Ti3AlC2 modified low-carbon MgO-C refractory material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of preparation of metallurgical refractory materials, and provides a Ti3AlC2 modified low-carbon MgO-C refractory material aiming at the problems of high cost, difficulty in dispersion and the like caused by directly introducing Ti3AlC2 into a low-carbon MgO-C refractory material in the prior art. The refractory material is prepared from the following raw material components in parts by weight: 65-75 parts of fused magnesite aggregate, 15-25 parts of Ti3AlC2 / magnesite composite powder, 3-7 parts of crystalline flake graphite, 1-3 parts of aluminum powder, 0.5-2 parts of silicon powder and 4 parts of phenolic resin. The Ti3AlC2 modified low-carbon MgO-C refractory material prepared by the preparation method disclosed by the invention is relatively good in dispersity, relatively good in normal-temperature mechanical property and thermal shock resistance, and excellent in oxidation resistance and slag corrosion resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of metallurgical refractory preparation, and in particular relates to a Ti3AlC2 modified low-carbon MgO-C refractory material, a preparation method and application thereof. Background Art

[0002] MgO-C refractory materials have excellent thermal shock stability and slag resistance, and are widely used in converters, electric furnaces, ladles, slide plates and off-furnace refining. However, they have the following problems during use: 1) Carbon oxidizes during service to form pores, which not only reduces the mechanical properties of the refractory materials but also aggravates the penetration and erosion of the slag on the refractory materials; 2) When smelting high-quality clean steel and ultra-low carbon steel, the carbon in the refractory materials is easily precipitated into the molten steel, reducing product quality.

[0003] Existing technologies mostly use methods such as refining carbon source particle size, modifying carbon source surface and adding high-efficiency antioxidants to improve the problems of large dosage and poor oxidation resistance. However, the above methods have problems such as high cost and limited improvement in antioxidant and slag resistance.

[0004] Ti3AlC2 has excellent properties such as a high melting point (about 3000°C), good mechanical properties, high thermal and electrical conductivity, strong damage resistance and good self-lubrication. In addition, it has a structure similar to graphite and excellent properties. Therefore, when preparing low-carbon refractory materials for clean steel smelting, Ti3AlC2 can replace graphite. However, directly introducing it into low-carbon MgO-C refractory materials has problems such as high cost and difficulty in dispersion. Therefore, it is necessary to develop a low-cost, easily dispersible preparation method for Ti3AlC2-modified low-carbon MgO-C refractory materials to improve their slag penetration resistance and oxidation resistance. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a Ti3AlC2 modified low-carbon MgO-C refractory material, a preparation method and applications thereof.

[0006] The first object of the present invention is to provide a Ti3AlC2 modified low-carbon MgO-C refractory material, which is made from the following raw material components in parts by weight:

[0007] 65-75 parts of fused magnesia aggregate, 15-25 parts of Ti3AlC2 / magnesia composite powder, 3-7 parts of flake graphite, 1-3 parts of aluminum powder, 0.5-2 parts of silicon powder and 4 parts of phenolic resin.

[0008] Preferably, the Ti3AlC2 / magnesia composite powder is made from the following raw material components in parts by weight:

[0009] 20-30 parts of fused magnesia fine powder and 3 parts of composite powder.

[0010] Preferably, the composite powder is made from the following raw material components in parts by weight:

[0011] 30 parts of titanium powder, 10 parts of aluminum powder and 20-25 parts of carbon black.

[0012] Preferably, the mass fraction of MgO in the fused magnesia aggregate is greater than 98%, and the gradation of the fused magnesia aggregate is: the mass ratio of 1-3 mm aggregate to 0-1 mm aggregate is 3:2.

[0013] Preferably, the mass fraction of carbon in the flake graphite is greater than 98%, and the flake graphite is 325 mesh flake graphite.

[0014] Preferably, the fused magnesia fine powder is 200 mesh fused magnesia fine powder, the particle sizes of titanium powder and aluminum powder are both less than 45 μm, and the particle size of carbon black is less than 0.5 μm.

