Anti-stripping mullite light brick and preparation process thereof

Abstract

The invention belongs to the technical field of refractory materials, and particularly relates to an anti-stripping mullite light brick and a preparation process thereof. The anti-stripping mullite light brick is prepared from 45 to 60 percent of silicon boride recrystallized light mullite, 5 to 10 percent of kyanite, 6 to 12 percent of andalusite, 5 to 10 percent of sillimanite, 4 to 10 percent of aluminum oxide superfine powder, 2 to 8 percent of aluminum silicide superfine powder and 5 to 12 percent of clay. The foaming agent accounts for 0.1-0.5%, the plasticizer accounts for 0.5-1.5%, and the water accounts for 30-35%. A layer of anti-stripping mullite light bricks with the thickness of 114-230 cm is built on the inner side of the thermotechnical kiln steel shell, the inner side of the steel shell is integrally protected through the anti-stripping mullite light bricks, the inner side of the steel shell can be isolated from a combustion medium, and it can be guaranteed that a lining material has enough anti-stripping performance.

Description

Technical Field

[0001] The invention belongs to the field of refractory materials, and in particular relates to an anti-stripping mullite lightweight brick and a preparation process thereof. Background Art

[0002] The production technology and application of conventional mullite lightweight bricks at home and abroad are very mature, and there are many related reports and academic papers. However, conventional mullite lightweight bricks have a density weakness, that is, the thermal shock resistance is too poor, resulting in poor anti-stripping performance. They cannot meet the use requirements of thermal devices with large temperature fluctuations in working conditions. Currently, heavy materials with high thermal conductivity are used, which cannot meet the requirements of energy saving and environmental protection. In order to achieve the lightweight, energy-saving and environmental protection of the lining structure of this type of thermal device, the development of a mullite lightweight with strong anti-stripping performance is the future development trend.

[0003] At present, there are no reports on how to improve the anti-stripping performance of mullite lightweight bricks at home and abroad, and no similar products have been applied. Therefore, how to develop an anti-stripping mullite lightweight brick that can meet the rapid temperature fluctuations of thermal equipment without damage and spalling has important environmental and practical significance. Summary of the invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide an anti-stripping mullite lightweight brick and a preparation process thereof in view of the shortcomings of the prior art, aiming to build a layer of anti-stripping mullite lightweight bricks with a thickness of 114-230 cm on the inner side of the steel shell of a thermal kiln, and to achieve overall protection of the inner side of the steel shell by the anti-stripping mullite lightweight bricks, which can not only isolate the inner side of the steel shell from the combustion medium, but also ensure that the lining material has sufficient anti-stripping performance.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] An anti-stripping mullite lightweight brick comprises the following components in percentage by mass:

[0007]

[0008] Preferably, the mullite lightweight brick further comprises an admixture, and the admixture comprises the following components in percentage by mass:

[0009] Foaming agent 0.1-0.5%

[0010] Plasticizer 0.5-1.5%

[0011] Water 30-35%.

[0012] Preferably, the particle size of the boronized silicon recrystallized lightweight mullite is 16-60 mesh;

[0013] The particle size of the kyanite is 100-150 mesh, and the Al2O3 content is ≥58%;

[0014] The andalusite has a particle size of 200-320 meshes and an Al2O3 content of ≥58%;

[0015] The particle size of the sillimanite is 200-320 meshes, and the Al2O3 content is ≥58%.

[0016] Preferably, the particle size of the ultrafine alumina powder is 3000-5000 mesh, and the Al2O3 content is ≥99%;

[0017] The particle size of the aluminum silicide powder is 5000-8000 mesh, and the Al2SiO5 content is ≥99.5%;

[0018] The particle size of the clay is 180-250 meshes, and the Al2O3 content is ≥36%.

[0019] Preferably, the foaming agent is one or more combinations of nitrogen compounds, nitroso compounds, ammonium carbonate, nitrosamines, and polyoxyethylene ethers.

[0020] Preferably, the plasticizer is one or more combinations of polyester polyurethane, polyether ester, and linoleic acid glyceride.

[0021] The second technical purpose of the present invention is to request protection for the preparation process of the above-mentioned anti-stripping mullite lightweight brick, comprising the following steps:

[0022] (1) Silicon boride, alumina powder and quartz powder are mixed evenly in a certain proportion, sawdust is added as the ablation material, water is added, stirred and extruded into a brick, and then fired at 1500℃ in a nitrogen kiln and processed and crushed;

[0023] (2) Pour all the granules and fine powder into a blender in proportion, add the dissolved foaming agent and plasticizer solution and mix evenly, then pour into a mold to foam and shape by itself.

[0024] (3) The foamed bricks are placed in a drying room at 80°C for drying. The dried bricks are fired at 1500°C and the fired products are cut and polished to the required dimensions.

[0025] The present invention discloses an anti-stripping mullite lightweight brick and a preparation process thereof, which has the following beneficial effects:

[0026] 1. The anti-stripping mullite lightweight brick of the present invention innovatively introduces pre-synthesized boronized silicon recrystallized lightweight mullite particles, and utilizes the characteristics of boronized silicon to effectively improve the anti-stripping performance of the product;

[0027] 2. The innovative introduction of foaming agent into the anti-stripping mullite lightweight brick of the present invention can effectively and controllably control the particle size and distribution of foam particles, thereby effectively improving the strength of the product;

[0028] 3. The innovative introduction of plasticizers into the anti-stripping mullite lightweight bricks of the present invention can further enhance the supporting force of wet bricks, ensure that the bricks will not collapse during the drying process, effectively control the fullness of the foam particles, and reduce the thermal conductivity of the product;

[0029] 4. The anti-stripping mullite lightweight brick of the present invention innovatively introduces aluminum silicide powder, and utilizes the characteristics of aluminum silicide powder to form a certain amount of metal phase during high temperature, thereby improving the anti-stripping performance of the product. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The word "embodiment" used here as an "exemplary" does not necessarily mean that any embodiment described is superior to or better than other embodiments. Unless otherwise specified, the performance index tests in the embodiments of this application are performed using conventional test methods in the art. It should be understood that the terms described in this application are only used to describe specific implementation methods and are not used to limit the content disclosed in this application.

