摘要 |
Recovery of Li from Li cells and batteries, which also contain heavy metals (Fe, Cu, Ni and Co) and/or Mn, involves comminution, leaching out most of the metal species with HCl, separating the insoluble phase, selective alkaline precipitation of insoluble heavy metal and/or hydroxides, and recovery of a insoluble fraction containing heavy metals and a solution containing Li. Any organic material is removed from the comminuted material, preferably by pyrolysis at a temperature below the vaporization temperature of Li, preferably around 550 deg C, before proceeding with the process. The molar concentration of the HCl leaching solution is 0.1N-6N, preferably 2N-4N. Selective alkaline precipitation of heavy metal hydroxides and/or Mn is carried out at a pH of 8-12, preferably around 9.5. The final solution containing mostly LiCl and also substantial amounts divalent metal chlorides, especially CaCl2, is enriched in LiCl by electrodialysis using a membrane able to separate monovalent cations from divalent ions. |