Highlights
- Program delivers further high-grade Rubidium-Lithium results up to 0.51% Rb2O and 0.94% Li2O:
- ME23-19 – 80m at 0.32% Rb2O and 0.11% Li20 from 25m
- ME23-15 – 5m at 0.27% Rb2O and 0.60% Li2O from 22m
- ME23-16 – 2m at 0.34% Rb2O and 0.42% Li2O from surface
- Company moves focus to commence mineralogical and processing studies for extraction of strategic critical mineral, Rubidium
- Planning for Stage-3 drilling program underway targeting new prospects and resource definition
COO Simon Phillips commented on the Stage-2 drilling results at Mt Edon:
“EMC’s latest round of drilling results confirms the existence of a geological setting that hosts high grade, world class Rubidium intersections coincident with increasing Lithium occurrences. EMC’s geological and management team will methodically continue developing its strategy to unlock a Rubidium/Lithium Resource on its ML. Planning for next stage drilling in conjunction with Mineralogical and Processing studies is now underway”.
Everest Metals Corporation Limited (ASX: EMC) (“EMC” or “the Company”)is pleased to announce the results from its Stage-2 Reverse Circulation (“RC”) drilling campaign at the Mt Edon LCT Project (M59/714) (“Mt Edon”) located 5km southwest of Paynes Find, in the Mid-West region of Western Australia (>About the Mt Edon Project).
REVERSE CIRCULATION PROGRAMME, STAGE-2
A total of 566m was drilled as part of the Stage-2 RC drilling campaign which was completed in early August 2023[1]. The drilling program was focused on lateral extension of high-grade zones intersected in the Stage-1 drilling program[2] and undrilled targets in the northeast corner of mining tenement (M59/714) designed to follow up the results from the Deep Ground Penetration Radar (“DGPR”) targets[3] and structural trends identified through surface sampling and geological mapping[4]. The drilling was conducted across six prospects and included 12 holes with an average depth of 47m (Figure 1). Samples collected during the recent drilling campaign were one-metre splits with 364 samples being sent to the ALS laboratory in Perth. Samples were assayed for a standard multi-element LCT pegmatite suite including rare earth elements using the process of a 4- acid digest followed by Lithium Borate Fusion ICP-MS for detection.
During Stage-1 drilling in late May 2023, drill hole ME23-07 intersected a mixed zone of altered mafic host rock and 62m of pegmatite up to a depth of 111m and remained open (Figure 1 and 2). Geological logging of the chip samples highlighted well-developed muscovite-rich zones. This zone is interpreted to be a mineralised alteration zone located between the intrusive pegmatites and the mafic country rock. The zoning and grade distribution suggests that there are lepidolite pegmatite pods near ME23-007, that was a target of the stage 2 drilling program. Hole ME23-007 intersected over 40 metres grading 0.26% Rb2O from 49m, including 19m at 0.33% Rb2O (0.43% Rb2O + Li2O), in addition to three higher grade zones of 2m @ 0.53% Rb2O + Li2O (14- 16m), 2m @ 0.53% Rb2O + Li2O (20-22m) and 2m @ 0.53% Rb2O + Li2O (30-32m). The entire mineralised intersection within ME23-007 indicates the highly fractionated and fertility of the pegmatite in the northeast corner of Mt Edon. The pegmatite body in this hole remained open at a depth of 111m (dip 60 degree) and shows there is high potential for lateral extensions particularly toward the northeast.
Based on the abovementioned interpretation; initially, Stage-2 drilling was designed to unlock the potential of a 600m pegmatite sitting along a northeast-southwest strike. This zone is interpreted to be a mineralised alteration zone located between the intrusive pegmatites and the mafic country rock.
10 x RC holes were drilled along this trend and all intercepted significant rubidium-lithium results. Some of the thickest and highest grade intersections are outlined below:
- Hole ME23-019 intersected over 80 metres grading 0.32% Rb2O and 0.11% Li2O from 25m, including 9m at 0.47% Rb2O from 87m.
- Hole ME23-018 intersected 31 metres grading 0.21% Rb2O and 0.12% Li2O from 35m, including 7m at 0.34% Rb2O from 39m.
- Hole ME23-016 intersected 2 metres grading 0.34% Rb2O and 0.42% Li2O from surface and 8 metres grading 0.13% Rb2O from 19m.
- Hole ME23-015 intersected 15 metres grading 0.22% Rb2O and 0.27% Li2O from 14m, including 5 meters at 0.27% Rb2O and 0.6% Li2O from 22m.
- Hole ME23-021 intersected 10 metres grading 0.21% Rb2O from 25m.
- Hole ME23-022 intersected 21 metres grading 0.14% Rb2O from surface.
- Hole ME23-023 intersected 3 metres grading 0.18% Rb2O from surface.
Figure 1: Location of RC drill holes in northeast corner of Mt Edon tenement (Stage-2 drilling)
Hole ME23-015 (N30E/60) was drilled perpendicular to drill hole ME23-07(N118/60E) and successfully hit higher grade rubidium-lithium (0.51% Rb2O and 0.94%Li2O) which was expected based on visual mineralisation mica rich zones from the chip tray[5].
