Method for preparing silicon dioxide and hydrogen chloride by means of hydrolysis of polysilicon by-product silicon tetrachloride

A technology of silicon tetrachloride and silicon dioxide, which is used in the preparation of chloride, silicon dioxide, chlorine/hydrogen chloride, etc., can solve the problems of complex process, achieve simple process, simplify process, and facilitate production and implementation. Effect

Inactive Publication Date: 2012-07-18
HEBEI UNIVERSITY OF SCIENCE AND TECHNOLOGY
View PDF3 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This process requires a large amount of water or dilute hydrochloric acid to treat a certain amount of silicon tetrachloride, and the hydrogen chloride gas generated needs to be concentrated in hydrochloric acid before being analyzed, so the process is relatively complicated.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Add 80L mass concentration of 20% hydrochloric acid solution in the closed reaction kettle, add 10kg additive magnesium chloride, 3kg surfactant sodium dodecylbenzenesulfonate, stir thoroughly and then feed steam in the jacket for heating, control The reaction temperature was 35°C. Slowly add silicon tetrachloride into the reactor, control the flow rate of silicon tetrachloride at 0.6m 3 / h, during the addition process, the temperature of the reaction liquid in the kettle is controlled to be 35-42°C by adjusting the amount of circulating cooling water. The hydrogen chloride gas produced in the reaction is sent to the trichlorosilane production unit after filtering, dust removal and drying. After the silicon tetrachloride reaction is completed, the feed liquid is aged for 1 hour and then discharged to the filter equipment for separation and washing. The mother liquor water is sent to the mother liquor storage tank, and the washing water is sent to the lean liquor storag...

Embodiment 2

[0029] Add 50L mass concentration of 28% hydrochloric acid solution in the airtight reaction kettle, add 8kg of additives magnesium chloride and ammonium chloride mixture, wherein magnesium chloride and ammonium chloride each account for 4kg, 2kg surfactant OP-10, stir well and then add Steam was passed into the jacket for heating, and the reaction temperature was controlled at 45°C. Slowly add silicon tetrachloride into the reactor, control the flow of silicon tetrachloride at 0.5m 3 / h, during the addition process, the temperature of the reaction liquid in the kettle is controlled to be 45-50°C by adjusting the amount of circulating cooling water. The hydrogen chloride gas produced in the reaction is sent to the trichlorosilane production unit after filtering, dust removal and drying. After the silicon tetrachloride reaction is completed, the feed liquid is aged for 1 hour and then discharged to the filter equipment for separation and washing. The mother liquor water is sen...

Embodiment 3

[0031] Add 60L of hydrochloric acid solution with a mass concentration of 18% in a closed reaction kettle, add 4kg of additive ammonium chloride, 6kg of calcium chloride; Steam was passed into the medium for heating, and the reaction temperature was controlled at 25°C. Slowly add silicon tetrachloride into the reactor, control the flow rate of silicon tetrachloride at 0.6m 3 / h, during the addition process, the temperature of the reaction liquid in the kettle is controlled to be 25-32°C by adjusting the amount of circulating cooling water. The hydrogen chloride gas produced in the reaction is sent to the trichlorosilane production unit after filtering, dust removal and drying. After the silicon tetrachloride reaction is completed, the feed liquid is aged for 1 hour and then discharged to the filter equipment for separation and washing. The mother liquor water is sent to the mother liquor storage tank, and the washing water is sent to the lean liquor storage tank as mother liq...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention relates to a method for preparing silicon dioxide and hydrogen chloride by means of hydrolysis of polysilicon by-product silicon tetrachloride. The method comprises the following steps of: adding additives and surfactants into an airtight reaction kettle with 5 to 30 mass percent of hydrochloric acid aqueous solution, adding the silicon tetrachloride into the airtight reaction kettle, wherein the input amount of the silicon tetrachloride is controlled to be between 0.4 and 0.9 m<3>/h; performing a hydrolysis reaction by controlling the temperature to be between 20 and 50 DEG C, and generating silica sol and hydrogen chloride gas; drying and recycling the hydrogen chloride gas; standing and aging the silica sol to form silicon dioxide precipitates; filtering and washing the silicon dioxide precipitates to remove the residual additives; and drying the washed silicon dioxide colloid, and thus obtaining precipitated white carbon black (silicon dioxide). The process has the characteristics of simple process flow, readily available raw materials, low production cost and the like.

Description

technical field [0001] The invention belongs to the field of inorganic chemical industry, and relates to a method for preparing silicon dioxide and hydrogen chloride by hydrolyzing silicon tetrachloride, a by-product of polycrystalline silicon. Background technique [0002] Silicon tetrachloride is the largest by-product in the production of polysilicon. Silicon tetrachloride recovered without treatment is a highly corrosive, toxic and harmful liquid, which is very harmful to safety and the environment. In 2010, my country's polysilicon output reached about 40,000 tons, and the by-product silicon tetrachloride was about 600,000 tons. The post-processing of a large amount of silicon tetrachloride has become a bottleneck restricting the development of the polysilicon industry. [0003] In recent years, there are mainly three methods for the post-treatment of polysilicon by-product silicon tetrachloride: one is hydrogenation reduction to produce trichlorosilane. Although this ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C01B33/12C01B7/03
Inventor 胡永其刘润静赵风云王建英刘玉敏张向京乔永志刘硕
Owner HEBEI UNIVERSITY OF SCIENCE AND TECHNOLOGY
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap