Development of heterogeneous equilibrium model for lithium solvent extraction using organophosphinic acid

End-of-life lithium-ion batteries can be recycled to manufacture new batteries. The focus of this study is the application of solvent extraction technology for lithium ion recovery from synthetic leach solutions. This study demonstrates that an organic solvent containing Cyanex 272, tributyl phosphate and kerosene can be used for this purpose. Additionally, a new heterogeneous equilibrium model for extraction is proposed and validated using experimental data. Both the model, and the isotherm test results obtained indicate that pH, extractant concentration and multivalent metal concentration (Co(II)) significantly impact lithium extraction, while the impact of temperature, ionic strength, monovalent metals (Na(I)) and modifier concentration is minimal.