Furthermore, two RC holes were drilled over pegmatite outcrops with a northwest-southeast trend located at the southern fault zone (Figure 1) – These holes were designed to test the depth of the pegmatites, with mineralisation being intercepted in both holes from surface:
- Hole ME23-012 intersected 3 metres grading 0.23% Rb2O and 0.1% Li2O from surface
- Hole ME23-013 intersected 5 metres grading 0.16% Rb2O and 0.1% Li2O from surface
The Stage-2 drilling program returned lithium-rubidium grades with a total of 14 intersections with grades in excess of 1.05% lithium-rubidium (Rb2O + Li2O) of varying widths, containing the high potassium values (K2O), of up to 10%, with significant caesium (up to 535 ppm). The Potassium / Rubidium (K/Rb) ratio in the entire pegmatite intersected in the holes reflects the degree of substitution of Rb for K in the mica’s crystal structure. The alteration zone indicates a high Rb/Li ratio and is interpreted to have a component of rubidium mica. Also, the highest rubidium grades were in mica rich pegmatites.
Significant anomalous LCT elements that occur in association with rubidium with a maximum value 0.51% Rb2O, include maximum values in individual drilling assayLi2O at 0.94%, Cs at 535 ppm, Nb at 247ppm, Ta at 278ppm and Sn at 155 ppm (Table 1). Additionally, findings from both the Stage-1 and Stage-2 drilling programs suggest that Mt Edon has the potential to be classified as a Rubidium-Lithium project[6].
It seems that the high value of rubidium grades is primarily associated with well-developed white mica zones. The Company is currently conducting mineralogical investigations using Electron Probe Micro-Analyzer (EPMA), and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) techniques. This research aims to provide a more comprehensive understanding of the mineral composition of the high-grade rubidium and to characterise the mineral assemblage within the LCT pegmatites at Mt Edon.
The Company now aims to focus mineralogical and geo-metallurgical studies to understand the nature of the resource as well as review various mineral processing technologies to enrich rubidium and lithium recoveries from the Mt Edon pegmatites.
Figure 2: A schematic cross section looking northwest – Shows significant mineralised intersections in hole MD23- 07, 15-16 and 18-19 located in the northwest area of the Mt Edon tenement
A summary of the important assessment and reporting criteria used for this exploration results announcement is provided in Appendix 2 – JORC Table 1 in accordance with the checklist in the Australian Code for the Reporting of Exploration Results, Mineral Resources, and Ore Reserves (The JORC Code, 2012 Edition). Criteria in each section apply to all preceding and succeeding sections.
RUBIDIUM PRICE AND MARKET
Rubidium is a US designated Critical (high value) Metal used for[7]:
- Fiber Optic Telecommunication Systems
- Photoelectric cells (solar panels)
- Motion sensor/Night Vision devices
- Medical Imaging
Rubidium’s potential as a component in sodium-ion batteries has seen growing interest in the rare metal market[8].
According to the January 2022 US Geological Survey of Mineral Commodities[9], rubidium and cesium can be used interchangeably in many applications because they have similar physical properties and atomic radii.
The price of Rubidium Carbonate is currently over $1,100/kg which is one of the highest value critical metals[10].
NEXT STEP
- Resource and new target drilling, planned to commence December 2023 quarter.
- Geo-metallurgical test work and mineralogical studies by EPMA and LA-ICP-MS to characterise the mineral assemblage of LCT pegmatites and mineralogy high grade rubidium.
[1] ASX: EMC announcement; Stage 2 Drilling at Mt Edon Successfully Intercepts Multiple Lithium-Caesium-Tantalum (LCT) pegmatites, dated 8 August 2023.
[2] ASX: EMC announcement; Mt Edon Drilling Results Confirms High Grade Rubidium, dated 13 July 2023.
[3] ASX: EMC announcement; Deep Ground Penetration Radar (DGPR) Geophysical Survey Successfully Identifies Previously Undiscovered Pegmatite Targets at Mt Edon Project, dated 1 May 2023.
[4] ASX: EMC announcement; Mt Edon Project Exploration Update, dated 29 March 2023.
[5] ASX: EMC announcement; Stage 2 Drilling at Mt Edon Successfully Intercepts Multiple Lithium-Caesium -Tantalum, dated 8 August 2023.
[6] The high grade intersected Rubidium is in line with world class Rubidium occurrences including the Karibib pegmatite deposit in Namibia (8.9 Mt at 0.23%Rb) and Guobaoshan deposit in China (234 Mt at 0.12%Rb).
[7] Global Rubidium Market Outlook to 2028, BlueQuark Research & Consulting, Q1, 2022
[8] Growing Rubidium Energy Metal Value Leads to Discovery Surge, The Assay, November 2022
[9] Mineral Commodity Summaries 2022, US Department of the Interior/US Geological Survey, 31 January 2022
