Separation and Recovery of Valuable Metals from Ammonia Leaching Solution of Spent Lithium-Ion Batteries
Jiancheng Yu, Baozhong Ma, Zhi‐Jun Qiu, Chengyan Wang, Yongqiang Chen
Abstract
The ammonia leaching system has gained widespread usage in the hydrometallurgical processing of spent lithium-ion batteries (LIBs) due to its exceptional selectivity. In this work, a novel process was developed to recover Li, Ni, Co, and Cu from the NH 3 ·H 2 O–(NH 4 ) 2 CO 3 leaching solution of spent LIBs. First, solvent extraction using Mextral 54-100 was employed to selectively recover more than 98% of Ni and Cu, with subsequent stepwise stripping of the organic phase using 15 g/L and 60 g/L H 2 SO 4 to prepare NiSO 4 and CuSO 4 products, respectively. The process realizes the selective separation and recovery of Ni and Cu. Later, the ammonia distillation process was applied to recover Li and Co from the raffinate. Approximately 93% of Co and 64% of Li were precipitated in the form of amorphous Co-bearing carbonate and Li 2 CO 3, respectively. After adjusting the mole ratio of Li and Co in the precipitation to 1, the LiCoO 2 cathode material was obtained via two-stage roasting, exhibiting excellent electrochemical performance. The collaborative recovery of Li and Co and the closed-loop circulation of ammonia are realized by ammonia distillation. Moreover, the residual liquid can also return to the ammonia leaching stage, thus avoiding resource waste and the generation of wastewater.