RECOVERY OF VALUABLE METALS FROM SPENT LITHIUM-ION BATTERIES BY SMELTING REDUCTION PROCESS BASED ON MnO-SiO_2-Al_2O_3 SLAG SYSTEM

摘要

Plenty of valuable metals, such as cobalt, nickel, copper, manganese and lithium, are present in spent lithium-ion batteries. A novel smelting reduction process based on MnO-SiO_2-Al_2O_3 slag system for spent lithium ion batteries is developed, using pyrolusite ore as the major flux. And Co-Ni-Cu-Fe alloy and manganese-rich slag contained lithium are obtained. The results show that it is reasonable to control MnO/SiO_2 ratio in the range of 2.05-3.23 (w/w) and Al_2O_3 content in 19.23-26.32wt.%, while the MnO and Li_2O contents in the manganese-rich slag can reach 47.03 wt.% and 2.63 wt.%, respectively. In the following leaching experiments of the manganese-rich slag by sulphuric acid solution, the recovery efficiency of manganese and lithium can reach up to 79.86% and 94.85%, respectively. Compared with the conventional hydro-pyrometallurgical process of spent lithium-ion batteries, the present can preferably recover Mn and Li besides Co, Ni and Cu.