Pan Asia Metals (ASX:PAM) has achieved lithium mica concentrate grades of up to 3% lithium oxide (Li2O) with lithium recoveries of up to 78% in recently completed metallurgical testwork at the Reung Kiet Project in Thailand.
The company says this testwork was conducted on 2 separate composites of fresh and weathered mineralisation derived from laboratory ‘coarse crush rejects’ (100% less than 3.35mm) from half HQ-size drill core selected from drillholes across the project.
The fresh composite sample weighed about 125kg and was derived from 278 individual samples from 16 holes, and returned a head assay of 0.62% Li2O.
The oxide composite weighed about 100kg, and was derived from 133 individual samples from 11 holes, returning a head assay of 0.77% Li2O.
Pan Asia says the samples were selected to represent mineralisation throughout the deposit and reflect what are considered to be mineable widths in a potential open-cut mine. As a result the samples also contain both internal and external dilution which is predominantly composed of ‘low-grade’ siltstone.
These samples were then delivered to the technology division of Beijing General Research Institute of Mining and Metallurgy (BGRIMM) in China, who Pan Asia notes has experience in metallurgical aspects of lithium mica ‘lepidolite’ deposits in China.
BGRIMM carried out ‘extensive’ process mineralogy and beneficiation research, as well as testwork on samples provided by Pan Asia. This research included inductively coupled plasma (ICP) spectrometry, chemical composition analysis, mineral composition, and relative content determination, characteristics, as well as grain size of the main lithium minerals.
It also conducted a study on the association and separation characteristics of main lithium minerals in different grinding products, and an analysis of mineralogical factors influencing lithium recovery.
Commenting on the metallurgical testwork results, Pan Asia Metals Managing Director Paul Lock says: “The metallurgical testwork results are exceptional , a 3% lithium oxide concentrate and 78% recoveries from a representative sample containing modelled internal and external dilution and reflecting what are considered to be mineable widths in an open cut mine, is a very good outcome.
With further optimisation testwork underway, which will incorporate the ore sorting results previously reported, we are confident that grade and recovery improvements will be seen.
“With further optimisation testwork underway, which will incorporate the ore sorting results previously reported, we are confident that grade and recovery improvements will be seen”
We are also very pleased to report that a lithium concentrate was produced from the weathered zone using industry standard methods and undergoing similar comminution and beneficiation to the fresh zone. This is important as the weathered zone can now be included as a source of lithium oxide concentrate for mine planning purposes, and although recoveries were slightly lower the weathered zone is essentially free dig and therefore is reasonable to expect lower mining costs.
The concentrate will now undergo roasting and conversion testwork with ALS Global in Perth to produce lithium carbonate. Testing will use a sulphate roast, a process predominantly used in China which is low-cost and de-risked.
We will also conduct preliminary oxidative acid leach test work with Glencore Technology in Brisbane. With a satisfactory outcome to the upcoming mineral resource upgrade PAM (Pan Asia Metals) intends to progress straight to a Prefeasibility Study (PFS) for the Reung Kiet Lithium Project and would be aiming for completion later this year.
PAM’s aim is to submit a mining licence application (MLA) for the Reung Kiet Lithium Prospect in mid-2023 and an MLA for the Bang I Tum Prospect in late 2023-early 2024. While the MLA process is underway PAM will be completing other studies relevant to the PFS.”
Pan Asia reports beneficiation research and testwork included acid-base process scheme comparison tests, floatation tests using grind sizes, contrast tests for desliming and not desliming, as well as different desliming quantities. Other testwork carried out included type and amount of reagents or conditioning tests, types and amount of collector tests, floatation time tests, floatation tests for the regrinding fineness, tests for cleaning conditions, rougher concentrate, several open circuit process comparison tests, and closed circuit tests.
The company says the technical means and instruments used in this study included chemical analysis, optical microscopy, scanning electron microscopy, electron microprobe analysis, advanced mineral identification, as well as characterisation system (AMICS) among other applicable measures.
Pan Asia says additional testwork is planned to be conducted on weathered and fresh mineralisation at ALS Global in Perth where samples will undergo roasting and conversion testwork to produce lithium carbonate. Additional lithium mica concentrate will also be sent to Glencore Technology in Brisbane to undergo oxidative acid leaching to solubilise the lithium for conversion to lithium carbonate.
The company also says it will continue drilling at Reung Kiet, aiming to provide a Mineral Resource Estimate (MRE) update in late February, as well as assessing the exploration target at the Bang I Tum Prospect to define a mineral resource.
Pan Asia Metals is a battery and critical metals explorer operating the Rueng Kiet Lithium Project, the Kata Thong Lithium Project, and the Khao Soon Tungsten Project in Thailand.
Images: Pan Asia Metals Ltd
