Process of preparing silicon tetrafluoride by using hydrogen fluoride gas

摘要

A process of preparing silicon tetrafluoride by introducing hydrogen fluoride gas into a dispersion of powdery silicon oxide material, which needs not to be pure SiO2, in sulfuric acid not lower than 65% in the concentration of H2SO4. The reaction takes place even at room temperature. By using amorphous silicon oxide material, the rate of reaction can be enhanced with better yield. Preferably, the concentration of H2SO4 in the liquid phase of the reaction system is maintained above 80% to obtain SiF4 containing little (SiF3)2O.