Jindalee Resources Limited (ASX:JRL) has confirmed that global engineering, construction, procurement and maintenance company Fluor Corporation has completed a review of the metallurgical testwork undertaken by Jindalee at the company’s wholly-owned McDermitt Lithium Project in the USA.
The review included an examination of various lithium extraction pathways and determined that acid leach with beneficiation is expected to produce the best economic outcome for the Project.
The review recommends that metallurgical testwork commences immediately to refine the preferred flowsheet in order to support further studies on the Project, incorporating the recently updated Mineral Resource Estimate (MRE).
Background:
Currently, there are two potential pathways for the extraction of lithium from sedimentary deposits such as McDermitt: sulphuric acid leaching of either whole or beneficiated ore, and alkali salt (sulphation) roasting.
Initial work completed by Jindalee focussed on beneficiation and sulphuric acid leaching, similar to the flowsheet proposed by the nearby Thacker Pass project.
The results of the acid leach testwork to date have been successful with highlights including:
• Lithium recoveries of over 95% with sulphuric acid (H2SO4) leach at moderate temperatures and atmospheric pressure on whole of ore samples.
• Increase of lithium content in the <0.01mm fraction by more than 50% (from 0.22% to 0.34%) via beneficiation of McDermitt ore (attrition scrubbing) at 20% solids which also reduced carbonate and analcime (both acid consuming minerals).
• Further attrition scrubbing test work demonstrated an increase in the lithium content in the <0.01mm fraction by 60.9% (from 0.23% to 0.37%)4.
• Leaching experiments on beneficiated samples demonstrated lithium extraction rates of 94-97% with 26% less acid consumed per lithium unit than for previous similar experiments on non-beneficiated ore.
In its 2021 Preliminary Scoping Study, Jindalee also assessed the alkali salt roasting. Jindalee subsequently undertook whole of ore alkali salt (sulphation) roasting testwork on McDermitt ore. Alkali salt roasting is the processing route proposed for the Sonora Lithium Project5, owned by Ganfeng Lithium. The alkali salt roasting testwork successfully produced lithium phosphate (Li3PO4) assaying 5.89% Li from ore grading 0.15% Li, indicating a 40x uplift in grade, before purification.
The testwork also confirmed lithium extraction of 89.5% using salts recycled from roasting and leaching, with positive implications for reduced reagent usage6. Investigation of the potential to apply beneficiation in the proposed sulphation roast flow sheet confirmed that this process is not applicable.
Next Steps:
Jindalee intends to immediately commence the metallurgical testwork recommended by Fluor to refine the preferred flowsheet. The results of this testwork will be integrated with optimised mine studies on the latest McDermitt MRE and will inform the next phase of studies at McDermitt.
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