Synthesis And Performance Of Inorganic Polymer Flocculant-fafc With Various Al/fe Molar Ratio

We selected the coal-kaolin of Inner Mongolian whose reserves were abundant as the basic raw material in this paper. The weight loss temperature and pyrolysis temperature of the kaolin were measured by TG-DTA, the phase composition was incestigated by X-ray diffraction and the major constituent by chemical techniques.Polyaluminum ferric chloride (a kind of netype inorganic polymer flocculant) was synthesized by a singlestage process of acid pickling. Synthetic raw materials were the coal-serial kaolinite (major reagent) and calcium oxide (subsidiary reagent). We adopted the orthogonal experiment of five factors and four levels to seek for the optimization reaction condition.The optimization results were shown as following: calcinations temperature was 800℃; dosage of hydrochloride was 50ml; polymerization temperature was 102℃; polymerization time was 5h; mass of calcium oxide was 5g. The liquid status material was orange and viscous. The density of the product was 1.271 g/cm3, pH value (the mass percentage of the product was 1 in aqueous solution) was 3.52, the concentrations of aluminum ion and ferric ion were 10.56%and 0.91% respectively, its basicity was more than 41.25%. And the solid status material was green-yellow. The density of the product was 1.713 g/cm3, pH value (the mass percentage of the product was 1 in aqueous solution) was 3.61, the concentrations of aluminum ion and ferric ion were 36.21%and 1.43% respectively, its basicity was 47.31%.The species distribution of aluminum was characterized by Ferron complexation timed spectorphotometry. And the structure of PAFC was analysised by infrared spectra. The IR spectra results showed that copolymer of both hydroxyl-bridged iron and aluminum was as the components of PAFC.Polyaluminum ferric chloride was prepared with different Al/Fe molar ratio. The product traits have been analyses: the concentration of aluminum ion is higher than 8.28%, ferric ion higher than 2.36%, and the basicity higher than 38.76%. The pH was between 2.78~3.64.The PAFC product was used in simulative Yellow Wtaer processing and good flocculation result was obtained. The removal rate of turbidity of simulative Yellow Wtaer was 99% or higher, and the ramoval rate of COD was high as 92% or higher, under the better conditions: the dosage 30mg / L, the pH 7 and the Al / Fe molar ratio 9:1.The PAFC trial production was designed based on the experiment.