Separation and recovery of nickel cobalt manganese lithium from waste ternary lithium-ion batteries

• A full-flow technological route for the separation and recovery of nickel, cobalt, manganese and lithium from waste ternary lithium-ion batteries was optimized by focusing on the extraction to decrease the loss of metal ions. • Leaching kinetics was analyzed as surface chemical reaction and diffusion of solid phase product layer. • The extraction mechanism was analyzed by FT-IR and slope method. • The DMG and extractant in the process can be recycled, which helps to protect the environment and save costs. In this paper, a combination of precipitation and solvent extraction was used to study the separation and recovery of nickel, cobalt, manganese and lithium from the acid leach solution of wasted ternary lithium-ion battery cathode materials. The effects of sulfuric acid concentration, hydrogen peroxide addition, liquid-to-solid ratio, time and temperature on the metal leaching rate were optimized, and the leaching kinetic analysis showed that the metal leaching was controlled by both the diffusion of the solid-phase product layer and the chemical reaction, but the diffusion of the solid-phase product layer was dominant. Dimethylglyoxime (DMG) was first used to remove nickel as Ni-(C 4 H 8 N 2 O 2 ) 2 , and P204 and C272 were used to extract manganese and cobalt ions from the post-nickel removal solution step by step. The effects of volume fraction of organic solvent, O/A, pH of the aqueous phase and extraction time on the extraction rate were optimized, and the extraction mechanism was analyzed by FT-IR and slope method as a cation exchange reaction, specifically the ionic exchange of metal ions with H + in the P-OH of the organic solvent, and also the coordination of trace metal ions with the P=O, Finally, the metals in loaded organic phase were stripped to the solution by dilute sulfuric acid which were recovered as MnO 2 , CoC 2 O 4 and Li 2 CO 3 , respectively. The recovery rates for nickel, cobalt, manganese and lithium in the whole process were 96.84%, 81.46%, 92.65% and 91.39% respectively, a technical route to recover nickel, cobalt, manganese and lithium from ternary LIBs was optimized, and extractants and DMG in the process could be recycled and reused.