A special corundum composite brick and its preparation method

Abstract

The present invention relates to a special corundum composite brick and a preparation method thereof, belonging to the technical field of refractory materials. The special corundum composite brick comprises the following raw materials: 50-70 parts of corundum mixture, 10-20 parts of fused mullite powder, 4-7 parts of alumina powder, 0.5-1.5 parts of fused magnesia, 10-15 parts of zircon sand, 10-15 parts of silicon carbide powder, 0.5-1.5 parts of silicon powder, 5-7 parts of sillimanite powder, 5-8 parts of andalusite, and 3-4 parts of binder; the corundum mixture is compounded by tabular corundum, white corundum and brown corundum with a weight ratio of (0-1):(1-3):(3-5). In the special corundum composite brick provided by the present invention, the raw materials cooperate with each other, and the performance of the obtained special corundum composite brick is significantly improved under the joint action. It can be widely applied to various parts of the whole cement rotary kiln line, various parts of the whole lime kiln rotary kiln line and the requirements under different usage scenarios, and has a wide range of uses.

Description

Technical Field

[0001] The present invention relates to the technical field of refractory materials, and particularly to a special corundum composite brick and a preparation method thereof. Background Art

[0002] With the increasing intensity of green environmental protection governance, low-carbon production, energy conservation and emission reduction, and consumption reduction are the only way for modern industrial enterprises to survive and develop rapidly. The market demand for energy conservation and emission reduction has become the main theme of the rapid development of modern industrial technologies. In the high-temperature industrial field, especially in industries using dynamic rotary kilns such as cement production, lime production, magnesium metal production, ceramsite production, zinc oxide production, and waste incineration, the requirements for the service life and lightweight of refractory furnace lining bricks are getting higher and higher. Equipment in these industries, such as rotary kilns, gasifiers, and reaction furnaces, are in harsh environments of high temperature, high pressure, chemical erosion, and material wear for a long time, posing extremely high requirements for the performance of refractory materials. Traditional refractory materials often have difficulty in balancing high temperature resistance, erosion resistance, and thermal shock stability. For example, although magnesia-ferrite spinel and magnesia-aluminum spinel bricks commonly used in cement kilns now have excellent refractoriness and relatively high load softening temperatures, their thermal shock stability, wear resistance, and service life still need to be improved; while lightweight insulating bricks have low thermal conductivity, but their refractoriness and strength are insufficient and are difficult to be directly used in high-temperature environments. Therefore, developing a refractory product with strong comprehensive performance, good thermal shock stability, good wear resistance, long service life, and energy consumption reduction has become a research hotspot in the current refractory material field. Summary of the Invention

[0003] To solve the above problems, the present invention provides a special corundum composite brick and a preparation method thereof.

[0004] In a first aspect, the present invention provides a special corundum composite brick. Calculated by weight parts, the special corundum composite brick comprises the following raw materials:

[0005] 50 - 70 parts of corundum mixture, 10 - 20 parts of fused mullite powder, 4 - 7 parts of alumina powder, 0.5 - 1.5 parts of fused magnesia, 8 - 15 parts of zircon sand, 10 - 15 parts of silicon carbide powder, 0.5 - 1.5 parts of silicon powder, 5 - 7 parts of sillimanite powder, 5 - 8 parts of andalusite, and 3 - 4 parts of binder;

[0006] The corundum mixture is compounded from tabular corundum, white corundum, and brown corundum in a weight ratio of (0 - 1):(1 - 3):(3 - 5).

[0007] Further, the total weight parts of each raw material in the special corundum composite brick is 100 parts.

[0008] Further, the particle size of the fused mullite powder is 325 mesh, and the particle size of the alumina powder is 4 μm.

[0009] Furthermore, the particle size of the fused magnesia is 325 mesh, the particle size of the zircon sand is 60 - 80 mesh, and the particle size of the silicon carbide powder is 325 mesh.

