Aluminum-magnesium refractory material for high-temperature alloy smelting and preparation method of aluminum-magnesium refractory material

Abstract

The invention discloses an aluminum-magnesium refractory material and a preparation method thereof. The technical scheme adopted by the invention is as follows: 75-90% of corundum, 1-10% of spinel-calcium aluminate multiphase material, 2-12% of magnesium aluminate spinel, 1-6% of calcium hydroxide and 2-8% of binding agent are added in percentage by weight, stirred, mixed, pressed and formed, baked at 150-300 DEG C for 4-24 hours and cooled, and the aluminum-magnesium refractory material is obtained. The prepared aluminum-magnesium material is high in melting point and stable in high-temperature thermodynamic property, and the thermal shock stability and the high-temperature breaking strength of the material can be remarkably improved by adding the spinel-calcium aluminate multiphase material. The material can be used as a refractory material for high-temperature alloy smelting.

Description

Technical Field

[0001] The present invention relates to the field of refractory materials, and in particular to an aluminum-magnesium refractory material for high-temperature alloy smelting and a preparation method thereof. Background Art

[0002] High-temperature alloys generally refer to alloys that can be used at temperatures between 600°C and 1200°C and exhibit excellent resistance to oxidation, corrosion, creep, and fatigue. Currently, the refractories commonly used for melting high-temperature alloys are primarily alumina, magnesia, aluminum-magnesium, and calcium oxide refractories.

[0003] For vacuum induction furnaces with a capacity of less than 500kg, people generally hope to use refractory crucibles as the furnace lining for smelting high-temperature alloys. Refractory crucibles are easy to use and quick to replace, which helps improve production efficiency. During the smelting process, damage to refractory crucibles is mainly caused by thermal shock. Specifically, during the hot and cold cycles, cracks appear in the lining of the refractory crucible, and the alloy liquid penetrates into the interior of the refractory crucible through the cracks, eventually causing damage to the crucible. Among the known refractory oxides, aluminum oxide and magnesium oxide are the most widely used refractory oxides. Their melting points are both above 2000℃, far higher than the melting temperature of the alloy. Ordinary high-temperature alloy smelting also often uses aluminum oxide and magnesium oxide crucibles as linings. Moreover, the reserves of these two minerals in my country are extremely abundant, and the overall cost is suitable.

[0004] However, the thermal shock stability of traditional alumina, magnesia and aluminum-magnesium refractory crucibles limits the service life of the crucible during the smelting process. The specific problem is that the crucible cracks and peels off during intervals of use, which not only affects the purity of the alloy liquid, but also increases the cost of the smelting company and the production efficiency of high-temperature alloys. Summary of the Invention

[0005] The purpose of the present application is to provide an aluminum-magnesium refractory material for high-temperature alloy smelting and a preparation method thereof. The aluminum-magnesium refractory material prepared by this method has good thermal shock stability and high-temperature flexural strength, and can be used to make refractory crucibles.

[0006] To achieve the above-mentioned purpose, the embodiment of the present application adopts the following technical solution: an aluminum-magnesium refractory material for high-temperature alloy smelting, which includes the following components by mass percentage: 75-90% corundum, 1-10% spinel-calcium aluminate composite material, 2-12% magnesium-aluminum spinel, 1-6% calcium hydroxide, and 2-8% binder.

[0007] In the above technical solution, the embodiment of the present application adds a spinel-calcium aluminate composite material. The main mineral phases of the spinel-calcium aluminate composite material are magnesium-aluminum spinel and calcium aluminate. Magnesium-aluminum spinel has good thermal shock stability and slag penetration resistance. The calcium aluminate material (CaO·Al2O3) can form a glass phase (a melt with a certain viscosity) with other components in the crucible, such as magnesium oxide and impurity silicon oxide in the raw material, at high temperatures. The glass phase not only isolates the alloy liquid from the refractory layer, but also the formation of a high-viscosity glass phase can improve the toughness of the material. Therefore, by introducing the spinel-calcium aluminate composite material, the thermal shock stability and high-temperature flexural strength of the aluminum-magnesium material can be significantly improved.

