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Purification method of low-pollution high-purity electronic grade polycrystalline silicon

A purification method and electronic-grade technology, which is applied in the direction of chemical instruments and methods, silicon hydride, silicon compounds, etc., can solve problems such as the impact on the purity of silane products, and achieve the effect of improving purity, reducing production costs and energy consumption

Pending Publication Date: 2021-12-10
南通友拓新能源科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, crude silane also contains CH 4 When impurity components with the same kinetic diameter as silane, CO, etc., co-adsorption or competitive adsorption may occur, resulting in a great impact on the purity of the silane product obtained from the adsorption phase

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] (1) The prepared crude silane is introduced into the first rectification tower through a gas compressor. The temperature inside the first rectification tower is -32°C, operated at 2.2 MPa, and light is separated from the top of the first rectification tower. Components, light components include hydrogen, ammonia and methane, and the rest come from the bottom fraction of the first rectification tower.

[0029] (2) At -32°C, the rest of the bottom fraction of the first rectification tower is directly introduced into the 4A molecular sieve adsorption column, and the internal pressure of the 4A molecular sieve adsorption column is controlled to 1.17MPa. Ethylene is removed, and the remaining unremoved ethylene is converted into ethylsilane, and the part after the adsorption is completed is discharged from the top of the 4A molecular sieve adsorption column.

[0030] (3) Introduce the part discharged from the top of the 4A molecular sieve adsorption column into the second re...

Embodiment 2

[0034] (1) The crude silane produced is introduced into the first rectification tower through a gas compressor. The temperature inside the first rectification tower is -33°C, operated at 2.1 MPa, and light is separated from the top of the first rectification tower. Components, light components include hydrogen, ammonia and methane, and the rest come from the bottom fraction of the first rectification tower.

[0035] (2) At -27°C, the rest of the bottom fraction of the first rectification tower is directly introduced into the 4A molecular sieve adsorption column, and the internal pressure of the 4A molecular sieve adsorption column is controlled to 1.37MPa, and most of the 4A molecular sieve adsorption column is Ethylene is removed, and the remaining unremoved ethylene is converted into ethylsilane, and the part after the adsorption is completed is discharged from the top of the 4A molecular sieve adsorption column.

[0036](3) Introduce the part discharged from the top of the ...

Embodiment 3

[0040] (1) The crude silane produced is introduced into the first rectification tower through a gas compressor. The temperature inside the first rectification tower is -32°C, operated at 2.0 MPa, and light is separated from the top of the first rectification tower. Components, light components include hydrogen, ammonia and methane, and the rest come from the bottom fraction of the first rectification tower.

[0041] (2) At -37°C, the rest of the bottom fraction of the first rectification tower is directly introduced into the 4A molecular sieve adsorption column, and the internal pressure of the 4A molecular sieve adsorption column is controlled to 1.48MPa, and most of the 4A molecular sieve adsorption column is Ethylene is removed, and the remaining unremoved ethylene is converted into ethylsilane, and the part after the adsorption is completed is discharged from the top of the 4A molecular sieve adsorption column.

[0042] (3) Introduce the part discharged from the top of the...

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PUM

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Abstract

The invention discloses a purification method of low-pollution high-purity electronic-grade polycrystalline silicon. The purification method comprises the following steps: (1) introducing prepared crude silane into a first rectifying tower through a gas compressor, separating light components from the top of the first rectifying tower, and distilling the rest from the bottom of the first rectifying tower; (2) introducing the rest into a 4A molecular sieve adsorption column, and discharging the adsorbed part from the top; (3) conducting introducing to a second rectifying tower, separating out heavy components from the tower bottom of the second rectifying tower, and distilling out the rest of the heavy components from the tower top; (4) discharging the part which is subjected to adsorption after being sequentially guided into a molecular sieve mixed combined filled adsorption column into a decomposing furnace from the top, and obtaining high-purity silane after high-temperature decomposition is completed; and (5) carrying out thermal decomposition reaction on the obtained high-purity silane to obtain the electronic-grade polycrystalline silicon. The method has the advantages that the purity of the prepared polycrystalline silicon is greatly improved, a rectifying tower required to be arranged subsequently is reduced, and the production cost and the energy consumption are reduced.

Description

technical field [0001] The invention relates to the technical field of production and preparation of electronic-grade polysilicon, in particular to a method for purifying electronic-grade polysilicon with low pollution and high purity. Background technique [0002] The production technologies of polysilicon are mainly the improved Siemens method and the silane method, among which the silane method refers to the method of finally producing polysilicon by pyrolysis of silane. [0003] Silane, also known as monosilane, silane, silicon tetrahydrogen. Silane is one of the most important gas materials in the electronics industry. It is the main raw material for high-purity semiconductor chips, polysilicon, silicon epitaxial films, silicon nitride films, etc. It is widely used in polysilicon, solar cells, liquid crystal displays, optical fibers, and colored glass. Manufacturing and other industries. The application of silicon-containing films and coatings has expanded from the tr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B33/04C01B33/021
CPCC01B33/046C01B33/021
Inventor 徐建均周同义
Owner 南通友拓新能源科技有限公司