Removal of Cu from the nickel electrolysis anolyte using amorphous MnS

• The amorphous MnS as a Cu removal agent can be synthesized easily.
• 99.2% of Cu in the nickel electrolyte can be removed in 30 min.
• The mass ratio of Cu/Ni in the Cu removal precipitates can exceed 50.
• The enlarged scale experiment result meets the requirement of industrial.
• Reaction conditions of Cu removal are easily controlled.

In this research, amorphous MnS was used to remove Cu from the nickel electrolysis anolyte. Through condition experiments, the effects of amorphous MnS dosage, reaction temperature, pH value and reaction time on copper removal were investigated. The experimental results showed that amorphous MnS had high reaction activity, and 99.2% of Cu in the nickel electrolyte was removed in 30 min. Under the optimal operating conditions, 1.6–1.8 times the theoretical amount of amorphous MnS, mean particle size 1.6 μm, reaction temperatures 60–80 °C, pH values 3.5–4.5 and retention time of more than 45 min, the concentration of Cu was reduced to less than 3 mg/L in the nickel electrolysis anolyte and Cu/Ni mass ratio in the Cu removal precipitates exceeded 15. The nickel electrolyte after Cu removal directly met the production requirement of qualified electrodeposited nickel and the precipitate was eligible for Cu matte smelting. The enlarged scale experiment confirmed that amorphous MnS can be used as a high-efficiency reagent to remove copper from the nickel electrolysis anolyte in large-scale industrial production.