The recycling of heavy-metalcontaining wastes: Mass balances and economical estimations

Abstract

As environmental legislation has become stricter in recent decades, efforts for treating residues have also increased. The existing pyrometallurgical reprocessing methods for metal-containing wastes recover mainly only one valuable metal or produce low-grade byproducts. The aim of developing an economic process has to be the simultaneous recovery of more than one valuable metal and increased product quality. In the case of zinccontaining residues the goal has to be a high-quality zinc product. Moreover, the target is a nearly zero waste process and, accordingly, small amounts of generated residues. In this paper four possible secondary raw materials are compared regarding their mass and energy balance for a treatment in a carbon-containing metal bath. Furthermore, an evaluation of the economy is given for a neutral leaching residue, Waelz kiln slag, dust from secondary copper industry as well as an electro arc furnace dust from carbon steel production.