| 摘要 |
1,155,575. Electrodes for electrolyzing hydrochloric acid. METALLGESELLSCHAFT A.G. Sept. 14, 1966 [Oct.9, 1965], No.41126/66. Heading C7B. In a method of electrolyzing aqueous hydrochloric acid, at least one of the electrodes, preferably the cathode has a coating of silver in a highly activated, finely dispersed state. The electrode body may be formed of graphite or of iron. The silver coating may be formed on a graphite electrode either by impregnating the electrode with a silver salt which is thereafter reduced with a reducing agent, or by electrodepositing thereon a silver-zinc alloy and thereafter dissolving the major part of the zinc in an alkaline immersion bath. An iron electrode may be coated using the latter method and may be given protective coating of silver prior to depositing the silver-zinc alloy coating. The protective coating of silver and the silver-zinc alloy coating may be deposited consecutively in the same electro-plating bath by changing the current density and the degree of agitation of the bath. A suitable bath may contain potassium silver cyanide, potassium zinc cyanide, potassium cyanide and sodium or potassium hydroxide. |
