Bio-hydrometallurgical circuit for treatment of exhaust alkaline batteries

In this work, bio-hydrometallurgical processes have been applied starting from exhaust alkaline batteries. Their disposal constituted a serious environmental problem in terms of heavy metals content when these devices are disposed off in inadequate way. High Mn and Zn content justifies the interest to recover metals from these wastes. The present experimental work involves the application of innovative processes, such as the utilisation of the physical-chemical method (electrowinning) and biological-chemical (bioleaching) method for Mn-Zn recovery from exhaust alkaline batteries. The results have demonstrated the technical feasibility of the application of the bio-hydrometallurgical circuit; in fact, high recoveries of manganese and zinc dissolved in solution were achieved (about 98 % of MnO2 and Zn).