Co, Ni, Cu, Fe, and Mn Integrated Recovery Process via Sulfuric Acid Leaching from Spent Lithium-ion Batteries Smelted Reduction Metallic Alloys

With increasing consumption of lithium-ion batteries (LIBs), recycling of spent LIBs has attracted much attention owing to their potential environmental impacts and metal values. In this work, a hydrometallurgical process for the recovery of metals from metallic alloys containing Co, Ni, Cu, Fe, and Mn generated from the reduction smelting of spent LIBs was developed. From the experimental data, optimum conditions for the complete leaching of the metals from the alloys were obtained as 2.0 mol/L H2SO4 and 10% (v/v) H2O2 solutions at 60°C for 240 min. The separation of metal ions from the sulfate leachate was achieved by using synthesized ionic liquids such as ALi-Cy301 and ALi-SCN and an oxidizing agent like NaClO. First, most of the Cu(II) was selectively extracted over others by 0.2 mol/L ALi-Cy30. Sequentially, Co(II) and Fe(III) from the Cu(II) free raffinate were co-extracted by 0.5 mol/L ALi-SCN and then Co(II) was selectively stripped over Fe(III) by 10% (v/v) NH3 solution. Finally, Mn(II) in the raffinate at pH 3 was precipitated to MnO2 by adding 10% (v/v) NaClO solution, while Ni(II) remained in the filtrate. Mass balance of the whole process indicated that the recovery and purity percentage of metals were higher than 99%. A process is proposed for the effective recovery of valuable metals from the spent LIBs.