A method for preparing anhydrous taphole mud for furnace protection

Abstract

The present invention belongs to the technical field of refractory materials. The invention provides a method for preparing anhydrous taphole mud for furnace protection, comprising the following steps: S1, adding, by weight, 15-17 parts of coke powder, 10-11 parts of clay, 7-8 parts of mica, 13-15 parts of silicon carbide, 28-32 parts of brown corundum, 4-6 parts of glass powder, 10-12 parts of ferrosilicon nitride, 13-15 parts of bauxite, 2.5-3.3 parts of cobalt-doped iron oxide, and 3.5-4.2 parts of aluminum-doped titanium dioxide to a mixer, and stirring at a temperature of 60-70°C for 10-15 minutes to obtain a first mixture; S2, adding 4-5 parts of asphalt and 18-20 parts of tar to the first mixture obtained in S1, and stirring at a temperature of 60-70°C for 25-30 minutes to obtain a second mixture; and S3, extruding the second mixture obtained in S2 from the outlet of the mixer to obtain the anhydrous taphole mud for furnace protection. The present invention can improve the high-temperature compressive strength of the prepared water-free mud and reduce its apparent porosity.

Description

Technical Field

[0001] The invention belongs to the technical field of refractory materials, and in particular relates to a method for preparing anhydrous taphole mud for furnace protection. Background Art

[0002] With advancements in ironmaking technology and the need for intensified blast furnace production, people have gradually recognized the importance of taphole clay quality to proper blast furnace operation. After years of research, trials, and improvements, taphole clay has rapidly evolved. Blast furnace taphole clay has evolved from water-based to anhydrous, significantly improving its strength and resistance to slag and iron corrosion, meeting the requirements for safe and smooth blast furnace operation and further intensified blast furnace production.

[0003] It is known in the prior art that adding ferrosilicon nitride to the preparation of anhydrous taphole mud can improve its high-temperature flexural and compressive strength. However, when the temperature reaches 1200°C, the following reactions (carburization-reduction reactions of ferrosilicon nitride) begin to occur in the system: 9Fe + Si3N4 → 3Fe3Si + 2N2, 3Fe + Si3N4 + C → Fe3Si + 2SiC + 2N2, producing a small amount of nitrogen. When the temperature reaches 1400°C, these reactions proceed rapidly, producing large amounts of nitrogen, which increases the apparent porosity of the anhydrous taphole mud. Summary of the Invention

[0004] In view of the above problems, the present invention proposes a method for preparing anhydrous taphole mud for furnace protection, which can improve the high-temperature compressive strength of the prepared anhydrous taphole mud and reduce its apparent porosity.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing anhydrous taphole mud for furnace protection comprises the following steps:

[0007] S1. Add 15-17 parts of coke powder, 10-11 parts of clay, 7-8 parts of mica, 13-15 parts of silicon carbide, 28-32 parts of brown corundum, 4-6 parts of glass powder, 10-12 parts of ferrosilicon nitride, 13-15 parts of bauxite, 2.5-3.3 parts of cobalt-doped iron oxide, and 3.5-4.2 parts of aluminum-doped titanium dioxide into a blender, and stir at 60-70° C. for 10-15 minutes to obtain a first mixture;

[0008] S2. Add 4-5 parts of asphalt and 18-20 parts of tar to the first mixture obtained in S1, and stir at a temperature of 60-70°C for 25-30 minutes to obtain a second mixture;

[0009] S3. The second mixed material obtained in S2 is squeezed out from the discharge port of the mixer to obtain anhydrous taphole mud for furnace protection.

[0010] Preferably, the preparation method of the cobalt-doped iron oxide is as follows:

[0011] A1. Add 2 mmol of iron oleate and 0.05-0.30 mmol of cobalt oleate to a flask, and then add 10 mL of octadecene and 0.7 mL of oleic acid as a surface coating agent to the flask to obtain a mixed solution;

[0012] A2. Place the flask containing the mixed solution in a heating mantle for heating. Before starting heating, introduce nitrogen into the flask at a uniform rate and keep the nitrogen flowing during the heating process. The mixture is pyrolyzed at a temperature of 300-320° C. for 1 h. After the reaction is completed, remove the heating mantle and allow the mixture to cool naturally at room temperature to obtain a reaction solution.