[0015] A second object of the present invention is to provide a method for preparing the above-mentioned Ti3AlC2 modified low-carbon MgO-C refractory material, comprising the following steps:

[0016] S1. Preparation of composite powder

[0017] Weigh 30 parts of titanium powder, 10 parts of aluminum powder and 20-25 parts of carbon black respectively by weight and mix them evenly to obtain a composite powder;

[0018] Preparation of S2, Ti3AlC2 / magnesia composite powder

[0019] Weigh 20-30 parts by weight of fused magnesia fine powder and 3 parts of the composite powder obtained in step S1, respectively, and mix them uniformly to obtain a mixture. In a reducing atmosphere, calcine the mixture at 1300-1500° C. for 2-4 hours to obtain a Ti3AlC2 / magnesia composite powder.

[0020] S3. Sample preparation

[0021] 65-75 parts of fused magnesia aggregate, 3-7 parts of flake graphite, 1-3 parts of aluminum powder, 0.5-2 parts of silicon powder, 4 parts of phenolic resin, and 15-25 parts of the Ti3AlC2 / magnesia composite powder obtained in step S2 were respectively weighed in parts by weight, mixed uniformly, and then pressed under 100 MPa to obtain a sample;

[0022] S4. Preparation of modified refractory materials

[0023] After the sample obtained in step S3 is dried, the dried sample is calcined at 1300-1500° C. for 2-4 hours in a reducing atmosphere to obtain a Ti 3 AlC 2 modified low-carbon MgO—C refractory material.

[0024] Preferably, in step S2 and step S4, the reducing atmosphere is a carbon burying condition.

[0025] Preferably, in step S4, the drying temperature is 240° C. and the drying time is 24 hours.

[0026] The third object of the present invention is to provide an application of the above-mentioned Ti3AlC2 modified low-carbon MgO-C refractory material in the preparation of ladle lining and key parts of continuous casting.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention carries out a calcination reaction between titanium powder, aluminum powder, carbon black and fused magnesia fine powder in a reducing atmosphere, thereby uniformly mixing Ti3AlC2 and the fused magnesia fine powder through the reaction to form a uniformly distributed Ti3AlC2 / magnesia composite powder, thereby solving the problem that Ti3AlC2 introduced into low-carbon magnesium-carbon refractory materials is difficult to disperse. The Ti3AlC2 modified low-carbon MgO-C refractory material prepared by the present invention has good dispersibility, good room-temperature mechanical properties and thermal shock resistance, and excellent oxidation resistance and slag corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a diagram of the appearance of the refractory materials prepared in Example 1 of the present invention and Comparative Example 1 after oxidation;

[0030] Figure 2 This is a graph showing the oxidation index results of the refractory materials prepared in Example 1 of the present invention and Comparative Example 1;

[0031] Figure 3 The appearance of the refractory materials prepared in Example 1 and Comparative Example 1 after erosion

[0032] Figure 4 This is a graph showing the erosion index results of the refractory materials prepared in Inventive Example 1 and Comparative Example 1;

[0033] Figure 5 This is a scanning electron microscope image of the refractory material prepared in Example 1 of the present invention;

[0034] In the figure: M0 is the refractory material of Example 1; M2 is the refractory material of Comparative Example 1. DETAILED DESCRIPTION

[0035] The following is a summary of the embodiments of the present invention. Figures 1 to 5The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0036] Example 1

[0037] The embodiment of the present invention provides a Ti3AlC2 modified low-carbon MgO-C refractory material, which is made from the following raw material components in parts by weight:

[0038] 70 parts of fused magnesia aggregate, 24 parts of Ti3AlC2 / magnesia composite powder, 3 parts of flake graphite, 1 part of aluminum powder, 2 parts of silicon powder and 4 parts of phenolic resin. In the embodiment of the present invention, the purity of the aluminum powder is 99% and the purity of the silicon powder is 98%.

