A kind of thermal insulation refractory porous ball and preparation method thereof

Abstract

The present application relates to the technical field of refractory materials, and specifically discloses a thermal insulation refractory porous ball and a preparation method thereof. The raw materials of the thermal insulation refractory porous ball mainly include a main material and an additional binder, and the addition amount of the additional binder accounts for 5-10% of the total weight of the main material; the main material is made of the following raw materials in weight percentage: kaolin 31-57%, mullite 25-45%, high-alumina bauxite 10-20%, carbon powder 3-15%, and ultrafine alumina powder 1-5%; the carbon powder is one or two of coconut shell activated carbon powder and coal activated carbon powder. The thermal insulation refractory porous ball, by adding carbon powder to the main material, can increase the uniformity of pores in the thermal insulation refractory porous ball, reduce thermal conductivity, and improve thermal insulation effect.

Description

Technical Field

[0001] The present application relates to the technical field of refractory materials, and more specifically, to a thermal insulation refractory porous ball and a preparation method thereof. Background Art

[0002] With the rapid development of society, refractory materials have also made rapid progress. Refractory materials are materials that can maintain physical and chemical stability under high temperature environment, and will not be melted, softened or severely deformed. Common refractory materials on the market include thermal insulation refractory hollow balls, which can be used for the insulation of molten castings. Adding thermal insulation refractory hollow balls to the casting sand box can greatly reduce the solidification time of molten steel, reduce the internal cavities and cracks of castings, increase the qualified rate, reduce the loss of finished products, and greatly improve the quality of castings. It can also be used for the insulation of kiln walls. Adding thermal insulation refractory hollow balls to the castable can achieve good insulation effect. However, the thermal insulation refractory hollow balls on the market have a high thermal conductivity, and the thermal insulation performance needs to be further improved. Summary of the invention

[0003] In order to reduce the thermal conductivity, the present application provides a thermal insulation refractory porous ball and a preparation method thereof.

[0004] In the first aspect, the present application provides a thermal insulation refractory porous ball, which adopts the following technical solution:

[0005] A thermal insulation refractory porous ball, the raw materials of which mainly include a main material and an external binder, wherein the amount of the external binder added accounts for 5-10% of the total weight of the main material;

[0006] The main material is made of the following raw materials in percentage by weight: 31-57% kaolin, 25-45% mullite, 10-20% high-alumina bauxite, 3-15% carbon powder, and 1-5% ultrafine alumina powder; the carbon powder is one or two of coconut shell activated carbon powder and coal-based activated carbon powder.

[0007] The thermal insulation refractory porous ball of the present application has no adhesion and agglomeration due to the mutual coordination between the raw materials, and has a compressive strength of more than 180N, a thermal conductivity of less than 0.5w / (mk) at 1100℃, and a bulk density of less than 1100Kg / m 3 , which makes it show the advantages of high compressive strength, low thermal conductivity, good thermal insulation and moderate bulk density. It has good comprehensive performance and meets market demand.

[0008] Moreover, the addition of an external binder can make the raw materials of the main material adhere together, and then after calcination, the carbon powder decomposes and gasifies at high temperature, and forms pores in the main material, and the remaining raw materials of the main material are sintered together, thereby obtaining a thermal insulation refractory porous ball. Since the carbon powder can be evenly dispersed in the main material, it can increase the uniformity of the pores in the thermal insulation refractory porous ball, so that the thermal insulation refractory porous ball contains more uniform pores, reduces the thermal conductivity, and improves the thermal insulation effect. It is suitable for the insulation of molten castings, the insulation of kiln walls, and also suitable for sewage treatment, expanding the scope of application and meeting market demand.

[0009] At the same time, the present application also selects the raw materials of carbon powder. When rice husk activated carbon powder is added to the raw materials of the main material, the thermal insulation and refractory porous balls will stick together and clump, and will be overburned, affecting the quality. When coconut shell activated carbon powder or coal activated carbon powder is added to the raw materials of the main material, the thermal insulation and refractory porous balls will not stick together and clump, and will also have the advantages of good bulk density, low thermal conductivity and high compressive strength, meeting the market demand.