[0013] A3. Add 20 mL of acetone to the reaction solution obtained in A2, centrifuge, disperse the precipitate in hexane, precipitate with acetone, and centrifuge again. Repeat this process three times, and then dry the precipitate to obtain the cobalt-doped iron oxide.

[0014] Preferably, in A2, the heating temperature rise rate is 5-8°C / min.

[0015] Preferably, in A3, the drying temperature is 60-65° C., and the drying time is 46-48 h.

[0016] Preferably, the preparation method of the aluminum-doped titanium dioxide is as follows:

[0017] B1. Pour 10 mL of anhydrous ethanol into a first beaker, then add 6.8-7.0 mL of tetrabutyl titanate into the first beaker and stir to obtain a first solution.

[0018] B2. Add 2.2 mL of acetic acid, 0.42-0.44 g of aluminum nitrate, 5.2 mL of ethanol, and 1.4 mL of deionized water to a second beaker and stir to mix to obtain a second solution;

[0019] B3, adding the first solution obtained in B1 to the second solution obtained in B2, and stirring to form a sol, which is then allowed to stand and naturally aged until cracking occurs, thereby obtaining a gel;

[0020] B4. The gel obtained in B3 is dried in an oven, taken out, ground into powder, and then calcined at 500° C. for 3-4 hours to obtain the aluminum-doped titanium dioxide.

[0021] Preferably, in B3, the standing time is 12-14 hours.

[0022] Preferably, in B4, the drying temperature is 80-85° C., and the drying time is 2-3 h.

[0023] Preferably, the particle size of the coke powder is <1 mm, the particle size of the clay is ≤250 mesh, the particle size of the mica is <0.074 mm, the particle size of the silicon carbide is <0.074 mm, the particle size of the bauxite is <0.074 mm, the particle size of the ferrosilicon nitride is <0.088 mm, and the particle size of the brown corundum is <3 mm.

[0024] Preferably, in the brown corundum, the mass proportion of particles with a diameter of less than 0.074 mm is 2 / 3.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. Aluminum-doped titanium dioxide is introduced into the raw material components of the water-free foam mud of the present invention. Ti in aluminum-doped titanium dioxide 3+ Vacancies and Al 3+ The doping sites can adsorb nitrogen generated by the carbonization-reduction reaction of silicon nitride iron, forming Ti-N bonds / Al-N bonds, fixing / anchoring nitrogen; the Al2O3-TiO2 composite phase forms a stable network structure at high temperature, encapsulating the adsorbed nitrogen molecules, inhibiting their desorption and escape, reducing the contribution of free nitrogen to the porosity, and thereby reducing the apparent porosity of the obtained water-free mud.

[0027] 2. Cobalt-doped iron oxide is also introduced into the raw material components of the waterless taphole mud of the present invention. On the one hand, cobalt-doped iron oxide accelerates / intensifies the generation of nitrogen, while aluminum-doped titanium dioxide instantly captures nitrogen, forming a "generation-consumption" dynamic balance, weakening / offsetting the negative impact of cobalt-doped iron oxide on apparent porosity, and effectively avoiding the increase in apparent porosity of the waterless taphole mud during use (1400°C).

[0028] On the other hand, Fe3Si and SiC generated by cobalt-doped iron oxide accelerating / promoting the carburization-reduction reaction of ferrosilicon nitride can better fill part of the pores, which is beneficial to reducing the apparent porosity; at the same time, high-melting-point compounds such as TiN / AlN generated by aluminum-doped titanium dioxide after adsorbing nitrogen can also further fill the pores. High-melting-point compounds such as TiN / AlN can also form a dense network, thereby synergistically reducing the apparent porosity of anhydrous cannon mud and improving the high-temperature strength of anhydrous cannon mud. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The figure is a comparative trend chart of the apparent porosity (1400°C×3h) and compressive strength (1400°C×3h) data of the anhydrous taphole muds prepared in Examples 1 to 4 of the present invention and Comparative Examples 1 to 3. DETAILED DESCRIPTION

[0030] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] Example 1: (1) The preparation method of cobalt-doped iron oxide is as follows:

[0032] A1. Add 2 mmol of iron oleate and 0.2 mmol of cobalt oleate into a flask, and then add 10 mL of octadecene and 0.7 mL of oleic acid as a surface coating agent into the flask to obtain a mixed solution.

