Refractory material for tundish insulation

Abstract

The application relates to the technical field of refractory materials, and discloses a kind of intermediate ladle heat preservation refractory materials, including the following weight parts component raw materials: alumina hollow ball 5~40 parts, hollow ceramic 5~40 parts, waste clay brick 5~30 parts, coke spar powder 10~20 parts, refractory clay 1~5 parts, andalusite powder 5~20 parts, refractory cement 5~20 parts, water reducing agent 0.1~0.5 parts, melamine 0.1~0.5 parts, alum 0.5~1 part, benzamide oxime 0.2~0.3 parts.Through the above technical scheme, the problem of insufficient strength of the intermediate ladle heat preservation refractory material in the related art is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of refractory materials, in particular to a kind of intermediate ladle heat-insulating refractory materials. BACKGROUND

[0002] Intermediate ladle is the core transition equipment in steel continuous casting production process, and its main function is to receive molten steel transferred from ladle, realize buffer storage, uniform distribution and purification treatment of molten steel, and the intermediate ladle heat-insulating refractory material refers to a kind of functional refractory material specially used for inner wall, cover or bottom of intermediate ladle.

[0003] In the prior art, the intermediate ladle body refractory material is generally divided into working layer, permanent layer and heat-insulating layer. The heat-insulating layer uses various refractory materials, and the common ones include nano heat-insulating plate, lightweight clay brick, lightweight amorphous refractory material and various refractory fiber plates and fiber blankets. Among them, the lightweight amorphous refractory material has good application effect because it has the advantages of controllable thickness of the heat-insulating layer obtained by construction, no influence of anchoring hooks, and construction to all parts without dead angle. When the lightweight amorphous refractory material improves the heat-insulating performance, it adds lightweight hollow substances. Such substances not only have low density, but also have large average particle size. In order to improve the density of the refractory material, some fine powder needs to be added to fill the gaps of the hollow substances, but the fine powder has the phenomenon of easy agglomeration, which cannot effectively realize filling, so that the strength of the refractory material is insufficient.

[0004] The refractory material with insufficient strength is easy to have microcracks in the initial service period, not only loses the heat-insulating core function, but also has block peeling due to insufficient strength, exposes the permanent layer below, and makes high temperature directly act on the non-heat-insulating structure, further aggravates the overall heat loss and structural damage.

[0005] Therefore, it is necessary to develop an intermediate ladle heat-insulating refractory material with high strength. SUMMARY

[0006] The present application provides an intermediate ladle heat-insulating refractory material, which solves the problem of insufficient strength of the intermediate ladle heat-insulating refractory material in the related art.

[0007] The technical scheme of the present application is as follows: the present application provides an intermediate ladle heat-insulating refractory material, which comprises the following components by weight: 5-40 parts of alumina hollow spheres, 5-40 parts of hollow ceramic granules, 5-30 parts of waste clay bricks, 10-20 parts of flint clay powder, 1-5 parts of refractory clay, 5-20 parts of cordierite powder, 5-20 parts of refractory cement, 0.1-0.5 parts of water reducing agent, 0.1-0.5 parts of melamine, 0.5-1 parts of alum, and 0.2-0.3 parts of benzamide oxime.

[0008] As a further technical solution, the main components of the waste clay brick include Al2O3 and SiO2, wherein the content of Al2O3 is 30wt%-50wt%, and the content of SiO2 is 40wt%-45wt%, and the average particle size of the waste clay brick is 1-5mm.

[0009] As a further technical solution, the average particle size of the fireclay is 0.045mm.

[0010] As a further technical solution, the water reducing agent includes one or both of a naphthalene series water reducing agent and a polycarboxylic acid water reducing agent, and preferably is a naphthalene series water reducing agent.

[0011] In the intermediate ladle heat preservation refractory material, the water reducing agent is added to the raw material, the addition of the water reducing agent can reduce the amount of water added, avoids the problems of billet delamination and water bleeding caused by excessive moisture, and can also reduce the internal porosity of the material and improve the stability of the refractory material.

[0012] As a further technical solution, the alumina hollow sphere is composed of first alumina hollow spheres and second alumina hollow spheres, and the volume densities of the first alumina hollow spheres and the second alumina hollow spheres are different.

[0013] As a further technical solution, the volume density of the first alumina hollow sphere is 0.6-0.7g / cm 3 , and the volume density of the second alumina hollow sphere is 1.0-1.1g / cm 3 .

