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Method for preparing trichlorosilane through silicon tetrachloride cold hydrogenation

A technology of silicon tetrachloride and trichlorosilane, applied in the direction of halogenated silicon compounds, halogenated silanes, etc., can solve the problems of high production cost, low conversion rate, large system, etc., achieve excellent high temperature stability performance, reduce production Cost, simple effect of system equipment

Active Publication Date: 2014-08-06
CHINA ENFI ENGINEERING CORPORATION +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] 1. Spare parts are expensive and maintenance costs are high
[0006] 2. The tail gas treatment system is complex and huge
[0007] 3. The conversion rate is not high, generally around 20%, and the power consumption is high
[0008] 4. The heating element is made of carbon material, which has a great influence on the quality of the final polysilicon product
[0012] 1. The catalyst used is nickel salt or granular nickel, which is expensive, resulting in high production costs
[0013] 2. After the catalyst is mixed with silicon powder, high temperature activation is required, resulting in high energy consumption and high production costs
[0014] 3. The heating device for the mixed gas of silicon tetrachloride and hydrogen is unreasonable, and the temperature is low, resulting in low conversion efficiency
[0015] 4. Dust removal adopts cloth bag filter, which is not resistant to high temperature, easy to damage, high frequency of replacement, and difficult to repair

Method used

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  • Method for preparing trichlorosilane through silicon tetrachloride cold hydrogenation
  • Method for preparing trichlorosilane through silicon tetrachloride cold hydrogenation
  • Method for preparing trichlorosilane through silicon tetrachloride cold hydrogenation

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preparation example Construction

[0081] Specifically, the preparation method of the catalyst for preparing trichlorosilane by cold hydrogenation of silicon tetrachloride of the present invention comprises the following steps:

[0082] 1) Weighing a certain amount of copper powder and nickel powder and mixing to obtain a mixed powder, the mass content of nickel in the mixed powder is 10% to 35%;

[0083] 2) melting the mixed powder to obtain a melt;

[0084] 3) subjecting the melt to high-pressure water atomization treatment to obtain particles with a predetermined specific surface area and shape;

[0085] 4) Reductively drying the particles in a hydrogen atmosphere to obtain the catalyst particles.

[0086] Thus, a catalyst for preparing trichlorosilane by cold hydrogenation of silicon tetrachloride can be prepared.

[0087] Regarding the step 1) and step 2), it should be understood that the method and equipment for mixing and melting the copper powder and nickel powder are not particularly limited, as long...

experiment example 1

[0108] Weigh 90g of copper powder and 10g of nickel powder and mix to obtain a mixed powder, which is melted to obtain a melt; the melt is subjected to high-pressure water atomization treatment at a pressure of 2MPa to obtain a specific surface area of ​​30m 2 / g of roughly spherical particles; the particles were reduced and dried in a hydrogen atmosphere to obtain catalyst particles.

[0109] The catalyst particles were pulverized and sieved to obtain a catalyst powder with a particle size of 10-200 mesh and a bulk density of 2.6 g / ml.

experiment example 2

[0111] Weigh 65g of copper powder and 35g of nickel powder and mix to obtain a mixed powder, melt the mixed powder to obtain a melt; process the melt with high-pressure water atomization at a pressure of 5MPa to obtain a specific surface area of ​​80m 2 / g of roughly spherical particles; the particles were reduced and dried in a hydrogen atmosphere to obtain catalyst particles.

[0112] The catalyst particles were crushed and sieved to obtain a catalyst powder with a particle size of 10-200 mesh and a bulk density of 2.9 g / ml.

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Abstract

The invention discloses a method for preparing trichlorosilane through silicon tetrachloride cold hydrogenation. The method comprises the steps that: (a) silicon powder and a catalyst are mixed, such that a mixed material is obtained; (b) the mixed material is dehydrated under a hydrogen atmosphere; (c) hydrogen is mixed with silicon tetrachloride, such that a first mixed gas is obtained; (d) the first mixed gas is heated to a temperature of 450-550 DEG C; (e) the mixed material and the first mixed gas are subjected to a reaction under the temperature of 450-500 DEG C, such that a second mixed gas is obtained; (f) the second mixed gas is subjected to dust collection and filtering by using a gas filtering device; (g) the second mixed gas obtained after dust collection and filtering is condensed, such that hydrogen and chlorosilane are obtained; and (h) chlorosilane is subjected to separation purification, such that trichlorosilane is obtained. According to the preparation method provided by the embodiment of the invention, copper-nickel alloy is adopted as the catalyst. High-temperature pre-activation is not needed before the reaction. After the reaction, produced residue can be directly discharged, and no pollution to the environment is caused.

Description

technical field [0001] The invention relates to the technical field of polysilicon production technology, more specifically, the invention relates to a method for preparing trichlorosilane by cold hydrogenation of silicon tetrachloride. Background technique [0002] More than 85% of the process technology of polysilicon project in my country at the present stage belongs to Siemens process technology. In this process technology, a very important link is the cold hydrogenation of silicon tetrachloride to produce trichlorosilane. [0003] In the process of producing polysilicon by the improved Siemens method, nearly 20 tons of silicon tetrachloride is produced as a by-product for every ton of polysilicon produced, and a 2,000-ton polysilicon factory produces more than 40,000 tons of silicon tetrachloride per year. Silicon tetrachloride is liquid at room temperature, so it is not suitable for storage and transportation. At the same time, the market capacity of silicon tetrachlo...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B33/107
Inventor 万烨严大洲毋克力肖荣晖汤传斌
Owner CHINA ENFI ENGINEERING CORPORATION