[0039] In the embodiment of the present invention, the Ti3AlC2 / magnesia composite powder is made of the following raw material components in parts by weight:

[0040] 20 parts of fused magnesia fine powder and 3 parts of composite powder.

[0041] In the embodiment of the present invention, the composite powder is made from the following raw material components in parts by weight:

[0042] 30 parts of titanium powder, 10 parts of aluminum powder and 25 parts of carbon black.

[0043] In the embodiment of the present invention, the mass fraction of MgO in the fused magnesia aggregate is greater than 98%, and the gradation of the fused magnesia aggregate is: the mass ratio of 1-3 mm aggregate to 0-1 mm aggregate is 3:2.

[0044] In the embodiment of the present invention, the mass fraction of carbon in the flake graphite is greater than 98%, and the flake graphite is 325 mesh flake graphite.

[0045] In the embodiment of the present invention, the fused magnesia fine powder is 200 mesh fused magnesia fine powder, the particle sizes of the titanium powder and the aluminum powder are both less than 45 μm, and the particle size of the carbon black is less than 0.5 μm.

[0046] The present invention also provides a method for preparing the Ti3AlC2 modified low-carbon MgO-C refractory material, which specifically comprises the following steps:

[0047] S1. Preparation of composite powder

[0048] Weigh 30 parts of titanium powder, 10 parts of aluminum powder, and 25 parts of carbon black by weight, and stir and mix for 60 minutes to obtain a composite powder;

[0049] Preparation of S2, Ti3AlC2 / magnesia composite powder

[0050] 20 parts of fused magnesia fine powder and 3 parts of the composite powder obtained in step S1 were weighed respectively by weight, and stirred and mixed for 40 minutes to make the mixture uniform, thereby obtaining a mixture. The mixture was placed in a high-temperature furnace and calcined at 1400° C. for 3 hours under carbon burial conditions to obtain a Ti3AlC2 / magnesia composite powder;

[0051] S3. Sample preparation

[0052] 70 parts of fused magnesia aggregate (specifically, the mass ratio of 1-3 mm fused magnesia aggregate to 0-1 mm fused magnesia aggregate is 3:2), 3 parts of flake graphite, 1 part of aluminum powder, 2 parts of silicon powder, 4 parts of phenolic resin, and 24 parts of the Ti3AlC2 / magnesia composite powder obtained in step S2 were weighed respectively by weight, and stirred and mixed for 15 minutes to make the mixture uniform, and then pressed under 100 MPa to obtain a sample;

[0053] S4. Preparation of modified refractory materials

[0054] The sample obtained in step S3 was dried at 240°C for 24 hours, and then calcined at 1400°C for 3 hours under carbon burial conditions to obtain Ti3AlC2 modified low-carbon MgO-C refractory material.

[0055] Example 2

[0056] The embodiment of the present invention provides a Ti3AlC2 modified low-carbon MgO-C refractory material, which is made from the following raw material components in parts by weight:

[0057] 65 parts of fused magnesia aggregate, 15 parts of Ti3AlC2 / magnesia composite powder, 7 parts of flake graphite, 2 parts of aluminum powder, 1 part of silicon powder and 4 parts of phenolic resin. In the embodiment of the present invention, the purity of the aluminum powder is 99% and the purity of the silicon powder is 98%.

[0058] In the embodiment of the present invention, the Ti3AlC2 / magnesia composite powder is made of the following raw material components in parts by weight:

[0059] 25 parts of fused magnesia fine powder and 3 parts of composite powder.

[0060] In the embodiment of the present invention, the composite powder is made from the following raw material components in parts by weight:

[0061] 30 parts of titanium powder, 10 parts of aluminum powder and 20 parts of carbon black.

[0062] In the embodiment of the present invention, the mass fraction of MgO in the fused magnesia aggregate is greater than 98%, and the gradation of the fused magnesia aggregate is: the mass ratio of 1-3 mm aggregate to 0-1 mm aggregate is 3:2.

