| 摘要 |
1392705 Electrowinning copper or nickel INTERNATIONAL NICKEL CO OF CANADA Ltd 8 Feb 1974 [9 Feb 1973] 05917/74 Heading C7B Cu or Ni is electrowon on vertical sheet cathodes in a cell having insoluble anodes in which the electrolyte is agitated by gas (e.g. air) bubbles introduced below the electrodes and flowing upwards along the cathode surfaces, and a froth layer at least 3 cm deep is maintained on the electrolyte surface; e.g. by incorporating in the electrolyte an anionic surfactant such as Na 2 dodecylated oxydibenzene disulphonate, covering the electrolyte surface with oil or providing a layer of foamed plastics spheres or particles. Acid sulphate electrolytes are specified for electrowinning Cu which contain Ni, Co, Fe, As or Al and cationic guar gum levelling agent. Preferably the electrolyte is first freed from impurities which are deposited as readily as or more readily than the desired metal: Se, Te, Bi and Ag for Cu, and Cu, Fe and Zn for Ni. Anodes containing Pb, e.g. of Pb - 6% Sb or Ti cores with PbO 2 or Pb surfaces, may be used. For electrowinning Ni, the cathodes are preferably enclosed in bags and the gas bubbles are introduced inside the bags. The electrolyte may be withdrawn, cooled and returned to the cell. |