[0010] Compared with other thermal insulation refractory hollow balls, the thermal insulation refractory porous balls of the present application significantly reduce the thermal conductivity and improve the thermal insulation effect through their internal porous structure. They also significantly increase the compressive strength, improve the stability of use, reduce the breakage rate during use, extend the service life, and achieve multiple recycling.

[0011] Optionally, the average particle size of the carbon powder is 5-15 μm. Preferably, the average particle size of the carbon powder is 5-10 μm.

[0012] Since the particle size of carbon powder directly affects the pore structure of thermal insulation refractory porous balls, if the particle size of carbon powder is too small, it is easy to stick together and clump, and also affect the air permeability and thermal insulation. If the particle size of carbon powder is too large, it is easy to have large pores and uneven pores, which also affect the thermal insulation. At this time, limiting the particle size of carbon powder is not only convenient for the selection of carbon powder, but also can make the pore size of thermal insulation refractory porous balls moderate, the pores are uniform, the air permeability is good, the thermal insulation is good, and the thermal insulation porous balls have good comprehensive performance.

[0013] Optionally, the carbon powder is coconut shell activated carbon powder.

[0014] Compared with adding coal-based activated carbon powder to the raw materials, adding coconut shell activated carbon powder to the raw materials not only ensures that the thermal insulation refractory porous balls have good compressive strength, but also significantly reduces the thermal conductivity, so that the thermal insulation refractory porous balls show better thermal insulation properties.

[0015] Optionally, the mesh number of kaolin is 300-800 mesh, the mesh number of mullite is 300-800 mesh, the mesh number of high-alumina bauxite is 300-800 mesh, and the average particle size of the ultrafine alumina powder is 1-100 μm. Preferably, the average particle size of the ultrafine alumina powder is 1-50 μm. More preferably, the average particle size of the ultrafine alumina powder is 1-20 μm.

[0016] By adopting the above technical scheme, the mesh sizes of kaolin, mullite and high-alumina bauxite are limited, and the particle size of ultrafine alumina powder is also limited, which not only facilitates the selection of raw materials, but also enables the main material to maintain good fluidity, increase bonding strength, and improve the compressive strength of thermal insulation refractory porous balls.

[0017] In multiple embodiments, the mesh number of kaolin is 325 mesh, and the mesh number can also be set to 300 mesh, 400 mesh, 500 mesh, 600 mesh, 800 mesh as needed, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable. In multiple embodiments, the mesh number of mullite is 325 mesh, and the mesh number can also be set to 300 mesh, 400 mesh, 500 mesh, 600 mesh, 800 mesh as needed, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable. In multiple embodiments, the mesh number of high-alumina bauxite is 500 mesh, and the mesh number can also be set to 300 mesh, 325 mesh, 400 mesh, 600 mesh, 800 mesh as needed, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable. In multiple embodiments, the average particle size of the ultrafine alumina powder is 2 μm, and the average particle size can also be set to 1 μm, 5 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm as needed, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] Optionally, the additional binder is one or more of polyvinyl alcohol, silica sol, sodium carbonate, and aluminum dihydrogen phosphate.

[0019] By adopting the above technical solution, the external binder is limited, which is convenient for the selection of the external binder, ensures the bonding strength between the raw materials, reduces the possibility of breakage, ensures the strength of the thermal insulation refractory porous balls, and increases the stability and life of use.

[0020] Optionally, the average particle size of the thermal insulation refractory porous ball is 0.5-20 mm. Preferably, the average particle size of the thermal insulation refractory porous ball is 0.5-10 mm. More preferably, the average particle size of the thermal insulation refractory porous ball is 0.5-6 mm. More preferably, the average particle size of the thermal insulation refractory porous ball is 4-6 mm.

[0021] By adopting the above technical solution, the thermal insulation refractory porous balls can be prepared into balls of different particle sizes according to needs, thereby increasing the scope of application and improving applicability.

[0022] Optionally, the raw material of the thermal insulation and refractory porous balls also includes polystyrene balls, and the added amount of the polystyrene balls accounts for 1-10% of the total weight of the main material.

