Preparation method and application of ceramic fiber board with high compressive strength

Abstract

The invention belongs to the technical field of refractory materials, and particularly relates to a preparation method and application of a ceramic fiber board with high compressive strength. The raw materials comprise ceramic fibers, silica powder, sodium dodecyl benzene sulfonate, triethanolamine dodecylbenzene sulfonate, a silicone resin polyether emulsion, cement, a suspending agent, a dispersing agent and water. According to the technical scheme provided by the invention, the cement is introduced as a curing agent, the dosage of a solvent is small, and the content of the curing agent is relatively high, so that wet-process normal-pressure rapid molding can be realized, the defect of vacuum adsorption molding strength is overcome, and the phenomena of strength reduction, slag falling and falling caused by fiber precipitation during long-term high-temperature use are avoided; in addition, a proper amount of sodium dodecyl benzene sulfonate is added, so that the fiber, the powder and the cement can generate a suspension effect and can be uniformly dispersed, the combination effect is relatively good, the isotropic performance of a sintered product is uniform and stable, and the compressive strength of the product is further improved.

Description

A method for preparing high compressive strength ceramic fiberboard and its application Technical Field

[0001] This invention belongs to the technical field of refractory materials, specifically relating to a method for preparing and applying a high compressive strength ceramic fiber board. Background Technology

[0002] Ceramic fiber is a fibrous, lightweight refractory material with advantages such as light weight, high temperature resistance, good thermal stability, low thermal conductivity, low specific heat, and resistance to mechanical vibration. Therefore, it has been widely used in industries such as machinery, metallurgy, chemical industry, petroleum, ceramics, glass, and electronics.

[0003] The preparation methods of ceramic fiber products are generally divided into wet forming and dry forming. They are suitable for mechanical processing and are mainly used for refractory and heat insulation. Due to the high water content of wet forming, if natural deposition is used for forming, the forming cycle will take more than 4 days, resulting in low production efficiency. All existing wet forming methods are generally wet vacuum adsorption forming. For example, Chinese patent CN116553941 discloses a high-temperature resistant ceramic fiber board and its preparation method. In order to achieve vacuum adsorption forming, the density of the product after wet vacuum forming is low, and the strength of the board is relatively low. Currently, the compressive strength of ceramic fiber boards formed by wet vacuum forming on the market is less than 1MPa. In order to improve the compressive strength of ceramic fiber boards, the only solution is to enhance the surface strength through composite coating. However, for load-bearing refractory materials, relying solely on external coating reinforcement cannot meet the requirements. Summary of the Invention

[0004] This invention provides a method for preparing and applying a ceramic fiberboard with high compressive strength to solve the above-mentioned technical problems.

[0005] To solve the above-mentioned technical problems, the present invention provides a method for preparing high compressive strength ceramic fiber board, the raw materials of which include ceramic fiber, silica powder, sodium dodecylbenzenesulfonate, triethanolamine dodecylbenzenesulfonate, silicone polyether emulsion, cement, suspending agent, dispersant and water.

[0006] The applicant abandoned the wet vacuum adsorption molding method and instead adopted wet atmospheric pressure curing molding. By introducing appropriate additives and cement curing agents, the problems of low solid content of the original wet molding slurry, long curing time, and low density and strength of the board caused by vacuum adsorption were overcome.

[0007] Optionally, the ceramic fiber is alumina fiber and / or aluminum silicate fiber, and the length of the ceramic fiber is 5-10 mm.

[0008] Optionally, the average particle size of the silicon micropowder is 3-5 μm.

[0009] Optionally, the cement is calcium aluminate cement or sulfoaluminate cement.

[0010] Optionally, the suspending agent is sodium carboxymethyl cellulose with a viscosity of 300-800 mPa·s, and the dispersant is ammonium citrate.

[0011] Optionally, the components in the raw material are proportioned in the following weight parts:

[0012] 20-40 parts ceramic fiber

[0013] 10-20 parts of silicon micro powder

[0014] Sodium dodecylbenzenesulfonate 0.1-0.2 parts

[0015] 0.1-0.2 parts of triethanolamine dodecylbenzenesulfonate aqueous solution

[0016] 0.1-0.3 parts of silicone polyether emulsion

[0017] 10-20 parts cement

[0018] 0.01-0.05 parts of suspension concentrate

[0019] Dispersant 0.1-0.5 parts

[0020] 30-50 parts water;

[0021] The weight percentage of triethanolamine dodecylbenzenesulfonate in the aqueous solution is 40%.

