氟硅酸钙热解制备四氟化硅的工艺研究

Study on Pyrolysis Process of Silicon Tetrafluoride Prepared from Calcium Fluosilicate

针对四氟化硅的行业需求,本研究探讨了由磷肥副产物氟硅酸制备的氟硅酸钙热解生成四氟化硅的工艺条件,通过正交实验分析获得了适用于工业生产的氟硅酸钙最优脱水及热解条件,并对制备的粗品四氟化硅、副产品氟化钙与市售产品进行了质量指标对比,本实验所得的目标产物和副产物均满足行业的质量要求。该工艺具有流程短、能耗低、对环境危害小的特点,不仅为四氟化硅生产提供了新的方法,也拓展了磷肥副产物氟硅酸的综合利用。

According to the demand of silicon tetrafluoride industry,the process conditions for preparing silicon tetrafluoride by pyrolysis of calcium fluorosilicate produced from by-product fluorosilicate of phosphate fertilizer was investigated in this study.The optimal conditions for dehydration and pyrolysis of calcium fluorosilicate suitable for industrial production was determined by orthogonal analysis,and the qualities of crude silicon tetrafluoride and by-product calcium fluoride were evaluated with commercial products,showing that the target products and by-products obtained in this study meet the quality requirements of relative industry.The said process features short productive process,low energy consumption and less harm to the environment.It not only provides a new method for the production of silicon tetrafluoride,but also expands the comprehensive utilization of fluorosilicic acid,a by-product of phosphate fertilizer.