Blast furnace stemming and preparation method thereof

Abstract

The invention discloses blast furnace stemming and a preparation method thereof. The invention discloses a high-temperature-resistant wear-resistant coating which is characterized by comprising the following components in parts by weight: 380-420 parts of brown aluminum oxide, 70-90 parts of a carburant, 50-70 parts of Guangxi white mud, 110-150 parts of silicon carbide, 15-30 parts of asphalt powder, 5-30 parts of vanadium carbide or chromium carbide or a mixture of vanadium carbide and chromium carbide or pore-forming vanadium chromium carbide and 50-100 parts of liquid resin. The blast furnace stemming disclosed by the invention has relatively high high-temperature breaking strength, normal-temperature compression strength and normal-temperature breaking strength, and excellent slag and molten iron erosion resistance and molten iron scouring resistance.

Description

Technical Field

[0001] This invention relates to the field of refractory materials technology. Specifically, it relates to blast furnace taphole clay and its preparation method. Background Technology

[0002] In the blast furnace smelting process, after the blast furnace has finished tapping iron, a taphole clay machine is used to drive the taphole clay material to a certain depth to seal it. When the molten iron in the blast furnace has been smelted and it is time to tap the iron, a taphole opening machine is used to drill through the taphole clay to allow for tapping again. With the continuous development of smelting technology and ironmaking auxiliary materials, anhydrous taphole clay is now mostly used to replace traditional wet taphole clay materials for sealing blast furnace tapholes.

[0003] Anhydrous taphole clay is an unshaped refractory material made with tar, resin, and other binders, along with refractory aggregates such as corundum, silicon carbide, bauxite, and coke powder. Due to the addition of coke powder, anhydrous taphole clay has high permeability, allowing for rapid heat transfer from the inside of the blast furnace to the outside, thus enabling effective sintering and improving its sealing strength. However, the addition of coke powder leads to higher porosity after sintering, resulting in decreased resistance to erosion and scour. Therefore, it is necessary to improve anhydrous taphole clay to enhance its high-temperature strength, scour resistance, and erosion resistance.

[0004] Chinese patent CN117923885A discloses a vanadium-titanium-aluminum alloy taphole clay for blast furnace taphole plugging. The taphole clay contains aluminum powder, titanium powder, and vanadium powder as antioxidants. Furthermore, vanadium and titanium can form high-hardness intermetallic compounds such as vanadium carbide and titanium carbide with carbon. The aluminum powder, titanium powder, and vanadium powder can form a vanadium-titanium-aluminum alloy at high temperatures, thereby effectively improving the strength, oxidation resistance, and erosion resistance of the anhydrous taphole clay. However, this vanadium-titanium-aluminum alloy taphole clay has the following defects: (1) The aluminum powder, titanium powder, and vanadium powder are used as antioxidants and sintering aids, respectively, to improve the performance of the taphole clay through liquid-phase sintering. However, due to the formation of liquid phase at high temperatures, it is not conducive to the high-temperature strength and slag-iron erosion resistance of the taphole clay; (2) The added titanium powder and vanadium powder need to be reacted under certain conditions to be converted into vanadium carbide and titanium carbide. The conversion rate is not high, and the cost of vanadium and titanium is higher.

