The role of CaCO3 in the extraction of valuable metals from low-nickel matte by calcified roasting - Acid leaching process

Abstract

The extraction of valuable metals from low-nickel matte via a calcified roasting-acid leaching process was investigated. The influences of process parameters on the extraction of metals were studied, including the roasting temperature, roasting time and the addition of CaCO3. Under the optimum condition, 92.4% of Ni, 97.1% of Cu, 95.1% of Fe, and 91.2% of Co were recovered. In addition, the removal of iron via goethite precipitation process was studied. The results show that 99.8% of Fe could be removed by goethite process. The reaction mechanism of calcified roasting of low-nickel matte was also studied by XRD and XRF analysis. It was shown that the formation of ferrite can be effectively inhibited by CaCO3 addition, leading to enhancement of the metal recovery.