Sovereign Metals Ltd (ASX:SVM, OTC:SVMLF, AIM:SVML) is encouraged by downstream test work demonstrating that spherical purified graphite (SPG) with world-leading specifications for use in lithium-ion batteries can be produced from the Kasiya Project in Malawi.
Tests at leading, independent consultancy ProGraphite GmbH in Germany delivered exceptionally low levels of residual impurities achieving a 99.99% loss-on-ignition (LOI).
SPG produced
The company provided Kasiya graphite concentrate to ProGraphite to produce and characterise coated spherical purified graphite (CSPG) active anode material for lithium-ion batteries.
This 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.
Kasiya SPG demonstrated all required parameters within industry standards with spheronisation yields of up to 68% with further scope to optimise in future test work.
“Outstanding results”
“These results clearly demonstrate that Kasiya has the potential to disrupt the China-dominated graphite supply chain as a long-term, secure source of high-quality graphite ex-China," managing director Frank Eagar said.
"We believe Kasiya graphite will have industry-low operating costs and is also one of the largest graphite resources globally holding a significant advantage over its graphite peers.
"We are very pleased to achieve these outstanding results at this stage of the program and will continue fast-tracking our graphite product development and qualification campaign.”
About the testing
Test work was undertaken as part of the company’s graphite strategy to qualify and commercialise graphite concentrate for use in the lithium-ion battery sector.
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.
High purity
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 (iron, sodium, chromium, copper, aluminium, molybdenum) show very low levels.
Further, the low silicon and calcium results highlight that high quality Kasiya graphite is well-suited to single-stage acids purification.
Aggressive dosing in acids purification can result in elevated calcium levels due to precipitation of CaF2, necessitating multiple stages of purification to reduce both silicon and calcium impurities. These initial purification results indicate that a single purification stage is sufficient for Kasiya graphite concentrate.
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, which will provide baseline data for offtake discussions. The results of these tests are expected in the coming weeks.