An Integrated Sulfation-Roasting-Leaching Process for Coextraction of Nickel and Cobalt from Laterite Ores with Enhanced SO ₃ Recovery

The sulfation-roasting-leaching process can be used for processing laterite ore for recovery of Ni and Co. However, the low leaching efficiency of Ni and Co, high sulfuric acid consumption, and the emission of sulfur trioxide (SO3) gas remain challenges. In this study, an integrated process for the co-roasting of limonitic and saprolitic laterite ore using the sulfation-roasting-leaching process was developed. The results demonstrated that SO3 could successively react with goethite in limonitic laterite ore and lizardite in saprolitic laterite ore to convert the Ni and Co to water-soluble phases by controlling the co-roasting conditions and employing an appropriate method based on the different ionic potentials of trivalent and divalent metal ions. The leaching efficiencies of Ni and Co in laterite ore were 96.2% and 99.9%, respectively, with over 70% SO3 recovery and approximately 60 wt % sulfuric acid consumption. This work presents a promising approach for the coextraction of Ni and Co from both limonitic and saprolitic laterite ores, and it holds immense potential for sustainable and economically viable Ni and Co extraction from a wide range of laterite ore deposits, contributing to the circular economy and fostering a greener future for battery metal production.