CN111099887A

CN111099887A - Preparation method of honeycomb ceramic carrier powder and prepared powder

Info

Publication number: CN111099887A
Application number: CN201911362762.5A
Authority: CN
Inventors: 孔秋民; 陈明祥
Original assignee: NANJING KERUI SPECIAL CERAMICS CO Ltd
Current assignee: NANJING KERUI SPECIAL CERAMICS CO Ltd
Priority date: 2019-12-26
Filing date: 2019-12-26
Publication date: 2020-05-05

Abstract

The invention discloses a preparation method of honeycomb ceramic carrier powder, which is characterized in that kaolin, talcum powder, alumina and fused silica micropowder are mixed in advance to prepare a mixture; stirring the mixture, the deionized water and the dispersant at the rotating speed of 100-; spraying the slurry in a dryer at 260-300 ℃, and drying to obtain powder. The powder prepared by the preparation method has good fluidity due to the microcosmic spherical shape, improves the smoothness of mud discharge in the molding and extrusion process, and the prepared carrier has low thermal expansion coefficient, good thermal shock resistance and high qualification rate.

Description

Preparation method of honeycomb ceramic carrier powder and prepared powder

Technical Field

The invention belongs to the technical field of ceramics, and particularly relates to a preparation method of honeycomb ceramic carrier powder and the prepared powder.

Background

With the implementation of the national emission standard of six, the wall thickness of the corresponding carrier needs to be controlled at 4 mils, namely 0.10mm, and compared with the wall thickness of the national carrier of 5-6.5 mils, the wall thickness of the carrier has higher requirements on the pug for producing the carrier, which is reflected in that the flowability of the pug is better. The conventional powder processing mode at present is that kaolin, talcum powder, alumina, fused silica powder and the like are mixed together through a mixer, namely, the powder is processed, the powder processed by the mode is used for producing a carrier with the wall thickness of 4mil, and due to the fact that the flowability of pug is relatively poor, the qualified rate of a formed product is low, the inherent performance of a final product is influenced, the thermal expansion coefficient is high, and the thermal shock resistance is poor.

Disclosure of Invention

In order to solve the problems of high thermal expansion coefficient, poor thermal shock resistance and low percent of pass of the carrier prepared by the conventional powder, the invention provides a preparation method of honeycomb ceramic carrier powder and the prepared powder.

The preparation method of the honeycomb ceramic carrier powder comprises the steps of premixing kaolin, talcum powder, alumina and fused silica micropowder to prepare a mixture; stirring the mixture, the deionized water and the dispersant at the rotating speed of 100-; spraying the slurry in a dryer at 260-300 ℃, and drying to obtain powder.

Preferably, 30-40 parts of kaolin, 38-42 parts of talcum powder, 12-18 parts of alumina, 8-12 parts of fused silica powder and 0.6-1.2 parts of dispersing agent by mass, wherein the mass ratio of the mixture to deionized water is 1: 1.0-1.6.

Preferably, the slurry has a solid content of 35 to 40% (mass percent).

Preferably, the dispersant is a low molecular weight polyacrylic acid.

Preferably, the moisture content of the powder is within 5 percent.

Preferably, the powder is microscopically spherical.

The invention also provides powder prepared by the preparation method.

Has the advantages that: the powder prepared by the preparation method has good fluidity due to the microcosmic spherical shape, improves the smoothness of mud discharge in the molding and extrusion process, and the prepared carrier has low thermal expansion coefficient, good thermal shock resistance and high qualification rate.

Drawings

FIG. 1 is an SEM image of the powder material after treatment according to the present invention;

FIG. 2 is an SEM image of the powder after conventional treatment.

Detailed Description

The technical solution of the present invention is described in detail by the following examples, but the scope of the present invention is not limited to the examples.

Example 1

Premixing 34 parts of kaolin, 40 parts of talcum powder, 16 parts of alumina and 10 parts of fused silica powder in parts by mass to prepare a mixture; mixing the mixture with 150 parts of deionized water, adding 0.6 part of polyacrylic acid with molecular weight of 2000, and stirring by using a stirrer at the rotating speed of 100r/min to prepare uniform slurry with solid content of 35%; the slurry was pressed into a 260 ℃ dryer by using a high-speed centrifugal spray dryer (GZ type, Sun drying Equipment Co., Ltd., No. Sn, the same shall apply hereinafter) to control the slurry to be atomized in the dryer, and after drying, powder 1 having a water content of 5% and a microscopic spherical shape was obtained.

