Castle Minerals Limited (ASX: CDT) ('Castle' or the 'Company') advises of another major achievement at its Kambale Graphite Project, Ghana, where a concentrate of a representative sample of mineralisation has been purified using conventional processes to an outstanding 99.97% Total Graphitic Carbon ('TGC') which exceeds the high-level benchmark required by the manufacturers of lithium-ion battery anodes ('Project'.

Test work was undertaken by Germany-based, ProGraphite GmbH ('ProGraphite') on 10kg of bulk fine flake graphite concentrate grading 95.1% TGC. The concentrate was produced from flotation test work on a composite sample of Kambale diamond core samples grading 10% TGC.

This test work was performed by Perth-based, Metallurgy Pty Ltd, under the supervision of Independent Metallurgical Operations Pty Ltd ('IMO'). The 99.97% purity achieved has been confirmed by an independent laboratory and, most importantly, with no impurities of concern noted. Prior to the actual purification process, the concentrate underwent various pre-treatments and analyses to obtain a comprehensive characterisation of the material. It was then micronised using an impact mill to generate a relatively uniform particle size range ahead of the spheronisation process where the fine graphite flakes are moulded in a special mill into sphere-shaped masses ('uSPG'). This is to increase carbon density, packing density and to maximise battery charge capacity. Spheronisation achieved a commendable uniform particle shape and size distribution (Photo 1). Purification of the spheronised material was achieved using a conventional alkaline, caustic soda based process. Importantly, it did not require the application of hydrofluoric acid (HF) which can introduce major handling and other safety considerations. The final process in the production of BAM (also referred to as Active Anode Material) is to apply a special coating to the purified, spheronised material. This process is highly specialised and often proprietary so at this stage is not being contemplated at Kambale.

Castle Managing Director, Stephen Stone said 'Increasing the purity of in-situ graphite mineralisation from

(C) 2024 Electronic News Publishing, source ENP Newswire