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

Practices of circular economy is promising relieves of the supply-chains stress, particularly for end-of-life lithiumion batteries whereby they are recycled to manufacture new batteries. This study focuses on applying solvent extraction technology to recover lithium from synthetic leach solutions. An organic solvent containing Cyanex 272/TBP/kerosene was found possible for the extraction of lithium. Here, a new heterogeneous equilibrium model for extraction has been developed to predict the extraction performance of lithium at different extracting conditions. The model was also validated by isotherm tests. Both the model and the isotherm tests indicate the impacts from pH, extractant concentration, and multivalent metals (Co(II)) are significant, while the impact from temperature, ionic strength, monovalent metals (Na(I)) and modifier concentration is minimal.