OD6 flags increase in metallurgical results from Splinter Rock with new method

OD6 Metals (ASX:OD6) has seen a 109% to 224% increase in total rare earth oxide (TREO) grades from samples at its Splinter Rock Project in Western Australia submitted to the Australian Nuclear Science Organisation (ANSTO) for metallurgical testing.  

The results were achieved after the removal of coarse material greater than 75 micrometres (μm). These results are expected to be fed into a Mineral Resource Estimate (MRE) upgrade. 

According to OD6, the results also delivered a simultaneous reduction in hydrochloric acid (HCI) consumption of up to 79%, to about 10kg HCI per tonne of screened ore. 

OD6 Metals Managing Director Brett Hazelden says lowering acid consumption provides a potential benefit to the overall cost profile of any future operation.

“Additional screening size optimisation will occur in future phases of work providing the potential for further improvements,” Hazelden says. 

In line with the additional tests, the company will conduct sighter bottle roll tests using selected phase three drill samples.  

Darren Holden, non-executive Chair of OD6, says the application of clever science, coupled with solid engineering, is key to the future development of clay rare earth element (REE) deposits in Australia. 

“We have already proven, with drilling, that OD6 has some of the best thickness and grades of clay REE in Australia,” Holden says. 

“This work will be applied to our ongoing geometallurgical exploration programs — where we are steadfastly prioritising the ‘best of the best’ zones within our vast thick clay basins — as well as to metallurgical programs and ultimately our economic studies.”  

A total of 13 phase one samples were selected from a wide variety of clays, locations and depths to further develop a geo-metallurgical understanding of acid consumption and recovery across the various regolith types at our four large prospects at Splinter Rock — Prop, Centre, Scrum and Flanker. 

Head samples were assayed prior to, and then after, screening out of material with greater than 75μm particle size. The screened and unscreened samples were subjected to the standard ANSTO diagnostic leach tests at 25 g/L hydrochloric, at notionally ambient conditions and pressures, over a 6-hour period. 

OD6 says the objectives of the tests were to determine if screening material resulted in decreased acid consumption and to identify any impacts (positive or negative) on MagREO recovery. A high-level assessment could then determine if screening was beneficial or not for each sample. 

Further screening tests will be undertaken from samples from phase two and three drilling programs that are currently underway, or have completed bottle roll testing.

The company notes the best results came from areas within clay basins and channel areas and away from the granite boundaries. 

OD6 Metals is pursuing exploration and development opportunities within the critical mineral sector. The company has a project portfolio focused on rare earths in the Esperance-Goldfields region of Western Australia.  

Write to Adam Drought at Mining.com.au

Images: OD6 Metals
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Written By Adam Drought
Born and raised in the UK, Adam is a sports fanatic with an interest in Rugby League and UFC/MMA. When not training in Muay Thai and Brazilian Jiu Jitsu, Adam attends Griffith University where he is completing his final year of a Communication & Journalism degree.