A Ti2O3-containing andalusite refractory material and preparation method thereof

Abstract

The invention discloses a Ti2O3-containing andalusite refractory material and a preparation method thereof, and belongs to the technical field of refractory materials. The raw materials of the Ti2O3-containing andalusite refractory material of the invention include, by weight, 69-90 parts of andalusite, 10-31 parts of mixed fine powder and 3.5 parts of phenolic resin binder; the mixed fine powder contains titanium dioxide and metal aluminum powder in a mass ratio of 28:3. The Ti2O3-containing andalusite refractory material prepared by the invention has the advantages of low creep, good thermal shock resistance, high density, high strength and high resistance to penetration and erosion. The invention utilizes the generated Al2O3 to further react with the silicon-rich glass phase of andalusite to generate secondary mullite, thereby improving the bonding strength of the system. At the same time, the finely dispersed Ti2O3 generated in situ is uniformly dispersed in the mullite grain boundary in the form of an independent phase, and is almost not solid-dissolved in the mullite, which can inhibit the anisotropic growth of the mullite crystal, promote the densification of the material, reduce the porosity, and improve its resistance to penetration and erosion.

Description

Technical Field

[0001] The invention relates to the technical field of refractory materials, and in particular to an andalusite refractory material containing Ti2O3 and a preparation method thereof. Background Art

[0002] Andalusite (Al2O3·SiO2) is a natural mineral with the characteristics of low thermal conductivity, stable volume, high mechanical strength, excellent creep resistance and CO erosion resistance. It can be directly used to manufacture refractory materials without calcination and is widely used in metallurgy, building materials and other industries.

[0003] Andalusite is usually in the form of long columnar crystals, and its cross section is close to a square. The content of andalusite phase in andalusite is generally 90% to 95%, and the impurity components are arranged in a direction in the crystal, and are cross-shaped in cross section. In fact, during the mullitization process, the grains of a single andalusite still retain their original morphology and chemical composition. Under high temperature, a single andalusite grain will be transformed into a unique composite structure: a reticular mullite with capillary pores and a silicon-rich glass phase filled therein. However, the long columnar arrangement of mullite crystals makes it difficult to densify the material, and the material has a high porosity, which affects the anti-penetration performance. Therefore, how to solve the problems of high porosity, difficulty in densification, and poor anti-penetration performance of andalusite-based refractory materials in the prior art, and design a new refractory material preparation scheme, is a problem that researchers in this field urgently need to solve. Summary of the invention

[0004] The object of the present invention is to provide a Ti2O3-containing andalusite refractory material and a preparation method thereof. The Ti2O3-containing andalusite refractory material prepared by the present invention has the advantages of low creep, good thermal shock resistance, high density, high strength and high resistance to penetration and erosion.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] One of the technical solutions of the present invention is to provide a Ti2O3-containing andalusite refractory material, wherein the raw materials, calculated by weight, include:

[0007] 69-90 parts of andalusite, 10-31 parts of mixed fine powder and 3.5 parts of phenolic resin binder;

[0008] The mixed fine powder contains titanium dioxide and metal aluminum powder in a mass ratio of 28:3.

[0009] Preferably, the particle size of the andalusite and the corresponding mass fractions are as follows: 15 to 25 parts of andalusite particles with a particle size of 0-1 mm and not 0, 15 to 25 parts of andalusite particles with a particle size of 1-3 mm, and 19 to 40 parts of andalusite particles with a particle size of 3-5 mm.

[0010] Preferably, the particle size of the titanium dioxide is ≤45 μm.

[0011] Preferably, the particle size of the metal aluminum powder is ≤45 μm.

[0012] The second technical solution of the present invention is to provide a method for preparing the above-mentioned Ti2O3-containing andalusite refractory material, comprising the following steps:

[0013] The raw materials are mixed, pressed into shape to obtain a green body, and sintered to obtain the Ti2O3-containing andalusite refractory material.

[0014] Preferably, the sintering temperature is 1300-1700° C., the time is 3-10 hours, and the sintering is performed in a protective atmosphere.

[0015] The beneficial technical effects of the present invention are as follows:

[0016] The present invention provides a method for preparing an andalusite refractory material containing Ti2O3. During the high-temperature sintering process, the metal aluminum powder in the present invention acts as a reducing agent to react with titanium dioxide (6TiO2+2Al=Al2O3+3Ti2O3, and this reaction occurs at about 800°C) to generate finely dispersed Ti2O3 and Al2O3 in situ. On the one hand, the generated Al2O3 is further reacted with the silicon-rich glass phase of andalusite to generate secondary mullite, thereby improving the bonding strength of the system. On the other hand, the finely dispersed Ti2O3 generated in situ is uniformly dispersed in the mullite grain boundaries in the form of an independent phase, and is almost not dissolved in the mullite, which can inhibit the anisotropic growth of mullite crystals, promote material densification, and reduce porosity (see Figure 2 ), improve its anti-penetration and erosion performance.

