Method for cleaning an electrode shield for polysilicon production reduction furnaces

A technology of protective cover and reduction furnace, which is applied in the direction of using liquid cleaning methods, cleaning methods and utensils, chemical instruments and methods, etc., which can solve problems such as non-reuse, equipment damage, and current short circuit, and achieve reduction of industrial solid waste discharge Quantity, fast cleaning speed, and the effect of reducing production costs

Inactive Publication Date: 2013-04-17
江西赛维LDK光伏硅科技有限公司
View PDF6 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, trichlorosilane and hydrogen can react to form polysilicon at 700°C. Therefore, in the production process of polysilicon, the surface of the protective cover is usually covered by polysilicon, and the coverage rate generally exceeds 97% (the coverage rate of the upper surface of the protective cover is 100%, and the side surface of the protective cover is 100%. and inner surface coverage >95%); the polysilicon on the inner surface of the protective cover is only 1-3cm away from the chassis, and the polysilicon on the upper surface of the protective cover is only 1-3mm away from the graphite chuck on the electrode; if not If the silicon on the surface of the protective cover is removed, it cannot be reused; otherwise, it will easily cause a short circuit during the polysilicon deposition process, causing serious damage to the equipment and seriously affecting normal production

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 cleaning an electrode shield for polysilicon production reduction furnaces
  • Method for cleaning an electrode shield for polysilicon production reduction furnaces
  • Method for cleaning an electrode shield for polysilicon production reduction furnaces

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] A method for cleaning an electrode protective cover for a polysilicon material production reduction furnace, comprising the following steps:

[0030] (1) Immerse the silicon dioxide electrode protection cover to be cleaned in sodium hydroxide alkali solution with a mass fraction of 10%, and perform ultrasonic cleaning at 60°C for 120 minutes; the ultrasonic frequency during the ultrasonic cleaning process is 0.2KHz;

[0031] (2) After the ultrasonic cleaning is completed, use 60°C deionized water to spray and wash until the pH of the eluate is neutral. After drying with nitrogen gas at 60°C for 60 minutes, a clean regenerative electrode protective cover A is obtained.

[0032] figure 1 It is the photo of the electrode protective cover before cleaning in this embodiment; figure 2 It is a photo of the regenerated electrode protective cover after cleaning in this embodiment. It can be seen from the figure that the surface of the electrode protective cover after cleaning...

Embodiment 2

[0036] A method for cleaning an electrode protective cover for a polysilicon material production reduction furnace, comprising the following steps:

[0037] (1) Immerse the silicon dioxide electrode protection cover to be cleaned in sodium hydroxide alkali solution with a mass fraction of 8%, and perform ultrasonic cleaning at 40°C for 200 minutes; the ultrasonic frequency during the ultrasonic cleaning process is 5KHz;

[0038] (2) After ultrasonic cleaning, clean the electrode protective cover with deionized water at 40°C for 30 minutes;

[0039] (3) Subsequently, the electrode protective cover was soaked and cleaned with hydrochloric acid at 30°C for 30 minutes;

[0040] (4) Finally, wash with deionized water at 40°C until the pH of the eluate is neutral, and dry with nitrogen at 80°C for 20 minutes to obtain a clean regenerative electrode protective cover B.

[0041] After testing, the removal rate of silicon on the surface of the electrode protective cover in this embodi...

Embodiment 3

[0043] A method for cleaning an electrode protective cover for a polysilicon material production reduction furnace, comprising the following steps:

[0044] (1) Immerse the silicon dioxide electrode protection cover to be cleaned in potassium hydroxide alkali solution with a mass fraction of 6%, and perform ultrasonic cleaning at 30°C for 60 minutes; the ultrasonic frequency during the ultrasonic cleaning process is 10KHz;

[0045] (2) After ultrasonic cleaning, clean the electrode protective cover with deionized water at 60°C for 2 minutes;

[0046] (3) Then, the electrode protective cover was soaked and cleaned with citric acid at 40°C for 20 minutes;

[0047] (4) Finally, wash with deionized water at 20°C by bubbling and spraying until the pH of the eluate is neutral, and dry with nitrogen gas at 50°C for 50 minutes to obtain a clean regenerative electrode protective cover C.

[0048] After testing, the removal rate of silicon on the surface of the electrode protective cov...

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 cleaning an electrode shield for polysilicon production reduction furnaces. The method includes the steps: dipping the electrode shield to be cleaned in alkali liquor 6-12% in mass fraction, ultrasonically cleaning for 10-20 minutes at 30-60 DEG C, after ultrasonic cleaning, cleaning by bubbling and sprinkling of deionized water at 20-60 DEG C until washings are neutral, and performing nitrogen drying to obtain the cleaned regenerated electrode shield. The process combining physical and chemical methods is simple and is available in effectively removing polysilicon depositing on the surface of the electrode shield of a reduction furnace, the electrode shield is reused, production cost of polysilicon can be lowered, and cost competitive advantage of polysilicon products is increased.

Description

technical field [0001] The invention relates to the field of polysilicon production, in particular to a method for cleaning an electrode protective cover used in a polysilicon material production reduction furnace. Background technique [0002] At present, the Siemens method is the mainstream technology for producing polysilicon, and the high-purity silicon produced by this technology accounts for about 80% of the world's total silicon production. In the production process of polysilicon, trichlorosilane will undergo a vapor deposition reaction on the surface of the silicon core heated to 1080°C under the hydrogen atmosphere in the reduction furnace, and polysilicon will be precipitated, and the electrode protection cover of the reduction furnace mainly plays the role of heat resistance. , so its surface temperature usually exceeds 800°C. However, trichlorosilane and hydrogen can react to form polysilicon at 700°C. Therefore, in the production process of polysilicon, the su...

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): B08B7/04B08B3/08B08B3/12
Inventor 敖小俊聂思武吴一兵辛钧启
Owner 江西赛维LDK光伏硅科技有限公司
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