The latest test results confirmed ‘significant’ increases in lithium grades and the removal of carbonate and other acid consumer minerals.
This test work was designed to evaluate the potential to further upgrade McDermitt ore and reduce acid consumption by removing carbonate prior to leaching.
Results from the first phase of this work confirm that beneficiation of ore through attrition scrubbing leads to what JRL describes as "a significant increase in head grade and reduction in carbonate and other acid consuming minerals".
Positive implications for capital costs
The potential for a substantial reduction in the volume of material being leached, coupled with removal of acid-consuming minerals through the application of conventional processing technologies has positive implications for both operating and capital costs for the project.
Jindalee is reviewing the results of this recent test-work before proposing further work.
Shares are up almost 10% to $A0.45, which represents a new high of more than nine years and since the market close on July 27 have risen from A$0.335.
Around 44 kilograms of coarse residues in crushed core from holes MDD-006 and MDD-012 was shipped to Hazen Research Inc, a well-regarded metallurgical laboratory in Colorado.
These holes were selected because, like MDD-008, they are in a relatively shallow part of the McDermitt resource and, therefore, represent portions of the deposit likely to encountered early in any future mining operation.
In the best results, attrition scrubbing at 20% solids was able to:
- Increase lithium in the <0.010mm fraction to 0.34%, representing an increase of more than 50% over the head sample; and
- Reduce carbonate to 3%, representing less than half the head sample.
Jindalee believes results from this experiment are encouraging with 90-91% of the lithium in the sub-samples reporting to the rougher tails (fine slimes) and 66-74% of the carbonate being rejected through the rougher concentrate.
June 2020 metallurgical test work
In June 2020 Jindalee released the results from metallurgical test-work on a sample of McDermitt ore from hole MDD-008, which had been shipped to Perth to trial alternative processing routes.
Initial results from this work confirmed that most of the lithium occurs in the fine (clay) fraction, with material sized <0.038mm, representing 58.5% of the mass but containing 80.4% of the lithium.
This work also returned very high leach rates using hydrochloric acid (HCI) with 97.9% of the lithium extracted after 30 minutes.