摘要
Cu and As were separated and recovered from copper electrolyte by multiple stage electrowinning, reduction with SO2and evaporative crystallization. Experimental results showed that when the current density was 200 A/m2, the electrolyte temperature was 55 °C, the electrolyte circulation rate was about 10 mL/min and the final Cu concentration was higher than 25.88 g/L, the pure copper cathode was recovered. By adjusting the current density to 100 A/m2 and the electrolyte temperature to 65 °C, the removal rate of As was 18.25% when the Cu concentration decreased from 24.69 g/L to 0.42 g/L. After As（V） in Cu-depleted electrolyte was fully reduced to As（Ⅲ） by SO2, the resultant solution was subjected to evaporative crystallization, then As2O3 was produced, and the recovery rate of As was 59.76%. The cathodic polarization curves demonstrated that both Cu2＋ concentration and As（V） affect the limiting current of Cu2＋ deposition.
通过分段电积、SO2还原、蒸发结晶使铜电解液中的铜砷得到分离与回收。当电流密度为200A/m2、电解液温度为55°C、电解液循环速率为10mL/min、终点铜浓度高于25.88g/L时,电积得到纯阴极铜。调节电流密度为100A/m2、电解液温度为65°C、铜离子浓度从24.69g/L降至0.42g/L时,砷的去除率为18.25%。通入SO2将脱铜电解液中的As(V)充分还原为As(Ⅲ)后,蒸发浓缩还原后液,冷却结晶得到As2O3晶体,砷的回收率为59.76%。阴极极化曲线表明,铜离子浓度和As(V)均影响铜还原的极限电流密度。
基金
Project(2011B0508000033)supported by the Special Project on the Integration of Industry,Education and Research of Ministry of Education and Guangdong Province,China
