低浓度酸性含铜废水经二次电积(第一次产出铜粉),可得到合格电铜。扩大试验(250升)表明该法比溶剂萃取法设备简单、投资少、成本低,适合于小厂。电积铜粉时电流密度应随铜浓度减小而降低,对于1～5(克/升)铜,D 为80～120(安/米~2)。为降 Low concentrations of acid copper wastewater by the second electrowinning (the first output of copper powder), can be qualified copper. Expansion test (250 liters) shows that the method is simpler than solvent extraction equipment, less investment, low cost, suitable for small plants. The current density in the electrodeposition copper powder should decrease with the decrease of copper concentration. For Dc of 1 ~ 5 (g / L), D is 80 ~ 120 (A / m ~ 2). To drop