OD6 Metals Ltd (ASX:OD6) has achieved what it describes as “excellent” metallurgical recoveries from Splinter Rock Project rare earth element (REEs) samples, which are being assessed with the aid of the Australian Nuclear Science Organisation (ANSTO).
Mineralisation taken from the Western Australian project achieved recoveries up to 90% for magnet REEs across 60 fresh samples and averaged magnet REE recoveries of about 62% at a concentration of 25 grams per litre of hydrochloric acid.
In an important discovery for the overall economics of the project, the recoveries for all magnet rare earth oxides (MREOs) were similar, whether it be neodymium, praseodymium, dysprosium or terbium.
“Premier clay REE deposit”
“The outstanding results from our metallurgical leaching studies continue to affirm the Splinter Rock project as Australia’s premier clay-hosted rare earth deposit,” OD6 Metals managing director Brett Hazelden said.
“With consistent recoveries averaging over 60% across multiple prospects, and notably high recoveries observed for each of the 15 rare earth elements, our confidence in the project’s potential remains high.
“The Inside Centre area within the Centre Prospect continues to shine, boasting dimensions of approximately 2 kilometres in length by 1 kilometre in width and thicknesses of up to 69 metres.
“Grades ranging between 1,400 parts per million (ppm) to 2,200ppm total rare earth oxide further underscore the project’s value proposition, complemented by leach recoveries averaging 64%.”
The metallurgical recovery percentages from each prospect include:
- Centre Prospect - 40% to 90% recovery of magnet REE (average 60%);
- Flanker Prospects - 41% and 62% recovery of MREE (average 53%);
- Prop Prospect - 30% to 84% recovery of MREE (average 70%); and
- Scrum Prospect - 40% to 89% recovery of MREE (average 65%).
The assays were produced with the 4-acid soluble digestion method, aligning with the reporting of geological drill assays and the mineral resource estimate.
“These metrics align closely with the essential value drivers we believe are crucial for the economic viability of clay-hosted rare earth projects,” Hazelden continued.
Of particular significance is the remarkable performance across all four magnetic rare earth elements, indicating a diversified resource base that is not reliant on just one or two elements.
“This diversification is a key factor for ensuring the economic sustainability of the project and sets Splinter Rock apart as a highly promising venture in the rare earth sector.”
Strong economic indicators
OD6 says it is particularly excited about its latest metallurgical results due to the high synergy with the project’s other features – mineralisation from Splinter Rock is high grade according to the company, requiring low stripping ratios, low acid consumption which coupled with high tonnage and strong recoveries provide a robust case for the project’s key economic drivers.
The company says the increased understanding of recovery rates has also furnished it with a better understanding of specific areas of the expansive clay basins at Splinter Rock, so it can target areas that offer the best recovery and thus highest economic value.
Further metallurgical leaching and processing optimisation is already underway.
“Two years ago we began the task of positioning OD6 at the forefront of research into geo-metallurgical exploration for Australian clay REE deposits,” OD6 Metals chair Dr Darren Holden said.
“Our extensive REE-bearing clay basins 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.
“The board extends its congratulations to the OD6 team and our esteemed research partners for achieving this significant milestone in metallurgical understanding.
“This progress serves as a strong indication that our research and exploration efforts are positioning OD6 as a frontrunner for the future development of clay REE in Australia.”