Challenge Methods with Manganese Effects in Copper Electrowinning

Manganese is commonly found in a copper solvent extraction solution. This ion also causes a lot of operational problems in the solvent extraction process and in the transition to the electrowinning stage due to the aqueous entrainment. The main problem with manganese in the electrowinning cell is oxidation to higher Mn5+ and Mn7+ valences, thereby increasing the oxidation and reduction potential of the cell. This action can increase corrosion of the anodes. The problem of most of the mixer-settler systems is entrainment and the formation of crud in the settler, which causes the majority of impurities to be transferred to the electrowinning stage. In this research, the methods for removal and control of manganese in solvent extraction-electrowinning circuit have been investigated. These methods include ion exchange, solvent extraction, reduction of manganese to electrolyte transfer and use of reducing agents. The results show that using the combination of ion exchange and treatment methods to remove not only manganese but also other impurities has a higher efficiency. Reducing manganese to electrowinning is another method that has no negative consequences on the performance of the circuit and is easy to use. Due to the complexity of the chemical reactions in the circuit, it is more reasonable to use a method that does not have a chemical effect on the circuit. So using physical methods will have better results.