[0010] Furthermore, the binder includes aluminum dihydrogen phosphate and pulp.

[0011] Furthermore, the physical and chemical index parameters of the special corundum composite brick include: the bulk density is 3.15 - 3.4 g / cm 3 , the refractoriness under load is ≥1700 °C, the thermal shock stability after water cooling at 1100 °C is >100 times, the normal temperature compressive strength is >130 mpa, the abrasion resistance is <4, the expansion coefficient is <0.0002, the thermal conductivity at 800 °C is <1 W / MK, and the flexural strength is >50 MPA.

[0012] In a second aspect, the present invention provides a method for preparing the special corundum composite brick according to any one of the first aspect, and the preparation method includes the following steps:

[0013] Premix the raw materials other than the binder in the special corundum composite brick to obtain a first mixture;

[0014] Add the binder to the first mixture and perform milling mixing to obtain a second mixture;

[0015] Form the second mixture into a blank to obtain a semi-finished product;

[0016] Sinter the semi-finished product to obtain the special corundum composite brick.

[0017] Furthermore, the time for premixing is 5 - 8 minutes, and the time for milling mixing is 20 - 30 minutes.

[0018] Furthermore, the working condition parameters for sintering include: the temperature is 1600 - 1700 °C, and the time is 10 - 16 h.

[0019] The above technical solutions provided by the embodiments of the present invention have at least the following advantages compared with the prior art:

[0020] The embodiments of the present invention provide a special corundum composite brick. In the special corundum composite brick provided by the present invention, the raw materials cooperate with each other, and the performance of the obtained special corundum composite brick is significantly improved under their common action. It can meet the requirements of various parts and different usage scenarios of dynamic rotary kilns such as cement, lime, metallic magnesium, ceramsite, zinc oxide, and waste incineration, and has a wide range of uses. Specific Embodiments

[0021] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0022] Unless otherwise specifically stated, all kinds of raw materials, reagents, instruments and equipment used in the present invention can be obtained through market purchase or can be prepared by existing methods.

[0023] In a first aspect, the present invention provides a special corundum composite brick. Calculated by weight parts, the special corundum composite brick comprises the following raw materials:

[0024] 50 - 70 parts of corundum mixture, 10 - 20 parts of fused mullite powder, 4 - 7 parts of alumina powder, 0.5 - 1.5 parts of fused magnesia, 10 - 15 parts of zircon sand, 10 - 15 parts of silicon carbide powder, 0.5 - 1.5 parts of silicon powder, 5 - 7 parts of sillimanite powder, 5 - 8 parts of andalusite, 3 - 4 parts of binder;

[0025] The corundum mixture is compounded by tabular corundum, white corundum and brown corundum with a weight ratio of (0 - 1):(1 - 3):(3 - 5).

[0026] The embodiments of the present invention provide a special corundum composite brick. In the special corundum composite brick provided by the present invention, the raw materials cooperate with each other, and the performance of the obtained special corundum composite brick is significantly improved under their common action, which can meet the requirements under different usage scenarios and has a wide range of uses.

[0027] In some specific embodiments, the total weight parts of the raw materials in the special corundum composite brick is 100 parts. When the total weight parts of the raw materials in the special corundum composite brick is 100 parts, calculated by weight percentage, the special corundum composite brick comprises the following raw materials: tabular corundum (0 - 1), white corundum (1 - 3) and brown corundum mixture (3 - 5) 50 - 70%, fused mullite 10 - 20% (325 mesh) (powder), alumina powder 4 - 7% (4μm), fused magnesia (325 mesh) 0.5 - 1.5%, zircon sand (60 - 80 mesh) 10% - 15%, silicon carbide (powder) 10 - 15% (325 mesh), industrial silicon powder 0.5 - 1.5% (325 mesh), sillimanite (powder) (200 mesh) 5 - 7%, andalusite 5 - 8%, binder 3 - 4% (pulp).

