Preparation method of light closed-pore zirconium oxide fiber thermal insulation material

Abstract

The invention discloses a preparation method of a lightweight closed-pore zirconium oxide fiber thermal insulation material, and relates to the field of lightweight thermal insulation materials, and the technology comprises the following steps: preparing zirconium oxide fibers by a template impregnation method, forming a fiberboard, and densifying the surface of the board. The preparation method comprises the following specific steps: crushing an obtained zirconium oxide fiber block, uniformly dispersing the crushed zirconium oxide fiber block into a prepared dispersion liquid containing zirconium sol to prepare stable slurry, pouring the stable slurry into a mold, carrying out filter pressing treatment to obtain a wet blank of a zirconium oxide fiber product, drying, and carrying out high-temperature heat treatment to obtain the zirconium oxide fiber board with a certain size. And then mixing transition metal powder and metal Si powder into slurry through a ball mill, uniformly smearing the slurry on the surface of the plate, performing drying treatment in a drying oven, and performing high-temperature heat treatment to form a compact binary silicide film on the surface of the zirconium oxide fiber, thereby obtaining the light closed-pore zirconium oxide fiber thermal insulation material with a compact surface. The preparation method has the advantages that the preparation method is simple and feasible, and the prepared zirconium oxide fiber heat insulation material is uniform in pore structure, low in density, good in heat insulation performance and high in strength.

Description

Technical Field

[0001] The invention relates to a method for preparing a lightweight closed-cell zirconium oxide fiber thermal insulation material, and belongs to the field of fiber thermal insulation materials. Background Art

[0002] In recent years, due to the continuous rise in global energy prices, energy conservation has become a development strategy for most countries. In this context, ceramic fibers with light weight, high temperature resistance, excellent chemical stability and low thermal conductivity have attracted widespread attention. Compared with traditional refractory materials such as various insulation bricks and castables, ceramic fibers not only have a good weight reduction effect, but also have an energy saving effect that is 10%-30% higher, and have good development prospects; common ceramic fibers mainly include aluminum silicate fiber, carbon fiber, SiC fiber, alumina fiber, zirconia fiber, etc. Compared with other ceramic fibers, zirconia fiber has lower thermal conductivity, better chemical stability and higher operating temperature due to the properties of zirconia itself. It is one of the few ceramic fibers that can meet the requirements of more than 1600℃, with a melting point of up to 2700℃, and can still maintain its fiber form at a temperature of 2480℃, and can be used for a long time in oxidizing environment, reducing environment and vacuum environment. However, although zirconia fiber insulation materials have excellent high temperature resistance, their strength is not high and they are easy to absorb moisture; therefore, it is necessary to design a method to improve the strength and hygroscopicity of zirconia fiber insulation materials to enhance their scope of application. Summary of the invention

[0003] In order to solve the above technical problems, the purpose of the present invention is to provide a method for preparing a lightweight closed-cell zirconia fiber thermal insulation material.

[0004] The present invention adopts the following technical scheme to achieve the above-mentioned purpose: A method for preparing a lightweight closed-cell zirconia fiber thermal insulation material, wherein the zirconia fiber obtained by a template impregnation method is filtered in a mold to form a zirconia fiber board, and then a slurry mixed with metal Si powder and transition metal powder is evenly brushed on the obtained zirconia fiber board, and a zirconia fiber thermal insulation material with a dense surface is obtained through high-temperature treatment; the specific preparation steps are as follows: a. Preparation method of zirconia fiberboard: crush the flaky zirconia fiber block and evenly disperse it into the prepared dispersion containing zirconium sol at a mass ratio of 1:200 to 1:500 to obtain a stable slurry, pour the slurry into a mold, filter press to obtain a wet blank of zirconia fiber product, then dry it, and perform high-temperature heat treatment to obtain a zirconia fiberboard; b. Preparation method of binary silicide film: using anhydrous ethanol as solvent, ball milling at a rate of 400-500r / min for 6-8h, respectively refining transition metal powder and metal Si powder, drying the refined powder in vacuum and weighing to a designed composition of 1:2.5-4; then, mixing the powder with a binder, preparing a uniform slurry by ball milling; brushing the slurry evenly on the surface of the zirconia fiberboard, putting it in an oven for drying after solidification, putting the dried sample in a high-temperature furnace, and heat treating it in a nitrogen atmosphere to form a dense binary silicide film, thereby obtaining a lightweight closed-cell zirconia fiber insulation material.

[0005] The zirconium sol dispersion is prepared by mixing metal zirconium salt, solvent, catalyst and additive in a mass ratio of 1:1-4:0.01-0.05:0.02-0.1, and stirring at a constant temperature in a water bath for 8-24 hours to obtain a precursor zirconium sol.

[0006] The metal zirconium salt is one of zirconium oxychloride, zirconium nitrate and zirconium acetate; the specification is analytical grade.

[0007] The solvent is one or two of water, ethanol and acetic acid; the purity is above 99%.

[0008] The catalyst is one or two of dilute nitric acid, dilute hydrochloric acid and formic acid.

[0009] The additive is one or two of polyethylene glycol-600, ethylenediamine and sodium dodecylbenzene sulfonate.

[0010] The heat treatment temperature of the precursor fiberboard is 400-700°C.

[0011] The transition metal powder is one or two of Cr, Nb and Ce.

[0012] The adhesive is polyvinyl butyral PVB or polyvinyl alcohol PVA.

[0013] The oven temperature is 60-110° C. and the drying time is 10-24 hours.

[0014] The heat treatment temperature after painting is 1500-1700℃, and the insulation time is 0-2 hours.

[0015] The present invention proposes a method for preparing a lightweight closed-cell zirconia fiber thermal insulation material, in which a binary silicide film is prepared on the surface of a zirconia fiber board. This type of membrane structure has good thermal stability, high oxidation resistance and corrosion resistance, and is a high-temperature structural material and functional material with great development prospects. DETAILED DESCRIPTION

[0016] The present invention is described in conjunction with the embodiments provided: Embodiment 1:

[0017] First, zirconium nitrate, water, hydrochloric acid, and hexadecyltrimethylammonium bromide are mixed in a ratio of 1:2:0.01:0.02, and stirred at a constant temperature of 40°C in a water bath for 8 hours to obtain a precursor zirconium-containing sol; the prepared zirconia fiber block is broken up and evenly dispersed into the prepared zirconium sol dispersion to obtain a stable slurry, which is poured into a mold of a certain size and subjected to filter press treatment to obtain a wet blank of a zirconia fiber product, which is then dried and subjected to a high-temperature heat treatment at 500 degrees to obtain a zirconia fiber insulation product of a certain size with good high-temperature resistance; after ball milling with an ethanol solvent at a rate of 400r / min for 6 hours, the Cr powder and the Si powder are refined respectively, and the refined powder is dried in a vacuum and weighed to a designed composition of 1:3. These powders were mixed with ethanol as a solvent and polyvinyl butyral (PVB) as a binder, and a uniform Si-Cr slurry was prepared by ball milling. The mixed slurry was evenly spread on the surface of the zirconia fiberboard and dried in an oven at 80°C for 8 hours. The dried sample was placed in a high-temperature furnace and heat treated in a nitrogen atmosphere at a heating rate of 10°C / min to 1500°C, and kept warm for half an hour to obtain a lightweight closed-cell zirconia fiber material. Embodiment 2:

[0018] First, zirconium acetate, acetic acid, hydrochloric acid, and sodium dodecylbenzene sulfonate are mixed in a ratio of 1:1:0.05:0.02, and stirred at a constant temperature of 40°C in a water bath for 16 hours to obtain a precursor zirconium sol. The prepared zirconia fiber blocks are broken up and evenly dispersed into the prepared dispersion containing zirconium sol to obtain a stable slurry, which is poured into a mold of a certain size and subjected to filter pressure treatment to obtain a wet blank of a zirconia fiber product, which is then dried and subjected to a high-temperature heat treatment at 600 degrees to obtain a zirconia fiber insulation product of a certain size with good high-temperature resistance. After ball milling with ethanol solvent at a rate of 500r / min for 8h, the Nb powder and Si powder are refined respectively, and the refined powders are dried in a vacuum and weighed to a designed composition of 1:2.5. These powders were mixed with ethanol as a solvent and polyvinyl butyral (PVB) as a binder, and a uniform Si-Nb slurry was prepared by ball milling. The mixed slurry was evenly spread on the surface of the zirconia fiberboard and dried in an oven at 90°C for 12 hours. The dried sample was placed in a high-temperature furnace and heat treated in a nitrogen atmosphere at a heating rate of 9°C / min to 1600°C, and kept warm for 1 hour to obtain a lightweight closed-cell zirconia fiber material. Embodiment 3:

