Removal of copper ions from dilute sulfuric acid solutions: Effect of solution composition and applied potential

Removal of copper from synthesized and real dilute sulfuric acid solutions was investigated. Effects of copper, iron concentrations and applied potential were studied. In pure copper solutions, increasing the Cu^2+ concentration from 1000 to 5000 mg.L^-1 increased the copper recovery from about 30-300% depending on the cathode potential and decreased the energy consumption by about 30%. Also, increasing the acid concentration from 15 to 50 g.L^-1 and about a 25% increase in copper recovery and a 30% decrease in energy consumption were observed. The addition of Fe^2+ to the solution improved the ionic conductivity and so that the copper recovery. The specified energy consumption for the real leaching solutions increased to 31-47 KWh.kg^-1. The diffusion coefficients for several synthesized and real copper electrowinning electrolytes were determined. Moreover, the maximum value of the diffusion coefficient (D) was obtained 2.27*10^-4 cm^2.s^-1 for the pure copper solution at a concentration of 1000 mg.L^-1 Cu^2+ which was higher than impure and real solutions.