Experimental Study On Preparation PAFC Flocculants Using Fly Ash

With the development of the economy of China, the problem of the energy consumption and environment pollution become more and more severely. As far as the Chinese energy structure, the fact of coal which is China main source exists for a long time, so the treatment of the fly ash which produced by coal combustion has become a research focus, at the same time, the develop trend of water treatment agent search will be more effective , cheaper and safer. In this study, fly ash was a material for a new flocculent polyaluminum ferric chloride (PAFC)’s synthesis. It not only realizes the high additional value of fly ash, but also reduces the cost of making PFAC.In the thesis, the study of solid excretory product fly ash, exhausted from a thermal power plant in Tuoxian, by analyzing the main material. This study based on the activation methods of other researchers, introduce Na2CO3 as the activating agent , roasted at 850℃for 2 hours in the muffle, which are used to increase the acid lixiviate property of fly ash. The study showed that the quantity of Na2CO3, the quantity of HCl, acid-dissolved time, acid-dissolved temperature have distinctly influence on the solubilization ratio of aluminum by single factor experiments. Through orthogonal experiments, the optimums conditions of acid dissolution experiment are found. They are as follows, the quantity of Na2CO3 and material ratio is 0.7:1; the quantity of HCl is 100ml; soaked in HCl for 1.5 hours at 90℃. The order of process parameters affecting the quality of product was the quantity of the quantity of HCl > Na2CO3 > acid-dissolved time> acid-dissolved temperature.Then, using the aluminum, to add in FeCl3 prepared PAFC and design an test for the several factors during the preparation: The result of test revealing that are better conditions of preparation: Al:Fe=9:1,reaction temperature is 90℃, reaction time is 2.5 hours, the product PAFC was prepared, its parameters are listed below:concentration of Al2O3 and Fe is 17.56% and 2.15%,basic ratio is 50%.Last, The self-prepared PAFC flocculants was analyzed by infrared spectrum and scanning electrode microscope and result showed that its micro-structure is not alike to polyferric chloride. It has large molecular structure to form net so that its flocculation efficiency is better than that of other flocculants. During the treatment to the Yellow River water,turbidity removal rate is up to 99.27%. The self-prepared polyaluminum ferric chloride flocculants (PAFC) was compared with PAC in the current market, its flocculation efficiency is superior to that of PAC, and it is more useful and easier to popularize.