Electrolyte parameter effects in the electrowinning of nickel from sulfate electrolytes

摘要

Nickel deposits were electrowon from acid sulfateelectrolytes to determine the effects of various parameters whenbuffer agents were not present. The nickel concentration, pH andtemperature of the electrolyte were varied over a relatively broadrange to evaluate changes in cathode morphology and currentefficiency. Both good quality deposits, ones which were flatsmooth and ductile, and degraded deposits, which werecharacterized by cracking, curling, pitting and brittleness, wereobtained depending on the conditions chosen for these three variables.A good quality deposit morphology and a high current efficiencywere favored by high nickel concentrations and electrolytetemperatures. The deposit morphology was improved at lower pH,but a decrease in deposit current efficiency resulted. Depositorientations were determined, but no specific trends were evident.Cyclic voltammetry tests did show some correlation to depositmorphology but not to current efficiency.