Mali Lithium (ASX: MLL) has achieved significant improvement in results from further metallurgical testwork of ore from its Goulamina Lithium Project in Mali.
The company’s Managing Director, Chris Evans, said that the company has brought in a range of new ideas since initial testing of Goulamina ore in the project’s PFS in June 2018.
Mr Evans said the Mali Lithium processing team has utilised innovation, experience and lessons learnt from recently commissioned Lithium concentration plants to improve lithium recovery and product quality by focusing on four main areas:
- Substituting reflux classification technology for selective mica pre-flotation to remove mica from the final product.
- Utilising innovative technology from CRIMM allowing the use of “High intensity permanent magnetic separators” to effectively remove Fe2O3 while minimising the corresponding loss of Lithium.
- Selection of flotation reagents specifically tailored to maximise recovery of Lithium from the Goulamina Ore, based on experience of the metallurgical team and the Nagrom Laboratory.
- Deletion of Dense Media Separation (DMS), which has thus far formed part of the recovery process, as it will only produce a small volume of coarse product.
The flotation, mica removal and magnetic separation testwork recently completed have demonstrated we can exceed our target of producing a high quality, high grade 6% Li2O concentrate with an overall 87% recovery from our ore at Goulamina,” Mr Evans said.
For this testwork programme a composite sample of drill core from six previously drilled HQ (64mm diameter) diamond drill holes located in the main and west pit was created.
The sample had an average grade of 1.74% Li2O which is higher than the PFS reserve grade of 1.56% Li2O. This is a consequence of selection of drill core to provide a representative sample of ore from the first five years of mining.
While higher feed grades can be associated with more easily achieving the 6% target product grade, the Mali Lithium team is confident that with the flotation testwork conducted and with further upcoming variability testwork, the excellent trends achieved in this round can be successfully replicated across a range of feed grades.
Water was shipped from the Goulamina site for use in the testwork to ensure realistic conditions and credible results.
Two separate batches of testwork were conducted. The first at the Nagrom Laboratory in Western Australia and the second at the Changsha Research Institute of Mining and Metallurgy (CRIMM) Laboratory in China.
The next step for testing of the Goulamina Ore is variability testwork, which will use the same flotation parameters across a range of feed grades of Li2O to ensure that the concentration process will deliver similar or improved results, under varying conditions and feed grades, invariably encountered in an operational mine site.