Sovereign Metals Limited announced the results of downstream testwork conducted at leading, independent consultancy ProGraphite GmbH in Germany. Sovereign provided Kasiya graphite concentrate to ProGraphite to produce and characterise coated spherical purified graphite (CSPG) active anode material for lithium-ion batteries. The overall program includes shaping and purification to produce SPG, coating of the material to produce CSPG and evaluation of the electrochemical performance of Kasiya CSPG in a battery.

The initial steps of shaping and purification to produce SPG have now been completed with the results showing Kasiya SPG has world-leading specifications. This SPG material is now undergoing coating and electrochemical testing to characterise CSPG active anode material for lithium-ion batteries. The micronisation and spheronisation of Kasiya graphite concentrates achieved excellent yields to spherical graphite for the coarse concentrate and typical yields to spherical graphite for the fines concentrate, with room for further optimisation.

The spherical graphite from the fine graphite concentrate in particular exhibited a narrow particle size distribution (D90/D10) ratio and both spherical graphite have reasonable Tap Density and typical BET for uncoated graphite. Coating of the graphite is expected to improve (increase) the tap density and improve (lower) the BET specific surface area. The spherical graphite products were purified with commercially proven acids purification and achieved excellent results with an exceptionally high LOI purity of 99.99%.

Assays on key trace elements (Fe, Na, Cr, Cu, Al, Mo) show very low levels. Further, the low Si and Ca results highlight that high quality Kasiya graphite is well-suited to single stage acids purification. Aggressive dosing in acids purification can result in elevated Ca levels due to precipitation of CaF2, necessitating multiple stages of purification to reduce both Si and Ca impurities.

These initial purification results indicate that a single purification stage is sufficient for Kasiya graphite concentrate. The SPG samples will undergo coating and electrochemical tests to provide baseline data for offtake discussions. The results of these tests are expected in the coming weeks.