Liberation of Valuable Materials from Spent Cylindrical Lithium-Ion Batteries via Semi-Autogenous Attrition

Abstract

Liberation of cathode materials (Co, Ni, Mn, Li) from spent lithium-ion batteries is essential to creating an acceptable leach feed in hydrometallurgical battery recycling. This study investigated the use of milled battery casing steel as the abrasive media in an attrition process, termed semi-autogenous attrition (SAA). The process aims to increase the liberation of the cathode materials, which are attached to other battery components, and also to release the agglomerated particles. The experimental parameters were pulp density, agitating speed and retention time. The performance of the SAA process was compared to wet sieving and attrition with agitation only. The optimum SAA conditions liberated 20% more cathode material to the <180 mm fraction and contained 90% Co with <2 wt% of contaminants (Al, Fe, and Cu). The results show that SAA can replace secondary milling. Moreover, the casing steel is a reliable abrasive media, which is already available in the system and easily separated from the cathode material. The casing steel can also be reused for multiple SAA.