Gradient-pore silicon nitride and silicon carbide combined film tube and preparation method therefor

A silicon carbide membrane and gradient pore technology, which is applied in the field of porous ceramic materials, can solve the problems of high sintering temperature and achieve the effects of firm bonding, high permeability and easy regeneration

Active Publication Date: 2016-07-06
INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] A technical problem to be solved by the present invention is: to avoid the existing silicon carbide filter materials mostly composed of clay and other low-temperature oxide partially bonded materials and the extremely high sintering temperature of conventional silicon carbide ceramic materials, and to provide a silicon nitride combined silicon carbide filter The material, the material preparation temperature is low, and the material composition is silicon nitride combined with silicon carbide, which makes this material more resistant to medium corrosion

Method used

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  • Gradient-pore silicon nitride and silicon carbide combined film tube and preparation method therefor
  • Gradient-pore silicon nitride and silicon carbide combined film tube and preparation method therefor
  • Gradient-pore silicon nitride and silicon carbide combined film tube and preparation method therefor

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preparation example Construction

[0047] The preparation method of the gradient pore silicon nitride bonded silicon carbide film tube of the present invention uses coarse silicon carbide, silicon powder and pore-forming agent as basic materials, uses polymer resin and curing agent as binder, mixes ingredients, and uses cold isostatic Press the support body with the press sleeve, and then use fine-grained silicon carbide, silicon powder, fiber additives and organic polymer resin to prepare the film layer raw materials, and use the impregnation method to prepare the film layer on the surface. After drying, sintering to obtain the finished film tube, mainly including the following step:

[0048] (1) Raw material preparation for support molding

[0049] Raw material coarse silicon carbide, silicon powder, polymer resin, pore-forming agent, and curing agent are (10-6): (5-3): (2-1): (3-1): (0.06 ~0.02) blended in an organic solvent, the organic solvent content is between 20% and 30% of the total mass of raw materi...

Embodiment 1

[0065] Support raw material preparation and molding:

[0066] The raw materials 100μm silicon carbide particles, 10μm silicon powder, furfural resin, polyvinyl alcohol PVA, and p-toluenesulfonic acid are blended in ethanol at a mass ratio of 10:5:2:3:0.06, and the ethanol content accounts for 30% of the total mass of raw materials. %, after being mechanically stirred and ball milled for 2 hours to obtain a slurry, then dried and pulverized at 80°C to obtain a raw material composite powder.

[0067] Put the above-mentioned composite powder in the isostatic pressing sheath, and use mechanical vibration during the filling. The isostatic pressing sheath is designed to have a tube blank size of 1000mm long, 80mm inner diameter, and 100mm outer diameter, and then put it into the cold isostatic pressing machine. The pressurized pressure is 100MPa, the pressure is maintained for 12 minutes, and then the jacket is removed to obtain a prefabricated support, and then cured at 120° C. for...

Embodiment 2

[0086] The difference from Example 1 is:

[0087] The raw material 40μm silicon carbide particles, 20μm silicon powder, phenolic resin, polyvinyl alcohol, and p-toluenesulfonic acid are blended in ethanol at a mass ratio of 6:4:2:1:0.03, and the ethanol content accounts for 30% of the total mass of raw materials , After being mechanically stirred and ball milled for 2 hours to obtain a slurry, then dried and pulverized at 80° C. to obtain a raw material composite powder.

[0088] Put the above composite powder in the isostatic pressing sheath, and use mechanical vibration during the filling. The isostatic pressing sheath is designed to have a tube blank size of 1000mm long, 5mm inner diameter, and 20mm outer diameter, and then put it into the cold isostatic pressing machine. The pressurized pressure is 150MPa, the pressure is maintained for 5 minutes, and then the jacket is removed to obtain the prefabricated support, and then cured at 120°C for 1 hour to obtain the prefabrica...

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Abstract

The invention belongs to the field of porous ceramic materials and particularly relates to a gradient-pore silicon nitride and silicon carbide combined film tube and a preparation method therefor. The film tube material is prepared from silicon nitride and silicon carbide, and a gradient filtering structure is formed by a supporting body layer and a surface film layer; a supporting body is formed through combining silicon nitride produced from a reaction with coarse silicon carbide grains and has the average pore size of 10 to 80 microns, the surface film layer is formed through combining the silicon nitride produced from the reaction with fine silicon carbide grains and has the average pore size of 0.1 to 20 microns, and the overall porosity of the film tube is 35% to 50%. The preparation method sequentially comprises the steps of carrying out batching, forming the supporting body, preparing the film layer and carrying out firing, wherein the forming is carried out by adopting isostatic pressing, the forming pressure is controlled to 40MPa to 150MPa, the firing temperature is controlled to 1,400 DEG C to 1,650 DEG C, and the heat preserving time is 3 to 5 hours. The film tube can be used in an oxidative atmosphere, can also be used in a reducing atmosphere, is high in acid-alkali corrosion resistance and can be applied to the filtering and purifying of various high- and low-temperature fluids of coal gasification chemical industry, IGCC and PFBC coal-gasified power generation, high-temperature flue gas, automobile exhaust gas, water purification and the like.

Description

technical field [0001] The invention belongs to the field of porous ceramic materials, in particular to a gradient pore silicon nitride bonded silicon carbide membrane tube and a preparation method thereof. Background technique [0002] High-temperature ceramic filter materials generally work under various harsh environmental conditions. As a high-temperature ceramic filter material for gas purification, it is usually required to have: (1) High mechanical strength, high temperature resistance (300-900°C) and excellent medium corrosion resistance Performance; (2) High filtration accuracy, filtration gas velocity and low pressure drop; (3) Easy to blow back, stable operation, high filtration efficiency; (4) Good thermal stability, able to withstand frequent high-pressure pulse cooling Thermal shock caused by blowback of gas. At the same time, according to the requirements of its application, the high-temperature ceramic filter must be able to withstand the influence of change...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01D71/02B01D69/04C04B35/565C04B35/584C04B35/622C04B38/06
Inventor 张劲松田冲杨振明曹小明刘强
Owner INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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