A hydration-resistant magnesium brick and its preparation method

Abstract

The present invention relates to the field of refractory materials, and in particular to a hydration-resistant magnesia brick and a preparation method thereof. Specifically, it comprises 40 parts of sintered magnesia with a particle size of 1 to 3 mm, 32 parts of sintered magnesia with a particle size of ≤1 mm, 28 parts of sintered magnesia powder with a particle size of ≤0.088 mm, 2 parts of a binder, 1 to 3 parts of a binder, and 1 to 3 parts of a nano-composite material. The raw material ratio of the hydration-resistant magnesia brick in the present invention has been carefully designed. The sintered magnesia with a larger particle size can provide the basic skeleton of the brick body and ensure the mechanical strength of the brick body; the sintered magnesia with a smaller particle size can fill the pores between the skeletons, reduce the porosity inside the brick body, make the brick body denser, and thus improve its hydration resistance. The addition of nano-composite materials, as well as reasonable raw material ratios and molding processes improve the strength and hydration resistance of the magnesia brick.

Description

Technical Field

[0001] The present invention relates to the field of refractory materials, in particular to a hydration-resistant magnesia brick and a preparation method thereof. Background Art

[0002] Sintered magnesia bricks are a type of magnesia refractory material with periclase as the primary crystalline phase. Magnesia refractories have abundant raw material sources. Magnesite, seawater magnesia, and dolomite are found in vast reserves worldwide, and the mining process is relatively simple. This provides a solid material foundation for their mass production. Furthermore, magnesia refractories boast exceptional refractoriness and are stable in extremely high temperature environments, resisting melting or softening. They also exhibit excellent thermal shock resistance, meaning they are less susceptible to cracking or spalling even under rapid temperature fluctuations, enabling them to withstand complex and variable temperature conditions in practical applications. Furthermore, magnesia refractories exhibit exceptional corrosion resistance, demonstrating strong resistance to both acidic and alkaline substances, thereby extending their service life. Furthermore, they possess excellent chemical stability, maintaining their properties in a variety of chemical reaction environments and resisting adverse reactions with other substances.

[0003] Precisely because of these significant advantages, magnesia refractories have been widely used in the metallurgical industry. In traditional fields, such as various furnace lining materials in steelmaking, magnesia refractories are indispensable. Furthermore, in high-tech fields, with technological advancements, the performance requirements for refractory materials are becoming increasingly demanding. Magnesia refractories, with their excellent performance, are continuously expanding their application scope, playing an increasingly important role and providing strong support for the development of numerous industries. Whether in terms of application value or market benefits, magnesia refractories demonstrate enormous potential and broad development prospects, becoming an indispensable part of the refractory industry.

[0004] The incorporation of rare earth oxides into refractory materials offers numerous advantages. They can form solid solutions with the primary crystalline phase, altering the lattice structure to a certain extent, thereby activating the lattice and promoting the sintering process, thereby increasing the density and strength of the refractory. Rare earth oxides can modify impurities within the material, reducing their negative impact on material properties and thereby improving the stability and consistency of the refractory. Furthermore, rare earth oxides can regulate the bonding between the primary crystalline phases through the formation of intercrystalline phases, resulting in a more rational and optimized microstructure within the material, thereby enhancing the overall performance of the refractory. However, the combined use of rare earth oxides requires further research. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a and a preparation method thereof.

[0006] The present invention is achieved through the following technical solutions:

[0007] A hydration-resistant magnesia brick comprises, by weight: 40 parts of sintered magnesia with a particle size of 1 to 3 mm, 32 parts of sintered magnesia with a particle size of ≤1 mm, 28 parts of sintered magnesia powder with a particle size of ≤0.088 mm, 2 parts of a binder, 1 to 3 parts of Y2O3, 1 to 3 parts of Nanocomposite materials.

[0008] Furthermore, the Y2O3 weight portion is 2 parts, the The nanocomposite material is 2 parts.

[0009] Furthermore, the binder is an aqueous solution of soluble polyvinyl alcohol fiber.

