ChemX Materials Ltd. provided an update on the development of its High Purity Manganese Sulphate Monohydrate (HPMSM) project. Testing on a composite sample of ore taken from historical reverse circulation (RC) drilling at ChemX's Jamieson Tank Manganese Project on the Eyre Peninsula in South Australia by previous tenement owners, produced manganese sulphate crystals with 99.7% purity. This initial testwork program was designed to
identify the efficacy of the chosen process. To achieve near specification quality without any purification steps is very encouraging. Manganese is an essential component of the Lithium battery, in particular Nickel-Cobalt Manganese (NCM) batteries. NCM batteries are the predominant battery chemistry utilised by major auto manufacturers including Volkswagen 1, Tesla 2 and Renault 3 stating that manganese is a key part of their future development. The Jamieson Tank Manganese Project is aimed at producing HPMSM for lithium battery cathodes. ChemX has successfully completed the initial testwork program aimed at determining the suitability for the ore to be upgraded and processed into HPMSM. The Company completed its maiden drill program on the Project in March 2022 and is currently awaiting assay results prior to planning follow up exploration and further processing testwork. This initial testwork program consisted of two main stages, ore beneficiation and the production of manganese sulphate. Two composite samples were blended using reverse circulation (RC) chips collected by previous tenement owners. The head grades of the composites were 12.2 and 25.5% Mn. The only other elements present at >1% were Al, Fe and Si. Mineralogical analysis showed the lower grade ore to be predominantly quartz along with the manganese oxides cryptomelane, birnessite and pyrolusite, the higher-grade composite contained goethite and 1cryptomelane. Both samples had a significant fraction of amorphous material which is not uncommon in manganese ores. The high-grade ore was notably coarser in particle size with 91% >45µm compared to 59.5% for low grade. The high proportion of fines is due to the use of RC chips as the feed material, as the percussive nature of the method tends to produce a greater proportion of fines. Heavy liquid separation was conducted on samples screened into size fractions of +600µm and 45-600µm, with specific gravities (SG) of 3.30 and 2.95 selected on the basis of the mineralogy. The -45µm material cannot be tested using heavy liquid separation for practical reasons. The table below indicates the Mn grade and recovery for the different size fractions at the selected specific gravities. The highest density fraction was predominantly composed of Mn-oxide with concentrate grades of >53% achieved in both samples. The use of RC chips is not ideal where grades and recoveries are concerned as the inherently fine particle size does not allow optimisation of the physical separation, as the -45µm fraction is not amenable to heavy liquid separation. Once analyses are available from the samples obtained during the recent drilling programme further composites will be selectively blended, crushed and ground to minimise the fraction of <45µm material. Selected 45-600µm concentrates (i.e. with SG >2.95) from the heavy liquid runs were composited to give a head-grade of 43.8% Mn, 11.1% SiO2 and 7.0% Fe. A subsample was reductively leached using a standard method and filtered to give a solution containing 185g/L of Mn and a solid residue. The final solution contained <2ppm of Al, Fe and Si. The major impurity was potassium which was present in the cryptomelane. The Mn dissolution was believed to be limited by the maximum solubility in water, despite this, ~83% of the Mn was leached. Future runs will better match the slurry density and manganese concentration to ensure the leaching is not solubility limited. The resultant filtrate was not further purified in order to better assess the deportment of the impurities during crystallisation. The solution was evaporated to ~60% of its original volume at which time the crystals were filtered, water washed, dried using acetone and analysed. The final crystals were estimated to contain 99.7% MnSO4.H2O, manganese sulphate monohydrate. The
crystallisation process increased purity with only low levels of minor elements being incorporated into the product. Chemical analysis of the crystals showed 32.1% Mn, noted to be above the 31.8% typically required for HPMSM. Of the impurities typically specified for battery grade HPMSM, only three were above the required limit. It is expected that these can be reduced to below the required levels by incorporating a purification step between the leaching and crystallisation stages. Further work on the production of HPMSM is planned once the beneficiation work has been undertaken on the freshly drilled samples from March 2022 drilling program.