Treating process for silicon tetrachloride

The invention provides a treating process for silicon tetrachloride. The process comprises the following steps: preheating, i.e., externally-supplied normal-temperature hydrogen enters a hydrogen preheater and exchanges heat with hydrogenated tail gas coming from a gas-to-gas heat exchanger; mixing, i.e., full mixing is carried out in a mixed vaporizer; heat exchanging, i.e., the mixed gas enters the gas-to-gas heat exchanger and exchanges the heat with the hydrogenated tail gas coming from a silica-powder filter; heat hydrogenation, i.e., the mixed gas entering a heat hydrogenation furnace reacts in the heat hydrogenation furnace and discharges high-temperature tail gas containing hydrogen, hydrogen chloride, silicon tetrachloride and trichlorosilane; cold hydrogenation, i.e. the high-temperature tail gas discharged from the heat hydrogenation enters a cold hydrogenation reactor, reacts with externally-supplied silica powder and discharges cold hydrogenated tail gas; condensation, i.e., the cold hydrogenation tail gas undergoes cooling and condenses, and mixed chlorosilane of trichlorosilane and silicon tetrachloride condenses into a liquid and enters a condensate storage tank; and separation. The treating process for silicon tetrachloride provided by the invention realizes the linkage of heat hydrogenation and cold hydrogenation in the whole process, so heat utilization is more reasonable, and energy saving effect is achieved.