ELECTROCHEMICAL PRODUCTION OF CUPROUS-OXIDE USING THE ANODE-SUPPORT SYSTEM

The preferred process for the production of cuprous oxide powder is by the anodic dissolution of copper in an alkaline solution of sodium chloride. The purpose of the present investigation was to develop a cuprous oxide process suitable for use on an industrial scale using the anode-support system, i.e. an anode comprising a titanium mesh basket loaded with small pieces of high-grade copper scrap. Laboratory investigations with this type of anode together with a titanium mesh cathode were conducted using cells having capacities up to 400 dm3. The recommended operating conditions based on 120 h runs using the 400 dm3 cell are as follows: NaCl: 250 g dm-3; c.d.: 6 A dm-2; CI: 0. 37 A dm-3; temperature: 80-degrees-C; pH 10. Of particular importance, especially as regards the quality of the product and cell scale-up, is the relationship between the current and the volume of the electrolyte, denoted as CI and expressed as A dm-3. The use of anode and cathode diaphragms of polypropylene obviated the need for additives to counteract copper redox reactions in the cell. The power yield was 0.8-0.9 kWh kg-1. The product was well within ASTM specification D912-65 for Cu2O for use in antifouling paints.