[0028] In some specific embodiments, the particle size of the fused mullite powder is 325 mesh, and the particle size of the alumina powder is 4μm.

[0029] In some specific embodiments, the particle size of the fused magnesia is 325 mesh, the particle size of the zircon sand is 60 - 80 mesh, and the particle size of the silicon carbide powder is 325 mesh.

[0030] In some specific embodiments, the binder includes aluminum dihydrogen phosphate and pulp.

[0031] In some specific embodiments, the physical and chemical index parameters of the special corundum composite brick include: the bulk density is 3.15 - 3.4 g / cm 3 , the refractoriness under load is ≥1700 °C, the thermal shock stability after water cooling at 1100 °C is >100 times, the cold crushing strength at room temperature is >130 mpa, the abrasion resistance is <4, the expansion coefficient is <0.0002, the thermal conductivity at 800 °C is <1 W / MK, and the flexural strength is >50 MPA.

[0032] In a second aspect, the present invention provides a method for preparing the special corundum composite brick according to any one of the first aspect, and the preparation method includes the following steps:

[0033] Premix the raw materials other than the binder in the special corundum composite brick to obtain a first mixture;

[0034] Add the binder to the first mixture and carry out milling mixing to obtain a second mixture;

[0035] Form the second mixture into a blank to obtain a semi-finished product;

[0036] Sinter the semi-finished product to obtain the special corundum composite brick.

[0037] In some specific embodiments, the time for premixing is 5 - 8 minutes, and the time for milling mixing is 20 - 30 minutes.

[0038] In some specific embodiments, the working condition parameters for sintering include: the temperature is 1600 - 1700 °C, and the time is 10 - 16 h.

[0039] It should be noted that for the raw materials involved in the special corundum composite brick and its preparation method provided in the embodiments of the present invention, if there is no special limitation or specific description, commercially available products can be directly used or prepared by using existing technologies; for the operation steps involved, if there is no special limitation or description, they can be carried out in the conventional manner in the art or by using existing equipment in the art, and will not be elaborated here one by one.

[0040] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The experimental methods without specific conditions noted in the following embodiments are generally determined according to national standards. If there is no corresponding national standard, they are carried out according to general international standards, conventional conditions, or conditions recommended by the manufacturer.

[0041] Example 1

[0042] In this example, a special corundum composite brick is provided. Calculated by weight parts, the special corundum composite brick comprises the following raw materials: 50 parts of corundum mixture, 10 parts of fused mullite powder, 4 parts of alumina powder, 1.0 part of fused magnesia, 10 parts of zircon sand, 10 parts of silicon carbide powder, 0.5 part of silicon powder, 6 parts of sillimanite powder, 7 parts of andalusite, and 3.5 parts of binder; the corundum mixture is compounded by tabular corundum, white corundum and brown corundum with a weight ratio of 1:2:4; the particle size of the fused mullite powder is 325 mesh, the particle size of the alumina powder is 4 μm, the particle size of the fused magnesia is 325 mesh, the particle size of the zircon sand is 60 - 80 mesh, the particle size of the silicon carbide powder is 325 mesh, and the binder is aluminum dihydrogen phosphate and pulp.

[0043] The preparation method of the special corundum composite brick comprises the following steps:

[0044] Premix the raw materials of the special corundum composite brick except the binder for 8 minutes to obtain a first mixture;

[0045] Add the binder to the first mixture and carry out milling and mixing for 25 minutes to obtain a second mixture;

[0046] Mold the second mixture to obtain a semi-finished product;

[0047] Sinter the semi-finished product at a sintering temperature of 1650 °C for 16 hours to obtain the special corundum composite brick.

