| The Fly Ash is residue collected from the gas refining equipment when the Municipal Solid Wastes are sintering at high temperature. Because it contains virulent heavy metal ions and dioxin-like organic pollutants, it is listed as hazardous waste, which need to be solidification/stabilization before satisfying the standard of security landfill. However, the safety of landfill not only occupies the land and costs more, but also doesn't completely rule out the potential threat of secondary contamination, as a bottleneck restricting the utilization of fly ash. Therefore, the reseach for disposal and application technology of fly ash fitting China's national conditions has become a hot topic in recent years.There are nearly 30 years for disposaling of hazardous industrial waste in cement klin in the industrialized countries. It is not only able to make use of waste, but also can completely elimination of toxic waste, which has been widely considered as a high utilization, broad scope and good effect of disposal of hazardous waste industry.First, we consider the feasibility of using the fly ash sintered the cement clinker byXRD,SEM,f-CaO and other modern analytical methods. After we make it sure, We study the influence of the content of fly ash to the sinterd clinker and confirm its largest dosage. Second, we research on the properties of sinterd clinker by using XRD,SEM,IR and so on, and discuss the curing mechanism of heavy metal ions in the hydration. Finally, we measure how much the clinker solidify heavy metal ions and leaching toxicity of heavy metal ions when it hydrates, and evaluate the environmental impact of fly ash product. In these experiments, some main conclusions can be considerated as follows:1. They are similar to the characteristic peaks in both the Ordinary Portland cement clinker and the sintered cement clinker by using fly ash. And there are any new peaks in samples. The burnability of samples are very good, because the content of f-CaO of the samples are all less then 2%, which are in the range of requirements that should be controlled in cement factory.2. Both calcination temperature and fly ash dosage play great influence on the burnability of the samples:with the calcination temperature increased, the content of f-CaO of samples are decreased; With the fly ash dosage increased, the content of f-CaO of samples are decreased first and increased later. As the content of fly ash is up to 5.2%, the cement clinker composition changes little; However, the content of C3S of the sample is larger than that of blank sample, and the content of f-CaO of the sample is the lowest, when it raise to 10.9%.3. Comparing with the blank sample, the early strength of the sample mixed with 10.9%fly ash is dropped slightly, but the late strength are increased. From XRD and SEM we can see, the sample, which the content of fly ash is 10.9%, hydrates more fully late than the blank sample. There are less silicate mineral but more C-S-H in hydration product, and the mortar is more compact.4. Metal oxide doping plays a great important role on the hydration of the cement clinker. PbO significantly reduced the relative content of silicate minerals in cement clinker and prevent hydration process; Cr2O3 prevents C2S from transforming to C3S, so it increases the content of C2S but decreases that of C3S in cement clinker, which promote the post-hydration; Ni2O3 can increase the relative content of silicate minerals in cement clinker, and promote early hydration.5. Under laboratory conditions, the solidification rate of heavy metal irons are up to 80%in cement clinkers. The curing rate of Pb is slightly low and Ni cann't be tested in cement clinkers. When the sample hydrates after 28d, the leaching toxicity is far less than the maximum allowable discharge standards, indicating it has little impact on the environment.
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