Method for preparing solar cell polysilicon raw material from rice hulls

A solar cell, polysilicon technology, applied in circuits, silicon oxide, electrical components, etc., can solve the problems that hinder wide practicability and the feasibility of large-scale commercial production, cannot use rice husk thermal energy, and high production costs, and achieve production costs. The effect of low, less sewage and less drug consumption

Inactive Publication Date: 2010-03-17
邵振亚
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Both of the above two methods belong to the processing route of acid treatment, chemical purification, high temperature (800-1000°C) carbonization and combustion of rice husks. Both of them need to consume a large amount of high-purity chemicals to decompose and process the bulky rice husks. Organic matter, can not utilize the heat energy of rice husk self again (unit calorific value is half of standard coal), so the method itself all exists problems such as large amount of medicine, sewage discharge is big and production cost is relatively high, so hindered the development of this kind of method greatly Wide availability and feasibility of large-scale commercial production

Method used

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  • Method for preparing solar cell polysilicon raw material from rice hulls
  • Method for preparing solar cell polysilicon raw material from rice hulls

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Experimental program
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Effect test

Embodiment 1

[0016] (1) Heat treatment of rice husks: 100 grams of rice husks are crushed, screened (100 mesh) and dried (moisture content 1%), and put into a tubular electric furnace crucible. The heat treatment temperature is 590 ° C, and nitrogen gas (1 liter flow rate) for 100 minutes of pyrolysis and carbonization treatment, then cooled to 500C, changed to air (2 liters flow rate per minute) for slow combustion for 180 minutes, to obtain C, SiO 2 Mixed powder with impurities.

[0017] (2) Activation treatment: grind the mixed powder obtained in step (1) into fine powder (to form a mixed powder) and put it into a microwave oven for heating (at a temperature of 500° C.) for 10 minutes of activation treatment.

[0018] (3) Purification treatment: the mixed powder obtained by step (2) is packed into the reflux condenser flask, then add analytically pure (AR) hydrogen peroxide 5ml, analytically pure (AR) nitric acid 8ml and high-purity deionized water (resistivity More than 10 megohm·cm) ...

Embodiment 2

[0020] (1) Heat treatment of rice husks: 100 grams of rice husks are crushed, screened (100 mesh) and dried (moisture content 1%), and put into a tubular electric furnace crucible. The heat treatment temperature is 540 ° C, and nitrogen gas (1 liter flow rate) for 120 minutes of pyrolysis and carbonization treatment, then heated up to 590 ° C, changed to air (2 liters flow per minute) and slow combustion for 100 minutes to obtain C, SiO 2 Mixed powder with impurities.

[0021] (2) Activation treatment: Grind the mixed powder obtained in step (1) into fine powder (to form a mixed powder) and put it into a microwave oven for heating (at a temperature of 590° C.) for 5 minutes of activation treatment.

[0022] (3) Purification treatment: put the mixed powder obtained in step (2) into a reflux condenser flask, then add 5ml of AR hydrogen peroxide, 8ml of AR hydrochloric acid and 20ml of high-purity deionized water, and heat to reflux (>100°C) for 60 Minutes, then add 50ml of high...

Embodiment 3

[0024] (1) Heat treatment of rice husks: 100 grams of rice husks are crushed, screened (100 mesh) and dried (moisture content 2%), and put into a tubular electric furnace crucible. The heat treatment temperature is 500 ° C, and nitrogen gas (1 1 flow rate) for pyrolysis and carbonization for 180 minutes, then the temperature was raised to 590° C., and air was changed (2 liters flow rate per minute) for slow combustion for 100 minutes.

[0025] (2) Activation treatment: grind the mixed powder obtained in step (1) into fine powder (to form a mixed powder), put it into a microwave oven for heating (at a temperature of 540° C.) and activate it for 8 minutes.

[0026] (3) Purification treatment: put the mixed powder obtained in step (2) into a reflux condenser flask, then add 5ml of AR hydrogen peroxide, 10ml of AR nitric acid and 20ml of high-purity deionized water, and heat to reflux (>100°C) for 60 Minutes, then add 50ml of high-purity deionized water, continue heating and reflu...

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Abstract

The invention relates to a method for preparing a solar cell polysilicon raw material from rice hulls. The method comprises the following steps: heat treatment, activation treatment and chemical purification treatment of rice hulls. The method has the advantages of small drug dose, less pollution discharging and low production cost. The grain size of finally prepared mixed powder of SiO2 and C isin a nano range, and when the mixed powder is applied to an arc furnace for reducing and smelting silicon, the mixed powder presents higher reactivity and lower specific energy consumption. The mixedpowder prepared from SiO2 and C comprises boron less than 0.8ppm and phosphorus less than 0.5ppm, the total impurity content is less than 100ppm, and high-purity (99.99 percent) polysilicon products containing low boron and phosphorus for solar cells can be smelted and produced by using the mixed powder (or pills) as a raw material. If a universal wet hydrogen boron removal type suspension zone smelting method continues to be used for physical purification, solar-grade polysilicon can be finally manufactured. The solar-grade polysilicon is then processed and drawn into single crystal ingots, and the single crystal ingots are cut into silicon chips which can be used for producing solar panel products.

Description

technical field [0001] The invention relates to a preparation method for producing polysilicon raw materials for solar cells, in particular to a method for preparing high-purity and high-activity silicon dioxide and carbon mixed powder with rice husks. It belongs to the field of fine chemical technology. technical background [0002] US.P4214920 (1980) patent introduces a method for preparing polycrystalline silicon for solar cells with rice husk as raw material. It first heat-corrodes rice husks with hydrochloric acid to remove most impurities and chemically purify them, then conduct high-temperature pyrolysis and carbonization on rice husk residues, and then burn them in a carbon dioxide atmosphere under high-temperature conditions to control the combustion time and adjust the carbon. content, and finally get SiO 2 Mixed with C powder, the purity can reach 99.99%, of which SiO 2 The molar ratio to C is 1:2, and it can be used as a raw material for arc furnace reduction ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L31/18C01B31/02C01B33/12
CPCY02P70/50
Inventor 邵振亚
Owner 邵振亚
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