[0005] Currently, coal tar is still widely used as a liquid binder in the preparation of blast furnace taphole clay. While this has the advantage of low cost, coal tar contains a large amount of toxic and harmful aromatic hydrocarbons, with benzo[a]pyrene content exceeding 10,000 ppm. Furthermore, many companies in the industry produce taphole clay at temperatures as high as 80–90°C, which not only increases energy consumption but also causes weight loss and cost waste due to the high-temperature volatilization of the liquid resin binder. Therefore, it is necessary to further improve existing blast furnace taphole clay and its preparation methods. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to provide anhydrous blast furnace taphole clay with high strength, excellent erosion resistance and scour resistance and its preparation method, so as to solve the technical problems that the existing blast furnace taphole clay has insufficient high temperature resistance, slag and molten iron erosion resistance and molten iron scour resistance.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0008] Blast furnace taphole clay is composed of the following components in parts by weight: 380–420 parts by weight of brown fused alumina, 70–90 parts by weight of recarburizing agent, 50–70 parts by weight of Guangxi white clay, 110–150 parts by weight of silicon carbide, 15–30 parts by weight of pitch powder, and 50–100 parts by weight of liquid resin; or it is composed of the following components in parts by weight: 380–420 parts by weight of brown fused alumina, 70–90 parts by weight of recarburizing agent, 50–70 parts by weight of Guangxi white clay, 110–150 parts by weight of silicon carbide, 15–30 parts by weight of pitch powder, 5–30 parts by weight of vanadium carbide or chromium carbide or a mixture of vanadium carbide and chromium carbide or pore-forming vanadium carbide and 50–100 parts by weight of liquid resin.

[0009] This invention utilizes the addition of specific amounts of vanadium carbide, chromium carbide, or mixtures of vanadium carbide and chromium carbide, or pore-forming vanadium-chromium carbide, to blast furnace taphole mud to improve its high-temperature strength and enhance its wear resistance, erosion resistance, and oxidation resistance. Adding appropriate amounts of brown fused alumina aggregate and fine powder to the taphole mud can improve its high-temperature strength and enhance its resistance to molten slag and iron abrasion and chemical corrosion. However, excessive brown fused alumina can lead to excessively high sintering strength, making drilling difficult; insufficient brown fused alumina will reduce the wear resistance, erosion resistance, and corrosion resistance of the taphole mud, hindering the maintenance of the taphole mud liner structure. The coal-based carbonizer in the taphole mud is characterized by low ash, low sulfur, low phosphorus, high calorific value, and high compressive strength. Compared with metallurgical coke, the coal-based carbonizer is denser, has higher fixed carbon content, and exhibits stronger resistance to blast furnace slag and iron corrosion. Excessive use of recarburizer in blast furnace taphole clay increases the amount of liquid resin required, reducing sintering strength; insufficient recarburizer reduces the clay's resistance to slag and iron corrosion. Excessive use of Guangxi white clay reduces the high-temperature resistance of the blast furnace taphole clay, increases the amount of liquid resin, and leads to excessive plasticity. Insufficient Guangxi white clay results in the clay lacking adequate plasticity, failing to evenly coat aggregates and powders to form a cohesive mass. High-hardness silicon carbide is a non-oxide that is not easily wetted by blast furnace slag and iron. Adding it to blast furnace taphole clay improves its wear resistance and chemical corrosion resistance, extends tapping time, and stabilizes the clay pack structure. Excessive silicon carbide increases cost and makes pore opening difficult; insufficient silicon carbide reduces wear resistance and corrosion resistance, hindering the extension of tapping time and the removal of slag and iron. Adding a certain amount of asphalt powder to blast furnace taphole clay can improve its plasticity, increase its sintering strength, and enhance its overall performance in forming a clay-like structure. Excessive use of asphalt powder will result in overly viscous, hard clay with a slow drying and sintering rate; insufficient asphalt powder will lead to a lack of plasticity and a tendency to crack. Liquid resin can tightly bind various particles and fine powders in the taphole clay together, forming a solid whole and ensuring that the clay does not easily loosen or fall off during use. After the clay is poured into the taphole, the liquid resin dries and solidifies at high temperatures to form solid carbon, increasing the clay's mechanical strength. Excessive use of liquid resin will result in overly soft clay with a slow drying and sintering rate, making it unable to plug the taphole; insufficient use will result in overly dry, hard, and loose blast furnace clay, making it difficult to pour a sufficient amount into the taphole and thus failing to plug it.

