Everest Metals Corporation has signed a memorandum of understanding (MOU) with Edith Cowan University (ECU) to collaborate on rubidium extraction tests on samples from its Mt Edon lithium-caesium-tantalum (LCT) pegmatite project, 5km south-west of Paynes Find in Western Australia’s Mid West region.
The company has been developing a strategy aimed at unlocking its combined rubidium-lithium resource since drilling results, including those from a recently completed 566m phase-two reverse-circulation (RC) program, focussed on higher-grade zones identified in a preceding program.
Everest says both campaigns have highlighted an interesting geological setting at the project, which hosts high-grade, world-class rubidium intersections that coincide with elevated lithium occurrences. Results include rubidium-lithium grades of up to 0.51 per cent rubidium oxide and 0.94 per cent lithium oxide.
The longest intercept from 10 RC drillholes, most of them along an exposed pegmatite, intersected a massive 80m grading 0.32 per cent rubidium oxide and 0.11 per cent lithium oxide from 25m, including 9m at 0.47 per cent rubidium oxide from 87m.
The stage-two drilling, which homed in on the previous best results, returned a total of 14 intersections of varying widths grading more than 1.05 per cent lithium oxide in combination with rubidium oxide and also contained other high values of up to 10 per cent potassium oxide and up to 535 parts per million caesium. Everest says that the high value of rubidium grades is primarily associated with well-developed white mica zones.
To date, the best intercepts appear to exist within a 600m-long, north-east/south-west-trending corridor about 1.5 to 2km wide, where multiple, roughly-parallel pegmatites are exposed at surface. Thick intercepts of LCT pegmatite mineralisation has been intersected in at least six RC holes less than 120m below the natural surface level.
The corridor is interpreted by the company as possibly a mineralised alteration zone between the intrusive pegmatites and the mafic country rock.
Everest Metals Corporation chief operating officer Simon Phillips said: “EMC’s high-grade intersections of the critical rubidium mineral has led to rapid assessment of processing options. EMC is excited to team up with the experienced team at ECU’s Mineral Recovery Research Centre to explore the extraction of rubidium at its Mt Edon project. Our management is very impressed with the substantial laboratory assets available to the team at the research centre it visited in recent weeks. EMC’s geological team will work through next steps of resource development in coming months. Grade is the key and grade is what we have.”
The company says its MOU will allow cooperative activities in ECU’s Mineral Recovery Research Centre (MRRC) for three years to undertake a direct rubidium extraction process using advanced processes such as ion exchange. Under the terms of the MOU, Everest will retain ownership of any intellectual property rights deriving from the project.
The processes involved extend to recovery, purification and refining, which will lead to final products such as rubidium salts and metal.
The company says the MRRC offers a world-class service to resource recovery challenges faced by mining corporations, State and national organisations and international industries looking to develop efficient mineral processing and recovery technologies. It says it is focussing on mineralogical and geo-metallurgical studies to gain a better understanding of the composition of its high-grade rubidium and to characterise the mineral assemblage within Mt Edon’s LCT pegmatites.
Additionally, it will continue to review mineral processing technologies in a bid to enrich rubidium and lithium recoveries.
Rubidium is a United States-designated critical metal used for fibre optic telecommunication systems, photoelectric cells (solar panels), motion sensors, night vision devices and in medical imaging. As rubidium carbonate, it is currently fetching about US$1100 (AU$1688) per kilogram, making it one of the highest-value critical metals.
Everest says it is now planning for follow-up drilling to run in conjunction with its mineralogical and processing studies.
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By Doug Bright
