In this diploma thesis, investigations for the processability of residues from pyrometallurgical lead-zinc extraction were carried out. In the first step, the formation of the residue, also simply referred as slag, is discussed. The relevant primary raw materials are briefly explained and how they are processed into a marketable concentrate that can be used in metallurgy. The roasting step before the unique Imperial Smelting process is explained, as well as the IS process in the lead-zinc shaft furnace itself. It is the only pyrometallurgical technology in which lead and zinc can be produced in one process. In particular the residues deposited from this process are addressed and discussed. Energy-intensive metallurgical processes already exist for the treatment of deposited residues, some of which contain high levels of economically relevant metallic elements. In the course of this work, the research-relevant question of whether processing steps can lead to a relief of the metallurgical processes was investigated. The raw material characterization as well as the processing tests were mainly carried out on a slag from Veles, North Macedonia. The raw material characterization was carried out according to the Leoben school of property class analysis. The sorting tests were carried out using small-scale processing test technology. In particular, the focus of the sorting tests was on the use of the separation characteristics density, magnetic susceptibility and wettability. It was possible to identify enrichment and depletion effects in individual products during the tests. However, these are considered too low for realization. From today's perspective, the intensive intergrowth of the phases involved in the slag makes the economic use of processing technology to relieve metallurgical processes unfeasible.