High-strength carbon-free steel ladle wall corundum brick and its application on steel ladle

Abstract

The application relates to the technical field of refractory materials, and discloses a high-strength carbon-free ladle wall bauxite brick, which is prepared from the following components in parts by weight: 60-70 parts of magnesia, 10-18 parts of bauxite, 10-15 parts of magnesium-aluminum spinel, and 8-10 parts of a composite binder; the composite binder is composed of a liquid phase and a solid phase; the liquid phase is an AlCl3 solution; and the solid phase is composed of alpha-Al2O3 micro powder and gamma-Al2O3 micro powder. Through the technical scheme, the problems of low thermal shock stability of the ladle wall brick in the prior art and adverse effects of the ladle wall brick on the carbon pick-up of molten steel during the smelting of steel grades are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of refractory materials, in particular to a high-strength carbon-free ladle wall corundum brick and its application on a ladle. BACKGROUND

[0002] The ladle is also called a steel ladle, a steel bucket, a large ladle, etc., and is used for steelmaking water. In the ladle, the steel water is also subjected to refining treatment and other process flows. The ladle is composed of an outer shell, an inner lining, and a flow control mechanism. The inner lining of the ladle is composed of a heat preservation layer, a permanent layer, and a working layer. The heat preservation layer is close to the steel plate, and the thickness is about 10-15mm, which is mainly used to reduce heat loss, and is commonly built with asbestos board; the permanent layer is inside the heat preservation layer, and the thickness is about 30-60mm, which is mainly used to prevent the steel water from burning through the ladle, and is commonly built with clay and high-aluminum bricks; the working layer is inside the permanent layer, which directly contacts with the steel water and slag, and is subjected to mechanical scouring and rapid cooling and heating, and is easy to peel off, and is commonly built with comprehensive bricks, that is, the ladle bottom is built with wax bricks or high-aluminum bricks, the ladle wall is built with high-aluminum bricks, aluminum-carbon bricks, and the slag line position is commonly built with magnesium-carbon bricks, and the service life of the ladle is related to the quality of the layer, so the selection of the material of the layer is very important.

[0003] At present, the ladle wall bricks in China are mainly magnesium-aluminum-carbon and magnesium-carbon, but these materials have poor thermal shock stability. Severe mechanical scouring and frequent cold and hot alternation cause thermal stress in the ladle wall bricks, which leads to peeling and cracking in the use process, and affects the safety and service life of the ladle. With the increasing demand for various high-quality steel grades, it is required to reduce the use of carbon-containing refractory materials in the steelmaking process as much as possible to reduce the adverse effects of carbon increase on the molten steel. Therefore, the steel plant requires that the ladle wall be built with carbon-free bricks. Therefore, a high-strength carbon-free ladle wall brick is needed to meet the current demand of the steel plant for high thermal shock stability and carbon-free of the ladle wall brick. SUMMARY

[0004] The present application provides a high-strength carbon-free ladle wall corundum brick and its application on a ladle, which solves the problems of low thermal shock stability of the ladle wall brick and adverse effects of carbon increase on the molten steel in the steelmaking process in the related art.

[0005] The technical scheme of the present application is as follows:

[0006] The present application provides a high-strength carbon-free ladle wall corundum brick, which comprises the following components by weight: 60-70 parts of magnesia, 10-18 parts of corundum, 10-15 parts of magnesium-aluminum spinel, and 8-10 parts of a composite binder.

[0007] The composite binder is composed of a liquid phase and a solid phase;

[0008] The liquid phase is an AlCl3 solution.

[0009] The solid phase is composed of alpha-Al2O3 micro powder and gamma-Al2O3 micro powder.

[0010] As a further technical solution, the magnesite is composed of 4-5mm magnesite, 3-4mm magnesite and 2-3mm magnesite.

[0011] As a further technical solution, the mass ratio of the 4-5mm magnesite, 3-4mm magnesite and 2-3mm magnesite is 1-3:1:1.

[0012] As a further technical solution, the mass ratio of the 4-5mm magnesite, 3-4mm magnesite and 2-3mm magnesite is 2:1:1.

[0013] As a further technical solution, the corundum is composed of 3.6g / cm3 corundum, 3.2g / cm3 corundum, 2.8g / cm3 corundum and 2.6g / cm3 corundum.

