Electrowinning of copper from chloride solutions in presence of gas sparging

Microporous ceramic tubes (15 micrometre pore diameter) and PVC membranes (10 micrometre diameter) have been used as spargers in the electrowinning of copper from concentrated and dilute chloride electrolytes. At a current density of 600 A/m2 and a nitrogen gas sparging flow rate (at NTP) of 1.53 cm3/s per unit electrode length, it was possible to electrowin planar rather than powdery deposits with copper concentrations as low as 0.157 M. To obtain a planar deposit at higher concentrations of cupric chloride the most realistic optimum current density appears to be between 1 000 and 1 500 A/m2.