[0023] By adopting the above technical solution, polystyrene balls are added to the raw materials, and the main material and the external binder can be coated on the surface of the polystyrene balls and increase the volume of the balls. Furthermore, during the calcination process, the carbon powder will decompose and gasify, and form pores in the main material. At the same time, the polystyrene balls will also decompose and gasify, and form a hollow in the center of the main material, thereby obtaining a heat-insulating refractory porous ball with a hollow core.

[0024] Under the same particle size, the hollow structure formed by the thermal insulation refractory porous balls can reduce weight, increase surface area, reduce heat conduction paths, reduce heat transfer rates, reduce thermal conductivity, improve thermal insulation, improve thermal stress caused by internal thermal expansion and contraction, and increase stability in use.

[0025] Optionally, the average particle size of the polystyrene spheres is 0.1-6 mm. Preferably, the average particle size of the polystyrene spheres is 0.1-4 mm. More preferably, the average particle size of the polystyrene spheres is 1-3 mm.

[0026] By adopting the above technical solution, the particle size of the polystyrene balls is limited, which is convenient for the selection of polystyrene balls and ensures that the hollow thermal insulation and refractory porous balls have good comprehensive performance. In multiple embodiments, the average particle size of the polystyrene balls is 2 mm, and the average particle size can also be set to 0.1 mm, 1 mm, 3 mm, 4 mm, 5 mm, 6 mm as needed, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0027] In a second aspect, the present application provides a method for preparing the thermal insulation refractory porous ball, which adopts the following technical solution:

[0028] A method for preparing the thermal insulation refractory porous ball comprises the following steps:

[0029] S1. Mix kaolin, mullite, high-alumina bauxite, carbon powder and ultrafine alumina powder to obtain a main material;

[0030] S2, under continuous rolling, spray part of the main material with additional binder, roll into balls, add the remaining main material, and at the same time, spray the remaining additional binder, continue to roll, dry, and obtain the ball blank;

[0031] S3, heating the ball blank to 1000-1500°C, calcining for 10-15h, cooling to room temperature, and obtaining a thermal insulation refractory porous ball;

[0032] Among them, the addition amount of some main materials accounts for 10-20% of the total weight of the main materials; the addition amount of some external binders accounts for 10-20% of the total weight of the external binders.

[0033] By adopting the above technical scheme, firstly, part of the main material and part of the external binder are used to cooperate with each other to roll into balls, and then the remaining main material is added while the remaining external binder is sprayed to make the balls roll continuously to increase the particle size. Then, after drying and calcining, the thermal insulation refractory porous balls are obtained, which is convenient for the preparation of the thermal insulation refractory porous balls and ensures stable preparation.

[0034] In multiple embodiments, the amount of the added main material accounts for 10% of the total weight of the main material, and the proportion can also be set to 13%, 15%, 18%, 20% as needed, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable. In multiple embodiments, the amount of the added external binder accounts for 10% of the total weight of the additional binder, and the proportion can also be set to 13%, 15%, 18%, 20% as needed, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0035] In a third aspect, the present application provides a method for preparing the thermal insulation refractory porous ball, which adopts the following technical solution:

[0036] A method for preparing the thermal insulation refractory porous ball comprises the following steps:

[0037] S1. Mix kaolin, mullite, high-alumina bauxite, carbon powder and ultrafine alumina powder to obtain a main material;

[0038] S2, under continuous rolling, spray part of the additional binder into the polystyrene ball to mix, add the main material, at the same time, spray the remaining additional binder, continue rolling, drying, and obtain the ball blank;

[0039] S3, heating the ball blank to 1000-1500°C, calcining for 10-15h, cooling to room temperature, and obtaining a thermal insulation refractory porous ball;

[0040] Among them, the added amount of some additional binders accounts for 10-20% of the total weight of the additional binders.

