Behavior of Heavy Metals in the Vitrification of MSWI Fly Ash with a Pilot-scale Diesel Oil Furnace

Characteristics of heavy metals during heat-treatment municipal solid waste incinerator (MSWI) fly ash were investigated in this paper. The experiment was performed using a pilot-scale oil furnace in the range 800-1350 °C.In this work we investigated the effect of temperature on solidification efficiency, evaporation of heavy metals and on composition change, X-ray diffractometer (XRD), the leach toxicity of molten slag. The results showed that the main contents, solidification efficiency and evaporation of heavy metals had a tremendous change between 1150-1260 °C. With temperature increasing, the percentage of CaO, SiO2 and Al2O3 increased, and SO3, K2O, Na2O and Cl decreased. Especially in 1260 °C, the four compositions decreased sharply from 43.72% to 0.71%. Finally, the leaching concentrations of all heavy metals in molten slag were far lower than the standard values of TCLP.