| 摘要 |
The present invention relates to a method to effectively exfoliate a coating layer from the surface of the conductive substrate comprising titanium or titanium alloy substrate material 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 substrates for recycling use. A method for exfoliating the coating layer from the surface of the electrode substrate, characterized in that in the exfoliation method for the coating layer from the surface of the electrode substrate, wherein the insoluble metal electrode surface having the coating layer containing electrode substance comprising noble metals and/or metal oxides thereof on the surface of the electrode substrate comprising valve metals including titanium and tantalum or valve metal alloys is treated, in succession, with the alkali treatment process using a caustic alkali aqueous solution, the heating and baking process and the acid treatment process by immersion in hydrochloric acid, sulfuric acid, nitric acid or the mixture thereof, the alkali treatment process is conducted by applying an alkali treatment solution prepared by adding thickener to the caustic alkali aqueous solution. |