[0041] By adopting the above technical scheme, the polystyrene balls and part of the additional binder are mixed, so that the surface of the polystyrene balls is coated with the additional binder, and then the main material is added while the remaining additional binder is sprayed, so that the balls are continuously rolled to increase the particle size. Then, after drying and calcining, the thermal insulation refractory porous balls are obtained, which is convenient for the preparation of the thermal insulation refractory porous balls and ensures stable preparation. In addition, since polystyrene will decompose and gasify during the calcination process, a hollow is formed, and a thermal insulation refractory porous ball with a hollow is obtained.

[0042] In multiple embodiments, the amount of added binder accounts for 10% of the total weight of the added binder. The proportion can also be set to 13%, 15%, 18%, or 20% as needed, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable.

[0043] In summary, this application has at least the following beneficial effects:

[0044] 1. The thermal insulation refractory porous balls of the present application add carbon powder to the main material, which can not only form pores, but also increase the uniformity of the pores in the thermal insulation refractory porous balls, reduce thermal conductivity, and improve thermal insulation effects because the carbon powder can be evenly dispersed in the main material.

[0045] 2. The carbon powder of the present application is coconut shell activated carbon powder, which can not only reduce the occurrence of overburning, but also significantly reduce the thermal conductivity, so that the thermal insulation refractory porous ball exhibits better thermal insulation properties. DETAILED DESCRIPTION

[0046] In order to make the present application easier to understand, the present application will be further described in detail below in conjunction with the examples, which are merely illustrative and are not intended to limit the scope of application of the present application. The raw materials or components used in the present application can be obtained through commercial routes or conventional methods unless otherwise specified.

[0047] Example

[0048] Table 1 Amount of thermal insulation refractory porous balls (unit: × 10g)

[0049]

[0050] Example 1

[0051] A thermal insulation refractory porous ball, the raw materials and raw material ratios of which are shown in Table 1.

[0052] Among them, the mesh number of kaolin is 325 mesh, the silica content in kaolin is 49wt%, and the alumina content is 35wt%; the mesh number of mullite is 325 mesh, the silica content in mullite is 22wt%, and the alumina content is 72wt%; the mesh number of high-alumina bauxite is 500 mesh, the silica content in high-alumina bauxite is 8%, and the alumina content is 86wt%; the carbon powder is coconut shell activated carbon powder, and the average particle size of the carbon powder is 13μm; the average particle size of the ultrafine alumina powder is 2μm.

[0053] The external binder is silica sol, and the silica sol is silica sol Levasil CS50-18, and is selected from Guangzhou Runhong Chemical Co., Ltd.

[0054] A method for preparing a thermal insulation refractory porous ball comprises the following steps:

[0055] S1. Add kaolin, mullite, high-alumina bauxite, carbon powder and ultrafine alumina powder into a blender and stir for 3 minutes to obtain the main material.

[0056] S2, add part of the main material in the ball rolling machine, under the rolling speed of 50r / min, spray part of the additional binder, the spray time is 10min, and continue to roll for 20min. At this time, part of the main material and part of the additional binder are rolled into balls. Add the remaining main material, at the same time, spray the remaining additional binder, the spray time is 20min, and continue to roll for 90min. Then at a temperature of 100°C, dry to constant weight to obtain a ball blank.

[0057] Among them, the addition amount of some main materials accounts for 10% of the total weight of the main materials; the addition amount of some external binders accounts for 10% of the total weight of the external binders.

[0058] S3, the ball blank is heated to 1100°C and calcined for 13 hours, and then cooled to 23°C to obtain a thermal insulation refractory porous ball.

[0059] Embodiment 2-6

[0060] A thermal insulation refractory porous ball, which is different from Example 1 in that the raw material ratio of the thermal insulation refractory porous ball is different, and the raw material ratio is shown in Table 1.

[0061] Example 7

[0062] A thermal insulation refractory porous ball, which is different from Example 4 in that the raw materials of the thermal insulation refractory porous ball and the raw materials of the main material have different sources of carbon powder, and the carbon powder is coal-based activated carbon powder.

[0063] Example 8

[0064] A thermal insulation refractory porous ball, which is different from Example 4 in that in the raw materials of the thermal insulation refractory porous ball and the raw materials of the main material, the particle size of the carbon powder is different, and the average particle size of the carbon powder is 5μm.

