Biohydrometallurgical Treatment of Spent Alkaline and Zinc-Carbon Batteries

Alkaline and zinc-carbon batteries are used in radios, toys, watches, calculators, cameras and in many other objects where small quantities of power are required. After exhausting of chemical energy batteries become hazardous waste, but contains useful parts particularly Zn and Mn in the different forms. Physical, pyrometallurgical and hydrometallurgical treatments represent the general ways of the batteries recycling. The physical processes for spent batteries represent the pre-treatment steps in pyrometallurgical processes. The significant disadvantages of pyrometallurgical processes are the great consumption of energy and production of dust and gases which require dust collecting/gas cleaning systems. The enormous application of the dangerous and harmful reductive inorganic matter brings additional safety risk to the hydrometallurgical processes. Therefore, development of environmental friendly and cost-effective recycling methods for the spent Zn-Mn batteries should be encouraged. Biohydrometallurgical processes particularly bioleaching offer the very interesting possibility.