Depolarized electrowinning of zinc

摘要

A process for electrolytic recovery of zinc wherein metallic zinc is deposited at the cathode while the anode is depolarized through oxidation of iodide ions to iodine, avoiding oxygen evolution at the anode. The iodide ions are chemically regenerated by extracellular oxidation of sulfur dioxide with water to produce iodide ions and hydrogen ions for recycle to the anode compartment. The utilization of iodide ions in the depolarization of the anode results in obtaining good deposits of elemental zinc at high faradic efficiencies resulting in energy saving of 30 to 40 percent over conventional electrowinning of zinc.