Application of Roasting Flotation Technology to Enrich Valuable Metals from Spent LiFePO₄ Batteries

The application of lithium-ion batteries (LIBs) in electric vehicles has attracted wide attention in recent years, especially LiFePO₄ batteries that have been extensively used in large electric buses and cars. The increased demand for LIBs has greatly stimulated lithium-ion battery production, which subsequently has led to greatly increased quantities of spent LIBs. From the perspective of environmental protection and resource recovery, the recycling of spent LIBs is of great significance. In this study, the roasting flotation technology was applied to enrich valuable metals from the mixed electrode powder of spent LiFePO₄ batteries. Roasting could thoroughly remove the organic outer layer coated on the surface of electrode-active materials, which improved the flotation enrichment efficiency of valuable metals in the mixed electrode powder of spent LiFePO₄ batteries. Under the optimum conditions of roasting at 500 °C for 1 h, the enrichment efficiency of Li and Fe reached the best. The recovery and the enrichment ratio of Li were 95.87% and 1.37, respectively, while the recovery and the enrichment ratio of Fe were 95.25% and 1.36, respectively. Roasting flotation was an efficient process to enrich valuable metals from spent LiFePO₄ batteries without wasting graphite resources.