Hydrometallurgical recovery process for nickel-cadmium spent batteries

The most recent literature on the treatment of nickel-cadmium spent batteries often describes mixed pyro- and hydrometallurgical processes with different options (precipitation, electrolysis, solvent extraction) for the recovery of the metal. The present work shows a completely hydrometallurgical process in which electrode powder is mechanically separated from the external case and the metal supports, and afterwards, the powder is leached with acid and then electrolyzed. It was thus possible to recover cadmium with 1.2% of nickel; nickel was finally precipitated as carbonate, containing less than 0.5% of cadmium.