Synergistic roasting of spent lithium-ion batteries and nickel matte for preferential lithium extraction and efficient leaching of transition metals
Yuxin Liao, Hongxian Huan, Dawei Yu, Dong Li, Xueyi Guo, Qinghua Tian
Abstract
The rapid advancement of new energy vehicles , coupled with their limited service life, has led to a significant increase in spent lithium-ion batteries (LIBs). Recognized for both their environmental and resource potential, these spent batteries represent an urban mineral resource whose recycling has emerged as a critical research focus. Notably, as an intermediate product in the nickel ore production process, nickel matte exhibits a significant resemblance to spent LIBs in terms of elemental composition . Consequently, this study innovatively proposes to utilize nickel matte as a sulfating agent and reductant for the synergistic roasting with spent LIBs and establishes a “S-O” atmospheric system to facilitate the targeted transformation of valuable metals. The lithium present in the cathode materials is selectively transformed into water-soluble Li 2 SO 4 through the regulation of the amount of air, roasting temperature, the dosage of nickel matte and the roasting time , enabling the preferential extraction of lithium via water leaching. Meanwhile, transition metals from the cathode materials and nickel from the matte are converted into lower-valent oxides , which are subsequently extracted by atmospheric acid leaching. Under the optimum roasting and leaching conditions, 96.03 wt% of Li, 99.10 wt% of Ni, 96.74 wt% of Co, and 90.23 wt% of Mn can be extracted. This strategy not only enhances the recovery of strategic metals from spent LIBs but also addresses the limitations inherent in the high-pressure leaching step of traditional nickel matte processing, providing a methodogical reference for the integrated treatment of urban minerals and primary ores.