[0008] Furthermore, according to an embodiment of the present application, the corundum is in the form of particles, fine powder, or a mixture of particles and fine powder.

[0009] Furthermore, according to an embodiment of the present application, the content of Al2O3 in the corundum is ≥98%.

[0010] Furthermore, according to an embodiment of the present application, the spinel-calcium aluminate multiphase material is in the form of particles, fine powder, or a mixture of particles and fine powder.

[0011] Furthermore, according to an embodiment of the present application, the content of MgO in the spinel-calcium aluminate composite material is ≥15%, the content of Al2O3 is ≥65%, and the content of CaO is ≤15%.

[0012] Furthermore, according to an embodiment of the present application, the binder may be a carboxymethyl cellulose solution.

[0013] Furthermore, according to an embodiment of the present application, the particle size of the magnesia-alumina spinel is 1 to 200 μm, the Al2O3 content is ≥90%, and the MgO content is ≥7%.

[0014] Furthermore, according to an embodiment of the present application, the particle size of calcium hydroxide is 1 to 200 μm, and the CaO content is ≥97%.

[0015] In order to achieve the above-mentioned object, the present application also discloses a method for preparing an aluminum-magnesium refractory material for high-temperature alloy smelting, comprising the following steps:

[0016] Take corundum, spinel-calcium aluminate composite material, magnesium aluminum spinel, calcium hydroxide and binder, stir and mix, press into shape, bake at 150-300° C. for 4-24 hours, and cool.

[0017] In order to achieve the above-mentioned purpose, the embodiment of the present application further discloses a refractory crucible, which is made of the refractory material described above.

[0018] Compared with the existing technology, the present application has the following beneficial effects: the main mineral phases of the spinel-calcium aluminate composite material are magnesia-alumina spinel and calcium aluminate. Magnesia-alumina spinel has good thermal shock stability and slag penetration resistance. At high temperatures, the calcium aluminate material (CaO·Al2O3) can form a glass phase (a melt with a certain viscosity) with other components in the crucible, such as magnesium oxide and impurity silicon oxide in the raw material. The glass phase not only isolates the alloy liquid from the refractory layer, but the formation of the high-viscosity glass phase also improves the toughness of the material. Therefore, by introducing the spinel-calcium aluminate composite material, the thermal shock stability and high-temperature flexural strength of the aluminum-magnesium material can be significantly improved. DETAILED DESCRIPTION

[0019] In order to clearly and completely describe the objectives and technical solutions of the present invention and make the advantages more clearly understood, the embodiments of the present invention are further described in detail. It should be understood that the specific embodiments described herein are part of the embodiments of the present invention, not all of the embodiments, and are only used to explain the embodiments of the present invention, not to limit the embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] In the description of the present invention, it should be noted that the terms "center," "middle," "upper," "lower," "left," "right," "inner," "outer," "top," "bottom," "side," "vertical," "horizontal," and the like, indicating positions or relationships, are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0022] For the purpose of simplicity and illustration, the principles of the embodiments are described primarily with reference to examples. In the following description, many specific details are provided to provide a thorough understanding of the embodiments. However, it will be apparent to those skilled in the art that these embodiments may not be limited to these specific details in practice. In some instances, well-known methods and structures are not described in detail to avoid unnecessarily obscuring the understanding of these embodiments. In addition, all embodiments may be used in combination with each other.

[0023] The present application discloses an aluminum-magnesium refractory material for high-temperature alloy smelting, which comprises the following components, calculated by mass percentage: 75-90% corundum, 1-10% spinel-calcium aluminate composite material, 2-12% magnesium-aluminum spinel, 1-6% calcium hydroxide, and 2-8% binder.