[0014] In the intermediate ladle heat preservation refractory material, the alumina hollow sphere is composed of first alumina hollow spheres and second alumina hollow spheres with different volume densities, the first alumina hollow sphere has excellent heat preservation performance but a thin wall, insufficient compressive strength, and is prone to breakage, which leads to a significant decrease in the strength of the refractory material, and the second alumina hollow sphere has a high volume density, can disperse stress, and avoid the breakage of the alumina hollow sphere caused by local stress concentration, and the two kinds of alumina hollow spheres are used in combination to form a synergistic effect of high and low densities, which retains the heat preservation advantage of the low-density sphere and improves the overall bearing capacity and the strength of the refractory material through the strong support of the high-density sphere.

[0015] As a further technical solution, the mass ratio of the first alumina hollow sphere to the second alumina hollow sphere is 7:2-3.

[0016] As a further technical solution, the average particle size of the hollow ceramsite is 1-5mm.

[0017] As a further technical solution, the average particle size of the waste clay brick is 3-5mm.

[0018] As a further technical solution, the raw material further comprises sodium alkyl benzene sulfonate 0.03-0.06 parts.

[0019] As a further technical solution, the sodium alkyl benzene sulfonate comprises one or more of sodium dodecyl benzene sulfonate, sodium heavy alkyl benzene sulfonate, and sodium decyl benzene sulfonate, preferably sodium heavy alkyl benzene sulfonate.

[0020] As a further technical solution, the method for preparing the refractory material comprises the following steps:

[0021] S1, dispersing benzamide oxime in anhydrous ethanol, adding flint powder and pyrophyllite powder, mixing and drying to obtain a composite powder;

[0022] S2, mixing the composite powder, alumina hollow sphere, hollow ceramic, waste clay brick, refractory clay, refractory cement, water reducing agent, melamine and alum to obtain the refractory material.

[0023] As a further technical solution, in step S1, the mass ratio of the flint powder and the pyrophyllite powder to the mass of the anhydrous ethanol is 1:3-8, for example, it can be 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, preferably 1:5.

[0024] As a further technical solution, in step S1, the mixing time is 2-4h, for example, it can be 2h, 2.5h, 3h, 3.5h, 4h, preferably 3h.

[0025] As a further technical solution, the method for preparing the refractory material comprises the following steps:

[0026] A1, dispersing sodium alkyl benzene sulfonate in water, adding refractory clay, mixing and drying to obtain a composite refractory clay;

[0027] A2, dispersing benzamide oxime in anhydrous ethanol, adding flint powder and pyrophyllite powder, mixing and drying to obtain a composite powder;

[0028] A3, mixing the composite refractory clay, the composite powder, alumina hollow sphere, hollow ceramic, waste clay brick, refractory cement, water reducing agent, melamine and alum to obtain the refractory material.

[0029] As a further technical solution, in step A1, the mass ratio of the refractory clay to the water is 1:5-8, for example, it can be 1:5, 1:6, 1:7, 1:8, preferably 1:6.

[0030] As a further technical solution, in step A1, the mixing time is 3-5h, for example, it can be 3h, 3.5h, 4h, 4.5h, 5h, preferably 4h.

[0031] In the raw material of the intermediate ladle heat preservation refractory in the application, the refractory clay is treated by using sodium alkyl benzene sulfonate to obtain a composite refractory clay. The refractory clay is easy to form agglomerates due to small particles and rich hydroxyl groups on the surface. However, in the refractory material, the refractory clay can bond granular raw materials such as alumina hollow spheres, hollow ceramsite, waste clay bricks, and powdery raw materials such as corundum powder and andalusite powder into a whole. After the treatment of the refractory clay by sodium alkyl benzene sulfonate, the agglomeration problem is effectively improved, so that the refractory clay is more uniformly dispersed in the raw material system in the subsequent mixing, and the density unevenness caused by local excessive bonding is avoided, and the strength of the refractory material is improved.

[0032] The working principle and beneficial effects of the application are as follows:

[0033] In the raw material of the intermediate ladle heat preservation refractory in the application, the addition of benzamide oxime can effectively promote the dispersibility of fine powders such as corundum powder and andalusite powder and the bonding force with cement hydration products, and enhance the strength of the refractory material. In the prior art, fine materials are often added to fill the gaps generated by light and large particle size hollow substances, but the fine materials are easy to form agglomerates, which seriously affects the strength of the refractory material. In the application, by adding benzamide oxime, on the one hand, hydrogen bonds can be formed with the hydroxyl groups on the surface of fine powders such as corundum powder and andalusite powder, and on the other hand, coordination bonds can be formed with the hydration products of cement, thereby enhancing the combination of fine powders and cement gel phase, improving the cementing strength, and further improving the strength of the intermediate ladle heat preservation refractory. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the application will be clearly and completely described below in combination with the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0035] In the following examples and comparative examples:

[0036] The first alumina hollow sphere has a bulk density of 0.6-0.7 g / cm 3 , and is purchased from Zhengzhou Rongsheng Kiln Refractory Material Co., Ltd.;

[0037] The second alumina hollow sphere has a bulk density of 1.0-1.1 g / cm 3 , and is purchased from Zhengzhou Rongsheng Kiln Refractory Material Co., Ltd.;

[0038] The hollow ceramsite has an average particle size of 3 mm;

[0039] Waste clay bricks: with an average particle size of 4mm, the main components include Al2O3 and SiO2, with Al2O3 content of 50wt% and SiO2 content of 40wt%. They are self-produced and recycled after the high-temperature kiln service.

