阅读说明：本技术 一种二次浸渍制备高密度陶瓷纤维板的方法 (Method for preparing high-density ceramic fiber board by secondary impregnation ) 是由 任大贵 刘超 唐锋 张成贺 郭金胜 宋传涛 于 2020-11-27 设计创作，主要内容包括：本发明提供了一种二次浸渍制备高密度陶瓷纤维板的方法,包括以下步骤：S1)将陶瓷纤维、有机结合剂、絮凝剂分散于水中,采用真空吸滤或长网抄取方式成型,得到湿坯a,将湿坯a干燥至含水率低于10％,得到湿坯b；S2)将湿坯b在浸渍液A中进行第一次浸渍,干燥至含水率低于5％,得到湿坯c；S3)将湿坯c在浸渍液B中进行第二次浸渍,干燥后得到高密度陶瓷纤维板。本发明通过二次浸渍,并控制第一次浸渍和第二次浸渍前经过干燥的湿坯的含水率,以提高浸渍的效果,使浸渍液与陶瓷纤维之间能够很好地结合。制备得到的高密度陶瓷纤维板,其密度和强度成倍提高,密度可达到1300kg/m～3,耐压强度可达到15MPa以上。(The invention provides a method for preparing a high-density ceramic fiber board by secondary impregnation, which comprises the following steps: s1) dispersing the ceramic fiber, the organic binder and the flocculating agent in water, forming by adopting a vacuum suction filtration or long net shoveling mode to obtain a wet blank a, and dryingDrying the wet blank a until the water content is lower than 10% to obtain a wet blank b; s2) carrying out primary impregnation on the wet blank b in the impregnation liquid A, and drying until the moisture content is lower than 5% to obtain a wet blank c; s3), carrying out secondary impregnation on the wet blank c in the impregnation liquid B, and drying to obtain the high-density ceramic fiber board. According to the invention, through secondary impregnation, the water content of the wet blank which is dried before the primary impregnation and the secondary impregnation is controlled, so that the impregnation effect is improved, and the impregnation liquid and the ceramic fibers can be well combined. The density and the strength of the prepared high-density ceramic fiber board are improved by times, and the density can reach 1300kg/m 3 The compressive strength can reach more than 15 MPa.)

1. A method for preparing a high-density ceramic fiber board by secondary impregnation comprises the following steps:

s1) dispersing ceramic fibers, an organic binding agent and a flocculating agent in water, forming by adopting a vacuum suction filtration or long net shoveling mode to obtain a wet blank a, and drying the wet blank a until the water content is lower than 10% to obtain a wet blank b;

s2) carrying out primary impregnation on the wet blank b in the impregnation liquid A, and drying until the moisture content is lower than 5% to obtain a wet blank c;

s3), carrying out secondary impregnation on the wet blank c in the impregnation liquid B, and drying to obtain the high-density ceramic fiber board.

2. The method of claim 1, wherein the organic binder is selected from the group consisting of pregelatinized starch, acrylic emulsion, or styrene-acrylic emulsion;

the flocculant is selected from polyacrylamide, polyaluminium chloride or aluminium sulphate.

3. The method of claim 1, wherein the weight ratio of the ceramic fiber, the organic binder and the flocculant is (5-10): 0.1-1.0: (0.01-0.05).

4. The method according to claim 1, wherein the impregnation liquid A is prepared by uniformly dispersing inorganic binder, dispersant and filler in water;

the inorganic bonding agent is selected from silica sol or aluminum sol;

the dispersant is selected from sodium polycarboxylate salts or sodium acrylate salts;

the filler is selected from one or more of silicon micropowder, alumina powder, zircon powder, silicon carbide, titanium dioxide and mullite powder.

5. The method according to claim 4, wherein the weight ratio of the water, the inorganic binder, the dispersant and the filler is (100-1000): (30-70): (0.1-5): (20-60).

6. The method according to claim 1, wherein the impregnation solution B is selected from a silica sol solution or an aluminum sol solution.

7. The method of claim 1, wherein the wet blank a has a thickness of 30 to 120 mm.

8. The method of claim 1, further comprising, after the first impregnation:

and (3) vacuumizing and pressing the wet blank b subjected to primary impregnation until the thickness of the wet blank b is 30-60%.

