垃圾焚烧炉飞灰熔融特性及重金属的分布

Fly ashes from municipal solid waste (MSW) incinerator were used to determine melting point and to perform differential thermal analysis. The weight loss and heavy metals distribution during calcination in air at different temperatures were discussed. It indicates that the minimum of weight loss is up to 27.5%. Melting reaction of fly ashes initially occurs at 1132℃ and exhibits the second melting reaction at 1252℃～1290℃. The proportions of Cr, Ni and Cu in melted samples increase with the elevation of their melting point and boiling point. The amounts of evaporation are above 95% for Pb, Cd, As, and Hg. The quantities of evaporation is in sequence of Pb>Cd>As>Hg. Zinc in fly ashes exists in the form of ZnO, which forms the nonvolatile compounds such as Zn2SiO4, ZnSiO3, and ZnAl2O4. The minimum rate of Zn evaporation in fly ashes is 66.7% at 1200℃.