Nickel recovery from the rinse waters of plating baths

An electrolytic process is applied to the de-metalization of rinse waters emerging from nickel-plating baths. Optimum conditions of nickel recovery from this type of solution have been investigated through a series of experiments carried out in a rotating packed cell (Rollsehichtzelle(R)). The effects of temperature and pH of electrolyte, current density, cell rotation speed, and diameter of the cathode granules were examined. Ninety percent of the nickel was recovered from a solution of 450 mL volume, with a pH of 5.5 +/- 0.05, 2 g/L initial nickel concentration, and by using cathode granules of 5 mm in diameter. At 50 degreesC electrolyte temperature and 325 A/m(2) current density, 74% current efficiency was attained with 4.2 kWh/kg Ni energy consumption. (C) 2002 Published by Elsevier Science B.V.