Preparation And Application Of Flocculant-Polyferric Silicate Sulfate

The coagulation effect is directly affected by coagulant's performance. It is interesting to study on high-effect, low-toxicity and low-cost coagulant.According to the research and development of polymeric silicic acid complex coagulants, Aiming at the character of gasfield water, using resourceful iron ore powder and industrial oil of vitriol as the main raw materials, a kind of ferric sulfate was prepared. In the process of iron lixiviation experiment, the paper discusses factors that influence the lixiviation rate of iron, such as calcining temperature, calcining time, vitriol density, pickling time and liquid to solid ratio. Then the mathematical model of lixiviation rate of iron was built and the best process conditions were obtained. Preparation and technology of macromolecular flocculant-Polyferric SilicateSulfate (PFSS) have been studied. The samples of PSS, which were high-effect, credible, fit for gasfield water treatment, were prepared.The interaction between polysilicic and ferric was examined by means of chemical analysis and modern instrumental analysis techniques, and the flocculating mechanism was also studied. The results indicated that coagulant PFSS wasn't the simple blending of the raw material, but combined as polymer form. Fe-O-Fe bond rapidly formed facilitates Si-O-Fe bond's shaping, and the Si-O-Si bond (active silicic acid polymer) formed very slowly baffles with Si-O-Fe bond's shaping. It's the essential reason that proper quantities not superfluous metal ion can stave silicic acid's gelling.The coagulant PFSS has the effect of charge neutrality and absorbing bridge flocculating function. In the experiment, self-regulating coagulant PFSS was respectively used to treat analog waste water and gasfield water, and which effects are compared to PFC, PAC used water treatment. Simultaneously, the main factors, which affect the treatment effect, were analyzed systematically and the best water treatment condition and technics parameters were ascertained. The results showed that the flocculation effect of PFSS was superior to PFS, PAC. In the condition of PFSS 350-400mg/L, PH 6, the COD of gasfield water can be removed over 70%.