Abstract
Integrated piloting testwork utilizing pressure oxidation, precipitation, solvent extraction, and the re-leaching of mixed Ni-Co hydroxide precipitates was carried out by the ALS Hydrometallurgy Centre of Excellence (HCE) as part of the Ta Khoa Refinery Definitive Feasibility Study (TKR DFS) for Blackstone Minerals. Concentrates from the Ban Phuc Nickel Mine were blended with two third party concentrates supporting the TKR DFS.
The main objective of the overall flowsheet was to remove impurities to produce battery grade nickel and cobalt sulphate whilst maximizing Ni and Co recovery as a precursor product suitable for EV battery purposes. The key issue in the operation of the autoclave was to control scale formation and maintain sufficient free acid whilst maximizing Ni and Co extractions.
This paper presents an overview of the challenges faced in the flowsheet development from batch testwork to continuous piloting of the selected concentrates through to the generation of high purity Ni and Co sulphate solutions from the solvent extraction circuits.