Volta Metals has completed an extensive bench scale test work aimed to de-risk the processing of the payable rare earths and gallium.
A series of tests were carried out SGS Lakefield on a master composite sample, representing the Lavergne-Springer ore, to generate metallurgical insights.
The Lavergne Springer (LV) ore, characterised by coarse-grained rare-earth carbonates, presents a potentially advantageous feedstock due to:
- Amenability to cost-effective concentration: A REE carbonate concentrate is anticipated at a relatively coarse grind size of P80 106 µm (typical ball mill product).
- Favourable downstream processing: The expected REE carbonate concentrate is generally amenable to lower-cost processing routes compared to more common phosphate feedstocks.
Synchysite/Parisite: The dominant REE-bearing mineral, identified as likely synchysite based on the calculated TREO content (approximately 50% of the mineral mass, consistent with theoretical values for synchysite of 51.4% TREO), exhibits good liberation (>75%) at P80 106 µm. This coarse grain size and liberation profile suggest that physical concentration methods are feasible. Heavy liquid separation (HLS) tests using an SG cut-off of 3 should produce a rough synchysite/parisite concentrate representing 10-16% of the feed mass, with a TREO grade of 12-19% in the heavy mineral concentrate.
The characterization work completed to date indicates that the LV ore, with its coarse-grained and liberated synchysite, is a promising REE resource. The potential for a cost-effective beneficiation process based on gravity separation is significant. A preliminary process flowsheet targeting the production of REE chlorides is proposed, with the initial focus on generating a synchysite concentrate.
The test work strongly suggests that gravity separation, after grinding to a P80 of 106 µm, would be the most efficient and cost-effective first-stage beneficiation method for this ore.
