International Graphite reports strong purification and electrochemical results from Springdale concentrate
International Graphite (ASX: IG6) has reported “exceptional” results from purification and electrochemical test work on graphite concentrates generated from its wholly-owned Springdale project in Western Australia.
The micronising, spheroidising and purification program was conducted in Germany by industry specialist ProGraphite GmbH, while the electrochemical work was carried out by a specialist battery testing group under ProGraphite’s supervision.
The concentrate came from reserves produced from previous beneficiation test work using Springdale drill core samples.
Purification test work involved the application of a modified caustic soda roast process at lower temperatures than previously applied and with a simplified number of stages.
Optimised tests achieved results ranging from 99.96% loss on ignition (LOI) to 99.97% LOI, exceeding the industry-standard purity grade of 99.95% and meeting all the element-specific requirements of major lithium-ion battery and electric vehicle manufacturers.
International Graphite said there was considerable scope to further optimise the results.
Electrochemical work
Electrochemical test work on the uncoated purified sample of concentrate achieved close to the theoretical-specific capacity for a graphite anode in lithium-ion batteries of 372 milliampere-hours per gram (mAh/g).
Battery stress testing over 46 charging and discharging cycles showed Springdale graphite concentrate to have a very high stability and durability, with the 46th cycle giving a reversible capacity of 368mAh/g.
Stress testing over longer cycles is due to be completed in the next stage of battery test work, using a 115-kilogram sample of Springdale graphite concentrate produced in a bulk concentrate test work program in late-2023.
Potential demonstrated
Technical director David Pass was pleased with the results to date.
“The purification results demonstrate the potential for an optimised and simplified process to be used as an alternative to the traditional industry-standard [hydrofluoric acid] method,” he said.
“The electrochemical results are highly encouraging as a first-phase sighter test program [and] will inform the optimisation of micronisation, spheroidisation and purification test work and flow-sheet development for our planned battery anode facilities.”
Pilot plant
Last month, International Graphite commissioned a new 200 tonnes per annum graphite micronising pilot plant at Collie, south of Perth.
The plant will be the first to produce graphite products in Australia for customer acceptance testing.
It has been developed ahead of the 4000tpa commercial micronising facility the company is aiming to bring online at Collie within 18 months.