| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that the concentration of trivalent chromium in a plating solution discharged from a chromium plating bath is increased during the electrolysis and thereby, a part of the chromium plating solution is replaced by a fresh one to keep proper balance with hexavalent chromium, the chromium plating solution is expensive and the waste treatement of the used chromium plating solution causes environmental trouble. SOLUTION: The plating solution discharged from the chromium plating bath is concentrated to have≥5 g/L trivalent chromium concentration and the trivalent chromium is anodically oxidized into hexavalent chromium by the electrolysis in a diaphragm type electrolytic bath. The efficiency of the oxidation is improved and the plating solution is regenerated in the system. COPYRIGHT: (C)2009,JPO&INPIT
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