[0010] The above-mentioned blast furnace taphole clay is composed of the following components in parts by weight: 390-410 parts by weight of brown corundum, 80-85 parts by weight of carburizing agent, 60-65 parts by weight of Guangxi white clay, 110-120 parts by weight of silicon carbide, 20-25 parts by weight of pitch powder, 7-21 parts by weight of vanadium carbide or chromium carbide or a mixture of vanadium carbide and chromium carbide or pore-forming chromium vanadium carbide, and 70-80 parts by weight of liquid resin.

[0011] The above-mentioned blast furnace taphole clay is composed of the following components in parts by weight: 392-406 parts by weight of brown corundum, 84 parts by weight of carburizing agent, 63 parts by weight of Guangxi white clay, 119 parts by weight of silicon carbide, 21 parts by weight of pitch powder, 7-21 parts by weight of vanadium carbide or chromium carbide, and 77 parts by weight of liquid resin.

[0012] The aforementioned blast furnace taphole clay comprises the following components in parts by weight: 392–406 parts by weight of brown corundum, 84 parts by weight of carburizing agent, 63 parts by weight of Guangxi white clay, 119 parts by weight of silicon carbide, 21 parts by weight of pitch powder, 7–21 parts by weight of pore-forming chromium vanadium carbide, and 77 parts by weight of liquid resin; the preparation method of the pore-forming chromium vanadium carbide is as follows:

[0013] Step A: Weigh carbon powder, chromium powder, vanadium powder and aluminum powder respectively according to the molar ratio of carbon, chromium, vanadium and aluminum of 1:1:1:(1~1.5) and mix them to obtain mixed raw material powder.

[0014] Step B: Mix the mixed raw material powder with methanol at a solid-liquid ratio of 1g:(2-4)mL and ball mill for 2-3 hours. Then, place the mixture in a vacuum drying oven and vacuum dry at 50-65℃ for 2-3 hours to obtain the pretreated raw material powder.

[0015] Step C: Sinter the pretreated raw material powder in an inert gas atmosphere at a temperature of 1600-1800℃ for 1-2 hours. After sintering, allow it to cool naturally to room temperature, then pulverize it through a 1000-mesh sieve and take the sieve-passing material, which is the pore-forming chromium vanadium carbide intermediate powder.

[0016] Step D: Soak the pore-forming chromium vanadium carbide intermediate powder in a 20-30 wt% hydrofluoric acid solution for 5-10 days at a solid-liquid ratio of 1 g: (5-10) mL. After soaking, perform solid-liquid separation. Wash the solid product obtained from the solid-liquid separation with water until the washing liquid is neutral, and then place it in a vacuum drying oven at 90-105℃ for 8-10 hours. After drying, pore-forming chromium vanadium carbide is obtained.

[0017] The above-mentioned blast furnace taphole clay is composed of the following components in parts by weight: 392-406 parts by weight of brown corundum, 84 parts by weight of carburizing agent, 63 parts by weight of Guangxi white clay, 119 parts by weight of silicon carbide, 21 parts by weight of pitch powder, 3.5-10.5 parts by weight of vanadium carbide, 3.5-10.5 parts by weight of chromium carbide, and 77 parts by weight of liquid resin.

