A Combined Hydro-Mechanical and Pyrometallurgical Recycling Approach to Recover Valuable Metals from Lithium-Ion Batteries Avoiding Lithium Slagging

Abstract

Meeting the increasing demand for energy storage based on lithium-ion batteries (LIB) is not only a question of resource availability but also an issue of resource conservation and efficient recycling management. In this respect, sustainable recycling concepts play a central role in mindful interactions with valuable materials. Based on this approach, a process interconnection of hydromechanical preparation, flotation, and pyrometallurgical treatment was investigated. The hydromechanical preparation showed promising results in achieving highly pure mixtures of LIB-active material. It was found that a pre-opening step could achieve an even better separation of impurities for downstream processes such as Cu and Al to avoid excessive particle size reduction. According to an optimized mixing stage during flotation, the C amount was reduced from 33 wt.% to 19.23 wt.%. A Li-free metal alloy was obtained through the subsequent pyrometallurgical treatment, and evidence for Li removal via the gas phase was provided. Furthermore, heating microscope trials confirmed the results of the process interconnection and showed that further optimization steps for the pre-treatment are necessary for favorable product quality. Therefore, a high-stratification plot was created, which allows a quick future statement about the suitability of the input material for use in the process.