ITech Minerals have struck a metallurgy breakthrough at Caralue Bluff, achieving recoveries of up to 86 per cent total rare earth oxide from the cornerstone prospect of its Kaolin rare earth project in South Australia’s Eyre Peninsula.
Recoveries were even higher for the magnetic oxides, and results suggest the bulk of rare earth will be extractible and unbound from clay particles and resistive minerals.
Hydrochloric acid was used to create the high chloride environment, which separated the valued metals from the clay, and the next test will see if economical table salt can do the same trick.
Last year’s drilling stamped a hefty 110 – 220 Mt @ 635 – 832 ppm TREO and 19-22% Al2O3 exploration target on Caralue, but iTech Managing Director Mike Schwarz said improving recoveries had been the real challenge.
“Over the past few months, through our partnership with METS Engineering, we have systematically explored all the processing options and uncovered the right conditions for exceptional Rare Earth Element recoveries,” Mr Schwarz said.
“This has opened the path to creating a low-cost and effective leaching process. While it is still early days, this has the potential to be an important breakthrough for the economics of the Caralue Bluff Prospect.”
Clay-hosted quarry
Carbonatite-related deposits form the backbone of Australia’s rare earth production. Still, exploration is active across the nation for the easily extractible clay-hosted deposits around which China has built dominance in the sector.
ITech made the South Australian discovery of clay-hosted deposits while exploring the Eyre Peninsula and was quickly joined in the fray by other explorers, including Taruga Minerals, Resource Base, and Australian Rare Earths.
The Northern Territory also has known ion adsorption clay deposits containing rare earth elements, while Western Australian exploration is underway in the Gascoyne, Goldfields and Esperance regions.
Forward plan
ITech will focus on exploration at its Lacroma graphite prospect after doubling the strike length of Sugarloafin the same Eyre Peninsula while undergoing further test work on the viability of various ion exchange salts at Caralue.