[0040] Roasted gemstone powder: average particle size is 325 mesh;

[0041] Refractory clay: average particle size 0.045mm, purchased from Henan Zhongnai Gaoke Furnace Lining Materials Co., Ltd.;

[0042] Andalusite powder: average particle size is 325 mesh;

[0043] Refractory cement: Model CA-60, purchased from Zhengzhou Kerui Refractory Materials Co., Ltd.

[0044] Water-reducing agents: naphthalene-based water-reducing agents, NSF water-reducing agents;

[0045] Alum: Product number AR-026, purchased from Suzhou Aorong Chemical Technology Co., Ltd.

[0046] Example 1

[0047] The preparation method of refractory materials includes the following steps:

[0048] S1. Disperse 0.3 parts of benzamide oxime in 150 parts of anhydrous ethanol, add 10 parts of charred gemstone powder and 20 parts of andalusite powder, mix for 3 hours and then dry to obtain composite powder;

[0049] S2. Mix the composite powder, 5 parts of alumina hollow spheres, 5 parts of hollow ceramsite, 5 parts of waste clay bricks, 1 part of refractory clay, 5 parts of refractory cement, 0.1 parts of water-reducing agent, 0.1 parts of melamine and 0.5 parts of alum to obtain the refractory material, wherein the alumina hollow spheres are the first alumina hollow spheres.

[0050] Example 2

[0051] The preparation method of refractory materials includes the following steps:

[0052] S1. Disperse 0.25 parts of benzamide oxime in 150 parts of anhydrous ethanol, add 15 parts of charred gemstone powder and 15 parts of andalusite powder, mix for 3 hours and then dry to obtain composite powder.

[0053] S2. Mix the composite powder, 20 parts of alumina hollow spheres, 20 parts of hollow ceramsite, 15 parts of waste clay bricks, 3 parts of refractory clay, 12 parts of refractory cement, 0.3 parts of water-reducing agent, 0.3 parts of melamine and 0.8 parts of alum to obtain the refractory material, wherein the alumina hollow spheres are the first alumina hollow spheres.

[0054] Example 3

[0055] The preparation method of refractory materials includes the following steps:

[0056] S1. Disperse 0.2 parts of benzamide oxime in 125 parts of anhydrous ethanol, add 20 parts of charred gemstone powder and 5 parts of andalusite powder, mix for 3 hours and then dry to obtain composite powder;

[0057] S2. Mix the composite powder, 40 parts of alumina hollow spheres, 40 parts of hollow ceramsite, 30 parts of waste clay bricks, 5 parts of refractory clay, 20 parts of refractory cement, 0.5 parts of water-reducing agent, 0.5 parts of melamine and 1.0 parts of alum to obtain the refractory material, wherein the alumina hollow spheres are the first alumina hollow spheres.

[0058] Example 4

[0059] The difference between Example 4 and Example 2 is that the hollow alumina spheres are second hollow alumina spheres.

[0060] Example 5

[0061] The difference between Example 5 and Example 2 is that the alumina hollow spheres are composed of a first alumina hollow sphere and a second alumina hollow sphere with a mass ratio of 7:2.

[0062] Example 6

[0063] The difference between Example 6 and Example 2 is that the alumina hollow spheres are composed of a first alumina hollow sphere and a second alumina hollow sphere with a mass ratio of 7:3.

[0064] Example 7

[0065] The preparation method of refractory materials includes the following steps:

[0066] A1. Disperse 0.03 parts of sodium dodecylbenzenesulfonate in 18 parts of water, add 3 parts of refractory clay, mix for 4 hours and then dry to obtain composite refractory clay;

[0067] A2. Disperse 0.25 parts of benzamide oxime in 150 parts of anhydrous ethanol, add 15 parts of charred gemstone powder and 15 parts of andalusite powder, mix for 3 hours and then dry to obtain composite powder.