9. The method according to claim 1, wherein the drying temperature in the step S1) is 90-200 ℃, and the drying time is 3-24 h;

the drying temperature in the step S2) is 90-150 ℃, and the drying time is 2-24 h;

the drying temperature in the step S3) is 90-130 ℃, and the drying time is 1-12 h.

10. The method of claim 1, wherein the ceramic fibers are selected from one or more of aluminum silicate fibers, chromium containing ceramic fibers, zirconium containing ceramic fibers, and soluble ceramic fibers.

Technical Field

The invention relates to the technical field of materials, in particular to a method for preparing a high-density ceramic fiber board by secondary impregnation.

Background

The common ceramic fiber board has high fiber content, light weight, heat shock resistance and other features, and may be used widely in various kinds of kiln back lining, but has low strength and easy falling off after long term use.

In some specific fields, ceramic fiber boards with higher strength and density are often needed, and the density of the existing high-density ceramic fiber board is 600-1000 kg/m³The compressive strength is less than or equal to 10MPa, and the application requirement cannot be met, so that the ceramic fiber board with higher density and strength is required.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide a method for preparing a high-density ceramic fiber board by secondary impregnation, wherein the prepared ceramic fiber board has high density and strength.

In order to achieve the aim, the invention provides a method for preparing a high-density ceramic fiber board by secondary impregnation, which comprises the following steps:

s1) dispersing ceramic fibers, an organic binding agent and a flocculating agent in water, forming by adopting a vacuum suction filtration or long net shoveling mode to obtain a wet blank a, and drying the wet blank a until the water content is lower than 10% to obtain a wet blank b;

s2) carrying out primary impregnation on the wet blank b in the impregnation liquid A, and drying until the moisture content is lower than 5% to obtain a wet blank c;

s3), carrying out secondary impregnation on the wet blank c in the impregnation liquid B, and drying to obtain the high-density ceramic fiber board.

Preferably, the ceramic fiber is selected from one or more of aluminum silicate fiber, chromium-containing ceramic fiber, zirconium-containing ceramic fiber and soluble ceramic fiber.

When the ceramic fiber is selected from a plurality of aluminum silicate fibers, chromium-containing ceramic fibers, zirconium-containing ceramic fibers and soluble ceramic fibers, the present invention is not particularly limited to the ratio of the components, and can be adjusted by a person skilled in the art.

Preferably, the ceramic fibers are subjected to a pulping process.

The method of beating is not particularly limited in the present invention, and beating methods known to those skilled in the art can be used. Preferably, the ceramic fibers are added to a beater for beating.

The preferable time of beating is 10-60 min.

Preferably, the concentration of the slurry after the ceramic fiber is pulped is 10-20 wt%. Specifically, it may be 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, or any range value having the above numerical value as an upper limit or a lower limit. According to the invention, preferably, only the ceramic fiber is pulped during pulping, then water is added for pulp preparation, and preferably, the pulp preparation is carried out until the concentration of the ceramic fiber is 1-10 wt%.

And then, conveying the slurry subjected to pulping treatment to a slurry preparation tank, adding an organic binding agent, and uniformly mixing.

And then adding a flocculating agent into the mixed materials to flocculate all the materials together so as to make the water become clear, namely finishing the operation of dispersing the ceramic fibers, the organic binding agent and the flocculating agent in the water.

Preferably, the organic binder is selected from pregelatinized starch, acrylic emulsion or styrene-acrylic emulsion.

Preferably, the flocculant is selected from polyacrylamide, polyaluminium chloride or aluminium sulphate.

Preferably, the flocculant is prepared into an aqueous solution when in use, and the concentration of the aqueous solution is preferably 0.5-3 wt%.

In the invention, the weight ratio of the ceramic fiber, the organic binder and the flocculating agent is (5-10): (0.1-1.0): (0.01-0.05), and more preferably (6-8): (0.3-0.7): (0.02-0.04).

And then, carrying out vacuum suction filtration or long net shoveling and forming on the flocculated slurry to obtain a wet blank a.

The forming method of the vacuum suction filtration or fourdrinier wire taking is not particularly limited in the present invention, and may be a vacuum suction filtration or fourdrinier wire taking method known to those skilled in the art.

