Physical and chemical properties of MSWI fly ash

Abstract

This paper presents a study of the properties of municipal solid waste incineration (MSWI) fly ash, including their size distribution, pH value, microscopic morphology, mineral components, heavy metal content, and leaching toxicity. It is found that: over 80% of fly ash particles have diameters between 0.105~0.154mm, and the mass ratios of particles smaller than 0.063mm and larger than 0.154mm are both lower than 5%; the fly ash particles tend to be strongly alkaline (pH≥11); their main elements are Cl, Ca, K, Na, Si, Al, O and S, and their main heavy metal elements are Zn, Pb, Cr and Cu. The material generally exists as irregularly shaped amorphous solids and polycrystalline aggregates. Their leaching toxicity has exceeded the criteria for hazardous wastes.