[0033] A2. Place the flask containing the mixed solution in a heating mantle and heat at a heating rate of 6°C / min. Pour nitrogen into the flask at a constant rate before starting heating and maintain the flow of nitrogen throughout the heating process. Heat to 310°C and thermolyze for 1 hour. After the reaction is complete, remove the heating mantle and allow the mixture to cool naturally at room temperature to obtain a reaction solution.

[0034] A3. Add 20 mL of acetone to the reaction solution obtained in A2, centrifuge, and disperse the precipitate in hexane. Repeat the process three times with acetone precipitation and centrifugation. Dry the precipitate at 62°C for 48 hours to obtain cobalt-doped iron oxide.

[0035] (2) The preparation method of aluminum-doped titanium dioxide is as follows:

[0036] B1. Pour 10 mL of anhydrous ethanol into the first beaker, then add 6.9 mL of tetrabutyl titanate into the first beaker, and stir at 800 rpm for 15 minutes to ensure uniform dispersion (no oily stratification by naked eye) to obtain the first solution.

[0037] B2. Add 2.2 mL of acetic acid, 0.43 g of aluminum nitrate, 5.2 mL of ethanol, and 1.4 mL of deionized water into a second beaker. Stir and mix at 400 rpm while ultrasonically assisting (40 kHz, 5 min) to eliminate undissolved particles to obtain a second solution.

[0038] B3. Add the first solution obtained in B1 to the second solution obtained in B2, and stir (in a constant temperature water bath at 25±1°C, magnetic stirring at 500 rpm) to form a sol. Let it stand for 13 hours and allow it to naturally age until it cracks to obtain a gel.

[0039] B4. Dry the gel obtained in B3 in an oven at 82°C for 2.5 hours, then take it out, grind it into powder (pass through a 200-mesh sieve), and then calcine it at 500°C for 3.5 hours to obtain aluminum-doped titanium dioxide.

[0040] (3) A method for preparing anhydrous taphole mud for furnace protection, comprising the following steps:

[0041] S1. Add 16 parts of coke powder, 10.5 parts of clay, 7.5 parts of mica, 14 parts of silicon carbide, 30 parts of brown corundum, 5 parts of glass powder, 11 parts of ferrosilicon nitride, 14 parts of bauxite, 3 parts of cobalt-doped iron oxide, and 3.8 parts of aluminum-doped titanium dioxide into a blender, and stir at 600 rpm for 12 min at 65° C. to obtain a first mixture.

[0042] S2. Add 4.5 parts of asphalt and 19 parts of tar to the first mixture obtained in S1, and stir at 800 rpm for 28 minutes at a temperature of 65° C. to obtain a second mixture.

[0043] S3. The second mixed material obtained in S2 is squeezed out from the discharge port of the mixer to obtain anhydrous taphole mud for furnace protection.

[0044] Among them, the particle size of each raw material is as follows: the particle size of coke powder is <1mm, the particle size of clay is ≤250 mesh, the particle size of mica is <0.074mm, the particle size of silicon carbide is <0.074mm, the particle size of bauxite is <0.074mm, the particle size of ferrosilicon nitride is <0.088mm, and the particle size of brown corundum is <3mm. In the brown corundum, the mass proportion of particles with a size of <0.074mm is 2 / 3.

[0045] Example 2: The difference between this example and example 1 is that: a method for preparing anhydrous taphole mud for furnace protection comprises the following steps:

[0046] S1. Add 15 parts of coke powder, 10 parts of clay, 7 parts of mica, 13 parts of silicon carbide, 28 parts of brown corundum, 4 parts of glass powder, 10 parts of ferrosilicon nitride, 13 parts of bauxite, 2.5 parts of cobalt-doped iron oxide, and 3.5 parts of aluminum-doped titanium dioxide into a blender, and stir at 60°C for 15 minutes to obtain a first mixture.

[0047] S2. Add 4 parts of asphalt and 18 parts of tar to the first mixture obtained in S1, and stir at 60°C for 30 minutes to obtain a second mixture.

