Reduction and deposition of arsenic in copper electrolyte

The influences of temperature, H 2SO 4 concentration, CuSO 4 concentration, reaction time and SO 2 flow rate on the reduction of arsenic(V) with SO 2 were studied and the deposition behavior of arsenic (III) under the effect of concentration and co-crystallization was investigated in copper electrolyte. The results indicate that reduction rate of arsenic (V) decreases with increasing temperature and H 2SO 4 concentration, but increases with increasing SO 2 flow rate and reaction time, and it can reach 92% under appropriate conditions that reaction temperature is 65°C, H 2SO 4 concentration is 203 g/L, CuSO 4 concentration is 80 g/L, reaction time is 2 h and SO 2 gas flow rate is 200 mL/min. To remove arsenic in the copper electrolyte, arsenic (V) is reduced to trivalence under the appropriate conditions, the copper electrolyte is concentrated till H 2SO 4 concentration reaches 645 g/L, and then the removal rates of As, Cu, Sb and Bi reach 83.9%, 87.1%, 21.0% and 84.7%. The XRD analysis shows that crystallized product obtained contains As 2O 3 and CuSO 4·5H 2O.