In the invention, the thickness of the wet blank a is preferably 30-120 mm, and more preferably 60-70 mm.

And conveying the wet blank a into a drying chamber for drying to obtain a wet blank b with the water content of less than 10%.

More preferably, the wet green b is dried to have a water content of 7% to 9.5%. In some embodiments of the invention, the wet green b is dried to a moisture content of 7%, 8% or 9.5%, or an interval between any of the above values.

Preferably, the drying temperature in the step S1) is 90-200 ℃, and the drying time is 3-24 h.

The wet green b is then subjected to a first impregnation in an impregnation bath a.

Preferably, the impregnation liquid A is prepared by uniformly dispersing an inorganic binder, a dispersing agent and a filler in water.

Preferably, the inorganic binder is selected from silica sol or aluminum sol.

Preferably, the concentration of the silica sol is 10 wt% to 40 wt%. Specifically, it may be 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, 40 wt%, or any of the above-mentioned values may be used as the upper limit or the lower limit.

Preferably, the aluminum sol is a solid powder.

Preferably, the dispersant is selected from sodium salts of polycarboxylic acids or acrylic acid.

Preferably, the filler is selected from one or more of silica micropowder, alumina powder, zircon powder, silicon carbide, titanium dioxide and mullite powder.

When the filler is a composition, the proportion of each component is not limited in the present invention, and can be adjusted by itself according to the filler combination well known to those skilled in the art.

In the invention, the weight ratio of the water, the inorganic bonding agent, the dispersing agent and the filler is (100-1000): (30-70): (0.1-5): (20-60), more preferably (300-700): (40-60): (0.5-2): (30-50).

In the above proportion, the inorganic binder is calculated according to the solid content.

Preferably, the method further comprises, after the first impregnation:

and (3) vacuumizing and pressing the wet blank b subjected to primary impregnation until the thickness of the wet blank b is 30-60%.

And then drying until the water content is lower than 5 percent to obtain a wet blank c.

More preferably, the wet green c is dried to a moisture content of 4.5% to 4.8%. In some embodiments of the invention, the wet green c is dried to a moisture content of 4.5% or 4.8%.

Preferably, the drying temperature in the step S2) is 90-150 ℃, and the drying time is 2-24 h.

The wet green c is then subjected to a second impregnation in an impregnation bath B.

In the present invention, the impregnation liquid B is preferably selected from a silica sol solution or an aluminum sol solution.

The concentration of the silica sol solution or the aluminum sol solution is preferably 10 wt% to 30 wt%. Specifically, it may be 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, or a range value having any of the above numerical values as an upper limit or a lower limit.

According to the invention, through the impregnation of the impregnation liquid B, the combination between the impregnation liquid and the ceramic fiber can be further improved, and the strength of the product is higher.

Preferably, the method further comprises the following steps after the second impregnation:

and removing the redundant impregnating solution B by vacuum filtration.

And then conveying the wet blank c subjected to the second impregnation into drying equipment for drying, and processing the wet blank c into a product after the drying is finished to obtain the high-density ceramic fiber board.

Preferably, the drying temperature in the step S3) is 90-130 ℃, and the drying time is 1-12 h.

Compared with the prior art, the invention provides a method for preparing a high-density ceramic fiber board by secondary impregnation, which comprises the following steps: s1) dispersing ceramic fibers, an organic binding agent and a flocculating agent in water, forming by adopting a vacuum suction filtration or long net shoveling mode to obtain a wet blank a, and drying the wet blank a until the water content is lower than 10% to obtain a wet blank b; s2) carrying out primary impregnation on the wet blank b in the impregnation liquid A, and drying until the moisture content is lower than 5% to obtain a wet blank c; s3), carrying out secondary impregnation on the wet blank c in the impregnation liquid B, and drying to obtain the high-density ceramic fiber board. According to the invention, through secondary impregnation, the water content of the wet blank which is dried before the primary impregnation and the secondary impregnation is controlled, so that the impregnation effect is improved, and the impregnation liquid and the ceramic fibers can be well combined. Compared with the existing high-density ceramic fiber board, the prepared high-density ceramic fiber board has the advantages of higher density and strength, the density and the strength of the high-density ceramic fiber board are improved by times, and the density can reach 1300kg/m³The compressive strength can reach more than 15 MPa. Meanwhile, the mode of secondary impregnation is adopted, and the ceramic fiber does not need to be chopped in advance. In the practical application process, the composition of the impregnation liquid A can be adjusted according to the use requirement, so that products with different functions can be prepared, and the application range is wider compared with that of a conventional high-density ceramic fiber board.

