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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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This article includes content from Jindalee Resources Limited, licensed for the purpose of publishing on Investing News Australia. This article does not constitute financial product advice. It is your responsibility to perform proper due diligence before acting upon any information provided here. Please refer to our full disclaimer here.
JRL:AU
Spodumene Pegmatite Discovery at Esperança Project in Brazil Yields LIBS Results up to 4.04% Li2O
The discovery has been made during early-stage exploration programs which include project scale geological mapping, ground reconnaissance, and soil sampling. These early-stage programs remain ongoing with further results to come over the coming weeks. The discovery supports the Company’s exploration thesis and uplifts the remaining prospectivity across all three project areas: Canabrava, Caraíbas and Esperança projects.
HIGHLIGHTS
- Artisanal excavations reveal a lithium bearing pegmatite with elongate crystalline spodumene crystals up to 50cm in length
- LIBS (Laser Induced Breakdown Spectroscopy) results of spodumene crystals return up to 18,800 ppm Lithium, or 4.04% Li2O
- Discovery provides walk up drill target for fully funded drilling campaign to begin Q1 2025
- Soil sampling and geological mapping continues across the Esperança, Canabrava and Caraíbas projects with further results due over the coming weeks
Lightning Minerals Managing Director Alex Biggs said, “I am highly encouraged by these results from Brazil. As I have spoken about, as a team we are committed to discovery and completing our works in a diligent and structured manner, the proof of which is in these results. The Company is progressing its projects in Brazil quickly and cost effectively and generating significant results for the business which we feel will be transformational. I am proud of and congratulate our geology teams both in Australia and Brazil who have conducted themselves in a professional and astute manner which has been crucial in making a discovery such as this. This is a great first step for us in Brazil and is testament to the prospectivity of the region as I have discussed previously. We look forward to drilling in Q1 2025 and further results to come imminently from all three project areas in Brazil. I would also like to thank our shareholders who have supported our vision and exploration strategy. As a Company we are firmly committed to the lithium thematic and firmly committed to Brazil where we see significant potential moving forwards”.
Lithium Discovery at Esperança Project
During geological mapping fieldwork conducted in mid-November 2024 field geologists encountered a previously unknown historical artisanal mine within the Esperança project area. The site presented with a small access which opened into a set of sub vertical shafts sunk several meters into schists of the Salinas formation. Upon investigation the geology team has discovered pegmatitic lithologies in the walls of the excavations, of which the suite of minerals indicates inclusion of macro crystalline (up to 50cm) elongate crystals of spodumene as shown in Figure 1(a) and Figure 1(b).
Figure 1a (left): Brazilian geologist Vitor Araujo Alves showing the spodumene rich portion of the zoned pegmatite discovered at the Esperança Property. Figure 1b (right): Large elongate spodumene crystals (Spd) up to 50cm in length showing homogeneous growth patterns amongst a quartz (Qtz) and Feldspar (Fdsp) rich matrix
The Company’s geologists have collected selective mineral specimen grab samples in sample VLM207 (Figure 2). Six separate minerals have been analysed via a SciAps Z-903 hand-held LIBS (Laser-Induced Breakdown Spectroscopy) device which has returned lithium endowment of up to 18,800 ppm lithium, which equates to a lithium oxide percentage of 4.04% Li2O.
The SciAps Z-903 handheld LIBS device is considered a qualitative analysis technique only and is used as an in-field preliminary check to establish if a mineral is lithium-bearing. Certified laboratory assays are required to provide accurate, quantitative analysis. A table of the six SciAps Z-903 handheld LIBS results testing the spodumene crystals is shown in Table 1. A full table of results are presented in Appendix 2, Table 2.
While the current field observations indicate that the mineral identified is a lithium-bearing mineral, the percentage of lithium produced from the LIBS analyser does not correlate to an accurate quantitative measurement of the lithium concentration of the mineral itself, or to the overall grade of the pegmatite.
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This article includes content from Lightning Minerals, licensed for the purpose of publishing on Investing News Australia. This article does not constitute financial product advice. It is your responsibility to perform proper due diligence before acting upon any information provided here. Please refer to our full disclaimer here.
