The Effect of Temperature on the Electrowinning of Antimony from Alkaline Sulfide Solution

In this research, the electrodeposition of antimony was studied in alkaline sulfide solution. The effect of time and temperature of electrowinning step on antimony recovery, current efficiency and specific energy in the temperature range of 45-65 °C for 0-6 h was investigated. Furthermore, the kinetics of electrodeposition was studied, and the results were used in developing mathematical model. Results show that increasing the temperature of electrowinning decreases antimony recovery, current efficiency and increases energy consumption. Hydrogen evolution at the cathode at low concentration of antimony in the solution and occurrence of harmful reactions at the electrodes lead to energy consumption and decrease current efficiency and antimony recovery. Maximum antimony recovery was 70 % after 6 h electrodeposition at 45 °C and maximum current efficiency was 90 % after one hour electrodeposition at the same temperature. The energy consumed per one kilogram of deposited antimony in the temperature range of the experiments was in the range of 1.35-2.28 kWh. Minimum value of consumed energy was achieved at 45 °C. The kinetic investigation shows that Avrami- Erofeyev equation can be used for prediction of antimony recovery with high accuracy.