OD6 enhances Splinter Rock understanding with ‘excellent’ recoveries

OD6 Metals (ASX:OD6) has enhanced its understanding of specific areas within its Splinter Rock Rare Earths Project in Western Australia, through conducting metallurgical leaching studies. 

Managing Director Brett Hazelden says the metallurgical program demonstrated excellent metallurgical recoveries, up to 90%, of Magnet Rare Earth Elements (MagREE) in multiple prospect areas across 60 new samples.

The recoveries averaged more than 60% across multiple prospects, which he says has add confidence in the Splinter Rock’s potential. 

The Australian Nuclear Science Organisation (ANSTO) undertook the program.

Samples were chosen based on differing geographic locations, REE grades, colours, chemical compositions, airborne electromagnetic (AEM) conductivity, proximity to granite, basin position, and inferred geological genesis. 

OD6, which has a market capitalisation of $9.22 million, is currently conducting further metallurgical leaching and processing optimisation work. 

An average 62% MagREE recovery at 25 grams per litre, with the Prop prospect averaging a recovery of 70%. 

The company says the recoveries for all magnetic rare earth oxides are similar, which is key to the overall project economics for any clay-hosted REE project. 

Meanwhile, the Inside Centre area of the Centre prospect achieved MagREE recoveries across all 4 MagREE elements averaging between 41% and 77%. 

Hazelden says: “The outstanding results from our metallurgical leaching studies continue to affirm the Splinter Rock Project as Australia’s premier clay-hosted rare earth deposit. 

The Inside Centre area within the Centre prospect continues to shine, boasting dimensions of approximately 2km in length by 1km in width and thicknesses of up to 69 metres. 

Grades ranging between 1,400 parts per million (ppm) to 2,200ppm TREO further underscore the project’s value proposition by leach recoveries averaging 64%. These metrics align closely with the essential value drivers we believe are crucial for the economic viability of clay-hosted rare earth projects.”

The Splinter Rock prospect areas are characterised by a combination of ionically adsorbed, acid-soluble and refractory REEs. 

All of the assays contained 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 (MRE). 

OD6 Chairman Darren Holden says 2 years ago the company began positioning itself at the forefront of research into geo-metallurgical exploration for Australian clay REE deposits. 

“Our extensive REE-bearing clay basin span hundreds of square kilometres, providing us with the ability to select basins based on superior grade, thickness, and recovery potential. 

Through ongoing collaborations with CSIRO, Murdoch University and ANSTO, we have made substantial progress in comprehending basin composition, regolith characteristics, REE mineralogy, and metallurgical recovery potential.”

OD6 plans to incorporate the latest results into a MRE to evaluate and potentially upgrade the mineral resource. 

A leach performance review and sighter bottle roll tests will be conducted, with the test using selected drill samples from the phase three program.

Further, the company will be investigating mixed rare earth precipitation methods, including carbonates and hydroxides and will then move onto develop process models and undertake techno-economic comparisons of various flowsheet options. 

Upon completing this, OD6 will apply process models to assess options for converting mixed rare earth carbonate/hydroxide in a downstream refinery to multiple potential rare earth oxides. 

OD6 Metals is an Australian critical minerals explorer and developer focused on its wholly owned assets in Western Australia. 

As of 31 December 2023, the company had $2.088 million cash and cash equivalents at hand, according to its latest quarterly report.

Write to Aaliyah Rogan at Mining.com.au   

Images: OD6 Metals
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Written By Aaliyah Rogan
Relocated from the East Coast in New Zealand to Queensland Australia, Aaliyah is a fervent journalist who has a passion for storytelling. When Aaliyah isn’t writing stories, she is either spending time with friends and family or down at the beach.