[0048] S3. The second mixed material obtained in S2 is squeezed out from the discharge port of the mixer to obtain anhydrous taphole mud for furnace protection.

[0049] Example 3: The difference between this example and Example 1 is that: a method for preparing anhydrous taphole mud for furnace protection comprises the following steps:

[0050] S1. Add 17 parts of coke powder, 11 parts of clay, 8 parts of mica, 15 parts of silicon carbide, 32 parts of brown corundum, 6 parts of glass powder, 12 parts of ferrosilicon nitride, 15 parts of bauxite, 3.3 parts of cobalt-doped iron oxide, and 4.2 parts of aluminum-doped titanium dioxide into a blender, and stir at 70°C for 10 minutes to obtain a first mixture.

[0051] S2. Add 5 parts of asphalt and 20 parts of tar to the first mixture obtained in S1, and stir at 70°C for 25 minutes to obtain a second mixture.

[0052] S3. The second mixed material obtained in S2 is squeezed out from the discharge port of the mixer to obtain anhydrous taphole mud for furnace protection.

[0053] Example 4: The difference between this example and Example 1 is that: a method for preparing anhydrous taphole mud for furnace protection comprises the following steps:

[0054] S1. Add 15 parts of coke powder, 11 parts of clay, 7 parts of mica, 15 parts of silicon carbide, 30 parts of brown corundum, 5 parts of glass powder, 11 parts of ferrosilicon nitride, 14 parts of bauxite, 3.2 parts of cobalt-doped iron oxide, and 4 parts of aluminum-doped titanium dioxide into a blender, and stir at 65°C for 12 minutes to obtain a first mixture.

[0055] S2. Add 5 parts of asphalt and 18 parts of tar to the first mixture obtained in S1, and stir at 65°C for 30 minutes to obtain a second mixture.

[0056] S3. The second mixed material obtained in S2 is squeezed out from the discharge port of the mixer to obtain anhydrous taphole mud for furnace protection.

[0057] Comparative Example 1: The only difference between this comparative example and Example 1 is that cobalt-doped iron oxide and aluminum-doped titanium dioxide are not added in the preparation of the anhydrous taphole mud for furnace protection.

[0058] Specifically, a method for preparing anhydrous taphole mud for furnace protection comprises the following steps:

[0059] S1. Add 16 parts of coke powder, 10.5 parts of clay, 7.5 parts of mica, 14 parts of silicon carbide, 30 parts of brown corundum, 5 parts of glass powder, 11 parts of ferrosilicon nitride and 14 parts of bauxite into a blender, and stir at 65°C for 12 minutes to obtain a first mixture.

[0060] S2. Add 4.5 parts of asphalt and 19 parts of tar to the first mixture obtained in S1, and stir at 65°C for 28 minutes to obtain a second mixture.

[0061] S3. The second mixed material obtained in S2 is squeezed out from the discharge port of the mixer to obtain anhydrous taphole mud for furnace protection.

[0062] Comparative Example 2: The only difference between this comparative example and Example 1 is that cobalt-doped iron oxide is not added in the preparation of the anhydrous taphole mud for furnace protection.

[0063] Specifically, a method for preparing anhydrous taphole mud for furnace protection comprises the following steps:

[0064] S1. Add 16 parts of coke powder, 10.5 parts of clay, 7.5 parts of mica, 14 parts of silicon carbide, 30 parts of brown corundum, 5 parts of glass powder, 11 parts of ferrosilicon nitride, 14 parts of bauxite and 3.8 parts of aluminum-doped titanium dioxide into a blender, and stir at 65°C for 12 minutes to obtain a first mixture.

[0065] S2. Add 4.5 parts of asphalt and 19 parts of tar to the first mixture obtained in S1, and stir at 65°C for 28 minutes to obtain a second mixture.

[0066] S3. The second mixed material obtained in S2 is squeezed out from the discharge port of the mixer to obtain anhydrous taphole mud for furnace protection.

[0067] Comparative Example 3: The only difference between this comparative example and Example 1 is that aluminum-doped titanium dioxide is not added in the preparation of the anhydrous taphole mud for furnace protection.