[0017] The present invention introduces Ti2O3 phase mainly to suppress the anisotropic development of mullite crystals, hinder its development into long columnar morphology and affect densification, that is, Ti2O3 is distributed at the mullite grain boundary, suppresses its radial development, changes its morphology, and makes it grow into a granular state that is easy to achieve densification. In order to achieve the purpose of making Ti2O3 dispersed in the mullite grain boundary to suppress its growth, it is required that Ti2O3 should be micron / nano small size and highly uniformly dispersed. If micron / nano Ti2O3 particles are directly introduced, it is difficult to achieve uniform dispersion and make it distributed at the mullite grain boundary.

[0018] During high-temperature service in the andalusite refractory material of the present invention, Ti2O3 therein can further react with C, N2, etc. in the system to in-situ generate non-oxide reinforcement phases such as TiC, TiN or Ti(C,N) solid solution with high melting point, high thermal conductivity and high corrosion resistance, thereby improving the corrosion resistance, thermal shock resistance and high-temperature strength of the material.

[0019] The Ti2O3-containing andalusite refractory material prepared by the invention has the advantages of low creep, good thermal shock resistance, high density, high strength and high resistance to penetration and erosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 Schematic diagram of the preparation process of Examples 1-3.

[0022] Figure 2 The microscopic morphology of the product of Example 1. Among them, (a), (b), (c), and (d) are microscopic morphology images at different magnifications. DETAILED DESCRIPTION

[0023] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0024] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0025] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0026] The words “include,” “including,” “have,” “contain,” etc. used in the present invention are open-ended terms, meaning including but not limited to.

[0027] The particle size and corresponding mass fraction of andalusite used in the following embodiments and comparative examples of the present invention are as follows: 25 parts of andalusite particles with a particle size of 0-1 mm and not 0, 25 parts of andalusite particles with a particle size of 1-3 mm, and 30 parts of andalusite particles with a particle size of 3-5 mm.

[0028] The particle size of the titanium dioxide used in the following embodiments and comparative examples of the present invention is ≤45 μm.

[0029] The particle size of the metal aluminum powder used in the following embodiments and comparative examples of the present invention is ≤45 μm.

[0030] The "normal temperature" in the present invention is 20-30°C unless otherwise specified.

[0031] All raw materials used in the following examples and comparative examples of the present invention are commercially available products.

[0032] Figure 1 Schematic diagram of the preparation process of Examples 1-3.

[0033] Example 1

[0034] The raw materials of andalusite refractory materials are composed of the following raw materials by mass:

[0035] 69 parts of andalusite, 28 parts of titanium dioxide, 3 parts of metallic aluminum powder and 3.5 parts of phenolic resin binder.

[0036] Preparation of andalusite refractory materials:

[0037] The raw materials are mixed and kneaded evenly to obtain a clay material, which is pressed into shape to obtain a green body, which is then dried to a moisture content of less than 1.5wt.%, placed in a tunnel kiln, and kept warm at 1300°C for 10 hours under an argon atmosphere to obtain a Ti2O3-containing andalusite refractory material.

[0038] The product of this embodiment has an apparent porosity of 11.3% and a bulk density of 2.95 g / cm 3 The room temperature compressive strength (tested according to the national standard GBT 5072-2008) is 251MPa, and the number of thermal shock stability cycles (1100℃, water cooling) is ≥28 times.

[0039] Figure 2 The microscopic morphology of the product of Example 1. Among them, (a), (b), (c), and (d) are microscopic morphology images at different magnifications.

[0040] Figure 2 The region labeled “1” in (c) and the region labeled “2” in (d) refer to the Ti2O3 occurrence region.

[0041] Example 2

[0042] The raw materials of andalusite refractory materials are composed of the following raw materials by mass:

[0043] 84.5 parts of andalusite, 14 parts of titanium dioxide, 1.5 parts of metallic aluminum powder and 3.5 parts of phenolic resin binder.

[0044] Preparation of andalusite refractory materials:

[0045] The raw materials are mixed and kneaded evenly to obtain a clay material, which is pressed into shape to obtain a green body, which is then dried to a moisture content of less than 1.5wt.%, placed in a tunnel kiln, and kept warm at 1500°C for 6 hours under an argon atmosphere to obtain a Ti2O3-containing andalusite refractory material.

[0046] The product of this embodiment has an apparent porosity of 12.9% and a bulk density of 2.92 g / cm 3 The room temperature compressive strength (tested according to the national standard GBT 5072-2008) is 219MPa, and the number of thermal shock stability cycles (1100℃, water cooling) is ≥28 times.

