Method of preparing ultrafine silica from chlorosilane residual liquid

A technology of ultra-fine silica and chlorosilane residual liquid, applied in silica, silica, chemical industry and other directions, can solve the problems of high treatment cost and waste of resources, achieve good adsorption, reduce treatment cost, reduce effect of dosage

Active Publication Date: 2015-12-09
云南冶金云芯硅材股份有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0009] Aiming at the problems of waste of resources and high processing cost in the treatment process of chlorosilane raffinate at present, the present invention provides a safe, reliable, low energy consumption, and pollution-free method for preparing ultrafine silicon dioxide by using chlorosilane raffinate. Solve the problem of resource recovery and utilization of chlorosilane raffinate in polysilicon production

Method used

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  • Method of preparing ultrafine silica from chlorosilane residual liquid
  • Method of preparing ultrafine silica from chlorosilane residual liquid

Examples

Experimental program
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Embodiment 1

[0043] A kind of method that utilizes chlorosilane raffinate to prepare superfine silicon dioxide described in this embodiment, comprises the following steps:

[0044] (1) Chlorosilane raffinate (25% SiH 2 Cl 2 , 50% SiHCl 3 , 20% SiCl 4 , 4% silicon powder, and 1% metal chloride) buffer and precipitate impurities in the raffinate storage tank 1, and then enter the hydrolysis tower 3 through the pipeline filter 2 with a flow rate of 0.4t / h. Under the action of nitrogen, the residual The liquid enters the hydrolysis tower 3 in an atomized form, and the flow rate of the hydrochloric acid solution with an absorbent mass fraction of 20% is 24m 3 / h, the temperature of the absorbent is 20°C, it is sprayed in two stages from the top and middle of the tower, the mass ratio of the absorbent to the raffinate is about 60:1, and the chlorosilane raffinate undergoes hydrolysis reaction with the absorbent in the hydrolysis tower 3 .

[0045] (2) Nitrogen, hydrogen produced by hydrolys...

Embodiment 2

[0050] A kind of method that utilizes chlorosilane raffinate to prepare superfine silicon dioxide described in this embodiment, comprises the following steps:

[0051] (1) Chlorosilane raffinate (2% SiH 2 Cl 2 , 5% SiHCl 3 , 90% SiCl 4 , 2.7% silicon powder, 0.3% metal chloride) after buffering and precipitating impurities in the raffinate storage tank 1, they enter the hydrolysis tower 3 through the pipeline filter 2 with a flow rate of 0.4t / h. Under the action of nitrogen, the residual The liquid enters the hydrolysis tower 3 in an atomized form, and the flow rate of the hydrochloric acid solution with an absorbent mass fraction of 28% is 24m 3 / h, the temperature of the absorbent is 25°C, it is sprayed from the top and middle of the tower in two stages, the mass ratio of the absorbent to the raffinate is about 70:1, and the chlorosilane raffinate undergoes hydrolysis reaction with the absorbent in the hydrolysis tower 3.

[0052] (2) Nitrogen, hydrogen produced by hydro...

Embodiment 3

[0057] A kind of method that utilizes chlorosilane raffinate to prepare superfine silicon dioxide described in this embodiment, comprises the following steps:

[0058] (1) Chlorosilane raffinate (2% SiH 2 Cl 2 , 5% SiHCl 3 , 90% SiCl 4 , 2.7% silicon powder, 0.3% metal chloride) after buffering and precipitating impurities in the raffinate storage tank 1, they enter the hydrolysis tower 3 through the pipeline filter 2 with a flow rate of 0.4t / h. Under the action of nitrogen, the residual The liquid enters the hydrolysis tower 3 in an atomized form, and the flow rate of the hydrochloric acid solution with an absorbent mass fraction of 15% is 32m 3 / h, the temperature of the absorbent is 30°C, it is sprayed in two stages from the top and middle of the tower, the mass ratio of the absorbent to the raffinate is about 80:1, and the chlorosilane raffinate undergoes hydrolysis reaction with the absorbent in the hydrolysis tower 3.

[0059] (2) Nitrogen, hydrogen produced by hydro...

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Abstract

The invention discloses a method of preparing ultrafine silica from chlorosilane residual liquid, and belongs to the technical field of treatment and recovery of chlorosilane residual liquid. The preparation method comprises the following steps: buffering chlorosilane residual liquid in a residual liquid storage tank, settling impurities in the tank, introducing the processed chlorosilane residual liquid to a hydrolysis tower, carrying out atomization by taking the nitrogen gas as the atomization gas source, contacting a prepared acidic absorber with the atomized chlorosilane residual liquid to carry out reactions, introducing the obtained mixed solution absorbed by hydrolysis reactions into a sealed intermediate collecting groove; subjecting the absorbed mixed solution to solid-liquid separation, delivering the separated hydrochloric acid, which can be used to prepare the absorber, to a hydrochloric acid storage tank; washing the separated silica to remove the hydrochloric acid and part of metal impurities, wherein the acid-containing water generated during the washing process can be used to prepare the absorber; and finally drying the washed silica so as to obtain the finished product of ultrafine silica. The nitrogen gas atomization is carried out under a sealed condition, and the provide method has the advantages of safety, reliability, low energy consumption, and no pollution, and converts the chlorosilane residual liquid into valuable resource.

Description

technical field [0001] The invention relates to a method for preparing ultrafine silicon dioxide by utilizing chlorosilane raffinate, and belongs to the technical field of treating and recycling chlorosilane raffinate. Background technique [0002] Polysilicon has excellent optical, electrical and thermal properties, and is the main raw material required by the electronics and photovoltaic industries. With the vigorous promotion of photovoltaic power generation, the global polysilicon production is growing at an alarming rate. After 2008, as the demand tended to be balanced, the contradiction between supply and demand slowed down, and the huge production capacity caused an oversupply situation. The price of polysilicon dropped sharply, causing many domestic polysilicon enterprises to close down. Compared with foreign polysilicon enterprises, my country's polysilicon industry has backward production technology and equipment, high energy consumption, small production scale, h...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B33/18
CPCY02P20/10
Inventor 罗平陈樑宋东明黄兵马启坤张雯雯沈宗喜章江洪丁炳恒徐灵通李银光宋良杰梁景坤王光跃和雪飙梁永坤邓亮王云坤
Owner 云南冶金云芯硅材股份有限公司
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