[0068] A3. Mix composite refractory clay, composite powder, 20 parts of alumina hollow spheres, 20 parts of hollow ceramsite, 15 parts of waste clay bricks, 12 parts of refractory cement, 0.3 parts of water-reducing agent, 0.3 parts of melamine and 0.8 parts of alum to obtain refractory material, wherein the alumina hollow spheres are the first type of alumina hollow spheres.

[0069] Example 8

[0070] The difference between Example 7 and Example 8 is that the amount of sodium dodecylbenzenesulfonate added is 0.06 parts.

[0071] Example 9

[0072] The difference between Example 9 and Example 8 is that sodium dodecylbenzenesulfonate is replaced with an equal amount of sodium heavy alkylbenzenesulfonate.

[0073] Example 10

[0074] The difference between Example 10 and Example 8 is that sodium dodecylbenzenesulfonate is replaced with an equal amount of sodium decylbenzenesulfonate.

[0075] Example 11

[0076] The difference between Example 11 and Example 8 is that sodium dodecylbenzenesulfonate is replaced with an equal amount of sodium dodecyl sulfonate.

[0077] Comparative Example 1

[0078] The preparation method of refractory material includes the following steps: mixing 15 parts of calcined gemstone powder, 15 parts of andalusite powder, 20 parts of alumina hollow spheres, 20 parts of hollow ceramsite, 15 parts of waste clay bricks, 3 parts of refractory clay, 12 parts of refractory cement, 0.3 parts of water-reducing agent, 0.3 parts of melamine and 0.8 parts of alum to obtain refractory material, wherein the alumina hollow spheres are the first alumina hollow spheres.

[0079] Experimental Example 1

[0080] The refractory materials for tundish insulation prepared in Examples 1-11 and Comparative Example 1 were mixed with 15% water by total mass, shaped, cured, and calcined. The compressive strength of the samples was tested at 110℃ for 24 hours according to the method of GB / T 5072-2008 "Test Method for Compressive Strength of Refractory Materials at Room Temperature".

[0081] The test results are shown in Table 1:

[0082] Table 1. Performance test results of the refractory materials for tundish insulation prepared in Examples 1-11 and Comparative Example 1

[0083]

[0084] Table 1 shows that adding benzamide oxime to the raw materials of refractory materials used for tundish insulation can improve the strength of the refractory materials. The strength of the refractory material is even better when the refractory clay is compounded with sodium alkylbenzene sulfonate.

[0085] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A refractory material for tundish insulation, characterized in that, The raw material comprises the following components by weight: 5-40 parts of alumina hollow spheres, 5-40 parts of hollow ceramic granules, 5-30 parts of waste clay bricks, 10-20 parts of flint clay powder, 1-5 parts of refractory clay, 5-20 parts of andalusite powder, 5-20 parts of refractory cement, 0.1-0.5 parts of water reducing agent, 0.1-0.5 parts of melamine, 0.5-1 parts of alum, and 0.2-0.3 parts of benzamide oxime.

2. The refractory material for a tundish for retaining heat according to claim 1, wherein The water reducing agent comprises one or both of a naphthalene series water reducing agent and a polycarboxylic acid water reducing agent.

3. The refractory material for a tundish for retaining heat according to claim 1, wherein The alumina hollow spheres are composed of first alumina hollow spheres and second alumina hollow spheres, the volume densities of the first alumina hollow spheres and the second alumina hollow spheres are different, the volume density of the first alumina hollow spheres is 0.6-0.7 g / cm 3 , and the volume density of the second alumina hollow spheres is 1.0-1.1 g / cm 3 .

4. The refractory material for a tundish for retaining heat according to claim 3, wherein The mass ratio of the first alumina hollow spheres to the second alumina hollow spheres is 7:2-3.

5. The refractory material for a tundish for retaining heat according to claim 1, wherein The average particle size of the hollow ceramic granules is 1-5 mm.

6. The refractory material for a tundish for retaining heat according to claim 1, wherein The average particle size of the waste clay bricks is 3-5 mm.

7. The refractory material for a tundish for retaining heat according to claim 1, wherein The raw material further comprises 0.03-0.06 parts of sodium alkyl benzene sulfonate.

8. A refractory material for a tundish for retaining heat according to claim 7, characterized by The sodium alkyl benzene sulfonate comprises heavy sodium alkyl benzene sulfonate.

9. The refractory material for a tundish for retaining heat according to claim 1, wherein The preparation method of the refractory material comprises the following steps: S1, dispersing benzamide oxime in anhydrous ethanol, adding flint clay powder and andalusite powder, mixing, and drying to obtain a composite powder; S2, mixing the composite powder, alumina hollow spheres, hollow ceramic granules, waste clay bricks, refractory clay, refractory cement, water reducing agent, melamine, and alum to obtain the refractory material.

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