[0063] In the embodiment of the present invention, the mass fraction of carbon in the flake graphite is greater than 98%, and the flake graphite is 325 mesh flake graphite.

[0064] In the embodiment of the present invention, the fused magnesia fine powder is 200 mesh fused magnesia fine powder, the particle sizes of the titanium powder and the aluminum powder are both less than 45 μm, and the particle size of the carbon black is less than 0.5 μm.

[0065] The present invention also provides a method for preparing the Ti3AlC2 modified low-carbon MgO-C refractory material, which specifically comprises the following steps:

[0066] S1. Preparation of composite powder

[0067] Weigh 30 parts of titanium powder, 10 parts of aluminum powder, and 20 parts of carbon black respectively by weight, and stir and mix for 60 minutes to make the mixture uniform to obtain a composite powder;

[0068] Preparation of S2, Ti3AlC2 / magnesia composite powder

[0069] 25 parts of fused magnesia fine powder and 3 parts of the composite powder obtained in step S1 were weighed respectively by weight, and stirred and mixed for 40 minutes to make the mixture uniform, thereby obtaining a mixture. The mixture was placed in a high-temperature furnace under carbon burial conditions and calcined at 1300° C. for 4 hours to obtain a Ti3AlC2 / magnesia composite powder;

[0070] S3. Sample preparation

[0071] 65 parts of fused magnesia aggregate (specifically, the mass ratio of 1-3 mm fused magnesia aggregate to 0-1 mm fused magnesia aggregate is 3:2), 7 parts of flake graphite, 2 parts of aluminum powder, 1 part of silicon powder, 4 parts of phenolic resin, and 15 parts of the Ti3AlC2 / magnesia composite powder obtained in step S2 were weighed respectively by weight, and stirred and mixed for 15 minutes to make the mixture uniform, and then pressed under 100 MPa to obtain a sample;

[0072] S4. Preparation of modified refractory materials

[0073] The sample obtained in step S3 was dried at 240° C. for 24 h, and then calcined at 1300° C. for 4 h under carbon burial conditions to obtain a Ti3AlC2 modified low-carbon MgO-C refractory material.

[0074] Example 3

[0075] The embodiment of the present invention provides a Ti3AlC2 modified low-carbon MgO-C refractory material, which is made from the following raw material components in parts by weight:

[0076] 75 parts of fused magnesia aggregate, 20 parts of Ti3AlC2 / magnesia composite powder, 5 parts of flake graphite, 3 parts of aluminum powder, 0.5 parts of silicon powder and 4 parts of phenolic resin. In the embodiment of the present invention, the purity of the aluminum powder is 99%, and the purity of the silicon powder is 98%.

[0077] In the embodiment of the present invention, the Ti3AlC2 / magnesia composite powder is made of the following raw material components in parts by weight:

[0078] 30 parts of fused magnesia fine powder and 3 parts of composite powder.

[0079] In the embodiment of the present invention, the composite powder is made from the following raw material components in parts by weight:

[0080] 30 parts of titanium powder, 10 parts of aluminum powder and 22 parts of carbon black.

[0081] In the embodiment of the present invention, the mass fraction of MgO in the fused magnesia aggregate is greater than 98%, and the gradation of the fused magnesia aggregate is: the mass ratio of 1-3 mm aggregate to 0-1 mm aggregate is 3:2.

[0082] In the embodiment of the present invention, the mass fraction of carbon in the flake graphite is greater than 98%, and the flake graphite is 325 mesh flake graphite.

[0083] In the embodiment of the present invention, the fused magnesia fine powder is 200 mesh fused magnesia fine powder, the particle sizes of the titanium powder and the aluminum powder are both less than 45 μm, and the particle size of the carbon black is less than 0.5 μm.

