Special Report: Ionic Rare Earths’ (ASX:IXR) metallurgical optimisation program has increased rare earths element recovery in some lower recovery areas by 700 per cent.
The company noted that while initial metallurgical testing at the Makutuu project in Uganda had achieved recoveries of up to 75 per cent total rare earth elements less cerium (TREE-Ce), samples from three holes returned recoveries of less than 10 per cent TREE-Ce.
However, its more recent testwork using lower pH leaching conditions and allowing a longer leach time has significantly improved recoveries of higher-value critical rare earth elements (CREE) and heavy rare earth elements (HREE) from a composite sample of the low recovery samples.
The use of more acidic leaching conditions to achieve the increase in recoveries has indicated that the REE recovered is not due to mineral dissolution, but colloidal REE sediment content within the ore, which is also observed in Chinese ionic clays in minor quantities.
Ionic Rare Earths added the resulting leach liquor contained about 51 per cent CREE and 47 per cent HREE, indicating the potential to produce a very high-value mixed rare earth product.
“These results are highly encouraging and the implication for the broader metallurgy of the Makuutu mineralisation is very promising,” technical director Dr Marc Steffens said.
“We had already demonstrated excellent recoveries of rare earth from a large portion of the drilled resource, and we fully expect that applying the outcomes and learnings from the optimisation tests to the larger area of Makuutu mineralisation will result in a marked positive impact on overall processing metrics.”
Metallurgical optimisation test work is ongoing to de-risk and add value to the project along with other aspects of the project development program.
Makuutu is one of very few ionic adsorption clay-hosted projects outside of China.
Besides a relatively simple method of rare earth recovery, it is located close to well maintained and available local infrastructure.
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