Method for recovering byproduct silicon tetrachloride produced in process of producing polycrystalline silicon

A silicon tetrachloride and polysilicon technology, applied in the directions of halogenated silicon compounds, halogenated silanes, energy input, etc., can solve the problems of the quality of trichlorosilane, high safety requirements, equipment wear, etc., and achieve easy industrialized continuous production. , The effect of production safety is good

Inactive Publication Date: 2012-12-05
NANJING UNIV OF INFORMATION SCI & TECH
View PDF3 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

(5) Ionic liquids have high viscosity
However, silicon powder has great hardness, which will cause considerable wear and tear on the equipment, and silicon powder also affects the quality of trichlorosilane after hydrogenation, so it needs to be rectified and recovered
[0012] This type of process requires high technology and high safety requirements. Therefore, the investment is large. For some enterprises, there are technical and financial difficulties.

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

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for recovering byproduct silicon tetrachloride produced in process of producing polycrystalline silicon
  • Method for recovering byproduct silicon tetrachloride produced in process of producing polycrystalline silicon
  • Method for recovering byproduct silicon tetrachloride produced in process of producing polycrystalline silicon

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] Absorption and analysis of silicon tetrachloride by 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid:

[0045] The simple diagram of the experimental device for the absorption and analysis of silicon tetrachloride by ionic liquid image 3 Shown: SHAPE \* MERGEFORMAT

[0046] Firstly, the system is evacuated to remove moisture as much as possible. Thereafter, the silicon tetrachloride waste liquid from which moisture has been removed is heated into a gas, which is passed into a container containing 100 g of ionic liquid for absorption. The absorption temperature is 20 ° C. After the absorption is saturated, the The ionic liquid was weighed to be 244g, and its absorption capacity was calculated to be 144g. Heat the weighed ionic liquid to 120 o C analysis, the gas passes through the cold trap device (-20 o C) Recycling, weighing the silicon tetrachloride obtained, and analyzing SiCl 4 140 g, the recovery rate was 97.2%.

Embodiment 2

[0048] Absorption and analysis of silicon tetrachloride by 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid:

[0049] First, vacuumize the system to remove moisture as much as possible. After that, heat the silicon tetrachloride waste liquid that has been removed into gas, and put it into a container with 100 g of ionic liquid for adsorption. The absorption temperature is 20 ° C. After the absorption is saturated, The ionic liquid was weighed to be 289g, and its absorption capacity was calculated to be 189g. Heat the weighed ionic liquid to 120 o C analysis, the gas passes through the cold well device (-20 o C) Recycling, weighing the silicon tetrachloride obtained, and analyzing SiCl 4 185 g, the recovery rate was 97.9%.

Embodiment 3

[0051] 1-methyl-3-alkylimidazolium hexafluorophosphate and 1-methyl-3-alkylimidazolium tetrafluoroborate ionic liquid, wherein the alkyl groups are respectively C 2 -C 12 , the prepared ionic liquids all have a good recovery effect on silicon tetrachloride.

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 provides a method for recovering a byproduct silicon tetrachloride produced in the process of producing polycrystalline silicon. Ionic liquid is recycled, so that SiCl4 is conveniently and efficiently recovered, the recovery rate is over 97 percent, hazards caused by the byproduct silicon tetrachloride produced in the process of producing the polycrystalline silicon are eliminated, and the silicon tetrachloride is recycled; a series of 1-alkyl-3-methylimidazole ionic liquid is synthesized under the condition of microwave radiation, and the imidazole ionic liquid with stable property is taken as an absorbent to absorb the SiCl4 by using the characteristic that the ionic liquid adsorbs gas; and after the ionic liquid is subjected to adsorption saturation, SiCl4 gas is released from the ionic liquid by heating and vacuumizing, so that the aim of recovering the SiCl4 is fulfilled.

Description

technical field [0001] The present invention relates to a new application of an important environment-friendly material. Specifically, a new method for recovering polysilicon by-product silicon tetrachloride. Background technique [0002] Introduction to ionic liquids: Ionic Liquids refer to salts that are completely composed of ions and are liquid at low temperatures (<100 °C), also known as room temperature molten salts, organic ionic liquids, etc. There is no unified name, but tend to be referred to as ionic liquid. It is generally composed of an equal number of organic cations and inorganic anions, and is generally electrically neutral; it is generally a liquid at room temperature. Therefore, ionic liquids often exhibit unique properties and unique functions. [0003] As a new type of green solvent that replaces volatile organic solvents, ionic liquids have remarkable characteristics that traditional solvents do not have, and can reduce or even eliminate the polluti...

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): C01B33/107
CPCY02P20/129
Inventor 陈敏东
Owner NANJING UNIV OF INFORMATION SCI & TECH
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