Leaching and separation of Co and Mn from electrode materials of spent lithium-ion batteries using hydrochloric acid: Laboratory and pilot scale study

The present work is focused on the leaching and separation of Co and Mn from electrode material of spent lithium-ion batteries. The influences of different process parameters like HCl concentration, time, and temperature on the leaching of Co and Mn are studied. Higher than 99% leaching efficiencies of Co and Mn were obtained in 90 min using 1.75 M HCl at 50 °C. In the subsequent precipitation study, Mn was removed selectively from the leach solution by using sodium hypochlorite solution (1.5 times stoichiometric requirement) at a pH of 1.5 in 30 min. X-ray diffraction analysis of precipitated manganese indicate the presence of mixtures of manganese oxides (MnO2, Mn3O4 and Na0.55Mn2O4.1.5H2O). Cobalt in the Mn free solution was precipitated by using sodium carbonate solution after removing the traces amount of Al and Cu. Overall recovery of Mn and Co is 95% and 90%, respectively in pilot scale. The flow sheet proposed for the leaching and separation of Co and Mn is of a simple and efficient technique for the recycling industries.