EFFECTS OF METALLIC AND D2EHPA IMPURITIES ON NICKEL ELECTROWINNING FROM AQUEOUS SULFATE BATHS

The presence of metallic and organic solvent impurities in pregnant el ectrolyte during hydrometallurgical processing causes problems in nick el electrowinning. To overcome these problems, a study on the combined effects of metallic and D2EHPA impurities, on nickel electrodepositio n has been carried out. The effects of such impurities on deposit phys ical appearance, current efficiency, deposit contamination, crystallog raphic orientation and deposit morphology are discussed. Based on the experimental data and observations, it is possible to achieve smooth a nd perfect nickel sheet with reasonable current efficiency and purity from the contaminated leach liquors of nickel bearing raw materials be ing processed in the Regional Research Laboratory, Bhubaneswar. Moreov er, the economy of the nickel electrowinning process can be improved b y careful selection of experimental conditions.