Hydrometallurgy process for the recovery of valuable metals from LiNi0.8Co0.15Al0.05O2 cathode materials

A hydrometallury process was developed to recover the valuable metals from LiNi0.8Co0.15Al0.05O2 cathode materials. In step 1, lithium and aluminum were selectively dissolved by oxalic acid. Utilizing Na2SO3 as the reducing reagent, the reaction was significantly accelerated. The aluminum and lithium in the liquid stream were recovered by chemical precipitation in steps 2 and 3, using KOH and K2CO3 as precipitants, respectively. The mixture of solid Ni and Co oxalates from step 1 was converted to sulfates through acid baking. After dissolution in water, cobalt was recovered as Co2O3 after oxidation and nickel stayed in the solution as NiSO4.