.
As of 31 December 2023, the company had $2.1 million cash at hand, according to its latest quarterly report.
Write to Aaliyah Rogan at Mining.com.au
Images: OD6 Metals
