Deformation of zinc electrowinning cathodes
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Can zinc cathode plates suffer any damage other than deformation during the electrolysis process? Is there only deformation, or is there etching as well? How do smelters usually handle damaged cathode plates on their own? Can it be used again by adding insulating sheets or conductive terminals? Does the aluminum sheet need only to be shaped to be ready?
The ions that cause the most severe cathodic corrosion are F-, Cl-, and other ions; for example, in solutions where the concentration of F is between 200–300 mg/L and that of Cl- is between 500–400 mg/L, the consumption of zinc per ton of cathode plates is 0.5–1 sheet. When the concentrations of F and Cl- ions are below 100 mg/L, the consumption per ton of zinc cathode plates is only 0.1–0.3 sheets, with some well-managed processes achieving a consumption of less than 0.1 sheet. As for cathode deformation, I believe it is caused by the following human factors: 1. Improper methods of stripping the sheets; 2. Difficulty in stripping the zinc sheets; and also quality issues with the cathode plates themselves