Silicon tetrachloride hydrogenating process of producing trichloro hydrosilicon

Abstract

The silicon tetrachloride hydrogenating process of producing trichloro-hydrosilicon includes: mixing powdered nickel catalyst and silicon powder in the mass ratio of 1-10 and activating the mixture in hydrogen atmosphere and at the temperature of continuously change from 20 deg.C to 420 deg.c; and making mixed gas of hydrogen and SiCl4 in the molar ratio of 1-10 pass through the activated catalyst and silicon powder layer for hydrogenating SiCl4 continuously at 400-500 deg.c temperature and 1.2-1.5 MPa pressure. The equipment, system and operation of the present invention has high once SiCl4 converting rate and low power consumption and may be used in large-scale production.

Description

technical field [0001] The invention belongs to the technology of hydrogenating silicon tetrachloride to produce trichlorosilane. Background technique [0002] At present, polysilicon factories using Siemens technology at home and abroad use silicon powder and hydrogen chloride to synthesize SiHCl 3 . Among the synthesized products, SiHCl 3 About 80%, SiCl 4 About 20%. After the synthesis gas condensate passes crude distillation and rectification, SiCl 4 Separated as impurities, SiHCl 3 It is used to produce polysilicon. [0003] in SiHCl 3 In the process of reducing and decomposing high-purity polysilicon products under the atmospheric conditions of about 1100 ° C, SiCl is produced per ton of products 4 Nearly 6 tons. Therefore, the by-product SiCl per ton of polysilicon products of a polysilicon plant that generally adopts the Siemens process 4 Nearly 10 tons must be recycled, otherwise it is impossible to implement large-scale production of polysilicon products....

AI Technical Summary

Problems solved by technology

[0007] 1. The ratio of HCl or CuCl, nickel salt, copper salt and other catalysts to silicon powder is generally 5%, and the primary conversion rate is low, generally 15-18%, so the consumption of raw materials is high and the production efficiency is low

[0008] 2. HCl, CuCl, and granular nickel salts and copper salts have low catalyst activity and require high reaction conversion conditions. The pressure is 2.1-3.5 MPa and the temperature is 500 ° C. Therefore, the energy consumption of the process is high, and the material and structure of the reactor are high and complex.

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