Economic Evaluation of Zinc Recovery from Air Pollution Control Residues of European Waste to Energy Plants

SUMMARY: In Europe almost 80 million tons of waste are annually combusted in Waste-to-Energy plants. Solid residues generated thereby contain altogether about 69,000 t/a of Zn, of which more than 50 % accumulates in air pollution control (APC) residues. Recent research activities aiming at Zn recovery from APC residues resulted in a large scale Zn recovery plant at a Swiss waste incinerator. By acidic leaching and subsequent electrolysis this technology (FLUREC) allows generating metallic Zn of purity >99.9%. In the present paper the economic viability of the FLUREC technology with respect to Zn recovery from different solid residues of waste incineration has been investigated and subsequently been classified according to the mineral resource classification scheme of McKelvey. The results of the analysis demonstrate that recovery costs are generally higher than the current market price of Zn, which implies that none of the identified Zn resources present in incineration residues can be economically extracted and thus cannot be classified as a reserve.