[0018] The particle size distribution of brown fused alumina in the aforementioned blast furnace taphole clay is as follows: 160-180 parts by weight of brown fused alumina particles with a particle size greater than 1 mm and less than or equal to 3 mm; 80-90 parts by weight of brown fused alumina powder with a particle size greater than 0.074 mm and less than or equal to 1 mm; and 120-160 parts by weight of fine brown fused alumina powder with a particle size less than or equal to 0.074 mm. Excessive use of brown fused alumina particles will result in a higher proportion of coarse particles in the taphole clay, preventing fine particles and powder from effectively coating the coarse particles, thus affecting its sintering performance and plasticity. Conversely, insufficient use of brown fused alumina particles will result in a lack of coarse aggregate in the blast furnace taphole clay, increasing the specific surface area of ​​the fine particles and powder, leading to liquid... Increased resin content affects sintering strength. Excessive brown fused alumina powder not only disrupts the optimal particle size distribution of the blast furnace clay but also affects the amount of liquid resin added and sintering strength. Insufficient powder results in a lower weight percentage of 0.074-1mm particles in the clay, impacting its overall plasticity and density. Fine brown fused alumina powder acts as a coating agent and matrix reinforcement in the clay. Excessive powder increases the specific surface area of ​​the clay raw materials, leading to increased liquid resin content. Insufficient powder reduces the resistance of the fine powder matrix to slag and iron erosion, lowering the sintering strength. This invention, by controlling the particle size distribution of brown fused alumina particles, powder, and fine powder, facilitates the preparation of blast furnace clay with suitable plasticity and density, exhibiting good sintering strength and resistance to slag and iron erosion.

[0019] The particle size distribution of brown fused alumina in the above-mentioned blast furnace taphole clay is as follows: 175 parts by weight of brown fused alumina particles with a particle size greater than 1 mm and less than or equal to 3 mm, 84 parts by weight of brown fused alumina powder with a particle size greater than 0.074 mm and less than or equal to 1 mm, and 133 to 147 parts by weight of brown fused alumina fine powder with a particle size less than or equal to 0.074 mm.

[0020] The aforementioned blast furnace taphole clay uses a coal-based recarburizer with a particle size of 0.7 mm or less (recarburizer is a dense carbon component that resists slag and iron corrosion; if the recarburizer particle size is too large, it will reduce its dispersion position in the blast furnace taphole clay, thereby weakening the overall performance of the blast furnace taphole clay). It has a fixed carbon content of 91% or more, an ash content of 6.0–8.5 wt%, a volatile matter content of 1.3 wt%, a moisture content of 0.5 wt%, and a bulk density of 1.6 g / cm³ or more. 3The Guangxi white clay is sieved through a 200-mesh sieve; the silicon carbide powder is sieved through a 180-mesh sieve (if the particle size of the silicon carbide powder is larger than 180 mesh, the resulting gunning clay will be too hard, making it difficult to open pores); the mass fraction of silicon carbide in the silicon carbide powder is greater than or equal to 97 wt%; the asphalt powder is high-temperature asphalt powder, sieved through a 150-mesh sieve (high-temperature asphalt, dispersed in the gunning clay in fine powder form, can better improve the plasticity of the gunning clay, ensuring that the gunning clay driven into the taphole forms a better clay-filled structure; if the high-temperature asphalt powder is added in the form of particles larger than 150 mesh, it will cause uneven distribution in the gunning clay, weakening its effect of increasing plasticity); the softening point is 160–200℃, and the ash content is less than or equal to 1.5 wt%. The fixed carbon content is greater than or equal to 50wt%; the liquid resin is a special liquid resin for gunning clay produced by Yanggu Xinmin Refractory Materials Co., Ltd.; vanadium carbide passes through a 1000-mesh sieve, chromium carbide passes through a 1000-mesh sieve, and porous vanadium carbide passes through a 1000-mesh sieve (the addition of vanadium carbide or chromium carbide or a mixture of vanadium carbide and chromium carbide or porous vanadium carbide can improve the sintering performance of gunning clay. The amount added is small but the effect is obvious. The purpose of adding it in the form of 1000-mesh fine powder is to allow it to be dispersed in more places so that it can play a better role; if vanadium carbide or chromium carbide or a mixture of vanadium carbide and chromium carbide or porous vanadium carbide with a particle size greater than 1000 mesh is used, its dispersion effect will be weakened, thereby weakening its role in improving the performance of gunning clay).