[0084] The present invention also provides a method for preparing the Ti3AlC2 modified low-carbon MgO-C refractory material, which specifically comprises the following steps:

[0085] S1. Preparation of composite powder

[0086] Weigh 30 parts of titanium powder, 10 parts of aluminum powder, and 22 parts of carbon black by weight, and stir and mix for 60 minutes to obtain a composite powder;

[0087] Preparation of S2, Ti3AlC2 / magnesia composite powder

[0088] 30 parts of fused magnesia fine powder and 3 parts of the composite powder obtained in step S1 were weighed respectively by weight, and stirred and mixed for 40 minutes to make the mixture uniform, thereby obtaining a mixture. The mixture was placed in a high-temperature furnace and calcined at 1500° C. for 2 hours under carbon burial conditions to obtain a Ti3AlC2 / magnesia composite powder;

[0089] S3. Sample preparation

[0090] 75 parts of fused magnesia aggregate (specifically, the mass ratio of 1-3 mm fused magnesia aggregate to 0-1 mm fused magnesia aggregate is 3:2), 5 parts of flake graphite, 3 parts of aluminum powder, 0.5 parts of silicon powder, 4 parts of phenolic resin, and 20 parts of the Ti3AlC2 / magnesia composite powder obtained in step S2 were weighed respectively by weight, and stirred and mixed for 15 minutes to make the mixture uniform, and then pressed under 100 MPa to obtain a sample;

[0091] S4. Preparation of modified refractory materials

[0092] The sample obtained in step S3 was dried at 240° C. for 24 h, and then calcined at 1500° C. for 2 h under carbon burial conditions to obtain a Ti3AlC2 modified low-carbon MgO-C refractory material.

[0093] Comparative Example 1

[0094] Using flake graphite as a carbon source: First, premix 24 parts of fused magnesia fine powder for 40 minutes and set aside. Then, mix 30 parts of titanium powder, 10 parts of silicon powder, and 25 parts of carbon black to create a composite powder. Then, mix 70 parts of fused magnesia aggregate in a mixer for 10 minutes. Add 4 parts of phenolic resin and continue mixing. After the aggregate is coated with the phenolic resin, add 1 part of aluminum powder, 2 parts of silicon powder, 3 parts of the composite powder, and 24 parts of fused magnesia fine powder. Mix for 15-20 minutes, and press into strip, cylindrical, and crucible shapes at 100 MPa. The pressed samples are heat-treated in a high-temperature oven at 240°C for 24 hours. Then, calcined at 1400°C for 3 hours under carbon-buried conditions to produce a MgO-C refractory. This comparative example represents a MgO-C refractory without the addition of Ti3AlC2.

[0095] The physical and chemical properties of the Ti3AlC2 modified low-carbon MgO-C refractory prepared in Example 1 of the present invention and the MgO-C refractory prepared in Comparative Example 1 are respectively as follows:

[0096] The refractory material prepared in Example 1 has the following characteristics: bulk density 3.0 g / cm 3 , apparent porosity 14%, room temperature compressive strength 45 MPa, room temperature flexural strength 6 MPa, oxidation index 64%, and erosion index 1.5.

[0097] The refractory material prepared in Comparative Example 1 has a volume density of 3.0 g / cm3, an apparent porosity of 13%, a compressive strength at room temperature of 46 MPa, a flexural strength at room temperature of 5 MPa, an oxidation index of 50%, and an erosion index of 1.2.

[0098] The above comparison of physical and chemical properties shows that, compared with the material of comparative example 1, the refractory material prepared in example 1 of the present invention has better physical and chemical properties.

[0099] The appearance of the refractory materials prepared in Example 1 of the present invention and Comparative Example 1 after oxidation and the oxidation index results are as follows: Figure 1 and Figure 2 As shown, the appearance of the refractory materials prepared in Example 1 of the present invention and Comparative Example 1 after erosion and the erosion index results are shown as follows: Figure 3 and Figure 4 As shown, through Figures 1 to 4 It can be seen from the results that compared with the material in comparative example 1, the refractory material prepared in embodiment 1 of the present invention has more excellent anti-oxidation and anti-slag erosion properties.