[0010] Furthermore, the concentration of the aqueous solution of soluble polyvinyl alcohol fiber in the binder is 2 wt %.

[0011] Furthermore, the MgO content in the sintered magnesia is 94% to 96%, and the CaO content is 2% to 3%.

[0012] Furthermore, the particle size of the Y2O3 is <50 nm.

[0013] Furthermore, the The preparation method of the nanocomposite material is as follows:

[0014] Mix 0.25 g of zirconium tert-butoxide with 15 mL of 30% (w / v) The solution was mixed and stirred for 0.5 h; then 50 mL of deionized water and 0.25 g of Cr2O3 particles were added, stirred for 24 h, transferred to an autoclave, and kept at 100 degrees Celsius for 12 h; after the autoclave was naturally cooled to room temperature, the precipitate was washed with deionized water and dried at 80 degrees Celsius for 24 h; the dried precipitate was heated to 500 degrees Celsius at a heating rate of 5 degrees Celsius / min, and then calcined at 500 degrees Celsius for 2 h to obtain The Cr2O3 nanocomposite material is prepared by adding 0.3M aqueous ammonia dropwise to a 0.1M aqueous solution of trivalent chromium nitrate nonahydrate until the pH reaches 6.0 to obtain a precipitate; washing the precipitate with deionized water and then drying it at 90°C for 24 hours; and calcining the dried product at 900°C for 5 hours to obtain the Cr2O3 particles.

[0015] The present invention also provides a method for preparing hydration-resistant magnesia bricks, comprising the following steps: mixing 1-3 mm sintered magnesia, 1 mm or less sintered magnesia and a binder for 20 minutes, then adding 0.088 mm or less sintered magnesia powder, Y2O3 and The nanocomposite material is mixed for another 2 minutes to obtain a mixture; the mixture is then hydraulically formed and then dried at 90 degrees Celsius to 120 degrees Celsius for 36 hours. The dried ligand is sintered at 1580 degrees Celsius for 4 hours to obtain a magnesia brick.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0017] The raw material ratio of hydration-resistant magnesia bricks has been carefully designed. The larger particle size of sintered magnesia sand can provide the basic skeleton of the brick body and ensure the mechanical strength of the brick body; the smaller particle size of sintered magnesia sand can fill the pores between the skeletons, reduce the porosity inside the brick body, make the brick body denser, and thus improve its hydration resistance. and Nanocomposite materials, as well as reasonable raw material ratios and molding processes, improve the strength and hydration resistance of magnesia bricks. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention.

[0019] Figure 1 For the present invention SEM image of nanocomposite materials. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0021] In the present invention, the particle size of Y2O3 is less than 50 nm.

[0022] In the present invention The preparation method of the nanocomposite material is as follows:

[0023] Step S1: Add 0.3 M aqueous ammonia dropwise to a 0.1 M aqueous solution of trivalent chromium nitrate nonahydrate until the pH reaches 6.0 to obtain a precipitate; wash the precipitate with deionized water and then dry it at 90° C. for 24 hours; calcining the dried product at 900° C. for 5 hours to obtain Cr2O3 particles;

[0024] Mix 0.25 g of zirconium tert-butoxide with 15 mL of 30% (w / v) The solution was mixed and stirred for 0.5 h; then 50 mL of deionized water and 0.25 g of Cr2O3 particles were added, stirred for 24 h, transferred to an autoclave, and kept at 100 degrees Celsius for 12 h; after the autoclave was naturally cooled to room temperature, the precipitate was washed with deionized water and dried at 80 degrees Celsius for 24 h; the dried precipitate was heated to 500 degrees Celsius at a heating rate of 5 degrees Celsius / min, and then calcined at 500 degrees Celsius for 2 h to obtain Nanocomposite materials. Figure 1 For the present invention SEM image of nanocomposite materials.