[0021] The preparation method of blast furnace taphole clay involves the following steps: Raw material inspection upon arrival – pretreatment of some raw materials (e.g., drying and dehydration of Guangxi white clay). The heating device is turned on in advance to heat the mixer. Then, the mixer is started, and 1-3mm and 0.074-1mm brown fused alumina and 0.7-0mm recarburizer are added and stirred. Liquid resin is then added and stirred further to ensure the liquid resin is evenly coated on the surface of the brown fused alumina particles and recarburizer. Next, other fine powder raw materials are added and crushed. The softness of the taphole clay is tested using a Marshal's value tester. If the material is too soft, bone meal is added and stirring is continued for 5 minutes. If the material is too hard, liquid resin is added and stirring is continued for 5 minutes, and the softness is tested again. If the material meets the technical requirements, it can be discharged from the furnace. If it does not meet the technical requirements, the softness needs to be adjusted until it is acceptable before discharging. During the rolling and mixing process of the blast furnace clay, it is essential to ensure that the temperature of the material inside the pot is controlled at 60~70℃. If the temperature of the blast furnace clay inside the mixer is lower than 60℃, it will not be conducive to the uniform dispersion of the material. If the temperature is higher than 70℃, it will easily cause the volatilization of liquid resin, increasing costs. Specifically, the preparation method of blast furnace clay of this invention includes the following steps:

[0022] Step (1): Prepare raw materials according to the above composition ratio of blast furnace taphole clay, and perform raw material pretreatment;

[0023] Step (2): Add the carbon raiser and brown fused alumina with a particle size greater than 0.074 mm to a preheated mixer and stir. Then add liquid resin and continue stirring. Then add Guangxi white mud, silicon carbide, asphalt powder, vanadium carbide or chromium carbide or a mixture of vanadium carbide and chromium carbide or pore-forming chromium vanadium carbide and crush and stir. After stirring, the gunning clay material is obtained. First, add the carbon raiser particles and brown fused alumina with a particle size greater than 0.074 mm to a preheated mixer and stir. The purpose is to mix the particles evenly and spread them evenly on the bottom plate of the mixer. Then inject the liquid resin binder into the mixer and continue stirring. The purpose is to make the viscous liquid resin evenly coat the surface of the carbon raiser and brown fused alumina particles. Then add the remaining fine powder and crush and stir. The purpose is to make the fine powder coat the surface of the particles and form a gunning clay with uniform dispersion of aggregate powder and liquid resin binder and with plasticity.

[0024] Step (3): Press the blast furnace clay into blocks, cut them into pieces, and package them into shapes to obtain blast furnace clay.

[0025] In the above-mentioned method for preparing blast furnace taphole clay, step (1) includes the pretreatment of raw materials, which includes drying and dehydrating Guangxi white clay. The drying and dehydration conditions are as follows: Guangxi white clay is spread in a thickness of 8-12 cm and dried at a temperature of 100-110℃ for 6-12 hours. Under these drying conditions, the moisture content in Guangxi white clay can be reduced to below 1.5 wt%, so as to avoid the phenomenon of iron splashing during the tapping process of blast furnace due to excessive moisture content in the prepared blast furnace taphole clay.

[0026] In step (2), the preheating temperature of the mixer is 40-50℃ (the liquid resin used in the production of gun clay has a certain viscosity and is relatively viscous at room temperature. Preheating the mixer in advance can reduce the viscosity of the liquid resin added to the mixer, which is conducive to uniform coating and dispersion on the surface of mineral particles; if the mixer is not preheated in advance, the liquid resin will have poor fluidity due to its high viscosity, making it difficult to disperse evenly, and the material in the pot will easily clump together; in this invention, the mixer is preheated to 40-50℃ before adding the carbon raiser, brown fused alumina particles and liquid resin, which can reduce the viscosity of the liquid resin to a suitable level, which is conducive to its uniform dispersion to the carbon raiser and brown fused alumina particles). On the surface); the mixing time for recarburizer and brown fused alumina is 2-3 minutes (to ensure uniform mixing of recarburizer and brown fused alumina particles); the mixing time after adding liquid resin is 3-5 minutes (to ensure uniform coating of liquid resin on the surface of recarburizer and brown fused alumina aggregate); the rolling and mixing time is 55-65 minutes (to ensure that the added fine powder is uniformly coated on the surface of the particles, so that the aggregate and powder are evenly dispersed under the binding effect of liquid resin to form blast furnace clay with viscoplasticity); the material temperature in the mixer is controlled at 60-70℃ during the rolling and mixing process; the mixing speed of the mixer is 5-10 rpm throughout the entire mixing process;

