Study On Chemical Stabilization Technologies Of Fly Ash From Waste Incineration Plant

Waste incineration fly ash contains large amount of highly toxic heavy metals and dioxins, and widely recognised as hazardous waste. Typically the fly ash through cement curing, put it to landfills. however,this method is Capacity large and poor stability. In this study, use the method of combining cement solidification and stabilization of phosphate chemical to treatment of heavy metals in incineration ash, find the method of improve the fly ash stabilization treatment efficiency.In this study, taking fly ash particle size analysis, phase analysis, the total amount of heavy metals analysis. On the basis of physical and chemical testing, Experimental use of "solid waste leaching toxicity Acetic acid buffer solution method"(HJ / T 300-2007) on fly ash original gray and 1% phosphoric acid, 1.5% phosphoric acid, 2% phosphoric acid leaching of heavy metal toxicity Experimental Inquiry. Using atomic absorption spectrophotometry to measure the concentrations of heavy metals in the leachate, Summary leaching of heavy metals concentration data, and heavy metals data and "Landfill Pollution Control Standard"(GB16889-2008) were compared, the results showed that:Incineration fly ash particle size substantially under the 200μm; Incineration ash composition main elements are Ca, Cl, K, S, Si, Fe,Wherein the total amount of CaO, SiO2, A12O3, CO2, SO2, and other metal and non-metal oxides of about 80%; Fly ash crystal structure consisting mainly KCl, NaCl, CaClOH, CaSO4, CaCO3, Ca(OH) 2; Heavy Metals in total far exceeds the background values of heavy metals in the soil in Shandong Province. a large number of sources of heavy metal pollution produced in the presence of heavy metals.Fly ash leaching toxic heavy metals Pb exceeds the concentration limits of "Waste Incineration Pollution Control Standard" requirements, The other five involved in this experiment, leaching toxic heavy metals are not exceeded the Standard. Phosphorylation of fly ash stabilization treatment, larger dosage of phosphate corresponding pH lower value affects the fly ash of Cr, Pb, Cu, Cd stability, and increased leaching toxicity. Data analysis showed that: the mass fraction of 1 percent of fly ash to phosphoric acid cement solidification- phosphoric acid stabilization treatment experiments, the treated fly ash leaching concentration of heavy metals in Pb concentration limits to meet the requirements of the standard, while another five heavy metals Cu, Zn, Cd, Ni, Cr leaching concentrations meet the standards.