[0024] In the above technical solution, the present application adds a spinel-calcium aluminate composite material. The main mineral phases of the spinel-calcium aluminate composite material are magnesium-aluminum spinel and calcium aluminate. Magnesium-aluminum spinel has good thermal shock stability and slag penetration resistance. The calcium aluminate material (CaO·Al2O3) can form a glass phase (a melt with a certain viscosity) with other components in the crucible, such as magnesium oxide and impurity silicon oxide in the raw material, at high temperatures. The glass phase can not only isolate the alloy liquid from the refractory layer, but also the formation of a high-viscosity glass phase can improve the toughness of the material. Therefore, by introducing the spinel-calcium aluminate composite material, the thermal shock stability and high-temperature flexural strength of the aluminum-magnesium material can be significantly improved.

[0025] Specifically, the corundum is in the form of granules, fine powder, or a mixture of granules and fine powder. The corundum granules have a size between 0.3 and 9 mm, and the fine powder has a particle size between 1 and 300 μm. The Al2O3 content in the corundum is ≥ 98%.

[0026] The spinel-calcium aluminate composite material is in the form of particles, fine powder, or a mixture of particles and fine powder. The particle size ranges from 0.3 to 9 mm, and the fine powder particle size ranges from 1 to 300 μm. The spinel-calcium aluminate composite material has a MgO content of ≥15%, an Al2O3 content of ≥65%, and a CaO content of ≤15%.

[0027] The binder may be a carboxymethyl cellulose solution.

[0028] The particle size of the magnesia-alumina spinel is 1-200 μm, wherein the Al2O3 content is ≥90%, and the MgO content is ≥7%.

[0029] The particle size of calcium hydroxide is 1 to 200 μm, wherein the CaO content is ≥97%.

[0030] Furthermore, the present application also discloses a method for preparing aluminum-magnesium refractory materials for high-temperature alloy smelting, which comprises taking corundum, spinel-calcium aluminate composite material, magnesium-aluminum spinel, calcium hydroxide, and a binder, stirring and mixing them, pressing them into shape, baking them at 150-300°C for 4-24 hours, and cooling them.

[0031] Below, the present application further illustrates the technical solution of the present application by listing embodiments and comparative examples, but the present application is not limited to these embodiments.

[0032] [Example 1]

[0033] An aluminum-magnesium refractory material is obtained by mixing 88% of corundum particles and corundum fine powder, 1% of spinel-calcium aluminate composite material powder, 3% of magnesium-aluminum spinel, 3% of calcium hydroxide, and 5% of CMC binder according to weight percentage, stirring and mixing, pressing and molding, baking at 150-200°C for 14-24 hours, and cooling.

[0034] [Example 2]

[0035] An aluminum-magnesium refractory material is obtained by mixing 83% of corundum particles and corundum fine powder, 4% of spinel-calcium aluminate composite material powder, 5% of magnesium-aluminum spinel, 3% of calcium hydroxide, and 5% of CMC binder according to weight percentage, stirring and mixing, pressing and molding, baking at 150-200°C for 14-24 hours, and cooling.

[0036] [Example 3]

[0037] An aluminum-magnesium refractory material is obtained by mixing 80% of corundum particles and corundum fine powder, 7% of spinel-calcium aluminate composite material powder, 5% of magnesium-aluminum spinel, 3% of calcium hydroxide, and 5% of CMC binder according to weight percentage, stirring and mixing, pressing and molding, baking at 150-200°C for 14-24 hours, and cooling.

[0038] [Example 4]

[0039] An aluminum-magnesium refractory material is obtained by mixing 75% of corundum particles and corundum fine powder, 10% of spinel-calcium aluminate composite material powder, 7% of magnesium-aluminum spinel, 3% of calcium hydroxide, and 5% of CMC binder according to weight percentage, stirring and mixing, pressing and molding, baking at 150-200°C for 14-24 hours, and cooling.

[0040] [Comparative Example 1]

[0041] 89% of corundum particles and corundum fine powder, 3% of magnesia-alumina spinel, 3% of calcium hydroxide and 5% of CMC binder are mixed by weight, pressed into shape, baked at 150-200°C for 14-24 hours and cooled to obtain an aluminum-magnesia refractory material.