[0014] As a further technical solution, the mass ratio of the 3.6g / cm3 corundum, 3.2g / cm3 corundum, 2.8g / cm3 corundum and 2.6g / cm3 corundum is 1-3:1:1:1.

[0015] As a further technical solution, the mass ratio of the 3.6g / cm3 corundum, 3.2g / cm3 corundum, 2.8g / cm3 corundum and 2.6g / cm3 corundum is 2:1:1:1.

[0016] As a further technical solution, the mass ratio of the liquid phase and the solid phase is 1-4:1.

[0017] As a further technical solution, the mass ratio of the liquid phase and the solid phase is 3:1.

[0018] As a further technical solution, the mass of the alpha-Al2O3 micro powder is 60%-70% of the mass of the solid phase.

[0019] As a further technical solution, the mass of the alpha-Al2O3 micro powder is 65% of the mass of the solid phase.

[0020] The application also includes a preparation method of the high-strength carbon-free steel ladle wall corundum brick, which comprises the following steps:

[0021] S1, uniformly mixing the raw materials to obtain a mud;

[0022] S2, pressing and forming the mud to obtain a green body;

[0023] S3, heat treating the green body to obtain a corundum brick.

[0024] As a further technical solution, the temperature of the heat treatment is 230-250 DEG C, and the time of the heat treatment is 28-30 hours.

[0025] As a further technical solution, the heat treatment is performed in a tunnel-type drying kiln; the inlet temperature of the tunnel-type drying kiln is 80-100 DEG C, and the outlet temperature is 80-100 DEG C.

[0026] The application also includes the use of the corundum brick on a steel ladle.

[0027] The working principle and beneficial effects of the application are as follows:

[0028] 1. In the application, magnesia, magnesium-aluminum spinel, corundum and carbon-free composite binder are selected as raw materials for the preparation of carbon-free steel ladle wall corundum brick, which does not produce carbon-increasing effect on molten steel during steelmaking, thereby solving the problem of adverse effects of steel ladle wall on molten steel carbon-increasing during steelmaking. By reasonably introducing the composite binder, the production process of the carbon-free brick is optimized, the thermal shock stability of the corundum brick is improved, and the composite binder composed of alpha-Al2O3 and gamma-Al2O3 can improve the compressive strength and thermal shock resistance of the corundum brick.

[0029] 2. In the application, by reasonably controlling the particle size of magnesia, the thermal shock resistance and compressive strength of the corundum brick can be further improved.

[0030] 3. In the application, by reasonably controlling the bulk density of corundum, the thermal shock resistance and compressive strength of the corundum brick can be further improved. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the application will be described below in conjunction with the embodiments of the application. Obviously, the described embodiments are only a 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.

[0032] In the following examples and comparative examples,

[0033] The model of magnesia is BY98DR, and the manufacturer is Baoyu Pinwei (Liaoning) Industry Co., Ltd.;

[0034] 3.6g / cm3 corundum, manufacturer: Zhengzhou Haixu Abrasive Co., Ltd.;

[0035] 3.2g / cm3 corundum, manufacturer: Shijiazhuang Xuanong Mineral Product Processing Co., Ltd.;

[0036] 2.8g / cm3 corundum, manufacturer: Gongyi Xianfeng Refractory Co., Ltd.;

[0037] 2.6g / cm³ corundum, manufacturer is Gongyi Xianfeng Refractory Co., Ltd.;

[0038] The density of magnesium aluminate spinel is 3.98g / cm 3 , and the thermal expansion coefficient is 5.8x10 -6 / K, and the manufacturer is Zhongke Ruizheng (Hangzhou) Technology Co., Ltd.;

[0039] The concentration of AlCl3 solution is 2mol / L;

[0040] The model of α-Al2O3 micropowder is DK410-1, and the manufacturer is Qinghe County Chaotai Metal Material Co., Ltd.;

[0041] The model of γ-Al2O3 micropowder is DK410-2, and the manufacturer is Qinghe County Chaotai Metal Material Co., Ltd.

