Metal bioleaching from spent lithium-ion batteries using acidophilic bacterial strains

Bioleaching processes were used to solubilize zinc and aluminium from lithium-ion batteries. In this study, a lithium-ion batteries-adapted pure culture of A.ferrooxidans, pure culture of A.thiooxidans and lithium-ion batteries-adapted mixed culture of A.ferrooxidans and A. thiooxidans were used for the metal recovery from lithium-ion batteries. This study showed that the highest zinc bioleaching efficiency, almost 100%, was reached using the pure culture of A. ferrooxidans. Solubilizing capabilities of zinc by the mixed culture of A.ferrooxidans and A.thiooxidans and the pure culture A.thiooxidans were 89% and 4%, respectively. The results revealed that Fe3+ ions produced by the bacterial culture of A.ferrooxidans are of a great importance in zinc recovery. Regarding aluminium dissolution, the highest bioleaching efficiency, 33%, was also obtained using the pure culture of A. ferrooxidans. By the use of the pure culture of A.thiooxidans and the mixed culture of A.ferrooxidans and A.thiooxidans only 17% and 20% Al, respectively, was dissolved. This indicates, that aluminium solubilization depends not only on ferric ions produced by metabolic activities of A.ferrooxidans but also on sulphuric acid producted by bacterial culture A.thiooxidans.