[0042] [Comparative Example 2]

[0043] 75% of corundum particles and corundum fine powder, 11% of magnesia-alumina spinel, 6% of calcium hydroxide and 8% of CMC binder are mixed by weight, pressed into shape, baked at 150-200°C for 14-24 hours and cooled to obtain an aluminum-magnesia refractory material.

[0044] The refractory materials obtained in the examples and comparative examples were tested below, and the test results are as follows:

[0045]

[0046] Among them, the test methods or instruments for the above parameters are:

[0047] Al2O3 content: Inductively coupled plasma optical emission spectrometer, Agilent 5800ICP-OES, USA

[0048] MgO content: Inductively coupled plasma optical emission spectrometer, Agilent 5800ICP-OES, USA

[0049] High-temperature flexural strength at 1400°C: HMOR-03AG, Luoyang Puruikangda Heat-resistant Equipment Co., Ltd.

[0050] Elastic modulus (RFDAHTVP 1600, IMCE, Belgium) retention rate: GB / T30873-2014 refractory thermal shock resistance test method (air quenching method) was used, with three heating-cooling cycles.

[0051] As shown in the table above, in Examples 1-4, by adding the spinel-calcium aluminate composite material, the calcium aluminate material (CaO·Al2O3) can form a glass phase (a melt with a certain viscosity) at high temperatures with other components in the crucible, such as magnesium oxide and impurity silicon oxide in the raw material. The glass phase not only isolates the alloy liquid from the refractory layer, but also the formation of a high-viscosity glass phase can improve the toughness of the material.

[0052] Although the above describes the illustrative specific implementation methods of the present application so that those skilled in the art can understand the present application, the present application is not limited to the scope of the specific implementation methods. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present application defined and determined by the attached claims, all application creations based on the concept of the present application are protected.

Claims

1. An aluminum-magnesium refractory material for high-temperature alloy smelting, characterized in that: Calculated by mass percentage, it comprises the following components: 75-90% corundum, 1-10% spinel-calcium aluminate composite material, 2-12% magnesium aluminum spinel, 1-6% calcium hydroxide, and 2-8% binder.

2. The aluminum-magnesium refractory material for high-temperature alloy smelting according to claim 1, characterized in that: The corundum is in the form of particles, fine powder, or a mixture of particles and fine powder.

3. The aluminum-magnesium refractory material for high-temperature alloy smelting according to claim 1, characterized in that: The content of Al2O3 in the corundum is ≥98%.

4. The aluminum-magnesium refractory material for high-temperature alloy smelting according to claim 1, characterized in that: The spinel-calcium aluminate composite material is in the form of particles, fine powder, or a mixture of particles and fine powder.

5. The aluminum-magnesium refractory material for high-temperature alloy smelting according to claim 1, characterized in that: The spinel-calcium aluminate composite material has a MgO content of ≥15%, an Al2O3 content of ≥65%, and a CaO content of ≤15%.

6. The aluminum-magnesium refractory material for high-temperature alloy smelting according to claim 1, characterized in that: The binder may be a carboxymethyl cellulose solution.

7. The aluminum-magnesium refractory material for high-temperature alloy smelting according to claim 1, characterized in that: The granularity of the magnesium-aluminum spinel is 1-200 μm, wherein the Al2O3 content is ≥90%, and the MgO content is ≥7%.

8. The aluminum-magnesium refractory material for high-temperature alloy smelting according to claim 1, characterized in that: The particle size of the calcium hydroxide is 1 to 200 μm, and the CaO content is ≥97%.

9. A method for preparing an aluminum-magnesium refractory material for high-temperature alloy smelting according to claim 1, characterized in that: The following steps are involved: Take corundum, spinel-calcium aluminate composite material, magnesium aluminum spinel, calcium hydroxide and binder, stir and mix, press into shape, bake at 150-300° C. for 4-24 hours, and cool.

10. A refractory crucible, characterized in that: The refractory material is prepared by using the aluminum-magnesium refractory material for high-temperature alloy smelting according to any one of claims 1 to 8, or is prepared by using the preparation method of the aluminum-magnesium refractory material for high-temperature alloy smelting according to claim 9.

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