Application of innovative processes for the valorization of alkaline spent batteries

Disposal of spent batteries constituted a serious environmental problem in terms of heavy metals content when these devices are disposed off in inadequate way. Alkaline and zinc-carbon batteries represent about 80 % of the market. In particular, alkaline batteries have an average content of manganese dioxide (MnO2) of 37 %, while zinc content is of 16 %. The high Mn and Zn content justifies the interest to recover the metals. The present experimental work involves the application of innovative processes, such as the utilisation of the physical-chemical method (electrolysis) and biological-chemical (bioleaching) method for Mn-Zn recovery from spent alkaline batteries. Results have demonstrated the technical feasibility of the processes.