表面活性剂存在下四氯化硅水解制备二氧化硅

多晶硅生产中主要副产物四氯化硅副产量大、腐蚀性强、难以安全处理。笔者以四氯化硅为原料,在表面活性剂存在下制备二氧化硅。研究了物料比例、反应温度、加料速率等因素对产品比表面及产率的影响,采用红外光谱仪、X射线衍射仪、比表面积测定仪和扫描电子显微镜对晶体结构、比表面积、产品的形貌进行了表征。结果表明,采用质量浓度0.5 g/L的十二烷基苯磺酸钠(SDBS)溶液为反应底物、四氯化硅加入量为1.5 mol/L(底物)、反应温度为45℃、加料速率为0.35 mol/h,反应混合物具有较好的过滤性能,并可得到粒径分布窄的二氧化硅产品,产品收率可达80%。

Preparation of silica by hydrolysis of silicon tetrachloride in presence of surfactant

Silicon tetrachloride is the main by-product of polysilicon with large output and strong corrosiveness.At present,it is hard to be treated safely.Silica was prepared by using silicon tetrachloride as raw material in the presence of surfactant.The effects of material mix ratio,reaction temperature,and feeding rate etc.on specific surface area and yield of the product were investigated.Crystal structure,specific surface area,and morphology of the product were characterized by Fourier transform infrared spectroscopy,X-ray diffraction,specific surface area analyzer,and scanning electron microscopy.Results showed that when SDBS with mass concentration of 0.5 g/L was selected as substrate,the feeding amount of silicon tetrachloride was 1.5 mol/L(substrate),reaction temperature was 45℃,and the feeding rate was 0.35 mol/h,the reaction mixture had a preferable filtering property and the silica with narrow particle size distribution could be obtained,and the product yield was 80%.