[0042] Embodiment 1

[0043] A preparation method of high-strength carbon-free steel ladle wall corundum brick, comprising the following steps:

[0044] S1, 20 parts of 4-5mm magnesia, 20 parts of 3-4mm magnesia, 20 parts of 2-3mm magnesia, 3.75 parts of 3.6g / cm³ corundum, 3.75 parts of 3.2g / cm³ corundum, 3.75 parts of 2.8g / cm³ corundum, 3.75 parts of 2.6g / cm³ corundum, 10 parts of magnesium aluminate spinel, 4 parts of AlCl3 solution, 2.4 parts of α-Al2O3 micropowder and 1.6 parts of γ-Al2O3 micropowder are added into a high-speed mixer, mixed for 30min, and a mud is obtained;

[0045] S2, the mud is added into a mold, and is pressed and formed on a brick press to obtain a green body;

[0046] S3, the green body is sent into a tunnel type drying kiln, the inlet temperature of the drying kiln is 80℃, the temperature interval of the holding zone is 230℃, and the outlet temperature is 80℃, and after heat treatment for 30h, a corundum brick is obtained.

[0047] Embodiment 2

[0048] A preparation method of high-strength carbon-free steel ladle wall corundum brick, comprising the following steps:

[0049] S1, 32.5 parts of 4-5mm magnesia, 16.25 parts of 3-4mm magnesia, 16.25 parts of 2-3mm magnesia, 4 parts of 3.6g / cm3 corundum, 2 parts of 3.2g / cm3 corundum, 2 parts of 2.8g / cm3 corundum, 2 parts of 2.6g / cm3 corundum, 13 parts of magnesium aluminate spinel, 4.5 parts of AlCl3 solution, 2.7 parts of α-Al2O3 micropowder and 1.8 parts of γ-Al2O3 micropowder are added into a high-speed mixer, mixed for 25 minutes to obtain a slurry;

[0050] S2, the slurry is added into a mold and formed by a brick press to obtain a green body;

[0051] S3, the green body is sent into a tunnel type drying kiln, the inlet temperature of the drying kiln is 90℃, the temperature interval of the holding zone is 240℃, the outlet temperature is 90℃, and after heat treatment for 29h, a corundum brick is obtained.

[0052] Example 3

[0053] A preparation method of a high-strength carbon-free steel ladle wall corundum brick, comprising the following steps:

[0054] S1, 42 parts of 4-5mm magnesia, 14 parts of 3-4mm magnesia, 14 parts of 2-3mm magnesia, 9 parts of 3.6g / cm3 corundum, 3 parts of 3.2g / cm3 corundum, 3 parts of 2.8g / cm3 corundum, 3 parts of 2.6g / cm3 corundum, 15 parts of magnesium aluminate spinel, 5 parts of AlCl3 solution, 3 parts of α-Al2O3 micropowder and 2 parts of γ-Al2O3 micropowder are added into a high-speed mixer, mixed for 20 minutes to obtain a slurry;

[0055] S2, the slurry is added into a mold and formed by a brick press to obtain a green body;

[0056] S3, the green body is sent into a tunnel type drying kiln, the inlet temperature of the drying kiln is 100℃, the temperature interval of the holding zone is 250℃, the outlet temperature is 100℃, and after heat treatment for 28h, a corundum brick is obtained.

[0057] Example 4

[0058] Compared with Example 1, the difference is only that 30 parts of 4-5mm magnesia, 15 parts of 3-4mm magnesia and 15 parts of 2-3mm magnesia are added.

[0059] Example 5

[0060] Compared with Example 1, the difference is only that 36 parts of 4-5mm magnesia, 12 parts of 3-4mm magnesia and 12 parts of 2-3mm magnesia are added.

[0061] Example 6

[0062] This example differs from Example 1 only in that 6 parts of 3.6 g / cm3 corundum, 3 parts of 3.2 g / cm3 corundum, 3 parts of 2.8 g / cm3 corundum and 3 parts of 2.6 g / cm3 corundum are added.

[0063] Example 7

[0064] This example differs from Example 1 only in that 7.5 parts of 3.6 g / cm3 corundum, 2.5 parts of 3.2 g / cm3 corundum, 2.5 parts of 2.8 g / cm3 corundum and 2.5 parts of 2.6 g / cm3 corundum are added.

[0065] Example 8

[0066] This example differs from Example 1 only in that 6 parts of AlCl3 solution, 1.2 parts of α-Al2θ3 micro powder and 0.8 parts of γ-Al2θ3 micro powder are added.

[0067] Example 9

[0068] This example differs from Example 1 only in that 6.4 parts of AlCl3 solution, 0.96 parts of α-Al2θ3 micro powder and 0.64 parts of γ-Al2θ3 micro powder are added.