[0047] Example 3

[0048] The raw materials of andalusite refractory materials are composed of the following raw materials by mass:

[0049] 90 parts of andalusite, 9.3 parts of titanium dioxide, 1 part of metallic aluminum powder and 3.5 parts of phenolic resin binder.

[0050] Preparation of andalusite refractory materials:

[0051] The raw materials are mixed and kneaded evenly to obtain a clay material, which is pressed into shape to obtain a green body, which is then dried to a moisture content of less than 1.5wt.%, placed in a tunnel kiln, and kept warm at 1700°C for 3 hours under an argon atmosphere to obtain a Ti2O3-containing andalusite refractory material.

[0052] The product of this embodiment has an apparent porosity of 14.7% and a bulk density of 2.90 g / cm 3 The room temperature compressive strength (tested according to the national standard GBT 5072-2008) is 221MPa, and the number of thermal shock stability cycles (1100℃, water cooling) is ≥28 times.

[0053] Comparative Example 1

[0054] The only difference from Example 1 is that the addition of titanium dioxide and metallic aluminum powder is omitted and an equal mass of andalusite is supplemented.

[0055] The product of this embodiment has an apparent porosity of 21.6% and a bulk density of 2.61 g / cm 3 The room temperature compressive strength (tested according to the national standard GBT 5072-2008) is 112MPa, and the number of thermal shock stability cycles (1100℃, water cooling) is ≥25 times.

[0056] Comparative Example 1 uses andalusite as a raw material. During the high-temperature sintering process, the andalusite is mullitized, accompanied by a large volume expansion. At the same time, there is no second phase that inhibits the anisotropic growth of mullite crystals. The mullite grows in long columns, is difficult to densify, has a low volume density, and has a high apparent porosity.

[0057] Comparative Example 2

[0058] The only difference from Example 1 is that the addition of titanium dioxide is omitted and an equal mass of andalusite is supplemented.

[0059] The product of this embodiment has an apparent porosity of 24.3% and a bulk density of 2.31 g / cm 3 The room temperature compressive strength (tested according to the national standard GBT 5072-2008) is 67MPa, and the number of thermal shock stability cycles (1100℃, water cooling) is ≥8 times.

[0060] Comparative Example 3

[0061] The only difference from Example 1 is that the addition of metallic aluminum powder is omitted and an equal mass of andalusite is supplemented.

[0062] The product of this embodiment has an apparent porosity of 22.9% and a bulk density of 2.23 g / cm 3 The room temperature compressive strength (tested according to the national standard GBT 5072-2008) is 53MPa, and the number of thermal shock stability cycles (1100℃, water cooling) is ≥7 times.

[0063] Comparative Example 4

[0064] The raw materials of andalusite refractory materials are composed of the following raw materials by mass:

[0065] 69 parts of andalusite, 8 parts of titanium dioxide, 23 parts of metallic aluminum powder and 3.5 parts of phenolic resin binder.

[0066] The product of this embodiment has an apparent porosity of 19.8% and a bulk density of 2.56 g / cm 3 The room temperature compressive strength (tested according to the national standard GBT 5072-2008) is 77MPa, and the number of thermal shock stability cycles (1100℃, water cooling) is ≥9 times.

[0067] Comparative Example 5

[0068] The only difference from Example 1 is that the titanium dioxide is replaced by an equal mass of nano-scale titanium dioxide powder (average particle size 100 nm), and the metal aluminum powder is replaced by an equal mass of aluminum oxide powder (particle size ≤ 45 μm).

[0069] The product of this embodiment has an apparent porosity of 24.5% and a bulk density of 2.67 g / cm 3The room temperature compressive strength (tested according to the national standard GBT 5072-2008) is 72MPa, and the number of thermal shock stability cycles (1100℃, water cooling) is ≥10 times.

[0070] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A Ti2O3-containing andalusite refractory material, characterized in that: Raw materials, calculated by mass, include: 69-90 parts of andalusite, 10-31 parts of mixed fine powder and 3.5 parts of phenolic resin binder; The mixed fine powder contains titanium dioxide and metal aluminum powder in a mass ratio of 28:3; The particle size of the titanium dioxide is ≤45 μm; The particle size of the metal aluminum powder is ≤45 μm; The preparation method of the andalusite refractory material containing Ti2O3 comprises the following steps: The raw materials are mixed, pressed into shape to obtain a green body, and sintered to obtain the Ti2O3-containing andalusite refractory material; The sintering temperature is 1300-1700° C., the time is 3-10 hours, and the sintering is carried out in a protective atmosphere.

2. The andalusite refractory material containing Ti2O3 according to claim 1, characterized in that: The particle size of the andalusite and the corresponding mass fractions are as follows: 15 to 25 parts of andalusite particles with a particle size of 0-1 mm and not 0, 15 to 25 parts of andalusite particles with a particle size of 1-3 mm, and 19 to 40 parts of andalusite particles with a particle size of 3-5 mm.

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