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Method for processing recycling waste silicon material

A treatment method and silicon material technology, applied in chemical instruments and methods, silicon compounds, inorganic chemistry, etc., can solve the problems of difficult mass production, waste, high operating costs, etc., and achieve the effect of realizing reuse and reducing losses

Inactive Publication Date: 2017-01-11
姚伟
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] In the prior art, methods such as sand blasting, foam flotation, centrifugal separation, and high-temperature fusion filtration have been used to remove impurities such as silicon carbide, silicon nitride, or graphite in silicon materials, but these methods have high operating costs and are not easy to carry out mass production , and because the impurity removal of the processed silicon material is not thorough enough, it is generally difficult to directly reuse it as a raw material for polysilicon ingots, thus causing great waste

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Embodiment 1, a treatment method for the recovery and reuse of waste silicon material: put the waste silicon material containing impurities into a high-temperature-resistant, high-pressure-resistant, corrosion-resistant container, add an appropriate amount of 35% sodium hydroxide solution to react, control The reaction temperature is 40°C, and the reaction time is 20 minutes; after the reaction, add hydrofluoric acid into the container, control the reaction temperature at 60°C, the pressure at 1MPa, and the reaction time for 2 hours; after the reaction is complete, place the silicon material in hydrofluoric acid and Soak in a mixed acid solution of concentrated sulfuric acid for 20 minutes, in which the volume ratio of hydrofluoric acid to concentrated sulfuric acid is 1:6, and finally undergo ultrasonic rinsing with pure water and dry to obtain solar-grade silicon materials that can be directly used for polysilicon ingot casting.

Embodiment 2

[0022] Embodiment 2, a treatment method for the recovery and reuse of waste silicon material: put the waste silicon material containing impurities into a high-temperature-resistant, high-pressure-resistant, corrosion-resistant container, add an appropriate amount of 40% sodium hydroxide solution to react, control The reaction temperature is 50°C, and the reaction time is 30 minutes; after the reaction, add hydrofluoric acid into the container, control the reaction temperature to 70°C, the pressure to 2MPa, and the reaction time to 3 hours; after the reaction is complete, place the silicon material in hydrofluoric acid and Soak in a mixed acid solution of concentrated sulfuric acid for 40 minutes, in which the volume ratio of hydrofluoric acid to concentrated sulfuric acid is 1:7, and finally undergo ultrasonic rinsing with pure water and dry to obtain solar-grade silicon materials that can be directly used for polysilicon ingot casting.

Embodiment 3

[0023] Embodiment 3, a kind of processing method of recycling waste silicon material: put the waste silicon material containing impurities into a high temperature resistant, high pressure resistant, corrosion resistant container, add an appropriate amount of 40% sodium hydroxide solution to react, control The reaction temperature is 60°C, and the reaction time is 40 minutes; after the reaction, add hydrofluoric acid into the container, control the reaction temperature to 80°C, the pressure to 3MPa, and the reaction time to 4 hours; after the reaction is complete, place the silicon material in hydrofluoric acid and Soak in a mixed acid solution of concentrated sulfuric acid for 60 minutes, in which the volume ratio of hydrofluoric acid to concentrated sulfuric acid is 1:8, and finally undergo ultrasonic rinsing with pure water and dry to obtain solar-grade silicon material that can be directly used for polysilicon ingot casting.

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PUM

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Abstract

The present invention discloses a method for processing recycling a waste silicon material, and the method comprises the following steps: putting an impurity-containing waste silicon material into a container, and adding an alkaline solution; after the reaction is completed, adding an acid solution into the silicon material, and controlling temperature, pressure and reaction time; after the reaction is completed, adding the silicon material into a prepared mixed acid solution for soaking; finally using pure water for multiple times of ultrasonic rinse of the silicon material until the pH of the rinsed solution is 7; and drying. The beneficial effects are that: by the method combing high temperature and high pressure with acid washing and alkali washing, a great quantity of silicon nitride, silicon carbide, graphite, organic glue and other impurities in a waste layer silicon material can be thoroughly removed so as to realize the reuse of the waste layer silicon material.

Description

technical field [0001] The invention relates to a method for recycling and reusing waste materials, in particular to a method for reusing and reusing waste silicon materials in the field of photovoltaic semiconductors. Background technique [0002] Photovoltaic is a new type of power generation system that uses the photovoltaic effect of solar cell semiconductor materials to directly convert solar radiation energy into electrical energy. The solar cell semiconductor material is mainly made of polysilicon processed silicon wafers to form solar cells. Therefore, in the field of photovoltaic semiconductors, polysilicon ingots are opened into multiple crystal bricks, and a lot of waste silicon materials will be generated in the process. , it can be seen from the above that there are a large number of voids on the surface of the silicon material, and it also contains more impurities such as silicon carbide, silicon nitride, aluminum oxide, iron oxide, and organic glue. The organ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B33/037
Inventor 姚伟
Owner 姚伟