[0100] The scanning electron microscope image of the refractory material prepared in Example 1 of the present invention is as follows: Figure 5 As shown, through Figure 5 It can be seen that the refractory material prepared in the embodiment of the present invention has good dispersibility.

[0101] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A Ti3AlC2 modified low-carbon MgO-C refractory material, characterized in that: Made from the following raw material components in parts by weight: 65-75 parts of fused magnesia aggregate, 15-25 parts of Ti3AlC2 / magnesia composite powder, 3-7 parts of flake graphite, 1-3 parts of aluminum powder, 0.5-2 parts of silicon powder and 4 parts of phenolic resin.

2. A Ti3AlC2 modified low-carbon MgO-C refractory material according to claim 1, characterized in that: The Ti3AlC2 / magnesia composite powder is made from the following raw material components in parts by weight: 20-30 parts of fused magnesia fine powder and 3 parts of composite powder.

3. A Ti3AlC2 modified low-carbon MgO-C refractory material according to claim 2, characterized in that: The composite powder is made from the following raw material components in parts by weight: 30 parts of titanium powder, 10 parts of aluminum powder and 20-25 parts of carbon black.

4. The Ti3AlC2 modified low-carbon MgO-C refractory material according to claim 1, characterized in that: The mass fraction of MgO in the fused magnesia aggregate is greater than 98%, and the gradation of the fused magnesia aggregate is: the mass ratio of 1-3 mm aggregate to 0-1 mm aggregate is 3:

2.

5. The Ti3AlC2 modified low-carbon MgO-C refractory material according to claim 1, characterized in that: The mass fraction of carbon in the flake graphite is greater than 98%, and the flake graphite is 325 mesh flake graphite.

6. The Ti3AlC2 modified low-carbon MgO-C refractory material according to claim 3, characterized in that: The fused magnesia fine powder is 200 mesh fused magnesia fine powder, the particle sizes of titanium powder and aluminum powder are both less than 45 μm, and the particle size of carbon black is less than 0.5 μm.

7. A method for preparing a Ti3AlC2 modified low-carbon MgO-C refractory material according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Preparation of composite powder Weigh 30 parts of titanium powder, 10 parts of aluminum powder and 20-25 parts of carbon black respectively by weight and mix them evenly to obtain a composite powder; Preparation of S2, Ti3AlC2 / magnesia composite powder Weigh 20-30 parts by weight of fused magnesia fine powder and 3 parts of the composite powder obtained in step S1, respectively, and mix them uniformly to obtain a mixture. In a reducing atmosphere, calcine the mixture at 1300-1500° C. for 2-4 hours to obtain a Ti3AlC2 / magnesia composite powder. S3. Sample preparation 70 parts of fused magnesia aggregate, 3 parts of flake graphite, 1 part of aluminum powder, 2 parts of silicon powder, 4 parts of phenolic resin, and 24 parts of the Ti3AlC2 / magnesia composite powder obtained in step S2 were respectively weighed and mixed uniformly, and then pressed under 100 MPa to obtain a sample; S4. Preparation of modified refractory materials After the sample obtained in step S3 is dried, the dried sample is calcined at 1300-1500° C. for 2-4 hours in a reducing atmosphere to obtain a Ti 3 AlC 2 modified low-carbon MgO-C refractory material.

8. The method for preparing a Ti3AlC2 modified low-carbon MgO-C refractory material according to claim 7, characterized in that: In step S2 and step S4, the reducing atmosphere is the carbon burying condition.

9. The method for preparing a Ti3AlC2 modified low-carbon MgO-C refractory material according to claim 7, characterized in that: In step S4, the drying temperature is 240° C. and the drying time is 24 hours.

10. Use of the Ti3AlC2 modified low-carbon MgO-C refractory material according to any one of claims 1 to 6 in the preparation of ladle linings and key parts of continuous casting.

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