Thermal hydrogenation method of silicon tetrachloride

Abstract

The invention discloses a thermal hydrogenation method of silicon tetrachloride. The thermal hydrogenation method comprises the following steps: conveying mixed gas of silicon tetrachloride and hydrogen into a reducing furnace, carrying out reaction on the surface of a silicon core to prepare solid silicon deposited on the surface of the silicon core, and treating the mixed gas after the reactionby virtue of bubble leaching, pressure condensing, absorption and desorption and activated carbon adsorption to finally obtain liquid trichlorosilane. According to the thermal hydrogenation method, polycrystalline silicon is generated, and trichlorosilane used as a raw material for producing polycrystalline silicon is also generated, thus the recycle of silicon tetrachloride is achieved and the actual yield of trichlorosilane is above 23%. In the thermal hydrogenation method, extra thermal hydrogenation equipment is not used, on the basis of polycrystalline silicon production equipment, a carburetor is additionally arranged and merged into a polycrystalline silicon production device to achieve closed cycle, and the cost is lowered.

Description

technical field [0001] The invention relates to a silicon tetrachloride thermal hydrogenation method. Background technique [0002] Silicon tetrachloride is a by-product of polysilicon production. Polysilicon is the main raw material required by the electronics industry and photovoltaic industry. In the production of polysilicon, for every ton of polysilicon produced, 15 tons of silicon tetrachloride need to be processed. The processing capacity Very big. Untreated silicon tetrachloride is a highly corrosive chemical. It releases heat when heated or meets moisture, and releases toxic and corrosive fumes, which are extremely harmful to the environment. Therefore, silicon tetrachloride is the first-class problem in the polysilicon industry, and there has been no good solution and approach in the industry. The harmless treatment of silicon tetrachloride has become one of the bottlenecks restricting the development of polysilicon. There is a method of cold hydrogenation of si...

AI Technical Summary

Problems solved by technology

In the polysilicon industry, there is a silicon tetrachloride cold hydrogenation method: put silicon tetrachloride and hydrogen into the hydrogenation furnace, and hydrogenate at about 500-700 ° C, but this method has a large investment cost and is not mature.