A kind of method for producing hcl gas from chlorosilane raffinate

A chlorosilane residual liquid and gas technology, applied in the direction of chlorine/hydrogen chloride, etc., can solve the problems of difficult cleaning, caking at the bottom of the pool, pipeline blockage, etc., so as to reduce the generation of silicate radicals, reduce the processing pressure, and prevent the generation of silicate radicals. Effect

Inactive Publication Date: 2017-06-13
KUNMING UNIV OF SCI & TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The lye treatment process only realizes the harmless disposal of chlorosilane residue, but the generated useful substances such as sodium silicate (calcium), silicon dioxide, sodium chloride (calcium) are not recycled, resulting in waste of resources
Secondly, using lye as an absorbent, due to the viscosity of lye and silicate, the pipeline will be severely blocked, and a large amount of sediment will be produced in the absorption liquid collection pool and circulation pool, and the bottom of the pool will agglomerate, making it difficult to clean

Method used

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  • A kind of method for producing hcl gas from chlorosilane raffinate

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Effect test

Embodiment 1

[0033] The method for producing HCl gas from a chlorosilane raffinate described in this embodiment is characterized in that it comprises the following steps:

[0034] The main component of the chlorosilane raffinate that this embodiment handles is 40% SiCl 4 , 40% SiHCl 3 , 15% SiH 2 Cl 2 , 5% HCl, a small amount of silicon powder and metal chloride, the treatment capacity is 0.5t / h.

[0035] (1) Transfer the chlorosilane raffinate that has been filtered to remove most of the silicon powder and metal chlorides to the raffinate storage tank 1, and use N 2Press the chlorosilane raffinate from the raffinate storage tank 1 to the stirred reactor 2 and the absorption liquid from the absorption tower 3 for hydrolysis reaction, the reaction residence time is 6 minutes, and the temperature of the stirred reactor 2 is controlled at 45-50°C.

[0036] (2) Use dilute hydrochloric acid to absorb the volatile gas produced by the stirred reactor 2 in the absorption tower 3, and the absor...

Embodiment 2

[0044] The method for producing HCl gas from a chlorosilane raffinate described in this embodiment is characterized in that it comprises the following steps:

[0045] The main component of the chlorosilane raffinate that this embodiment handles is 60% SiCl 4 , 30% SiHCl 3 , 9% SiH 2 Cl 2 , 1% HCl, a small amount of silicon powder and metal chloride, the processing capacity is 0.5t / h.

[0046] (1) Transfer the chlorosilane raffinate that has been filtered to remove most of the silicon powder and metal chlorides to the raffinate storage tank 1, and use N 2 Press the chlorosilane raffinate from the raffinate storage tank 1 to the stirred reactor 2 and the absorption liquid from the absorption tower 3 for hydrolysis reaction, the reaction residence time is 8 minutes, and the temperature of the stirred reactor 2 is controlled at 40~45°C.

[0047] (2) Use dilute hydrochloric acid to absorb the volatile gas produced by the stirring reactor 2 in the absorption tower 3, and the abs...

Embodiment 3

[0055] The method for producing HCl gas from a chlorosilane raffinate described in this embodiment is characterized in that it comprises the following steps:

[0056] The main component of the chlorosilane raffinate that this embodiment handles is 90% SiCl 4 , 5% SiHCl 3 , 4.5% SiH 2 Cl 2 , 0.5% HCl, a small amount of silicon powder and metal chloride, the treatment capacity is 0.5t / h.

[0057] (1) Transfer the chlorosilane raffinate that has been filtered to remove most of the silicon powder and metal chlorides to the raffinate storage tank 1, and use N 2 Press the chlorosilane raffinate from the raffinate storage tank 1 to the stirred reactor 2 and the absorption liquid from the absorption tower 3 for hydrolysis reaction, the reaction residence time is 10 minutes, and the temperature of the stirred reactor 2 is controlled at 35-40°C.

[0058] (2) Use dilute hydrochloric acid to absorb the volatile gas produced by the stirred reactor 2 in the absorption tower 3, and the a...

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Abstract

The invention discloses a method for producing HCl gas from chlorosilane raffinate, and belongs to the field of resource utilization of chlorosilane raffinate in the polysilicon industry. The present invention adopts the mode that the stirred reactor and the absorption tower are used together, the residual liquid of chlorosilane is hydrolyzed in the stirred reactor, and the H produced by the hydrolysis of the residual liquid is 2 , HCl gas and unreacted SiCl 4 , SiHCl 3 、SiH 2 Cl 2 After the volatile gas is fully absorbed by the absorption tower, more than 99% of the chlorine is absorbed in the form of hydrogen chloride, and the tail gas is discharged up to the standard after alkali washing. The generated HCl gas can be returned to the synthesis process of trichlorosilane, and the decomposed dilute hydrochloric acid is used as the absorbent of the system of the present invention, realizing the resource recycling of chlorine. The invention realizes the effective recovery and resource utilization of chlorine in the chlorosilane raffinate, reduces the amount of chloride ions entering subsequent sewage treatment devices, and reduces the cost of factory wastewater treatment.

Description

technical field [0001] The invention relates to a method for producing HCl gas from chlorosilane raffinate, and belongs to the field of resource utilization of chlorosilane raffinate in the polysilicon industry. Background technique [0002] In recent years, the tight supply of non-renewable energy such as petroleum, coal, and electricity and the rapid development of the photovoltaic industry have greatly promoted the development of the polysilicon industry. At present, the domestic polysilicon industry mostly adopts the improved Siemens method, that is, the closed-loop trichlorosilane hydrogen reduction method. However, due to the joint technology blockade of developed countries such as the United States, Japan, and Germany, the improved Siemens method has not been fully mastered in China, and closed-loop production cannot be realized. Therefore a large amount of material becomes chlorosilane raffinate and waste gas. [0003] The main source of chlorosilane raffinate: the ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C01B7/01
Inventor 黄兵罗平陈樑宋东明张雯雯沈宗喜章江洪马启坤李银光宋良杰徐灵通丁炳恒梁景坤郑慧文赵义王光跃和雪飙梁永坤邓亮王岭
Owner KUNMING UNIV OF SCI & TECH
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