[0027] In step (3), the pressure of the clay material during the molding process is 5-10 MPa, and the holding time is 3-5 s.

[0028] The technical solution of the present invention achieves the following beneficial technical effects:

[0029] 1. The blast furnace taphole mud of this invention is based on the existing Al2O3-SiC-C anhydrous taphole mud. By adding vanadium carbide or chromium carbide or a mixture of vanadium carbide and chromium carbide or pore-forming vanadium carbide, and adjusting the proportions of these materials with brown fused alumina, carbon raiser, Guangxi white clay, silicon carbide powder, pitch powder and binder liquid resin, as well as the particle size distribution of brown fused alumina and the particle size of each raw material, it can form a sealing body with high high-temperature flexural strength, room-temperature compressive strength and room-temperature flexural strength, as well as excellent resistance to slag and molten iron erosion and resistance to molten iron scouring when used for sealing the blast furnace taphole. This improves the problem of poor resistance to slag and molten iron erosion and resistance to molten iron scouring when using existing anhydrous taphole mud for sealing blast furnace tapholes. After aluminum is corroded with hydrofluoric acid, pore-forming chromium vanadium carbide is obtained, which can adsorb liquid resin into the internal pores. After the liquid resin is carbonized at high temperature, it adheres to the inner wall of the pores, thereby improving the corrosion resistance. At the same time, the slag and iron can penetrate into the pores and form a slag layer on the inner wall of the taphole, effectively preventing the taphole diameter from continuously expanding during the tapping process and affecting the tapping process.

[0030] 2. Existing technologies for producing taphole clay involve temperatures as high as 80-90℃, which not only increases energy consumption but also causes weight loss and cost waste due to the high-temperature volatilization of the liquid resin binder. This invention controls the material temperature within the range of 60-70℃ during taphole clay preparation, and achieves thorough mixing of the various raw material components in the taphole clay by adjusting the viscosity of the liquid resin binder. Furthermore, compared to existing technologies that commonly use taphole clay with a fixed carbon content of 80-83%, apparent porosity ≥30%, and a bulk density of only 1.06 g / cm³, this invention achieves significantly better results. 3 Compared to metallurgical coke, the blast furnace taphole mud prepared in this invention uses a coal-based carbon raiser with a particle size of less than or equal to 0.7 mm, resulting in a higher fixed carbon content (≥91%) and a greater bulk density (≥1.6 g / cm³). 3 This results in a lower oil absorption rate, thus effectively reducing the amount of liquid binder used in the production of clay. Attached Figure Description

[0031] Figure 1 Real-life photographs showing the blast furnace slag erosion test results of the comparative blast furnace taphole mud "FMZL-0" of this invention;

[0032] Figure 2 Actual photograph of the blast furnace slag erosion test results of blast furnace taphole mud "FMZL-3" in Example 3 of this invention;

[0033] Figure 3Actual photograph of the blast furnace slag erosion test results of blast furnace taphole mud "FMZL-6" in Example 6 of this invention;

[0034] Figure 4 Actual photograph of the blast furnace slag erosion test results of blast furnace taphole mud "FMZL-9" in Example 9 of this invention. Detailed Implementation