[0032] Unless otherwise specified, the technical and scientific terms used in this document have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.

[0033] In order to better illustrate the content of the present application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present application.

[0034] Under the premise of no conflict, the technical features disclosed in the embodiments of the present application can be combined arbitrarily, and the resulting technical solutions belong to the contents disclosed in the embodiments of the present application.

[0035] In order to better understand the present invention, the present invention is further specifically described below through the following examples, but it should not be understood as a limitation of the present invention. Some non-essential improvements and adjustments made by technicians in this field based on the above invention content are also considered to fall within the protection scope of the present invention.

[0036] Example 1 (weight ratio)

[0037]

[0038]

[0039] Plus:

[0040] Foaming agent 0.5%

[0041] Plasticizer 1.0%

[0042] Water 32%.

[0043] Example 2 (weight ratio)

[0044]

[0045] Plus:

[0046] Foaming agent 0.5%

[0047] Plasticizer 1.0%

[0048] Water 31%.

[0049] Example 3 (weight ratio)

[0050]

[0051]

[0052] Plus:

[0053] Foaming agent 0.3%

[0054] Plasticizer 1.0%

[0055] Water 33%.

[0056] Example 4 (weight ratio)

[0057]

[0058] Plus:

[0059] Foaming agent 0.3%

[0060] Plasticizer 1.5%

[0061] Water 35%.

[0062] According to the mass percentage disclosed above, the anti-stripping mullite lightweight brick is prepared according to the following operation steps. The specific operation contents are as follows:

[0063] (1) The raw materials of the mass percentages described in Examples 1 to 4 are mixed in a certain proportion, sawdust is added as a burnt material, water is added, stirred and extruded into a brick, and then fired at 1500° C. in a nitrogen kiln and processed and crushed;

[0064] (2) Pour all the granules and fine powder into a blender according to the proportion, add the dissolved foaming agent and plasticizer solution and mix evenly, then pour into a mold to foam and shape by itself;

[0065] (3) The foamed bricks are placed in a drying room at 80°C for drying. The dried bricks are fired at 1500°C and the fired products are cut and polished to the required dimensions.

[0066] project Testing standards Example 1 Example 2 Example 3 Example 4 Compressive strength MPa GB / T5072-2008 3.8 4.1 3.7 2.9 Thermal conductivity W / mk GB / T5990-2006 0.28 0.35 0.29 0.27 Erosion and spalling% GB / T8931-2007 7.3 6.7 3.1 5.4

[0067] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An anti-stripping mullite lightweight brick, characterized in that: The mullite lightweight brick comprises the following components in percentage by mass:

2. The anti-stripping mullite lightweight brick according to claim 1, characterized in that: The mullite lightweight brick also includes an admixture, and the admixture includes the following components in percentage by mass: Foaming agent 0.1-0.5% Plasticizer 0.5-1.5% Water 30-35%.

3. The anti-stripping mullite lightweight brick according to claim 1 or 2, characterized in that: The particle size of the boronized silicon recrystallized lightweight mullite is 16-60 mesh; The particle size of the kyanite is 100-150 mesh, and the Al2O3 content is ≥58%; The andalusite has a particle size of 200-320 meshes and an Al2O3 content of ≥58%; The particle size of the sillimanite is 200-320 meshes, and the Al2O3 content is ≥58%.

4. The anti-stripping mullite lightweight brick according to claim 1 or 2, characterized in that: The particle size of the ultrafine alumina powder is 3000-5000 mesh, and the Al2O3 content is ≥99%; The particle size of the aluminum silicide powder is 5000-8000 mesh, and the Al2SiO5 content is ≥99.5%; The particle size of the clay is 180-250 meshes, and the Al2O3 content is ≥36%.

5. The anti-stripping mullite lightweight brick according to claim 1 or 2, characterized in that: The foaming agent is one or more combinations of nitrogen compounds, nitroso compounds, ammonium carbonate, nitrosamines, and polyoxyethylene ethers.

6. The anti-stripping mullite lightweight brick according to claim 1 or 2, characterized in that: The plasticizer is one or more combinations of polyester polyurethane, polyether ester, and linoleic acid glyceride.

7. A process for preparing the anti-stripping mullite lightweight brick according to claim 1 or 2, characterized in that: The steps include: (1) Silicon boride, alumina powder and quartz powder are mixed evenly in proportion, sawdust is added as ablation material, water is added, stirred and extruded into a brick, and then fired at 1500°C in a nitrogen kiln and processed and crushed; (2) Pour all the granules and fine powder into a blender according to the proportion, add the dissolved foaming agent and plasticizer solution and mix evenly, then pour into a mold to foam and shape by itself; (3) The foamed bricks are placed in a drying room at 80°C for drying. The dried bricks are fired at 1500°C and the fired products are cut and polished to the required dimensions.

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