Exceptional Metallurgical Results from McD​ermitt

Jindalee Resources Limited (to be renamed “Jindalee Lithium Limited”) (Jindalee, the Company) announced initial head assay results for metallurgical samples from the Company’s 100% owned McDermitt Lithium Project located in Oregon, USA and noted that beneficiation was underway, ahead of acid leach testwork². The testwork is being undertaken at consultant metallurgists Hazen (Colorado, USA) and being managed by leading global engineering, procurement, construction and maintenance company Fluor Corporation.

• Exceptional results from beneficiating McDermitt ore using simple screening
• Attrition scrubbing at a coarse cut size of 250 microns returns 92.0% Li recovery with 25.3% mass rejection
• Lithium grade to leach increases to 2,107 ppm Li, 57% higher than the average Mineral Resource grade (1,340 ppm Li)¹
• Potential for further improvements by optimising cut size for specific mineralised units
• Leach testwork on beneficiated samples currently underway with results to feed into PFS

Jindalee is pleased to advise that beneficiation of these samples via attrition scrubbing has been completed, returning excellent results. Pit shell composites consisting of Units 4, 6, 8 and 10 from conceptual Pit Shell 6 (nominal 43 years) (Figures 2 and 3), recovered 92.0% of the lithium to leach feed and rejected 25.3% of the mass at a cut size of 250 microns (Table 1). The average grade to leach was 2,107 ppm Li, 18% higher than the average head grade of the metallurgical samples (1,790 ppm Li)² and 57% higher than the average Mineral Resource grade (1,340 ppm Li; refer Table 2).

Table 1 – Summary of Lithium Recoveries via Attrition Scrubbing at 250 micron cut size (Pit Shell 6)

Beneficiation testwork on individual units has confirmed higher lithium concentrations in the finer fractions of Units 4 and 6, where the minus 38-micron fraction contains 90.5% and 81.1% of the contained lithium respectively (Figure 1). This has positive implications for processing of these deeper units with the potential to optimise lithium recoveries by adopting a finer cut size as development progresses.

The 250-micron cut size will be adopted for initial acid leaching testwork for the McDermitt Pre-feasibility Study (PFS), with variable attrition times and cut sizes, and scrubbing of coarse material (to increase recovery of lithium to fines), to be further investigated. Initial results are expected early December 2023.

Figure 1 – Lithium Recovery to Leach Feed by particle size (Units 4, 6, 8 and 10)

Discussion

In March 2023 Jindalee announced that previous metallurgical testwork undertaken at McDermitt had been reviewed and that acid leaching with ore beneficiation (to upgrade the leach head grade) had been determined to deliver the best financial outcome among the alternatives considered³. It was also noted that the very large Mineral Resource Estimate (MRE) at McDermitt (21.5 Mt LCE, Table 2)¹ allowed flexibility in development, providing the opportunity to optimise mining and feed higher grade ore early in the mine life. Subsequently, a comprehensive metallurgical testwork program has commenced to provide testwork data upon which the preferred flowsheet for the processing of McDermitt ore can be designed.

Recent relogging of McDermitt drilling has recognised up to 12 distinctive stratigraphic units which can be tracked across the Project (Figure 2). Four of these units (Units 4, 6, 8 and 10) carry elevated lithium grades and selective mining of these units has the potential to deliver significantly higher grade material (when compared to the MRE average grade) for processing².

Figure 2 – Schematic Section C-C’ with completed drilling, simplified geology and conceptual Pit Shell 6 (nominal 43 years). (Note: lateral projection onto section plane and 3x vertical exaggeration may cause distortion)

In June 2023 leading mine engineering group Cube Consulting generated conceptual pit shells using the McDermitt MRE geological model (Figures 2 and 3) to assist with selection of samples for the metallurgical testwork program. Samples from Units 4, 6, 8 and 10 within the Indicated portion of Pit Shell 6 (nominal 43 years) were selected and approximately 700kg of drill core was despatched to Hazen for testing. Initial head assays for these samples were announced on 23 October 2023² with results from beneficiation of these samples now being reported.

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