Recycling of NiCd batteries by hydrometallurgical process on small scale

High recovery of cadmium metal from household spent nickel cadmium batteries through hydrometallurgical process on small scale was conducted. Recovery of metal through separation of leached metal ions using ion exchange resin was examined. Hydrochloric acid (4.0 M) solution showed relatively better leaching potential than other acids, however, considering overall efficiency of the process, sulphuric acid was suggested to be employed as leaching and regeneration reagent in this study. Variations in solid/liquid ratio did not show a significant difference in the amount of heavy metal ions leached out; however, leaching temperature greatly affected the leaching efficiency. Changes in bed volume of the resin greatly influenced the sorption of cadmium metal ions while concentration and flow rate of the regeneration reagent were found important parameters affecting regeneration capacity of the resin. (author)