[0065] Example 9

[0066] A thermal insulation refractory porous ball, which is different from Example 4 in that in the raw materials of the thermal insulation refractory porous ball and the raw materials of the main material, the particle size of the carbon powder is different, and the average particle size of the carbon powder is 15μm.

[0067] Example 10

[0068] A thermal insulation refractory porous ball, which is different from Example 4 in that in the preparation method, in step S3, the calcination temperature is 1000°C.

[0069] Embodiment 11

[0070] A thermal insulation refractory porous ball, which is different from Example 4 in that in the preparation method, in step S3, the calcination temperature is 1300°C.

[0071] Example 12

[0072] A thermal insulation refractory porous ball, which is different from Example 4 in that in the preparation method, in step S3, the calcination temperature is 1500°C.

[0073] Table 2 Amount of thermal insulation refractory porous balls (unit: × 10g)

[0074]

[0075] Example 13

[0076] A thermal insulation refractory porous ball, which is different from Example 11 in that polystyrene balls are further added to the raw materials of the thermal insulation refractory porous ball, and the raw materials and raw material ratios of the thermal insulation refractory porous ball are shown in Table 2. At the same time, the preparation method of the thermal insulation refractory porous ball is different.

[0077] The polystyrene balls are polystyrene foam balls selected from Henan Haojiesi Environmental Protection Technology Co., Ltd., and the average particle size of the polystyrene balls is 2 mm.

[0078] A method for preparing a thermal insulation refractory porous ball comprises the following steps:

[0079] S1. Add kaolin, mullite, high-alumina bauxite, carbon powder and ultrafine alumina powder into a blender and stir for 3 minutes to obtain the main material.

[0080] S2, add polystyrene balls to the ball rolling machine, and spray part of the additional binder at a rolling speed of 50r / min, the spraying time is 10min, and the rolling process is continued for 10min. Add the main material, and at the same time, spray the remaining additional binder, the spraying time is 20min, and the rolling process is continued for 90min. Then dry at a temperature of 100°C to constant weight to obtain a ball blank.

[0081] Among them, the added amount of some external binders accounts for 10% of the total weight of the external binders.

[0082] S3, heating the ball blank to 1300°C, calcining for 13 hours, and then cooling to 23°C to obtain a thermal insulation refractory porous ball.

[0083] Examples 14-15

[0084] A thermal insulation refractory porous ball, which is different from Example 11 in that the raw material ratio of the thermal insulation refractory porous ball is different, and the raw material ratio is shown in Table 2.

[0085] Comparative Example

[0086] Comparative Example 1

[0087] A thermal insulation refractory porous ball, which differs from Example 11 in that among the raw materials of the thermal insulation refractory porous ball, among the raw materials of the main ingredient, an equal amount of kaolin is used to replace coconut shell activated carbon powder.

[0088] Comparative Example 2

[0089] A thermal insulation, refractory porous ball, which differs from Example 11 in that in the raw materials of the thermal insulation, refractory porous ball, in the raw materials of the main ingredient, an equal amount of starch is used to replace coconut shell activated carbon powder, and the starch is wheat starch selected from Hebei Baipin Biotechnology Co., Ltd.

[0090] Comparative Example 3

[0091] A thermal insulation, refractory porous ball, which is different from Example 11 in that among the raw materials of the thermal insulation, refractory porous ball, among the raw materials of the main ingredient, an equal amount of hydroxypropyl methylcellulose ether is used to replace coconut shell activated carbon powder, and the hydroxypropyl methylcellulose ether is selected from Wuhan Runxingyuan Technology Co., Ltd.

[0092] Comparative Example 4

[0093] A thermal insulation refractory porous ball, which differs from Example 11 in that among the raw materials of the thermal insulation refractory porous ball, among the raw materials of the main ingredient, an equal amount of rice husk activated carbon powder is used to replace coconut shell activated carbon powder.

[0094] Comparative Example 5

[0095] A thermal insulation refractory porous ball, which differs from Example 11 in that among the raw materials of the thermal insulation refractory porous ball, the weight percentage of coconut shell activated carbon powder in the main material is 25%, and at the same time, the weight percentage of kaolin is 22%.

