Deep removal of copper from nickel electrolyte using manganese sulfide
(School of Metallurgy and Environment, Central South University, Changsha 410083, China)
Abstract: Copper is difficult to separate from nickel electrolyte due to low concentration of copper (0.53 g/L) with high concentration of nickel (75 g/L). Manganese sulfide (MnS) was used to deeply remove copper from the electrolyte. Experimental results show that the concentration of copper (ρ(Cu)) decreases from 530 to 3 mg/L and the mass ratio of copper to nickel (RCu/Ni) in the residue reaches above 15 when the MnS dosage is 1.4 times the theoretical valueDt,MnS (Dt,MnS=0.74 g) and the pH value of electrolyte is 4-5 with reaction time more than 60 min at temperatures above 60 °C. The concentration of newly generated Mn2+(ρ(Mn)) in the solution is also reduced to 3 mg/L by the oxidation reaction. The values ofρ(Cu), ρ(Mn)and RCu/Ni meet the requirements of copper removal from the electrolyte. It is shown that MnS can be considered a highly effectivedecoppering reagent.
Key words: MnS; decoppering reagent; copper removal; manganese removal; nickel anodic electrolyte