[0069] Example 10

[0070] This example differs from Example 1 only in that 3 parts of AlCl3 solution, 3 parts of α-Al2θ3 micro powder and 2 parts of γ-Al2θ3 micro powder are added.

[0071] Example 11

[0072] This example differs from Example 1 only in that 7 parts of AlCl3 solution, 0.6 parts of α-Al2θ3 micro powder and 0.4 parts of γ-Al2θ3 micro powder are added.

[0073] Example 12

[0074] This example differs from Example 1 only in that 2.6 parts of α-Al2θ3 micro powder and 1.4 parts of γ-Al2θ3 micro powder are added.

[0075] Example 13

[0076] This example differs from Example 1 only in that 2.8 parts of α-Al2θ3 micro powder and 1.2 parts of γ-Al2θ3 micro powder are added.

[0077] Example 14

[0078] This example differs from Example 1 only in that 2 parts of α-Al2θ3 micro powder and 2 parts of γ-Al2θ3 micro powder are added.

[0079] Example 15

[0080] The embodiment is different from example 1 only in that 3.2 parts of α-Al2O3 micro powder and 0.8 parts of γ-Al2O3 micro powder are added.

[0081] Comparative example 1

[0082] The comparative example is different from example 1 only in that no α-Al2O3 micro powder and γ-Al2O3 micro powder are added.

[0083] Comparative example 2

[0084] The comparative example is different from example 1 only in that no α-Al2O3 micro powder is added.

[0085] Comparative example 3

[0086] The comparative example is different from example 1 only in that no γ-Al2O3 micro powder is added.

[0087] Comparative example 4

[0088] The comparative example is different from example 1 only in that no 4-5 mm magnesia is added.

[0089] Comparative example 5

[0090] The comparative example is different from example 1 only in that no 3.6 g / cm3 corundum is added.

[0091] Performance test:

[0092] The corundum bricks obtained in examples 1-15 and comparative examples 1-5 are determined for thermal shock resistance according to the method in GB / T 30873-2014 “Refractory materials-Thermal shock resistance test method”, and for compressive strength according to the method in GB / T 3995-2014 “Refractory materials-Thermal shock resistance test method”, and the test results are shown in Table 1.

[0093] Table 1 Performance test results of corundum bricks obtained in examples and comparative examples

[0094]

[0095] In the present application, compared with example 1, comparative example 1 does not add α-Al2O3 micro powder and γ-Al2O3 micro powder, comparative example 2 does not add α-Al2O3 micro powder, and comparative example 3 does not add γ-Al2O3 micro powder, and the results are that the compressive strength and thermal shock times of the corundum bricks in comparative examples 1-3 are less than those in example 1, which indicates that adding α-Al2O3 micro powder and γ-Al2O3 micro powder in the composite binder of the corundum brick can improve the thermal shock resistance and compressive strength of the corundum brick.

[0096] Compared with Example 1, the addition of 4-5 mm magnesia in Comparative Example 4, the results of the compressive strength and thermal shock times of the corundum bricks in Comparative Example 4 are less than those of Example 1, indicating that the addition of 4-5 mm magnesia, 3-4 mm magnesia and 2-3 mm magnesia in the corundum bricks can further improve the thermal shock resistance and compressive strength of the corundum bricks, and the change of the mass ratio of 4-5 mm magnesia, 3-4 mm magnesia and 2-3 mm magnesia in Examples 4-5, the results of the compressive strength and thermal shock times of Example 4 are greater than those of Example 1 and Example 5, indicating that when the mass ratio of 4-5 mm magnesia, 3-4 mm magnesia and 2-3 mm magnesia is 2:1:1, the thermal shock resistance and compressive strength of the corundum bricks can be further improved.

[0097] Compared with Example 1, the addition of 3.6 g / cm³ corundum in Comparative Example 5, the results of the compressive strength and thermal shock times of the corundum bricks in Comparative Example 5 are less than those of Example 1, indicating that the addition of 3.6 g / cm³ corundum, 3.2 g / cm³ corundum, 2.8 g / cm³ corundum and 2.6 g / cm³ corundum in the corundum bricks can further improve the thermal shock resistance and compressive strength of the corundum bricks, and the change of the mass ratio of 3.6 g / cm³ corundum, 3.2 g / cm³ corundum, 2.8 g / cm³ corundum and 2.6 g / cm³ corundum in Examples 6-7, the results of the compressive strength and thermal shock times of Example 6 are greater than those of Example 1 and Example 7, indicating that when the mass ratio of 3.6 g / cm³ corundum, 3.2 g / cm³ corundum, 2.8 g / cm³ corundum and 2.6 g / cm³ corundum is 2:1:1:1, the thermal shock resistance and compressive strength of the corundum bricks can be further improved.