[0022] Optionally, the method for preparing high compressive strength ceramic fiber boards includes the following steps:

[0023] 1) Ceramic fibers, silica powder, dispersant, and water are mixed to obtain a slurry;

[0024] 2) Add sodium dodecylbenzenesulfonate and triethanolamine dodecylbenzenesulfonate to the mixed slurry, mix and stir. When the volume of the slurry increases to 2-3 times, add silicone polyether emulsion, suspending agent and cement to obtain a viscous slurry.

[0025] 3) Pour the viscous slurry into the molding mold and let it stand in an environment of 35-50℃ for 6-8 hours to obtain a solidified sample;

[0026] 4) After demolding, place the sample block in a drying oven for drying;

[0027] 5) The dried sample is calcined at high temperature to obtain ceramic fiber products.

[0028] Optionally, in step 2), after adding sodium dodecylbenzenesulfonate and triethanolamine dodecylbenzenesulfonate, the mixing speed is 800-1200 rpm, and after adding silicone polyether emulsion, suspending agent and cement, the mixing speed is 1500-1700 rpm.

[0029] Optionally, in step 4), the drying is carried out in two stages: first, drying at 55-65℃ for 10-14 hours, and then drying at 110-130℃ for 20-26 hours.

[0030] Drying at a low temperature first can prevent cracking and reduced board strength caused by large temperature differences between the surface and the interior and inconsistent moisture evaporation. After most of the moisture has evaporated, the drying temperature can be increased to shorten the drying time.

[0031] The present invention also provides a ceramic fiber board, which is obtained by the above-described method for preparing a high compressive strength ceramic fiber board.

[0032] The technical solution provided by this invention introduces cement as a curing agent, with a small amount of solvent and a high content of curing agent. Therefore, it can achieve rapid molding under normal pressure using wet process, overcoming the drawbacks of vacuum adsorption molding in terms of strength. Furthermore, it will not cause fiber precipitation leading to reduced strength or flaking during long-term high-temperature use. In addition, the addition of an appropriate amount of sodium dodecylbenzenesulfonate can create a suspension effect for the fiber, powder, and cement, allowing them to be evenly dispersed and having a good bonding effect. The sintered product has uniform and stable properties in all directions, thereby further improving the compressive strength of the product. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0034] Unless otherwise specified, all reagents used in the examples are commercially available products. The specific implementation method is based on the production of ceramic fiberboard. Other products can be obtained by referring to similar preparation methods.

[0035] Example 1:

[0036] The specific formula for a high-strength ceramic fiberboard is as follows:

[0037] 3 kg of aluminum silicate fiber, 5-7 mm in length;

[0038] 1.5 kg of silicon micro powder, purity ≥ 99%, average particle size approximately 4 micrometers;

[0039] Calcium aluminate cement (CA70 type) 1.5kg;

[0040] 15g sodium dodecylbenzenesulfonate, purity ≥99%;

[0041] 15g of triethanolamine dodecanebenzenesulfonic acid aqueous solution, 40% by weight;

[0042] 20g of silicone polyether microemulsion (content approximately 55%)

[0043] 3g of sodium carboxymethyl cellulose, viscosity 400 Pa·s.

[0044] 30g ammonium citrate

[0045] 4kg of clean water.

[0046] 1) Weigh the above components according to the formula ratio and set aside. First, stir the aluminum silicate fiber, silica powder, dispersant and water in the slurry tank at 300-500 rpm for 10 minutes to obtain the mixed slurry.

[0047] 2) Add sodium dodecylbenzenesulfonate and triethanolamine dodecylbenzenesulfonate to the mixed slurry, stir at 800-1200 rpm until the volume of the slurry increases by about 2 times, and stir for about 15 minutes. Then add silicone polyether microemulsion and hydroxymethyl cellulose, stir at 1500-1700 rpm for 10 minutes, and finally add calcium aluminate cement. Continue stirring for about 10 minutes to obtain a viscous slurry.

