METHOD FOR EXFOLIATING COATING LAYER OF ELECTRODE FOR ELECTROLYSIS

• Main Authors: KAWAGUCHI, NOBUYUKI, UENO, KENICHI, KAGAMI, MIHO, HAYASHI, TAMOTSU
• Format: Patent
• Language: English; Polish
• Published: 30.08.2019
• Subjects: APPARATUS THEREFOR; CHEMISTRY; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTIONOF COMPOUNDS OR NON-METALS; METALLURGY; PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY ORREFINING OF METALS

The present invention relates to a method for effectively exfoliating a coating layer from the surface of the conductive substrate of a used electrode for electrolysis comprising an insoluble metal electrode having the coating layer containing electrode substance comprising noble metals and/or their metal oxides on the surface of the used electrode substrate comprising valve metals, such as titanium and tantalum or valve metal alloys, and then to recover the electrode substances and/or electrode substrate for recycling use. The method for exfoliating comprises the steps of treating the insoluble metal electrode surface having the coating layer, in succession, with an alkali treatment process using a caustic alkali aqueous solution, a heating and a baking process and an acid treatment process, the alkali treatment process being conducted by applying an alkali treatment solution prepared by adding thickener to the caustic alkali aqueous solution.