Recovery of Copper, Cobalt and Nickel From Spent Lithium Ion Batteries by a Combined Process of Acid Leaching and Bioleaching.

A bacterial strain ESY06 with the properties of high efficiency and high tolerant metals, identified as Thiobacillus ferrooxidansi (T.f.), was obtained by isolating and long term cultivating. The bioleaching of the copper, cobalt and nickel in spent lithium ion batteries using strain ESY06 were investigated. And the effect of Fe²⁺ concentration on the growth of a strain ESY06 was examined. The results show that the tolerant ability of the strain ESY06 to copper, cobalt and nickel are respectively 1.22, 2.21 and 0.29 g/L. Under the condition of Fe²⁺ concentration of 20 g/L, the growth of the strain ESY06 is the best. The leaching rate of cobalt and nickel in positive electrode can reach 99. 93% and 99. 46%, respectively, and the leaching rate of copper in negative electrode is 99.78%. For the mixed electrodes, the leaching rate of copper, cobalt and nickel are 99. 88%, 99.39% and 99 55%, respectively. The combined process of acid leaching pre-treated and bioleaching has good effect on leaching of copper, cobalt and nickel, and can recovery the valuable metals in battery electrode materials. [ABSTRACT FROM AUTHOR]