Reuse of residues arising from lead batteries recycle: a feasibility study

The performance of products arising from the stabilization/solidification of slags from lead batteries recycle into a Portland cement matrix has been evaluated not only in order to get a stabilized waste to be disposed of according to the current legislation, but also to obtain a recyclable material, with both economic and environmental benefits. Under this respect a detailed characterization of raw slags has been performed and different slag-cement samples have been prepared by varying the slag content. The parameters related to the cementation process have been evaluated and a series of tests on the final waste forms have been carried out, aimed at assessing both mechanical performance and leaching behaviour. In spite of the acceptable values for flexural, compressive and tensile strength, however, the high release of lead from the solidification products seems to be a limiting factor for a reusable material. While explanations of such phenomenon are given (high alkalinity of Portland cement; early "doping" of cementitious components by lead in the amorphous state), the main conclusion of the research work is that further efforts should be addressed to the adoption of a different or a modified incorporation matrix.