Process of preparing silicon tetrafluoride by using hydrogen fluoride gas
AssigneeCentral Glass Company, Limited
InventorsToyozo Otsuka, Naomichi Kitsugi, Teruo Fujinaga
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Abstract
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 SiO.sub.2, in sulfuric acid not lower than 65% in the concentration of H.sub.2 SO.sub.4. 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 H.sub.2 SO.sub.4 in the liquid phase of the reaction system is maintained above 80% to obtain SiF.sub.4 containing little (SiF.sub.3).sub.2 O.
Claims9
A process of preparing silicon tetrafluoride, comprising the step of introducing hydrogen fluoride gas into a slurry obtained by dispersing a silicon oxide material in finely divided form in sulfuric acid wherein the principle component of said silicon oxide material is amorphous silicon oxide such that the concentration of H.sub.2 SO.sub.4 in the liquid phase of the reaction system never becomes lower than 65% before completion of reaction between hydrogen fluoride and silicon oxide wherein the reaction is carried out at a temperature between room temperature and about 55.degree. C.
Dependencies are inferred from the claim text.