Consistent metallurgical tests are a big plus for Ionic’s rare earths project
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Special Report: Ionic Rare Earths’ initial test work on Makuutu Eastern Zone samples have returned results consistent with those from the central zone and other similar projects confirming potential for a very large resource.
The metallurgical testing applied similar parameters and simple process methods used during the optimisation program earlier this year and returned up to 34 per cent higher recovery of total rare earth elements minus cerium (TREE-Ce).
Encouragingly for Ionic Rare Earths (ASX:IXR), recovery of high-value critical rare earth elements (CREE) and heavy rare earth elements (HREE) from the project in Uganda continues to be favoured over lower value light rare earth elements (LREE).
This result could support a second processing module at the Makuutu Eastern Zone (MEZ) that produces also product dominant in heavy and critical rare earth oxides.
Previous test work has already confirmed that rare earth recovery of up to 75 per cent TREE-Ce can be achieved using a relatively simple method while recent optimisation work has increased rare earths element recovery in some lower recovery areas from less than 10 per cent TREO-Ce by seven fold.
“The results confirm a major improvement on expected extractions of the rare earths and reinforce the metallurgical optimisation results identified in the previous programs,” chief executive officer Tim Harrison said.
“Most significantly, these initial results indicate we can expect such recoveries – which are in-line with other globally significant Rare Earths projects – throughout the greater Makuutu project area.
“Furthermore, the simple process regime is modular and scalable, which could enable rapid replication of low-cost process modules to ramp up REO production.”
Makuutu currently has a resource of 78.6 million tonnes grading 840 parts per million TREO.
Metallurgical test work at the MEZ returned an average TREE-Ce recovery of 20 per cent at pH3.5 and 41 per cent at the more acidic pH1.
HREO recovery was 22 per cent at pH3.5 and 52 per cent at pH1, indicating that the majority of HREOs are present in the ionic or colloidal form.
This makes the HREOs readily recoverable using simple, low-cost mild desorption/leaching conditions.
Recoveries are also consistent with other ionic clay projects such as those in China, which are reported to have average REO extractions of 50 per cent.
Scandium recovery is also favourable and has increased to about 30 per cent with pH1 conditions.
Ionic noted that larger-scale tests are expected to be carried out in the ensuing field trials program.
It added that larger scale testing is likely to reduce reagent consumption and pH conditions over a longer test duration.