Physical upgrading of scrap from Ni-Cd batteries. A first step toward an integrated metal-recycling process

This paper deals with the initial stages of an integrated, metal-recycling process for Ni-Cd batteries (potable, sealed type), that is with the dismantling of spent cells and the physical processing of their resulting scrap. The experiments herein are focused on the performance of a customised shredder and granulometric analysis as to the ability of optimising the waste stream prior to the subsequent recovery operations. The results point to some major separation between value and waste fractions around the 14 mesh (1.40 mm) threshold. The value metals (Ni, Cd, Co) seem to concentrate in the lower (finer) fractions, whereas the upper (coarser) fractions are mostly made up of ferrous and organic materials. Even if a definitive cutoff value cannot be put forward as yet, all results so far indicate that the joint optimisation of the former procedures is likely to provide a simple yet effective means of keeping undesirable components out from actual recovery steps downstream.