[0096] Comparative Example 6

[0097] A thermal insulation refractory porous ball, which differs from Example 11 in that among the raw materials of the thermal insulation refractory porous ball, among the raw materials of the main material, high alumina and ultrafine alumina powder are replaced by equal amounts of kaolin.

[0098] Comparative Example 7

[0099] A thermal insulation refractory porous ball, which differs from Example 11 in that among the raw materials of the thermal insulation refractory porous ball, among the raw materials of the main material, an equal amount of high-alumina bauxite is used to replace the alumina ultrafine powder.

[0100] Comparative Example 8

[0101] A thermal insulation refractory porous ball, which differs from Example 11 in that among the raw materials of the thermal insulation refractory porous ball, among the raw materials of the main material, an equal amount of ultrafine alumina powder is used to replace high alumina.

[0102] Performance Testing

[0103] (1) 10 professionals were selected to evaluate the sticking and agglomeration of the thermal insulation and refractory porous balls obtained in Examples 1-15 and Comparative Examples 1-8. The evaluation results of the sticking and agglomeration are shown in Table 3.

[0104] (2) The thermal insulation refractory porous balls obtained in Examples 1-15 and Comparative Examples 1-8 were respectively taken as samples, and the following performance tests were performed on the samples. The test results are shown in Table 3.

[0105] Among them, the compressive strength of thermal insulation refractory porous balls was tested according to GB / T5072-2008 "Test method for compressive strength of refractory materials at room temperature".

[0106] According to GB / T5990-2021 "Test method for thermal conductivity, specific heat capacity and thermal diffusion coefficient of refractory materials (hot wire method)", the thermal conductivity of thermal insulating refractory porous balls is tested.

[0107] According to GB / T2999-2016 "Test method for bulk density of refractory particles", the bulk density of thermal insulation refractory porous balls is tested.

[0108] Table 3 Test results

[0109]

[0110] Note: “ / ” means not detected.

[0111] It can be seen from Table 3 that the thermal insulation refractory porous ball of the present application has no adhesion and agglomeration, and its compressive strength is 183-209N, the thermal conductivity at 1100℃ is 0.321-0.448w / (mk), and the bulk density is 963-1052Kg / m 3 , the average particle size is 4.2-4.5mm, which makes it show the advantages of high compressive strength, low thermal conductivity, good thermal insulation and moderate bulk density. It has good comprehensive performance and meets market demand.

[0112] Comparing Example 11 with Comparative Examples 1-3, no coconut shell activated carbon powder was added to the raw materials of the main material of Comparative Example 1; starch was added to the raw materials of the main material of Comparative Example 2; hydroxypropyl methylcellulose ether was added to the raw materials of the main material of Comparative Example 3; and coconut shell activated carbon powder was added to the raw materials of the main material of Example 11. It can be seen that adding coconut shell activated carbon powder to the raw materials of the main material basically does not affect the compressive strength, but significantly reduces the thermal conductivity and bulk density. Combined with Comparative Example 3, rice husk activated carbon powder was added to the raw materials of the main material of Comparative Example 3. It can be seen that although rice husk activated carbon powder and coconut shell activated carbon powder are both carbon powders, their use effects in thermal insulation and refractory porous balls are quite different, that is, only when the carbon powder is coconut shell activated carbon powder or coal-based activated carbon powder can the thermal insulation and refractory porous balls show better comprehensive performance.

[0113] Comparing Comparative Examples 6-7, high alumina bauxite and ultrafine alumina powder were not added to the raw materials of the main material of Comparative Example 6; high alumina bauxite was added to the raw materials of the main material of Comparative Example 7. It can be seen that adding high alumina bauxite to the raw materials of the main material can increase the compressive strength. Combined with Comparative Example 8, ultrafine alumina powder was added to the raw materials of the main material of Comparative Example 8. It can be seen that adding ultrafine alumina powder to the raw materials of the main material can also increase the compressive strength, but significantly improve the thermal conductivity, which may be due to the small particle size of the ultrafine alumina powder, which causes clogging of the pores. Combined with Example 11, high alumina bauxite and ultrafine alumina powder were added to the raw materials of the main material of Example 11. It can be seen that high alumina bauxite and ultrafine alumina powder were added to the raw materials of the main material at the same time, and the synergistic effect between them was utilized to ensure that the thermal insulation refractory porous balls have good thermal conductivity and bulk density, and the compressive strength of the thermal insulation refractory porous balls is significantly increased, so that the thermal insulation refractory porous balls show better comprehensive performance.

