Study on Recovery of Valuable Metals in Spent Lithium-Ion Batteries by Al2O3-SiO2-CaO-Fe2O3 Slag System

This study investigated the recovery behavior of valuable metals (Co, Ni, Cu and Mn) in spent lithium ion-batteries based on Al2O3-SiO2-CaO-Fe2O3 slag system via DC submerged arc smelting process. The valuable metals were recovered by 93.9% at the 1250°C for 30 min on the 20 Al2O3-40SiO2-20Cao-20Fe2O3 (mass%) slag system. From the analysis of the slag by Fourier-transform infrared spectroscopy, it was considered that Fe2O2 and Al2O3 acted as basic oxides to depolymerize SiO4 and AlO4 under the addition of critical 20 mass% Fe2O3 in 20 Al2O3-40SiO2-Cao-Fe2O3 (Cao + Fe2O3 = 40 mass%). in addition, it was observed that the addition of Fe2O3 ranging between 20 and 30 mass% lowers the melting point of the slag system.