[0019] First, zirconium oxychloride, water, nitric acid and polyethylene glycol 600 are mixed at a ratio of 1:4:0.05:0.05, and stirred at a constant temperature of 40°C in a water bath for 20 hours to obtain a precursor zirconium sol; the prepared zirconia fiber block is broken up and evenly dispersed into the prepared dispersion containing zirconium sol to obtain a stable slurry, which is poured into a mold of a certain size and subjected to filter pressure treatment to obtain a wet blank of a zirconia fiber product, which is then dried and subjected to a high-temperature heat treatment at 700 degrees to obtain a zirconia fiber insulation product of a certain size with good high-temperature resistance; after ball milling with ethanol solvent at a rate of 500r / min for 7h, the Fe powder and Si powder are refined respectively, and the refined powder is dried in a vacuum and weighed to a designed composition of 1:2.5. These powders were mixed with ethanol as a solvent and polyvinyl butyral (PVB) as a binder, and a uniform Si-Fe slurry was prepared by ball milling; the mixed slurry was evenly applied to the surface of the zirconia fiberboard and placed in an oven for drying at 90°C for 12 hours. The dried sample was placed in a high-temperature furnace and heat-treated in a nitrogen atmosphere at a heating rate of 11°C / min to 1700°C, and kept warm for 1 hour to obtain a lightweight closed zirconia fiber material.

[0020] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the scope consistent with the principles and novel features applied for herein.

Claims

1. A method for preparing a lightweight closed-cell zirconia fiber thermal insulation material, characterized in that: The preparation method is to filter the zirconia fiber obtained by the template impregnation method into a zirconia fiber board in a mold, and then evenly brush the slurry mixed with metal Si powder and transition metal powder on the obtained zirconia fiber board, and obtain a zirconia fiber insulation material with a dense surface after high-temperature treatment; the specific preparation steps are as follows: a. Preparation method of zirconia fiberboard: crush the flaky zirconia fiber block and evenly disperse it into the prepared dispersion containing zirconium sol at a mass ratio of 1:200 to 1:500 to obtain a stable slurry, pour the slurry into a mold, filter press to obtain a wet blank of zirconia fiber product, then dry it, and perform high-temperature heat treatment to obtain a zirconia fiberboard; b. Preparation method of binary silicide film: using anhydrous ethanol as solvent, ball milling at a rate of 400-500r / min for 6-8h, respectively refining transition metal powder and metal Si powder, drying the refined powder in vacuum and weighing to a designed composition of 1:2.5-4; then, mixing the powder with a binder, preparing a uniform slurry by ball milling; brushing the slurry evenly on the surface of the zirconia fiberboard, putting it in an oven for drying after solidification, putting the dried sample in a high-temperature furnace, and heat treating it in a nitrogen atmosphere to form a dense binary silicide film, thereby obtaining a lightweight closed-cell zirconia fiber insulation material.

2. The method for preparing a lightweight closed-cell zirconia fiber thermal insulation material according to claim 1, characterized in that: The zirconium sol dispersion is prepared by mixing metal zirconium salt, solvent, catalyst and additive in a mass ratio of 1:1-4:0.01-0.05:0.02-0.1, and stirring at a constant temperature in a water bath for 8-24 hours to obtain a precursor zirconium sol.

3. The method for preparing a lightweight closed-cell zirconia fiber thermal insulation material according to claim 2, characterized in that: The metal zirconium salt is one of zirconium oxychloride, zirconium nitrate and zirconium acetate; the specification is analytical grade.

4. The method for preparing a lightweight closed-cell zirconia fiber thermal insulation material according to claim 2, characterized in that: The solvent is one or two of water, ethanol and acetic acid; the purity is above 99%.

5. The method for preparing a lightweight closed-cell zirconia fiber thermal insulation material according to claim 2, characterized in that: The catalyst is one or two of dilute nitric acid, dilute hydrochloric acid and formic acid.

6. The method for preparing a lightweight closed-cell zirconia fiber thermal insulation material according to claim 2, characterized in that: The additive is one or two of polyethylene glycol-600, ethylenediamine and sodium dodecylbenzene sulfonate.

7. The method for preparing a lightweight closed-cell zirconia fiber thermal insulation material according to claim 1, characterized in that: The heat treatment temperature of the precursor fiberboard is 400-700°C.

8. The method for preparing a lightweight closed-cell zirconia fiber thermal insulation material according to claim 1, characterized in that: The transition metal powder is one or two of Cr, Nb and Ce.

9. The method for preparing a lightweight closed-cell zirconia fiber thermal insulation material according to claim 1, characterized in that The oven temperature is 60-110°C and the time is 10-24 hours.

10. The method for preparing a lightweight closed-cell zirconia fiber thermal insulation material according to claim 1, characterized in that: The heat treatment temperature after painting is 1500-1700℃, and the insulation time is 0-2 hours.