THE BOURSE WHISPERER: Lithium Australia (ASX: LIT) has commenced pilot plant testing of the company’s Sileach process for the recovery of lithium from silicates.
The testing was conducted at ANSTO Minerals’ (a division of the Australian Nuclear Science and Technology Organisation) Lucas Heights testing facility, located on the outskirts of Sydney, New South Wales.
Lithium Australia explained that hot commissioning of the plant was undertaken over a one day run, the nature of leach liquors and residues was evaluated and final adjustments made to plant components in preparation for continuous operation.
The pilot plant was fed continuously for six days, treating ore from LIT’s Lepidolite Hill deposit in Western Australia, using the Sileach process.
Approximately 650 kilograms of lepidolite ore was processed at an average throughput of 6kg/h.
The pilot plant design consisted of leaching and impurity removal circuits, based on test work conducted by ANSTO Minerals on similar ore to that processed during the continuous pilot plant run.
LIT said the campaign produced a purified lithium-containing liquor, devoid of impurities, which will be processed through to high-purity lithium carbonate in a second pilot campaign in the near future.
Extraction of lithium in the Sileach process exceeded 95 per cent in the leach circuit, which LIT declared to have validated both the overall extraction and accelerated rate of extraction of lithium achieved in the laboratory test work program.
The company went on to explain that the performance in the impurity removal circuits was comparable with the laboratory test work program, producing a liquor suitable for further processing.
“Plant performance could not have been better,” Lithium Australia managing director Adrian Griffin said in the company’s announcement to the Australian Securities Exchange.
“The results show that exceptional lithium extractions can be achieved without the need for fine grinding, or the production of clean concentrates.
“The material processed was not subjected to pre-concentration but still achieved outstanding performance with minimal feed preparation.
“These are key parameters for processing at low cost. Lower-grade spodumene concentrates (about 4.5 per cent Li2O) from Pilbara Minerals’ Pilgangoora project, will be processed in one of the subsequent test runs.
“We are intentionally concentrating on the lower-grade, hard rock products, from which no other processes can recover lithium commercially.
“Sileach provides significant processing advantages.
“Successful processing of spodumene from Pilgangoora is the first step of our commercialisation agreement with Pilbara Minerals, aimed at establishing a lithium chemical processing plant in Port Hedland.”