Method for treating silicon tetrachloride hydrogenated by-products

Abstract

The invention provides a method for treating silicon tetrachloride hydrogenated by-products. The method includes following steps of supplying the silicon tetrachloride hydrogenated by-products to a gas and solid separating device to perform gas and solid separation so as to obtain solid particles and first gas mixture containing trichlorosilane, silicon tetrachloride, dichlorosilane and hydrogen; and performing heat exchange for the first gas mixture and second gas mixture in a heat exchanger. The second gas mixture is mixture of silicon tetrachloride and hydrogen. The method for treating the silicon tetrachloride hydrogenated by-products in an embodiment of the invention is low in energy consumption and cost, and high in heat recovery rate. Besides, the solid particles can be prevented from blocking pipes, the utilization rate of the solid materials is improved, and accordingly normal running of the pipes and equipment is guaranteed.

Description

technical field [0001] The invention relates to the field of polysilicon production, more specifically, to a method for treating by-products of hydrogenation of silicon tetrachloride. Background technique [0002] In the polysilicon production process, a large amount of by-product silicon tetrachloride is produced. For example, when polysilicon is produced using the hydrogen reduction process of trichlorosilane (improved Siemens process), 10-20 tons of silicon tetrachloride will be produced for every ton of polysilicon produced. Silicon tetrachloride is a toxic chemical substance, which is easily hydrolyzed to generate silicic acid and hydrogen chloride, which seriously pollutes the environment. Therefore, how to safely handle silicon tetrachloride has become a hot research topic at present. At present, the most effective way to deal with silicon tetrachloride is to convert silicon tetrachloride into trichlorosilane, the raw material for polysilicon production, under certa...

AI Technical Summary

Problems solved by technology

Silicon tetrachloride is a toxic chemical substance, which is easily hydrolyzed to produce silicic acid and hydrogen chloride, which seriously pollutes the environment

[0003] However, because the by-products containing silicon tetrachloride contain a small amount of solid particles such as silicon powder and catalyst, it is easy to block equipment and pipelines, and its heat cannot be recovered, resulting in high energy consumption, high cost, and unstable operation

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