[0068] Specifically, a method for preparing anhydrous taphole mud for furnace protection comprises the following steps:

[0069] S1. Add 16 parts of coke powder, 10.5 parts of clay, 7.5 parts of mica, 14 parts of silicon carbide, 30 parts of brown corundum, 5 parts of glass powder, 11 parts of ferrosilicon nitride, 14 parts of bauxite and 3 parts of cobalt-doped iron oxide into a blender, and stir at 65°C for 12 minutes to obtain a first mixture.

[0070] S2. Add 4.5 parts of asphalt and 19 parts of tar to the first mixture obtained in S1, and stir at 65°C for 28 minutes to obtain a second mixture.

[0071] S3. The second mixed material obtained in S2 is squeezed out from the discharge port of the mixer to obtain anhydrous taphole mud for furnace protection.

[0072] Test example: 1. The anhydrous taphole mud prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was dried to about 80°C, divided into finger-sized pieces, and filled into a triple mold of 40mm×40mm×160mm, paying attention to the four corners. It was then hammered with a wooden hammer to make it tightly filled. After the strips were cooled and hardened, they were taken out and placed in an iron box (the size of the iron box was slightly larger than the size of the strips). The strips were placed in an oven for heat treatment at 450°C for 5h, and the heat-treated strips were sintered in an electric furnace (at 1400°C for 3h). Finally, the apparent porosity was tested with reference to GB / T 2997-2000.

[0073] 2. According to the same method, the anhydrous taphole clay prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was made into samples with a size of 114 mm × 114 mm × 65 mm. After sintering (1400°C for 3 h), the compressive strength was tested with reference to YB / T 5115-2014.

[0074] Test results: See Table 1.

[0075]

[0076] Result analysis: Combining the data in Table 1 and Figure 1 From the analysis of Examples 1 to 4, it can be seen that the apparent porosity (1400°C×3h) of the sewage cannon mud prepared by the present invention (Examples 1 to 4) is as low as below 24.2%, and the compressive strength (1400°C×3h) is as high as above 28.9MPa.

[0077] Combining the data in Table 1 and Figure 1 An analysis of Example 1 and Comparative Examples 1-3, specifically comparing Comparative Example 1 with Comparative Example 2, shows that, compared to Comparative Example 1, the addition of aluminum-doped titanium dioxide alone to the raw material components in Comparative Example 2 reduced the apparent porosity (1400°C × 3h) of the resulting anhydrous blister mud from 27.2% (Comparative Example 1) to 24.7% (Comparative Example 2), while increasing the compressive strength (1400°C × 3h) from 26.6% (Comparative Example 1) to 28.5% (Comparative Example 2). This indicates that the addition of aluminum-doped titanium dioxide alone to the raw material components can reduce the apparent porosity (1400°C × 3h) and increase the compressive strength (1400°C × 3h) of the resulting anhydrous blister mud.

[0078] A specific comparison between Comparative Examples 1 and 3 shows that, compared to Comparative Example 1, the addition of cobalt-doped iron oxide alone to the raw material components in Comparative Example 3 resulted in an increase in the apparent porosity (1400°C x 3h) of the resulting water-free blister mud from 27.2% (Comparative Example 1) to 28.0% (Comparative Example 3), while a decrease in the compressive strength (1400°C x 3h) from 26.6% (Comparative Example 1) to 25.8% (Comparative Example 3). This indicates that the addition of cobalt-doped iron oxide alone to the raw material components actually increases the apparent porosity (1400°C x 3h) and decreases the compressive strength (1400°C x 3h) of the resulting water-free blister mud. This is primarily because the addition of cobalt-doped iron oxide alone accelerates / facilitates the carburization-reduction reaction of ferrosilicon nitride, accelerating / intensifying nitrogen generation. Furthermore, iron oxide itself can also undergo a reduction reaction with carbon at high temperatures to produce CO2, both of which lead to an increase in the apparent porosity of the water-free blister mud.

[0079] Combined with Example 1 for comparison, it can be seen that by adding aluminum-doped titanium dioxide and cobalt-doped iron oxide to the raw material components at the same time, the two can produce a synergistic effect, synergistically reducing the apparent porosity of the obtained anhydrous taphole mud (1400℃×3h) and improving the compressive strength of the anhydrous taphole mud (1400℃×3h).

