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Waste incineration technology because of the reduction, sound and resource advantages, many cities are vigorously developing incineration technology to deal with the garbage. However, the resulting secondary pollution problem, especially in emissions in the flue gas and fly ash of persistent organic pollutants, heavy metals and other pollution problems, more and more public attention. Fly ash is the main waste incineration residue, which enriched a higher concentration of heavy metals and dioxin-like persistent organic pollutants, of as hazardous waste, subsequent harmless treatment is required to the relevant standards. In this paper, for the study of heavy metals in the waste incinerator fly ash and fly ash, the review describes the hazards of heavy metals, waste incineration fly ash harmless treatment methods, review heavy metal migration mechanism and influencing factors in the analysis of the incineration process. On this basis, the current commercial operation of two typical incinerator - a fluidized bed waste incinerator (actual handling capacity of 550 tons / day) and a grate incinerator (actual handling capacity of 350 tons / day) The incineration process in different points of the fly ash samples the sampling and laboratory research and analysis. Firstly, three samples from each collected two incinerator fly ash samples (each furnace), the basic physical and chemical characteristics of the study: the use of energy dispersive spectroscopy (EDX) analysis of the element composition of the fly ash, using Markov Man particle size analyzer and artificial screening analysis of the particle size distribution of fly ash by inductively coupled plasma mass spectrometry (ICPMS) analysis of Pb, Cd, Zn, As, Cu, Cr, Ni, Hg, mainly heavy metals in the fly ash content characteristics. The analysis results show that: the distribution of the particle size of the fly ash to an approximately normal distribution, the particles are concentrated in the more than 80% between 38-150μm, and the particle size is less than 38μm and greater than 106μm the mass fraction of the particle occupied are rarely. Grate incinerator fly ash, Cl, S element content higher than the fluidized bed incinerator, Zn, Pb is the highest content of heavy metals in the incineration fly ash grate incinerator fly ash concentrations of heavy metals in the fluidized bed fly ash. The paper then the particle size of the fly ash samples screening, Pb, Cd, Zn, As, Cu, Cr, Ni, Hg and other heavy metals content test and the segment of the fly ash of different particle size, the comparative analysis of the furnace , temperature, particle size, and other parameters on the characteristics of the accumulation of heavy metals in the fly ash. Volatile heavy metals in the fly ash content in order of Zn> Pb> Cd> As a fluidized bed incinerator at each sampling point fly ash particle size segment volatile heavy metals concentration distribution is not very different, and the grate incinerator each different fly ash particle size segment of the sampling points in volatile heavy metals content varied. The fluidized bed incinerator convection tube volatile heavy metals in fly ash mainly distributed in small particles (38-56μm), and the economizer in the fly ash intermediate particles (56-106μm) contribution rate increases, the bag fly ash 56 - 75μm segment contribution rate based. For difficult volatile heavy metals, fly ash content in the order of Cu> Ni> Cr, the difficult volatile heavy metal content in the fly ash grate is substantially greater than the fluidized bed incinerator fly ash. Difficult volatile heavy metals in the fly ash of different particle size segment because of the difficulty of volatile heavy metals properties, particle size mass ratio distribution similar to the contribution rate of the total ash in such heavy metals. The study found more than 400 ℃ fly ash, regardless of the particle size, Hg content were lower in the bag working temperature with bag of fly ash Hg content.
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