Enhanced Hydrometallurgical Recovery of Valuable Metals from Spent Lithium-ion Batteries by Mechanical Activation Process
Abstract
Recycling of valuable metals from spent lithium-ion batteries (LIBs) is desirable for resource recovery and environmental protection. In this work, hydrometallurgical recovery of valuable metals from spent LIBs was enhanced by the mechanical activation process. The leaching rates of both Co and Li increased dramatically with increasing the ball milling time, rotation speed and ball-to-powder mass ratio. The recovery of Co and Li increased with increasing the concentration of leachates, while the leaching rates of metals decreased dramatically owing to the decreased available surface area per unit volume of solution with increasing the solid-to-liquid (S/L) ratio. In addition, the leaching rates of Co and Li were both higher than those of the non-activated samples, indicating that mechanical activation process could enhance the metal recovery. Moreover, the leaching kinetics results showed that the mechanical activation process could alter the leaching behavior of valuable metals. Ultimately, the recovery of Co and Li from actual cathode materials disassembled from the spent LIBs was also explored. The leaching rates of Co and Li were 93% and 100%, respectively. This efficient mechanical activation process is of great significance for recovering valuable metals from the spent LIBs under mild conditions.