Hydrometallurgical Recovery of Metal Values From Spent Dry Battery Cells

This study focuses on the recovery of metal values from spent dry battery cells (DBC) applying a hydro-pyrometallurgical method. A process flow sheet was followed up starting with cutting the DBC with toothed cutter disc followed by water soaking and rinsing. Water soluble ingredients were filtered. Solid residue was assorted with the help of magnetic separation and water flotation.The method utilizes hydrogen peroxide to enhance dissolution of these metals in acidic or alkaline leachants. Parameters affecting the recovery efficiency such as stoichiometric ratio, solid: liquid ratio, temperature, time and ph of the system were investigated. In this concern, experiments were executed with a battery sample weighing up to 15 kg. Atomic absorption analysis showed that the input DBC contain appreciable amounts of metal zinc, zinc chloride and manganese that are recoverable.Results obtained revealed that metallic parts, carbon rods and paper were safely separated for recycling. From the water-soluble salts, pure NH4CI, MnO2 and ZnCI2 salts are obtained meeting the standard specifications. Temperature up to 55 degree enhances the recovery process. Under the optimum conditions, maximum recovery efficiency obtained amounts to 93% for Mn, and 99.5% for Zn and NH4CI. A model for explaining the obtained results was also given. Dissolution of metals concerned increases in the order nitric> hydrochloric acid. Results were explained in the premise of the kinetic and thermodynamic properties of the reactions involved. Cost estimate of the products shows that the prices of the products are competitive to those of the market prices