[0048] 3) Pour the viscous slurry into the molding mold and place it in a constant temperature and humidity chamber at 40℃ for 8 hours to obtain a cured sample block;

[0049] 4) After demolding, place the sample in a hot air drying oven. First, dry at 60℃ for 12 hours, and then at 120℃ for 24 hours, or make a sample block with a thickness of about 100mm.

[0050] 5) The dried sample was calcined at 1400℃ to obtain ceramic fiber board.

[0051] Performance testing method: Extract a 15mm thick test sample 1 from the center of a 100mm thick sample block and a 15mm thick test sample 2 cut from one side. Further process them into a 25mm×25mm pressing surface. Apply a load along the vertical direction of the pressing surface. Use the 10% compression load of the test sample block as the compressive strength (MPa). Use more than 3 samples for testing and take the average value. The result of test sample 1 is the internal compressive strength, and the result of test sample 2 is the external compressive strength.

[0052] Test results: Internal compressive strength 2.63 MPa, external compressive strength 2.73 MPa.

[0053] Example 2:

[0054] The specific formula for a high-strength ceramic fiberboard is as follows:

[0055] 0.5 kg of alumina fiber, with an average length of 7-10 mm;

[0056] 2.5 kg of aluminosilicate fiber, with an average length of 5-7 mm.

[0057] 2 kg of silicon micropowder, purity ≥ 99%; average particle size approximately 3 micrometers;

[0058] Calcium aluminate cement (CA70 type) 1kg;

[0059] 15g sodium dodecylbenzenesulfonate, purity ≥99%;

[0060] 15g of triethanolamine dodecanebenzenesulfonic acid solution, with a purity of 40%;

[0061] 20g of silicone polyether microemulsion (content approximately 55%)

[0062] 3g of sodium carboxymethyl cellulose, viscosity 400 Pa·s.

[0063] 30g ammonium citrate

[0064] 5kg of clean water.

[0065] 1) Weigh the above components according to the formula ratio and set aside. First, stir the alumina fiber, aluminum silicate fiber, silica powder, dispersant and water in the slurry tank at 300-500 rpm for 10 minutes to obtain the mixed slurry.

[0066] 2) Add sodium dodecylbenzenesulfonate and triethanolamine dodecylbenzenesulfonate to the mixed slurry, stir at 800-1200 rpm until the volume of the slurry increases by about 2 times, and stir for about 15 minutes. Then add silicone polyether microemulsion and hydroxymethyl cellulose, stir at 1500-1700 rpm for 10 minutes, and finally add calcium aluminate cement. Continue stirring for about 10 minutes to obtain a viscous slurry.

[0067] 3) Pour the viscous slurry into the molding mold and place it in a constant temperature and humidity chamber at 40℃ for 8 hours to obtain a cured sample block;

[0068] 4) After demolding, place the sample in a hot air drying oven to dry. First, dry at 60℃ for 12 hours, and then at 120℃ for 24 hours. The sample thickness is about 100 mm.

[0069] 5) The dried sample was calcined at 1400℃ to obtain ceramic fiber board.

[0070] The test results showed an internal compressive strength of 2.85 MPa and an external compressive strength of 3.06 MPa.

[0071] Comparative Example 1:

[0072] The difference from Example 1 is that the amount of sodium dodecylbenzenesulfonate is 60g and the amount of triethanolamine dodecylbenzenesulfonate solution is 60g.

[0073] Test results: Internal compressive strength 1.33 MPa, external compressive strength 1.60 MPa.

[0074] Comparative Example 2:

[0075] The difference from Example 1 is that it does not contain sodium dodecylbenzenesulfonate and triethanolamine dodecylbenzenesulfonate solution, but adds 15g sodium rosinate and 15g sodium dodecyl sulfate.

[0076] Test results: Internal compressive strength 1.73 MPa, external compressive strength 1.75 MPa.

[0077] Comparative Example 3:

[0078] The difference from Example 1 is that sodium dodecylbenzenesulfonate was not added.

[0079] Test results: Internal compressive strength 1.75 MPa, external compressive strength 1.87 MPa.

[0080] The above examples demonstrate that sodium dodecylbenzenesulfonate produces a foaming effect with good stability, which is beneficial for the formation of the internal structure of the board and can improve its internal strength.

