Method for producing silicon nitride powder

A silicon nitride powder and production method technology, applied in the direction of ammonium chloride, ammonium halide, etc., can solve the problems of low purity, irregular particle shape, high technical cost of silicon nitride powder, etc., and achieve the effect of low reaction temperature

Pending Publication Date: 2019-09-24
JIANGSU ZHONGNENG POLYSILICON TECH DEV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] Aiming at the problems of coarse particle size, low purity, and irregular particle shape of silicon nitride powder produced in domestic industrialization, and the above-mentioned silicon nitride powder preparation technology costs are high, equipment is complicated, an

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  • Method for producing silicon nitride powder
  • Method for producing silicon nitride powder

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Embodiment 1

[0045] A kind of production method of silicon nitride powder of the present invention specifically comprises the following steps:

[0046] 1) Repeatedly replace the gas in the tubular reactor 1 with nitrogen to anhydrous and oxygen-free conditions, send silicon tetrachloride to the tubular reactor 1, and then pass the mixed gas of nitrogen and ammonia into the tubular reactor 1 (the molar ratio of nitrogen and ammonia is 1:1), the direction of gas flow is consistent with the flow direction of silicon tetrachloride, and the temperature of tubular reactor 1 is controlled at -50 °C. After the reaction, the mixed product is filtered through a filter to obtain the solid product Si(NH) 2 and NH 4 Cl, silicon tetrachloride returns in the silicon tetrachloride storage tank, recycles in the reaction system, filters the solid product Si(NH) that obtains 2 and ammonium chloride into the washing filter kettle, and then pass through liquid ammonia for cleaning to remove ammonium chloride...

Embodiment 2

[0050] A kind of production method of silicon nitride powder of the present invention specifically comprises the following steps:

[0051] 1) Repeatedly replace the gas in the tubular reactor 1 with nitrogen to anhydrous and oxygen-free conditions, send silicon tetrachloride to the tubular reactor 1, and then pass the mixed gas of nitrogen and ammonia into the tubular reactor 1 (the molar ratio of nitrogen and ammonia is 1:4), the direction of gas flow is consistent with the flow direction of silicon tetrachloride, and the temperature of tubular reactor 1 is controlled at -50 °C. After the reaction, the mixed product is filtered through a filter to obtain solid product and silicon tetrachloride, and silicon tetrachloride is returned to the silicon tetrachloride storage tank for recycling in the reaction system, and the solid product Si(NH) obtained by filtration is 2 and ammonium chloride into the washing filter kettle, and then pass into liquid ammonia for cleaning to remove ...

Embodiment 3

[0055] A kind of production method of silicon nitride powder of the present invention specifically comprises the following steps:

[0056] 1) Repeatedly replace the gas in the tubular reactor with nitrogen to the condition of anhydrous and oxygen-free, send silicon tetrachloride to the tubular reactor, and then pass the mixed gas of nitrogen and ammonia into the tubular reactor 1 ( The molar ratio of nitrogen and ammonia is 1:9), the direction of gas flow is consistent with the flow direction of silicon tetrachloride, and the temperature of the tubular reactor is controlled at 0 °C. After the reaction, the mixed product is filtered through a filter to obtain solid product and silicon tetrachloride, and silicon tetrachloride is returned to the silicon tetrachloride storage tank for recycling in the reaction system, and the solid product Si(NH) obtained by filtration is 2 and ammonium chloride into the washing filter kettle, and then pass into liquid ammonia for cleaning to remo...

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Abstract

The invention discloses a method for producing silicon nitride powder. The method comprises the following steps: 1) reacting silicon tetrachloride and ammonia which are used as raw materials in order to synthesize a silicon nitride precursor Si(NH)2 solid, and obtaining pure Si(NH)2 powder; 2) transferring the Si(NH)2 into a high temperature furnace, and calcining the Si(NH)2 to obtain amorphous silicon nitride powder; and 3) refining and briquetting the obtained silicon nitride powder, transferring the briquetted powder into a high temperature crystallization furnace, and performing calcination to obtain crystalline silicon nitride powder. The method can continuously synthesize the silicon nitride precursor, and can flexibly control the particle size, the shape and the phase composition of the final product silicon nitride powder by adopting two calcination treatments which are low temperature decomposition of the Si(NH)2 and high-temperature crystallization of the amorphous silicon nitride powder; no organic solvents participate in the whole process, so carbon impurities in the silicon nitride powder are avoided; and the raw materials used for the product are produced in large scale in China, so low-cost production of high-purity sub-micron isometric silicon nitride powder is achieved.

Description

technical field [0001] The invention relates to a method for producing silicon nitride powder, in particular to a method for producing high-purity submicron equiaxed silicon nitride powder, and belongs to the technical field of silicon nitride powder preparation. Background technique [0002] As a high-temperature structural material, silicon nitride-based ceramics have the characteristics of light specific gravity, small thermal expansion coefficient, high hardness, high elastic modulus, wear resistance, thermal shock resistance, chemical stability and high-temperature thermodynamic properties. Silicon has special use value in the working environment of high temperature, high speed, strong corrosive medium and high wear, and is widely used in energy, chemical industry, military industry, aerospace, automobile industry, nuclear power engineering, electronic appliances, machinery and metallurgy and other fields . At present, the methods for preparing silicon nitride powder i...

Claims

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Application Information

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IPC IPC(8): C04B35/584C01C1/16C04B35/64
CPCC04B35/584C01C1/164C04B35/64C04B2235/661C04B2235/785
Inventor 王亮孟祥曼江宏富王敬强李前程郄丽曼
Owner JIANGSU ZHONGNENG POLYSILICON TECH DEV
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