[0080] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. 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 method for preparing anhydrous taphole mud for furnace protection, characterized in that: The following steps are involved: S1. Add 15-17 parts of coke powder, 10-11 parts of clay, 7-8 parts of mica, 13-15 parts of silicon carbide, 28-32 parts of brown corundum, 4-6 parts of glass powder, 10-12 parts of ferrosilicon nitride, 13-15 parts of bauxite, 2.5-3.3 parts of cobalt-doped iron oxide, and 3.5-4.2 parts of aluminum-doped titanium dioxide into a blender, and stir at 60-70° C. for 10-15 minutes to obtain a first mixture; S2. Add 4-5 parts of asphalt and 18-20 parts of tar to the first mixture obtained in S1, and stir at a temperature of 60-70°C for 25-30 minutes to obtain a second mixture; S3. The second mixed material obtained in S2 is squeezed out from the discharge port of the mixer to obtain anhydrous taphole mud for furnace protection.

2. The method for preparing anhydrous taphole mud for furnace protection according to claim 1, wherein: The preparation method of the cobalt-doped iron oxide is as follows: A1. Add 2 mmol of iron oleate and 0.05-0.30 mmol of cobalt oleate to a flask, and then add 10 mL of octadecene and 0.7 mL of oleic acid to the flask to obtain a mixed solution; A2. Place the flask containing the mixed solution in a heating mantle for heating. Before starting heating, introduce nitrogen into the flask at a uniform rate and keep the nitrogen flowing during the heating process. The mixture is pyrolyzed at a temperature of 300-320° C. for 1 h. After the reaction is completed, remove the heating mantle and allow the mixture to cool naturally at room temperature to obtain a reaction solution. A3. Add 20 mL of acetone to the reaction solution obtained in A2, centrifuge, disperse the precipitate in hexane, precipitate with acetone, and centrifuge again. Repeat this process three times, and then dry the precipitate to obtain the cobalt-doped iron oxide.

3. The method for preparing anhydrous taphole mud for furnace protection according to claim 2, wherein: In A2, the heating rate is 5-8°C / min.

4. The method for preparing anhydrous taphole mud for furnace protection according to claim 2, wherein: In A3, the drying temperature is 60-65°C and the drying time is 46-48h.

5. The method for preparing anhydrous taphole mud for furnace protection according to claim 1, wherein: The preparation method of the aluminum-doped titanium dioxide is as follows: B1. Pour 10 mL of anhydrous ethanol into a first beaker, then add 6.8-7.0 mL of tetrabutyl titanate into the first beaker and stir to obtain a first solution. B2. Add 2.2 mL of acetic acid, 0.42-0.44 g of aluminum nitrate, 5.2 mL of ethanol, and 1.4 mL of deionized water to a second beaker and stir to mix to obtain a second solution; B3, adding the first solution obtained in B1 to the second solution obtained in B2, and stirring to form a sol, which is then allowed to stand and naturally aged until cracking occurs, thereby obtaining a gel; B4. The gel obtained in B3 is dried in an oven, taken out, ground into powder, and then calcined at 500° C. for 3-4 hours to obtain the aluminum-doped titanium dioxide.

6. The method for preparing anhydrous taphole mud for furnace protection according to claim 5, characterized in that: In B3, the standing time is 12-14h.

7. The method for preparing anhydrous taphole mud for furnace protection according to claim 5, characterized in that: In B4, the drying temperature is 80-85°C and the drying time is 2-3h.

8. The method for preparing anhydrous taphole mud for furnace protection according to claim 1, wherein: The particle size of the coke powder is less than 1 mm, the particle size of the clay is ≤250 mesh, the particle size of the mica is less than 0.074 mm, the particle size of the silicon carbide is less than 0.074 mm, the particle size of the bauxite is less than 0.074 mm, the particle size of the ferrosilicon nitride is less than 0.088 mm, and the particle size of the brown corundum is less than 3 mm.

9. The method for preparing anhydrous taphole mud for furnace protection according to claim 8, characterized in that: In the brown corundum, the mass proportion of particles with a diameter of less than 0.074 mm is 2 / 3.

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