Example 2

Premixing 34 parts of kaolin, 40 parts of talcum powder, 16 parts of alumina and 10 parts of fused silica powder in parts by mass to prepare a mixture; mixing the mixture with 120 parts of deionized water, adding 0.6 part of polyacrylic acid with molecular weight of 2000, and stirring at the rotating speed of 100r/min to prepare uniform slurry with solid content of 40%; and pressing the slurry into a drier at 300 ℃ by using a high-speed centrifugal spray drier to control the slurry to be atomized in the drier, and drying to obtain the powder 2 with the water content of 5% and the microscopic spherical shape.

Example 3

Premixing 34 parts of kaolin, 40 parts of talcum powder, 16 parts of alumina and 10 parts of fused silica powder in parts by mass to prepare a mixture; mixing the mixture with 140 parts of deionized water, adding 0.6 part of polyacrylic acid with molecular weight of 2000, and stirring at the rotating speed of 120r/min to prepare uniform slurry with the solid content of 37%; and pressing the slurry into a dryer at 280 ℃ by using a high-speed centrifugal spray dryer to control the slurry to be atomized in the dryer, and drying to obtain the powder 3 with the water content of 5% and the microscopic sphere shape.

Comparative example

Powder 4 was obtained using conventional methods.

Measurement of Performance

The honeycomb ceramic carrier 1, carrier 2, carrier 3, and carrier 4 were prepared using powder 1, powder 2, powder 3, and powder 4, and the following performance measurements were performed.

The thermal expansion coefficient was measured by using a thermal expansion coefficient measuring instrument (NETZSCH ⊕ D11-402PC type, Germany Chinesh resistance).

Thermal shock resistance: the measurement was carried out in a muffle furnace (SX2-12-12 type, Yixing Qianjin Kaiki Co., Ltd.).

Wall thickness: measured by an image measuring instrument (MVP type, Megaku instruments Co., Ltd.).

The measurement results are shown in table 1.

TABLE 1

	Percent of pass	Wall thickness	Coefficient of thermal expansion	Thermal shock resistance
					Carrier 1	92％	0.10mm	0.65	No cracking after three cycles at 750 DEG C
Carrier 2	95％	0.10mm	0.62	No cracking after three cycles at 750 DEG C
					Carrier 3	90％	0.10mm	0.70	No cracking after three cycles at 750 DEG C
Carrier 4	75％	0.10mm	0.85	No cracking after three cycles at 650 DEG C

From table 1 above, it can be seen that: the carrier prepared by the powder material has the qualification rate improved by more than 20 percent compared with the carrier prepared by the existing powder material, further reduces the thermal expansion coefficient, and has the thermal shock resistance improved from 650 ℃ to 750 ℃ for three times of circulation without cracking.

As noted above, while the present invention has been shown and described with reference to certain preferred embodiments, it is not to be construed as limited thereto. Various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A preparation method of honeycomb ceramic carrier powder is characterized in that kaolin, talcum powder, alumina and fused silica micropowder are mixed in advance to prepare a mixture; stirring the mixture, the deionized water and the dispersant at the rotating speed of 100-; spraying the slurry in a dryer at 260-300 ℃, and drying to obtain powder.

2. The preparation method of the honeycomb ceramic carrier powder according to claim 1, wherein 30-40 parts of kaolin, 38-42 parts of talcum powder, 12-18 parts of alumina, 8-12 parts of fused silica micropowder and 0.6-1.2 parts of dispersing agent are calculated according to parts by mass, and the mass ratio of the mixture to the deionized water is 1: 1.0-1.6.

3. The method of claim 1, wherein the slurry has a solids content of 35-40%.

4. The method of claim 1, wherein the dispersant is a low molecular weight polyacrylic acid.

5. The method for preparing a honeycomb ceramic carrier powder according to claim 1, wherein the powder has a water content of 5% or less.

6. The method of claim 1, wherein the powder is microscopically spherical.

7. A powder material obtained by the production method according to any one of claims 1 to 6.