Research of fly ash and slag (Bottom Ash) from municipal waste incineration. The possibilities of secondary use

Abstract

Incineration of MSWI allows a great reduction in the quantity of the wastes of 65–80% in mass and 85–90% in volume. Nevertheless, several residues, with different characteristics of hazard, remain after the incineration. They can be broadly divided into bottom ashes (slag) and fly ashes. MSWI fly ash are fine and are normally characterized by a high content of chlorides (NaCl, KCl, CaCl, KCaCl) even higher than 10-15%) and significant amounts of dangerous substances (As, Pb, Cr, Cu, Hg) such as heavy metals ). MSWI bottom ashes (slag) have coarser dimensions (particles can reach several tens of millimeters in size), and the amount of chlorides and hazardous chemicals is usually much lower than that of MSWI fly ash.