用废铁屑和酸洗废液制备聚硅酸铁（PSF）的研究

研究了用废铁屑、硫酸酸洗废液和硅酸钠为原料，经酸浸、催化氧化、水解和聚合等过程制备聚硅酸铁（PSF）絮凝剂的方法。探索了对铁浸出率和PSF絮凝性能有影响的各种因素，包括硫酸温度、浸出时间、氧气流量、Fe／Si比、硅酸活化PH、硅酸活化时间、陈化时间。确定了合理的制备工艺条件，并对絮凝剂PSF处理工业废水的絮凝性能进行了研究，与聚合硫酸铁（PFS）和聚合氯化铝（PAc）的絮凝性能进行了比较。结果表明，PSF具有良好的絮凝性能，能有效改善废水中的浊度和色度，去除悬浮物（SS）和CODcr；用量为90mg／L时，浊度、色度、SS和CODcr的去除率分别可达92．3％，93．3％，92．9％，80．4％。

Study on the Preparation of Polysilicate Ferric(PSF) by Acid Pickling Solution and Scrap Iron Leavings

Polysilicate ferric （PSF） flocculant was prepared with scrap iron, acid pickling solution and sodium silicate as the raw materials by the process of acid leaching, catalytic oxidation, hydrolysis and polymerization. The factors that may effect the iron soaking-out rate and PSF flocculation property were studied, including the sulfuric acid temperature, leaching time, flow of oxygen, Fe-to-Si ratio, pH, and the activating and ageing time of silicie acid, etc. The technological conditions for the preparation were obtained. Besides, the performance of PSF flocculant in dealing with industrial sewage was investigated,, and it was compared with that of polymerization ferric sulfate （PFS） and polyaluminium chloride （PAC）. Results show that PSF has excellent flocculation performance, and it can dislodge the turbidity, colourity, seston （SS） and CODcr effectively. When the dosage is 90 rag/L, the dislodging rates of turbidity, colourity, SS and CODer can reach 92.3%, 93.3%, 92.9% and 80.4% respectively.