Sintering of Municipal Solid Waste Incineration Bottom Ash

The sinterability of the bottom ashes from two municipal solid waste (MSW) incinerators in Thailand was investigated. Initially, the bottom ashes were chemically and mineralogically characterised by X-ray fluorescence (XRF) and X-ray diffraction (XRD). Both bottom ashes consisted mainly of CaO and SiO2, with a relatively high CaO content. After sintering over a temperature range of 1000°C–1125°C, the physical properties, flexural strength, crystalline phases and leaching of heavy metals were examined. Based on the results, the bottom ashes from these two incinerators were able to sinter to high final density without any sintering aid at 1100°C, and the sintered materials had good physical and mechanical properties that complied with the standard.