[0025] The preparation method of Cr2O3 particles in the present invention is as follows: 0.3M ammonia water is added dropwise to a 0.1M trivalent chromium nitrate nonahydrate aqueous solution until the pH reaches 6.0 to obtain a precipitate; the precipitate is washed with deionized water and then dried at 90°C for 24 hours; and the dried product is calcined at 900°C for 5 hours to obtain Cr2O3 particles.

[0026] In the present invention The preparation method of nanoparticles is:

[0027] Mix 0.25 g of zirconium tert-butoxide with 15 mL of 30% (w / v) The solution was mixed and stirred for 0.5 h; then 50 mL of deionized water was added, stirred for 24 h, transferred to an autoclave, and kept at 100 degrees Celsius for 12 h; after the autoclave was naturally cooled to room temperature, the precipitate was washed with deionized water and dried at 80 degrees Celsius for 24 h; the dried precipitate was heated to 500 degrees Celsius at a heating rate of 5°C / min, and then calcined at 500 degrees Celsius for 2 h to obtain Nanoparticles.

[0028] Example 1

[0029] A hydration-resistant magnesia brick, comprising, by weight: 40 parts of sintered magnesia with a particle size of 1 to 3 mm, 32 parts of sintered magnesia with a particle size of ≤1 mm, 28 parts of sintered magnesia powder ≤0.088 mm, 2 parts of a binder, 1 part of Y2O3, 1 part of nanocomposites;

[0030] The binder is a 2 wt% aqueous solution of soluble polyvinyl alcohol fiber.

[0031] The preparation method is as follows: sintered magnesia with a particle size of 1-3 mm, sintered magnesia with a particle size of less than or equal to 1 mm and a binder are mixed and stirred for 20 minutes, and then sintered magnesia powder with a particle size of less than or equal to 0.088 mm, Y2O3 and The nanocomposite material is mixed for another 2 minutes to obtain a mixture; the mixture is then hydraulically formed and then dried at 90 degrees Celsius to 120 degrees Celsius for 36 hours. The dried ligand is sintered at 1580 degrees Celsius for 4 hours to obtain a magnesia brick.

[0032] Example 2

[0033] A hydration-resistant magnesia brick, comprising, by weight: 40 parts of sintered magnesia with a particle size of 1 to 3 mm, 32 parts of sintered magnesia with a particle size of ≤1 mm, 28 parts of sintered magnesia powder ≤0.088 mm, 2 parts of a binder, 1 part of Y2O3, 2 parts of nanocomposites;

[0034] The binder is a 2 wt% aqueous solution of soluble polyvinyl alcohol fiber.

[0035] The preparation method is the same as that in Example 1.

[0036] Example 3

[0037] A hydration-resistant magnesia brick, comprising, by weight: 40 parts of sintered magnesia with a particle size of 1 to 3 mm, 32 parts of sintered magnesia with a particle size of ≤1 mm, 28 parts of sintered magnesia powder ≤0.088 mm, 2 parts of a binder, 1 part of Y2O3, 3 parts of nanocomposites;

[0038] The binder is a 2 wt% aqueous solution of soluble polyvinyl alcohol fiber.

[0039] The preparation method is the same as that in Example 1.

[0040] Example 4

[0041] A hydration-resistant magnesia brick, comprising, by weight: 40 parts of sintered magnesia with a particle size of 1 to 3 mm, 32 parts of sintered magnesia with a particle size of ≤1 mm, 28 parts of sintered magnesia powder ≤0.088 mm, 2 parts of a binder, 2 parts of Y2O3, 1 part nanocomposites;

[0042] The binder is a 2 wt% aqueous solution of soluble polyvinyl alcohol fiber.

[0043] The preparation method is the same as that in Example 1.

[0044] Example 5

[0045] A hydration-resistant magnesia brick, comprising, by weight: 40 parts of sintered magnesia with a particle size of 1 to 3 mm, 32 parts of sintered magnesia with a particle size of ≤1 mm, 28 parts of sintered magnesia powder ≤0.088 mm, 2 parts of a binder, 2 parts of Y2O3, 2 parts of nanocomposites;

[0046] The binder is a 2 wt% aqueous solution of soluble polyvinyl alcohol fiber.

