Characteristic Analysis During Vitrification of MSWI Fly Ash by Diesel-Fuel Furnace

A diesel fuel furnace was used to heat-treat the municipal solid waste incineration(MSWI) fly ash and its washed-ash from a MSWI plant in Hangzhou city for more than 6 months.In this pilot scale experiment,the parameters including volume reduction and weight loss,composition change,characteristic of crystalline phases and the leach toxicity of molten slag were investigated at 1 260—1 350 ℃.The results indicate that the volume reduction of fly ash and washed-ash was 83.7% and 81.5%,respectively,and the weight loss fraction was 28.6% and 21.9%,respectively at 1 350 ℃.During the vitrification,the contents of CaO,A12O3,SiO2 in fly ash increased as the temperature went up,especially of SiO2.After melt-solidification,the leaching concentrations of all selected heavy metals were lower than standard value.The concentration of dioxin in flue gas was investigated by National Research Center for Environmental Analysis and Measurements to be 0.053 ng/m3,which is much lower than the national total emissions,and the other pollutants in flue gas also meet the national standard(GB18484—2001).