Simplified solvent extraction process for high-purity Ni/Co mixed solution for lithium–ion batteries

Abstract

ABSTRACT The demands for Ni-based raw materials increase as Ni–Co–Mn ternary cathode materials become the main axis of the battery industry. Conventional hydrometallurgical process to produce raw materials from Ni ore for battery application is as follows: (i) leaching of metal ions by acid, (ii) solvent extraction process to extract target metals, and (iii) crystallization process to produce final single-metal compound as powder products. The conventional solvent extraction process is a three-circuit process comprising impurity removal, Co extraction, and Ni extraction circuits. Unlike conventional process, in this work, we suggest a simplified two-circuit process to simultaneously extract Ni and Co to produce Ni/Co mixed solution for cathode material precursor production. Accordingly, the efficiency of site utilization can be maximized by reducing the investment cost for the manufacturing process and downsizing mixer-settler facilities. Further, eco-friendly effects such as reducing the consumption of titrants and cutting down the process costs and wastewater discharge can be realized.