BatZink – Removal of zinc-containing batteries and impurities from municipal solid waste incineration iron scrap

For this purpose, iron scrap fractions from various Swiss slag processing plants were sampled and examined regarding their composition, battery load, and the proportion of accompanying waste incineration plant (WIP) slag. Based on the results, various mechanical processing and separation methods were developed to remove batteries and other contaminants, and these methods were investigated both in the laboratory and in pilot-scale facilities. Among other things, methods for the targeted destruction of batteries and the subsequent separation of the zinc-containing fine fraction released during the process were examined. Additionally, methods involving AI-based, sensor-supported robotic sorting were employed to produce the highest possible quality of iron scrap. The different approaches were evaluated in terms of separation performance, product quality, and transferability to a technical facility.

Furthermore, an analysis was conducted to determine the extent to which the material streams generated during processing could be further utilized. Using a life cycle assessment, the ecological benefits of processing WIP iron scrap and removing the zinc-containing batteries within it were assessed. Based on a rough cost estimate, the environmental benefit per Swiss franc invested was also calculated.