[0098] Compared with Example 1, the change of the mass of AlCl3 solution and the ratio of the mass of α-Al2O3 micropowder and γ-Al2O3 micropowder in Examples 8-11, the results of the compressive strength and thermal shock times of Examples 1 and 8-9 are greater than those of Examples 10-11, indicating that when the mass of AlCl3 solution and the ratio of the mass of α-Al2O3 micropowder and γ-Al2O3 micropowder are 1-4:1, the thermal shock resistance and compressive strength of the corundum bricks can be further improved, and the results of the compressive strength and thermal shock times of Example 8 are greater than those of Example 1 and Example 9, indicating that when the mass of AlCl3 solution and the ratio of the mass of α-Al2O3 micropowder and γ-Al2O3 micropowder are 3:1, the thermal shock resistance and compressive strength of the corundum bricks can be further improved.

[0099] Compared with example 1, examples 12-15 change the ratio of the mass of the α-Al2O3 micropowder in the mass sum of the α-Al2O3 micropowder and the γ-Al2O3 micropowder, and the results show that the compressive strength and the thermal shock times of examples 1 and 12-13 are greater than examples 14-15, which indicates that when the mass of the α-Al2O3 micropowder is 60%-70% of the mass sum of the α-Al2O3 micropowder and the γ-Al2O3 micropowder, the thermal shock resistance and the compressive strength of the corundum brick can be further improved, and the compressive strength and the thermal shock times of example 12 are greater than examples 1 and 13, which indicates that when the mass of the α-Al2O3 micropowder is 65% of the mass sum of the α-Al2O3 micropowder and the γ-Al2O3 micropowder, the thermal shock resistance and the compressive strength of the corundum brick can be further improved.

[0100] The above only is the preferred embodiment of the present application, and does not limit the present application, any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A high strength carbon-free steel ladle wall corundum brick, characterized by, Raw materials comprising the following components in parts by weight: 60-70 parts of magnesia, 10-18 parts of corundum, 10-15 parts of magnesium aluminate spinel, 8-10 parts of composite binder; The composite binder is composed of a liquid phase and a solid phase; The liquid phase is an AlCl3 solution; The solid phase is composed of α-Al2O3 micro powder and γ-Al2O3 micro powder; The mass of the α-Al2O3 micro powder is 60%-70% of the mass of the solid phase; The mass ratio of the liquid phase to the solid phase is 1-4:

1.

2. A high strength carbon-free steel ladle wall corundum brick according to claim 1, characterized in that, The magnesia is composed of 4-5 mm magnesia, 3-4 mm magnesia, and 2-3 mm magnesia.

3. A high strength carbon-free steel ladle wall corundum brick according to claim 2, characterized in that The mass ratio of the 4-5 mm magnesia, 3-4 mm magnesia, and 2-3 mm magnesia is 1-3:1:

1.

4. A high strength carbon-free steel ladle wall corundum brick according to claim 1, characterized in that, The corundum consists of 3.6 g / cm 3 Corundum, 3.2 g / cm 3 Corundum, 2.8 g / cm 3 Corundum and 2.6 g / cm 3 Corundum.

5. A high strength carbon-free steel ladle wall corundum brick according to claim 4, characterized in that, The 3.6 g / cm 3 corundum, 3.2 g / cm 3 corundum, 2.8 g / cm 3 corundum and 2.6 g / cm 3 The mass ratio of corundum is 1-3:1:1:

1.

6. The method of manufacturing high strength carbon-free steel ladle wall corundum brick according to any one of claims 1-5, characterized in that, The method comprises the following steps: S1, uniformly mixing the raw materials to obtain a mud; S2, pressing the mud to form a green body; S3, heat treating the green body to obtain a corundum brick.

7. The method of producing a high-strength carbon-free steel ladle wall corundum brick according to claim 6, characterized by, The heat treatment temperature is 230-250°C, and the heat treatment time is 28-30 h.

8. Use of the corundum brick according to any one of claims 1-5 on a steel ladle.

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