[0048] Example 2

[0049] This example provides a special corundum composite brick. By weight, the special corundum composite brick comprises the following raw materials: 50 parts of corundum mixture, 20 parts of fused mullite powder, 4 parts of alumina powder, 0.5 part of fused magnesia, 15 parts of zircon sand, 10 parts of silicon carbide powder, 0.5 part of silicon powder, 5 parts of sillimanite powder, 5 parts of andalusite, and 3 parts of binder; the corundum mixture is compounded from tabular corundum, white corundum and brown corundum with a weight ratio of 0.5:3:3; the particle size of the fused mullite powder is 325 mesh, the particle size of the alumina powder is 4 μm, the particle size of the fused magnesia is 325 mesh, the particle size of the zircon sand is 60 - 80 mesh, the particle size of the silicon carbide powder is 325 mesh, and the binder is aluminum dihydrogen phosphate and pulp.

[0050] The preparation method of the special corundum composite brick comprises the following steps:

[0051] Premix the raw materials of the special corundum composite brick except the binder for 8 minutes to obtain a first mixture;

[0052] Add the binder to the first mixture and carry out milling and mixing for 25 minutes to obtain a second mixture;

[0053] Form the second mixture into a blank to obtain a semi-finished product;

[0054] Sinter the semi-finished product at a sintering temperature of 1650 °C for 12 hours to obtain the special corundum composite brick.

[0055] Comparative Example 1

[0056] This example provides a special corundum composite brick and its preparation method. The difference from Example 1 is only that: the dosage of the corundum mixture is adjusted to 10 parts, and the dosage of the fused mullite powder is adjusted to 50 parts.

[0057] This example provides a special corundum composite brick. By weight, the special corundum composite brick comprises the following raw materials: 10 parts of corundum mixture, 50 parts of fused mullite powder, 4 parts of alumina powder, 1.0 part of fused magnesia, 10 parts of zircon sand, 10 parts of silicon carbide powder, 0.5 part of silicon powder, 6 parts of sillimanite powder, 7 parts of andalusite, and 3.5 parts of binder; the corundum mixture is compounded from tabular corundum, white corundum and brown corundum with a weight ratio of 1:2:4; the particle size of the fused mullite powder is 325 mesh, the particle size of the alumina powder is 4 μm, the particle size of the fused magnesia is 325 mesh, the particle size of the zircon sand is 60 - 80 mesh, the particle size of the silicon carbide powder is 325 mesh, and the binder is aluminum dihydrogen phosphate and pulp.

[0058] The preparation method of the special corundum composite brick comprises the following steps:

[0059] Premix the raw materials of the special corundum composite brick except the binder for 8 minutes to obtain the first mixture;

[0060] Add the binder to the first mixture and mill and mix for 25 minutes to obtain the second mixture;

[0061] Mold the second mixture to obtain a semi-finished product;

[0062] Sinter the semi-finished product at a sintering temperature of 1650 °C for 12 hours to obtain the special corundum composite brick.

[0063] Comparative Example 2

[0064] This example provides a special corundum composite brick and its preparation method, which is only different from Example 1 in that: silicon powder is adjusted to sillimanite powder.

[0065] This example provides a special corundum composite brick. By weight, the special corundum composite brick includes the following raw materials: 50 parts of corundum mixture, 10 parts of fused mullite powder, 4 parts of alumina powder, 1.0 part of fused magnesia, 10 parts of zircon sand, 10 parts of silicon carbide powder, 6.5 parts of sillimanite powder, 7 parts of andalusite, and 3.5 parts of binder; the corundum mixture is compounded by tabular corundum, white corundum and brown corundum with a weight ratio of 1:2:4; the particle size of the fused mullite powder is 325 mesh, the particle size of the alumina powder is 4 μm, the particle size of the fused magnesia is 325 mesh, the particle size of the zircon sand is 60 - 80 mesh, the particle size of the silicon carbide powder is 325 mesh, and the binder is pulp.