Detailed Description

In order to further illustrate the present invention, the method for preparing a high density ceramic fiber board by the secondary impregnation provided by the present invention is described in detail below with reference to examples.

Example 1

(1) 120kg of 30% silica sol, 1kg of sodium polycarboxylate and 30kg of alumina powder are added into 200kg of water and uniformly dispersed to prepare impregnation liquid A for later use.

(2) 60kg of high-alumina aluminum silicate fiber is added into a pulping machine for pulping for 50 min. The concentration of the pulped pulp is 10 wt%.

(3) And (3) conveying the slurry obtained in the step (2) to a slurry preparation tank, adding 5kg of pregelatinized starch, and uniformly mixing.

(4) And (4) adding 20kg of 1 wt% polyacrylamide solution into the slurry in the step (3) to flocculate all materials together and clear water.

(5) And (3) forming the flocculated slurry through vacuum suction filtration, wherein the thickness of a wet blank a is 60mm, and conveying the wet blank a into a drying chamber for drying to obtain a wet blank b with the water content of 8%.

(6) And (3) conveying the wet blank b into the impregnation liquid A, impregnating, then vacuumizing and pressing until the thickness of the wet blank b is 32mm, drying until the water content is 4.8%, carrying out secondary impregnation, immersing into a 30% silica sol solution, carrying out vacuum filtration, conveying into drying equipment for drying, and processing into a product after drying.

The high-density ceramic fiber board prepared by secondary impregnation has the volume density of 1000kg/m³The compressive strength was 13MPa, and the thermal conductivity was 0.15W/(m.k).

Example 2

(1) 300kg of alumina sol, 5kg of sodium polycarboxylate, 200kg of alumina powder and 100kg of titanium dioxide are added into 3000kg of water to be uniformly dispersed to prepare impregnation liquid A for later use.

(2) Adding 300kg of zirconium-containing ceramic fiber into a beating machine for beating for 50 min. The concentration of the pulped pulp is 15 wt%.

(3) And (3) conveying the slurry obtained in the step (2) to a slurry preparation tank, adding 30kg of acrylic emulsion, and uniformly mixing.

(4) 70kg of 1 wt% polyacrylamide solution was added to the slurry of step (3) to flocculate all the materials together and clear the water.

(5) And (3) taking the flocculated slurry through a long net, molding, conveying the wet blank a with the thickness of 70mm to a drying chamber, and drying to obtain a wet blank b with the water content of 9.5%.

(6) And (3) conveying the wet blank b into the impregnation liquid A, impregnating, then vacuumizing and pressing until the thickness of the wet blank b is 25mm, drying until the water content is 4.5%, carrying out secondary impregnation, immersing into a 15% aluminum sol solution, carrying out vacuum filtration, conveying into drying equipment for drying, and processing into a product after drying.

The high-density ceramic fiber board prepared by secondary impregnation has the volume density of 1200kg/m³The compressive strength was 15MPa, and the thermal conductivity was 0.16W/(m.k).

Example 3

(1) 200kg of 30% silica sol, 1kg of sodium polycarboxylate and 50kg of alumina powder are added into 200kg of water and uniformly dispersed to prepare impregnation liquid A for later use.

(2) 60kg of zirconium-containing ceramic fiber is added into a beating machine for beating for 50 min. The concentration of the pulped pulp is 12 wt%.

(3) And (3) conveying the slurry obtained in the step (2) to a slurry preparation tank, adding 6kg of pregelatinized starch, and uniformly mixing.

(4) To the slurry of step (3), 25kg of a 1 wt% polyacrylamide solution was added to flocculate all the materials together and clear the water.

(5) And (3) forming the flocculated slurry through vacuum suction filtration, wherein the thickness of a wet blank a is 60mm, and conveying the wet blank a into a drying chamber for drying to obtain a wet blank b with the water content of 7%.

