标题：Analysis of reasons for decline of bioleaching efficiency of spent Zn-Mn batteries at high pulp densities and exploration measure for improving performance
作者：Xin, B.;Jiang, W.;Li, X.;Zhang, K.;Liu, C.;Wang, R.;Wang, Y.
作者机构：School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing 100081, China;School of Chemical Engine
来源：Bioresource Technology: Biomass, Bioenergy, Biowastes, Conversion Technologies, Biotransformations, Production Technologies
关键词：Bioleaching;Efficiency decline;High pulp density;Recovery of zn and mn;Spent zn-Mn batteries
摘要：The reasons for decline of bioleaching efficiency of Zn and Mn from spent batteries at high pulp densities were analyzed; the measures for improving bioleaching efficiency were investigated. The results showed that extraction efficiency of Zn dropped from 100% at 1% of pulp density to 29.9% at 8% of pulp density, with Mn from 94% to only 2.5%. It was almost the linear reduction of the activity of the sulfur-oxidizing bacteria with increase of pulp density that witnessed declined bioleaching efficiency of Zn; it was the complete inactivation of the iron-oxidizing bacteria at 2% of pulp density or higher that witnessed declined bioleaching dose of Mn. By means of reducing initial pH value of leaching media, increasing concentration of energy matters and exogenous acid adjustment of media during bioleaching, the maximum extraction efficiency of almost 100% for Zn and 89% for Mn at 4% of pulp density was attained, respectively.