[0066] The preparation method of the special corundum composite brick includes the following steps:

[0067] Premix the raw materials of the special corundum composite brick except the binder for 8 minutes to obtain the first mixture;

[0068] Add the binder to the first mixture and mill and mix for 25 minutes to obtain the second mixture;

[0069] Mold the second mixture to obtain a semi-finished product;

[0070] Sinter the semi-finished product at a sintering temperature of 1650 °C for 12 hours to obtain the special corundum composite brick.

[0071] Comparative Example 3

[0072] This example provides a special corundum composite brick and its preparation method, which is only different from Example 1 in that: sillimanite powder is adjusted to silicon powder.

[0073] This example provides a special corundum composite brick. By weight, the special corundum composite brick comprises the following raw materials: 50 parts of corundum mixture, 10 parts of fused mullite powder, 4 parts of alumina powder, 1.0 part of fused magnesia, 10 parts of zircon sand, 10 parts of silicon carbide powder, 6.5 parts of silicon powder, 7 parts of andalusite, and 3.5 parts of binder; the corundum mixture is compounded from tabular corundum, white corundum, and brown corundum with a weight ratio of 1:2:4; the particle size of the fused mullite powder is 325 mesh, the particle size of the alumina powder is 4 μm, the particle size of the fused magnesia is 325 mesh, the particle size of the zircon sand is 60 - 80 mesh, the particle size of the silicon carbide powder is 325 mesh, and the binder is pulp.

[0074] The preparation method of the special corundum composite brick comprises the following steps:

[0075] Premix the raw materials other than the binder in the special corundum composite brick for 8 minutes to obtain a first mixture;

[0076] Add the binder to the first mixture and carry out milling and mixing for 25 minutes to obtain a second mixture;

[0077] Form the second mixture into a blank to obtain a semi-finished product;

[0078] Sinter the semi-finished product at a sintering temperature of 1650 °C for 12 hours to obtain the special corundum composite brick.

[0079] Test example

[0080] In this example, the special corundum composite bricks provided in Examples 1 - 2 and Comparative Examples 1 - 3 were subjected to performance testing, and the test results are shown in Table 1.

[0081] Table 1

[0082]

[0083] In summary, the embodiments of the present invention provide a special corundum composite brick and its preparation method. The raw materials in the special corundum composite brick cooperate with each other, and the performance of the obtained special corundum composite brick is significantly improved under their common action, which can meet the requirements in different usage scenarios and has a wide range of uses.

[0084] The various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be construed as a rigid limitation on the scope of the present invention; therefore, it should be considered that the described range description has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and individual numbers within the range, such as 1, 2, 3, 4, 5, and 6, and this applies regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any recited number (fraction or integer) within the indicated range.

[0085] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A special corundum composite brick, characterized in that, In parts by weight, the special corundum composite brick comprises the following raw materials: 50 parts of corundum mixture, 10 parts of fused mullite powder, 4 parts of alumina powder, 1.0 part of fused magnesia, 10 parts of zircon sand, 10 parts of silicon carbide powder, 0.5 part of silicon powder, 6 parts of sillimanite powder, 7 parts of andalusite, and 3.5 parts of binder; the corundum mixture is compounded from tabular corundum, white corundum and brown corundum in a weight ratio of 1:2:4; the particle size of the fused mullite powder is 325 mesh, the particle size of the alumina powder is 4 μm, the particle size of the fused magnesia is 325 mesh, the particle size of the zircon sand is 60-80 mesh, the particle size of the silicon carbide powder is 325 mesh, and the binder is aluminum dihydrogen phosphate and pulp; The preparation method of the special corundum composite brick comprises the following steps: Premix the raw materials except the binder in the special corundum composite brick for 8 minutes to obtain a first mixture; Add the binder to the first mixture and mix it by rolling for 25 minutes to obtain a second mixture; Form the second mixture into a blank to obtain a semi-finished product; Sinter the semi-finished product at a sintering temperature of 1650 °C for 16 hours to obtain the special corundum composite brick.

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