[0047] The preparation method is the same as that in Example 1.

[0048] Example 6

[0049] A hydration-resistant magnesia brick, comprising, by weight: 40 parts of sintered magnesia with a particle size of 1 to 3 mm, 32 parts of sintered magnesia with a particle size of ≤1 mm, 28 parts of sintered magnesia powder ≤0.088 mm, 2 parts of a binder, 2 parts of Y2O3, 3 parts of nanocomposites;

[0050] The binder is a 2 wt% aqueous solution of soluble polyvinyl alcohol fiber.

[0051] The preparation method is the same as that in Example 1.

[0052] Example 7

[0053] A hydration-resistant magnesia brick, comprising, by weight: 40 parts of sintered magnesia with a particle size of 1 to 3 mm, 32 parts of sintered magnesia with a particle size of ≤1 mm, 28 parts of sintered magnesia powder ≤0.088 mm, 2 parts of a binder, 3 parts of Y2O3, 1 part nanocomposites;

[0054] The binder is a 2 wt% aqueous solution of soluble polyvinyl alcohol fiber.

[0055] The preparation method is the same as that in Example 1.

[0056] Example 8

[0057] A hydration-resistant magnesia brick, comprising, by weight: 40 parts of sintered magnesia with a particle size of 1 to 3 mm, 32 parts of sintered magnesia with a particle size of ≤1 mm, 28 parts of sintered magnesia powder ≤0.088 mm, 2 parts of a binder, 3 parts of Y2O3, 2 parts of nanocomposites;

[0058] The binder is a 2 wt% aqueous solution of soluble polyvinyl alcohol fiber.

[0059] The preparation method is the same as that in Example 1.

[0060] Example 9

[0061] A hydration-resistant magnesia brick, comprising, by weight: 40 parts of sintered magnesia with a particle size of 1 to 3 mm, 32 parts of sintered magnesia with a particle size of ≤1 mm, 28 parts of sintered magnesia powder ≤0.088 mm, 2 parts of a binder, 3 parts of Y2O3, 3 parts of nanocomposites;

[0062] The binder is a 2 wt% aqueous solution of soluble polyvinyl alcohol fiber.

[0063] The preparation method is the same as that in Example 1.

[0064] Comparative Example 1

[0065] A hydration-resistant magnesia brick, comprising, by weight: 40 parts of sintered magnesia with a particle size of 1 to 3 mm, 32 parts of sintered magnesia with a particle size of ≤1 mm, 28 parts of sintered magnesia powder ≤0.088 mm, 2 parts of a binder, 2 parts of Y2O3, 2 parts of particles;

[0066] The binder is a 2 wt% aqueous solution of soluble polyvinyl alcohol fiber.

[0067] The preparation method is as follows: sintered magnesia with a particle size of 1-3 mm, sintered magnesia with a particle size of less than or equal to 1 mm and a binder are mixed and stirred for 20 minutes, and then sintered magnesia powder with a particle size of less than or equal to 0.088 mm, Y2O3 and The particles are mixed for another 2 minutes to obtain a mixture; the mixture is then hydraulically formed and then dried at 90 degrees Celsius to 120 degrees Celsius for 36 hours. The dried ligand is sintered at 1580 degrees Celsius for 4 hours to obtain a magnesia brick.

[0068] Comparative Example 2

[0069] A hydration-resistant magnesia brick, comprising, by weight: 40 parts of sintered magnesia with a particle size of 1 to 3 mm, 32 parts of sintered magnesia with a particle size of ≤1 mm, 28 parts of sintered magnesia powder ≤0.088 mm, 2 parts of a binder, 2 parts of Y2O3, 2 parts of Nanoparticles;

[0070] The binder is a 2 wt% aqueous solution of soluble polyvinyl alcohol fiber.

