Isolation of Ti(IV) Concentrate from Spent Lithium-Ion Batteries

Lithium–titanate anodes are increasingly being used in the manufacturing of lithium-ion batteries due to their advantages in charge/discharge speed and safety of use relative to graphite anodes. The addition of titanium to the battery composition, along with the high content of cobalt and lithium, results in a further growth of their cost, and the reprocessing of such batteries becomes an extremely topical problem. In the framework of the present article, a comparative analysis of the hydrometallurgical reprocessing of batteries containing a lithium-titanate anode and a nickel–manganese–cobalt cathode by leaching with mineral acids (sulfuric and hydrochloric acids) is performed. In the work, the dependences of the leaching degree of the metals from real samples of the anode and cathode in their mixture on the mineral acid concentration, auxiliary additives, and solid : liquid ratio are demonstrated and the temperature and kinetic dependences for this process are obtained. Based on the results of qualitative and quantitative analysis of the leaching solutions, conditions for processing of the leaching process are proposed for further extractive separation. It is demonstrated that two-step successive leaching with hydrochloric and then sulfuric acid with the release of titanium concentrate is optimal. An important aspect of the work is the study of the joint leaching of the cathode and anode, since in the known processes of mechanical processing the stage of their separation is absent.