(6) And (3) conveying the wet blank b into the impregnation liquid A, impregnating, then vacuumizing and pressing until the thickness of the wet blank b is 32mm, drying until the water content is 4.5%, carrying out secondary impregnation, immersing into a 30% silica sol solution, carrying out vacuum filtration, conveying into drying equipment for drying, and processing into a product after drying.

The high-density ceramic fiber board prepared by adopting the secondary impregnation has the volume density of 1300kg/m³The compressive strength is 15MPa, and the thermal conductivity is 0.17W/(m.k)

Comparative example 1:

(1) 120kg of 30% silica sol, 1kg of sodium polycarboxylate and 30kg of alumina powder are added into 200kg of water and uniformly dispersed to prepare impregnation liquid A for later use.

(2) 60kg of high-alumina aluminum silicate fiber is added into a pulping machine for pulping for 50 min.

(3) And (3) conveying the slurry obtained in the step (2) to a slurry preparation tank, adding 5kg of pregelatinized starch, and uniformly mixing.

(4) And (4) adding 20kg of 1 wt% polyacrylamide solution into the slurry in the step (3) to flocculate all materials together and clear water.

(5) And (3) forming the flocculated slurry through vacuum suction filtration, wherein the thickness of a wet blank a is 60mm, and conveying the wet blank a into a drying chamber for drying to obtain a wet blank b with the water content of 8%.

(6) And (3) conveying the wet blank b into the impregnation liquid A for impregnation, then vacuumizing and pressing until the thickness of the wet blank b is 32mm, conveying the wet blank b into drying equipment for drying, and processing the wet blank b into a product after drying.

The high-density ceramic fiber board prepared by one-time impregnation has the volume density of 900kg/m³The compressive strength was 7 MPa.

Comparative example 2

(1) 60kg of high-alumina aluminum silicate fiber is added into a pulping machine for pulping for 50 min.

(2) And (2) conveying the slurry obtained in the step (1) to a slurry preparation tank, adding 5kg of pregelatinized starch, and uniformly mixing.

(3) And (3) adding 20kg of 1 wt% polyacrylamide solution into the slurry in the step (2) to flocculate all materials together and clear water.

(4) And (3) forming the flocculated slurry through vacuum suction filtration, wherein the thickness of a wet blank a is 60mm, and conveying the wet blank a into a drying chamber for drying to obtain a wet blank b with the water content of 4.8%.

(6) And (3) conveying the wet blank B into the impregnation liquid B for impregnation, then vacuumizing and pressing until the thickness of the wet blank B is 32mm, conveying the wet blank B into drying equipment for drying, and processing the wet blank B into a product after drying.

The high-density ceramic fiber board prepared by one-time impregnation has the volume density of 800kg/m³The compressive strength was 5 MPa.

Comparative example 3

(1) 120kg of 30% silica sol, 1kg of sodium polycarboxylate and 30kg of alumina powder are added into 200kg of water and uniformly dispersed to prepare impregnation liquid A for later use.

(2) 60kg of high-alumina aluminum silicate fiber is added into a pulping machine for pulping for 50 min.

(3) And (3) conveying the slurry obtained in the step (2) to a slurry preparation tank, adding 5kg of pregelatinized starch, and uniformly mixing.

(4) And (4) adding 20kg of 1 wt% polyacrylamide solution into the slurry in the step (3) to flocculate all materials together and clear water.

(5) And (3) forming the flocculated slurry through vacuum suction filtration, wherein the thickness of a wet blank a is 60mm, and conveying the wet blank a into a drying chamber for drying to obtain a wet blank b with the water content of 20%.

(6) And (3) conveying the wet blank b into the impregnation liquid A, impregnating, then vacuumizing and pressing until the thickness of the wet blank b is 32mm, drying until the water content is 10%, carrying out secondary impregnation, immersing into a 30% silica sol solution, carrying out vacuum filtration, conveying into drying equipment for drying, and processing into a product after drying.

The high-density ceramic fiber board prepared by secondary impregnation has the volume density of 1000kg/m³The compressive strength was 10 MPa.

As is apparent from the above examples and comparative examples, the present invention improves the density and strength of the high-density ceramic fiber sheet to the maximum extent by the secondary impregnation method and the specific moisture content of the wet mat.

The above description of the embodiments is only intended to facilitate the understanding of the method of the invention and its core idea. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.