氟硅酸钠热解制备四氟化硅气体影响因素研究

Research on influencing factors of preparation of silicon tetrafluoride gas by pyrolysis from sodium fluosilicate

磷肥副产物氟硅酸钠热解可制备四氟化硅气体,该方法无废弃物产生,生产成本较低,具有广阔的发展前景。对影响氟硅酸钠热解的各种因素进行了一系列静态实验研究,实验发现,氟硅酸钠热解的最佳反应温度应保持在中温区(500～700℃),反应压力维持在常压或微负压状态。利用该法生产四氟化硅气体具有气体纯度高和无副产物产生的特点。

Silicon tetrafluoride gas could be prepared by the pyrolysis from phosphate fertilizer by-product sodium fluorosili- care.This method produced no waste, and had lower production cost and a broad development prospect.A series of static ex- periments were carried out to investigate various factors that affect the pyrolysis of sodium fluosilicate.It was found that the op- timum reaction temperature of sodium fluosilicate pyrolysis should be maintained in the intermediate temperature region （500-700℃ ）, and the reaction pressure was maintained at atmospheric pressure or slightly negative pressure state.The pro- duction of silicon tetrafluoride gas with this method had the characteristics of high purity and no by-products.