Experimental Study On The Melting Of Hazardous Waste Incineration Fly Ash

Disposing of Hazardous Waste (HW) by incineration has been an increasingly adopted technology all over the world due to its advantages of remarkable volume-reduction, weight-reduction and energy-recovery. But the fly ash brought by incineration is listed as hazardous waste for its high leaching toxicity of heavy metals, and should be particularly treated. Melting treatment technique becomes one of the most significant research communities.Fundamental research of hazardous waste incineration fly ash melting technique was done in this paper. The properties of fly ash sample such as physical and chemical characteristics, micro-morphology, mineralogical characteristics, leaching toxicity were analyzed, and the results show that the appearance of fly ash samples is loose and the specific surface area is large. SiO2, CaO, Na2SO4 are the principal components, and there are a little content of heavy metals as well. The leaching toxicity of Pb exceeded greatly compared with the national standard.The processes of melting were characterized through the TGA-DSC system. The other experiments were conducted in a self-developed furnace system and mainly focused on the analysis of influence of melting point by the additional reagent and the atmosphere, and the alkalinity criterion was set up.The partition of heavy metals during melting process was also studied in this paper, and the influences of temperature, atmosphere, and the additional reagent was systematically analyzed. The results showed that after the melting of fly ash, the microstructure of slag turned to be much more impact and the leaching toxicity of heavy metals was sharply reduced and could be safely land filled.