Recovery of manganese from sulfuric acid leaching liquor of spent lithium-ion batteries and synthesis of lithium ion-sieve

A novel process of recovery of Mn as lithium ion-sieve from H2SO4 leaching liquor of spent lithium-ion batteries was developed. After precipitation of Fe3+ and Cu2+ in the leaching liquor, Mn was recovered with D2EHPA extraction followed by two-step stripping with H2SO4 solution. Lithium ion-sieve was synthesized by oxidation of the stripping solution using KMnO4, then roasting at atmosphere followed by acid leaching. The effects of solvent extraction parameters on Mn recovery rate and Co doping content on the performance of lithium ion-sieve were investigated. The result indicates that through secondary countercurrent solvent extraction, Mn is fully separated from Ni and a MnSO4 solution containing a small amount of Co is obtained. Co can incorporate into the lattice of lithium ion-sieve and improve the structure stability and adsorption capacity. The Co doped lithium ion-sieve shows Li adsorption capacity of 33.1 mg g−1 and Mn dissolution rate of 1.39%. The total recovery efficiency of Mn is 84.6%. The process provides a simple method for recovery and utilization of Mn in the spent lithium-ion batteries.