Effective recovery of Ni and Cu from low-grade nickel sulfide concentrate: Process kinetics and preparation of Ni80Cu20O material

Abstract

In this work, NaCl was used to synchronously extract metal from a low-grade nickel sulfide concentrate. Optimized process parameters were determined as follows: particle size 80–96 μm, temperature 400 °C, time 100 min, and NaCl dosage 100 %. The transformation mechanism of mineral phase was clarified using the means of XRD, SEM and EDS. The roasting process contained solid–solid and gas–solid reactions, and the valuable metal was effectively extracted by the combined action of sulfation of sodium sulfate and chlorination of chlorine gas. The kinetic study of the roasting process showed that the transformation of metals depends on the diffusion control between solid and solid phases. The reaction activation energies of valuable metal were calculated to be 9.15 kJ/mol for Ni, 11.14 kJ/mol for Cu, and 12.72 kJ/mol for Co. Nickel and copper were recovered from the leaching solution by purification and solvent extraction process to prepare Ni80Cu20O material. The Ni80Cu20O electrode material prepared at calcination temperature of 400 °C has excellent electrochemical performance. A new process of recovering metals from minerals to prepare Ni80Cu20O cathode material was established, which was proved to be a clean and promising technology.