A continuous process is disclosed for the production, with a high yield, of high purity silicon tetrafluoride, by starting from an aqueous solution of fluosilicic acid, which comprises:
a) the reaction of an aqueous solution of fluosilicic acid with concentrated sulphuric acid, carried out with a short residence time and preferably under fluido-dynamic conditions of turbulence, inside a reaction zone; b) the separation of a gaseous stream containing silicon tetrafluoride from a liquid stream of aqueous sulphuric acid, carried out inside a separation zone, directly connected with the reaction zone; c) the washing, with concentrated and cold sulphuric acid, of said gaseous stream, carried out inside a washing zone, for the purpose of separating a gaseous stream of purified silicon tetrafluoride; and, possibly d) the further purification of said gaseous stream of purified silicon tetrafluoride, by means of techniques of adsorption on an adsorbent solid material.