Separation and recovery of cathode materials from spent Li-ion batteries using flotation

The separation and recovery of cathode materials and anode materials using conventional flotation are not satisfactory. In the present research, hierarchical flotation and shearing flocculation enhanced flotation are employed and the surface properties and particle size of electrode materials during the pre-treatment and their effects on flotation performance are investigated. Results show that in hierarchical flotation, the recovery and grade of the cathode materials for coarse particles could reach 97.64% and 97.67%, respectively. However, the separation performance of fine particles is far behind. This is due to the fact that the binder is removed after thermal treatment, and more importantly, the particles of the cathode materials grow up and the size of the graphite keeps almost unchanged. By using shearing flocculation enhanced flotation, for both coarse and fine particles, the recovery and grade of cathode materials are 95.64% and 94.51%, respectively. Graphite also achieved the highest recovery simultaneously.