The release of Zn and Mn from spent Zn-C batteries by using ultrasound-assisted bioleaching

In this study, A. thiooxidans was used for bioleaching Zn and Mn from the spent Zn-C batteries electrode materials. The release efficiency and dynamics of Zn and Mn among the chemical leaching, the biological leaching and the different ultrasound-assisted bioleaching systems were compared. The results show that ultrasound-assisted-bioleaching was optimal for the dissolution of Zn and Mn at different ultrasound-assisted systems, which was better than the biological leaching and chemical leaching systems. the optimal leaching rates of Zn and Mn in the spent Zn-C batteries reached to 94.2% and 61.5% respectively. In addition, dissolution kinetics studies show that the chemical reaction controlled model described best bioleaching behavior of Zn for all the systems, the Stoke's regime model best described bioleaching behavior of Mn for the bioleaching and ultrasound-assisted-bioleaching systems and the diffusion controlled model was better than other models for the chemical leaching system.