[0071] The preparation method is as follows: sintered magnesia with a particle size of 1-3 mm, sintered magnesia with a particle size of less than or equal to 1 mm and a binder are mixed and stirred for 20 minutes, and then sintered magnesia powder with a particle size of less than or equal to 0.088 mm, Y2O3 and The nanoparticles are mixed for another 2 minutes to obtain a mixture; the mixture is then hydraulically formed and then dried at 90 degrees Celsius to 120 degrees Celsius for 36 hours. The dried ligand is sintered at 1580 degrees Celsius for 4 hours to obtain a magnesia brick.

[0072] Test Example 1

[0073] The room temperature flexural strength of the sample was tested according to the three-point bending method (span 25 mm, indenter loading speed 0.5 mm / min).

[0074] The different sintered samples were crushed and sieved to separate out particles of 1 to 3 mm. The particles were then loaded into crucibles and placed in a high-pressure reactor. They were hydrated at 0.2 MPa for 30 min. The mass of the samples before and after hydration was measured to evaluate their anti-hydration properties.

[0075] Table 1 Performance test

[0076]

[0077] As can be seen from Table 1, when Y2O3 and Nanocomposites, especially Y2O3 and When the weight ratio of nanocomposite materials is 2 parts, the obtained material has good compressive strength and hydration resistance at room temperature. When used in combination, the compressive strength is significantly reduced.

[0078] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A hydration-resistant magnesia brick, characterized in that: The components by weight include: 40 parts of sintered magnesia with a particle size of 1-3 mm, 32 parts of sintered magnesia with a particle size of ≤1 mm, 28 parts of sintered magnesia powder with a particle size of ≤0.088 mm, 2 parts of binder, 1-3 parts of Y2O3, 1-3 parts of nanocomposites; described The preparation method of the nanocomposite material is as follows: Mix 0.25 g of zirconium tert-butoxide with 15 mL of 30% (w / v) The solution was mixed and stirred for 0.5 h; then 50 mL of deionized water and 0.25 g of Cr2O3 particles were added, stirred for 24 h, transferred to an autoclave, and kept at 100 degrees Celsius for 12 h; after the autoclave was naturally cooled to room temperature, the precipitate was washed with deionized water and dried at 80 degrees Celsius for 24 h; the dried precipitate was heated to 500 degrees Celsius at a heating rate of 5 degrees Celsius / min, and then calcined at 500 degrees Celsius for 2 h to obtain nanocomposites; The preparation method of the Cr2O3 particles is as follows: In a 0.1 M aqueous solution of trivalent chromium nitrate nonahydrate, 0.3 M ammonia water was added dropwise until the pH reached 6.0 to obtain a precipitate; the precipitate was washed with deionized water and then dried at 90°C for 24 h; the dried product was calcined at 900°C for 5 h to obtain Cr2O3 particles.

2. The hydration-resistant magnesia brick according to claim 1, characterized in that: The Y2O3 weight portion is 2 parts, the The nanocomposite material is 2 parts.

3. The hydration-resistant magnesia brick according to claim 1, characterized in that: The binder is an aqueous solution of soluble polyvinyl alcohol fiber.

4. The hydration-resistant magnesia brick according to claim 3, characterized in that: The concentration of the aqueous solution of soluble polyvinyl alcohol fiber in the binder is 2 wt %.

5. The hydration-resistant magnesia brick according to claim 1, characterized in that: The sintered magnesia has a MgO content of 94% to 96% and a CaO content of 2% to 3%.

6. The hydration-resistant magnesia brick according to claim 1, characterized in that: The particle size of the Y2O3 is less than 50 nm.

7. The method for preparing the hydration-resistant magnesia brick according to any one of claims 1 to 6, wherein: The following steps are involved: Mix 1~3mm sintered magnesia, 1mm or less sintered magnesia and binder for 20min, then add 0.088mm or less sintered magnesia powder, Y2O3 and The nanocomposite material is mixed for another 2 minutes to obtain a mixture; the mixture is then hydraulically formed and then dried at 90 degrees Celsius to 120 degrees Celsius for 36 hours. The dried ligand is sintered at 1580 degrees Celsius for 4 hours to obtain a magnesia brick.

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