[0114] It should be noted that the embodiments described above are only used to explain the present application and do not constitute any limitation to the present application. The present application is described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present application may be modified as specified within the scope of the claims of the present application, and the present invention may be revised without departing from the scope and spirit of the present application. Although the present application described therein relates to specific methods, materials and embodiments, it does not mean that the present application is limited to the specific examples disclosed therein. On the contrary, the present application can be extended to all other methods and applications with the same functions.

Claims

1. A thermal insulation refractory porous ball, characterized in that: The raw materials of the thermal insulation refractory porous ball include a main material and an additional binder, wherein the amount of the additional binder added accounts for 5-10% of the total weight of the main material; The main material is made of the following raw materials in percentage by weight: 31-57% kaolin, 25-45% mullite, 10-20% high-alumina bauxite, 3-15% carbon powder and 1-5% ultrafine alumina powder; the carbon powder is one or two of coconut shell activated carbon powder and coal-based activated carbon powder.

2. The thermal insulation refractory porous ball according to claim 1, characterized in that: The average particle size of the carbon powder is 5-15 μm.

3. The thermal insulation refractory porous ball according to claim 1, characterized in that: The carbon powder is coconut shell activated carbon powder.

4. The thermal insulation refractory porous ball according to claim 1, characterized in that: The mesh number of the kaolin is 300-800 meshes, the mesh number of the mullite is 300-800 meshes, the mesh number of the high-alumina bauxite is 300-800 meshes, and the average particle size of the ultrafine alumina powder is 1-100 μm.

5. The thermal insulation refractory porous ball according to claim 1, characterized in that: The external binder is one or more of polyvinyl alcohol, silica sol, sodium carbonate, and aluminum dihydrogen phosphate.

6. The thermal insulation refractory porous ball according to claim 1, characterized in that: The average particle size of the thermal insulation refractory porous balls is 0.5-20mm.

7. The thermal insulation refractory porous ball according to claim 1, characterized in that: The raw materials of the thermal insulation and refractory porous balls also include polystyrene balls, and the added amount of the polystyrene balls accounts for 1-10% of the total weight of the main material.

8. The thermal insulation refractory porous ball according to claim 7, characterized in that: The average particle size of the polystyrene spheres is 0.1-6 mm.

9. A method for preparing a thermal insulation refractory porous ball according to any one of claims 1 to 6, characterized in that: The steps include: S1. Mix kaolin, mullite, high-alumina bauxite, carbon powder and ultrafine alumina powder to obtain a main material; S2, under continuous rolling, spray part of the main material with additional binder, roll into balls, add the remaining main material, and at the same time, spray the remaining additional binder, continue to roll, dry, and obtain the ball blank; S3, heating the ball blank to 1000-1500°C, calcining for 10-15h, cooling to room temperature, and obtaining a thermal insulation refractory porous ball; Among them, the addition amount of some main materials accounts for 10-20% of the total weight of the main materials; the addition amount of some external binders accounts for 10-20% of the total weight of the external binders.

10. A method for preparing a thermal insulation refractory porous ball according to any one of claims 7 to 8, characterized in that: The steps include: S1. Mix kaolin, mullite, high-alumina bauxite, carbon powder and ultrafine alumina powder to obtain a main material; S2, under continuous rolling, spray part of the additional binder into the polystyrene ball to mix, add the main material, at the same time, spray the remaining additional binder, continue rolling, drying, and obtain the ball blank; S3, heating the ball blank to 1000-1500°C, calcining for 10-15h, cooling to room temperature, and obtaining a thermal insulation refractory porous ball; Among them, the added amount of some additional binders accounts for 10-20% of the total weight of the additional binders.

Images