[0081] Comparative Example 4

[0082] The difference from Example 1 is that sodium dodecylbenzenesulfonate and triethanolamine dodecylbenzenesulfonate were added to the mixed slurry, and the stirring rate was 500 rpm, followed by a stirring rate of 1200 rpm.

[0083] Test results: internal average compressive strength 1.83 MPa, external average compressive strength 1.95 MPa.

[0084] Insufficient stirring speed prevents the added sodium dodecylbenzenesulfonate and triethanolamine dodecylbenzenesulfonate from functioning effectively.

[0085] Comparative Example 5

[0086] The difference from Example 1 is that the drying process is directly dried at 120°C for 36 hours.

[0087] Test results: internal average compressive strength 1.63 MPa, external average compressive strength 2.32 MPa.

[0088] Large temperature differences between the surface and interior, and inconsistent moisture evaporation, lead to a decrease in the strength of the board.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a high compressive strength ceramic fiber board, characterized in that, The raw materials include ceramic fibers, silica powder, sodium dodecylbenzenesulfonate, triethanolamine dodecylbenzenesulfonate, silicone polyether emulsion, cement, suspending agent, dispersant and water.

2. The method for preparing the high compressive strength ceramic fiber board according to claim 1, characterized in that, The ceramic fiber is alumina fiber and / or aluminum silicate fiber, and the length of the ceramic fiber is 5-10 mm.

3. The method for preparing the high compressive strength ceramic fiber board according to claim 1, characterized in that, The average particle size of the silicon micropowder is 3-5 μm.

4. The method for preparing the high compressive strength ceramic fiber board according to claim 1, characterized in that, The cement is calcium aluminate cement or sulfoaluminate cement.

5. The method for preparing the high compressive strength ceramic fiber board according to claim 1, characterized in that, The suspending agent is sodium carboxymethyl cellulose with a viscosity of 300-800 mPa·s, and the dispersant is ammonium citrate.

6. The method for preparing the high compressive strength ceramic fiber board according to claim 1, characterized in that, The components of the raw materials are proportioned by weight as follows: ceramic fiber 20-40 parts, silica powder 10-20 parts, sodium dodecylbenzenesulfonate 0.1-0.2 parts, triethanolamine dodecylbenzenesulfonate aqueous solution 0.1-0.2 parts, silicone resin polyether emulsion 0.1-0.3 parts, cement 10-20 parts, suspending agent 0.01-0.05 parts, dispersant 0.1-0.5 parts, and water 30-50 parts; the weight percentage of triethanolamine dodecylbenzenesulfonate in the triethanolamine dodecylbenzenesulfonate aqueous solution is 40%.

7. The method for preparing the high compressive strength ceramic fiber board according to claim 1, characterized in that, The preparation method of high compressive strength ceramic fiber board includes the following steps: 1) Mix ceramic fiber, silica powder, dispersant and water to obtain a mixed slurry; 2) Add sodium dodecylbenzenesulfonate and triethanolamine dodecylbenzenesulfonate to the mixed slurry, mix and stir, and when the volume of the slurry increases to 2-3 times, add silicone polyether emulsion, suspending agent and cement to obtain a viscous slurry; 3) Pour the viscous slurry into a molding mold and let it stand in an environment of 35-50℃ for 6-8 hours to obtain a cured sample; 4) After demolding, put the sample into a drying oven for drying; 5) Calcine the dried sample at high temperature to obtain ceramic fiber products.

8. The method for preparing the high compressive strength ceramic fiber board according to claim 7, characterized in that, In step 2), after adding sodium dodecylbenzenesulfonate and triethanolamine dodecylbenzenesulfonate, the mixing speed is 800-1200 rpm. After adding silicone polyether emulsion, suspending agent and cement, the mixing speed is 1500-1700 rpm.

9. The method for preparing the high compressive strength ceramic fiber board according to claim 7, characterized in that, In step 4), the drying is carried out in two stages: first, drying at 55-65℃ for 10-14 hours, and then drying at 110-130℃ for 20-26 hours.

10. A ceramic fiberboard, characterized in that, The high compressive strength ceramic fiber board is obtained by any of the preparation methods described in claims 1-9.