[0035] Example 1

[0036] The blast furnace taphole clay in this embodiment is composed of the following components by weight: 1750g of brown fused alumina (particle size 1-3mm), 840g of brown fused alumina (particle size 1-0.074mm), 1470g of brown fused alumina (passing through a 200-mesh sieve); 840g of carbon raiser (particle size ≤0.7mm), 630g of Guangxi white clay (passing through a 200-mesh sieve), 1190g of 97 silicon carbide powder (passing through a 180-mesh sieve), 210g of high-temperature pitch powder (passing through a 150-mesh sieve), 70g of vanadium carbide (passing through a 1000-mesh sieve), and 770g of liquid resin (a special liquid resin for taphole clay produced by Yanggu Xinmin Refractory Materials Co., Ltd.).

[0037] The preparation method of blast furnace taphole clay in this embodiment includes the following steps:

[0038] Step (1): Prepare raw materials according to the above composition ratio of blast furnace clay and perform raw material pretreatment; the raw material pretreatment includes drying and dehydrating Guangxi white clay. The drying and dehydrating conditions are: spread Guangxi white clay 10cm thick and dry it at 105℃ for 12h.

[0039] Step (2): Add the carbon raiser, brown fused alumina particles with a particle size greater than 1 mm and less than or equal to 3 mm, and brown fused alumina powder with a particle size greater than 0.074 mm and less than or equal to 1 mm to a preheated (50°C) mixer and stir for 2 minutes. Then add liquid resin and continue stirring for 3 minutes. Then add other powders and crush and stir for 55 minutes. During the crushing and stirring process, the material temperature in the mixer is controlled at 65°C. During the entire stirring process, the stirring speed of the mixer is 6 rpm. After the stirring is completed, the gunning mud material is obtained.

[0040] Step (3): Press the blast furnace clay into blocks (the pressure during molding is 10MPa and the holding time is 5s), cut them into blocks (6kg each) and package them to obtain blast furnace clay, named "FMZL-1".

[0041] Example 2

[0042] The blast furnace taphole clay in this embodiment is composed of the following components by weight: 1750g of brown fused alumina (particle size 1-3mm), 840g of brown fused alumina (particle size 1-0.074mm), 1400g of brown fused alumina (passing through a 200-mesh sieve); 840g of carbon raiser (particle size ≤0.7mm), 630g of Guangxi white clay (passing through a 200-mesh sieve), 1190g of 97 silicon carbide powder (passing through a 180-mesh sieve), 210g of high-temperature pitch powder (passing through a 150-mesh sieve), 140g of vanadium carbide (passing through a 1000-mesh sieve), and 770g of liquid resin (a special liquid resin for taphole clay produced by Yanggu Xinmin Refractory Materials Co., Ltd.).

[0043] The above components were prepared using the same method as in Example 1 to obtain blast furnace taphole clay, which was named "FMZL-2".

[0044] Example 3

[0045] The blast furnace taphole clay in this embodiment is composed of the following components by weight: 1750g of brown fused alumina (particle size 1-3mm), 840g of brown fused alumina (particle size 1-0.074mm), 1330g of brown fused alumina (passing through a 200-mesh sieve); 840g of carbon raiser (particle size ≤0.7mm), 630g of Guangxi white clay (passing through a 200-mesh sieve), 1190g of 97 silicon carbide powder (passing through a 180-mesh sieve), 210g of high-temperature pitch powder (passing through a 150-mesh sieve), 210g of vanadium carbide (passing through a 1000-mesh sieve), and 770g of liquid resin (a special liquid resin for taphole clay produced by Yanggu Xinmin Refractory Materials Co., Ltd.).

[0046] The above components were prepared using the same method as in Example 1 to obtain blast furnace taphole clay, which was named "FMZL-3".

[0047] Example 4

[0048] The blast furnace taphole clay in this embodiment is composed of the following components by weight: 1750g of brown fused alumina (particle size 1-3mm), 840g of brown fused alumina (particle size 1-0.074mm), 1470g of brown fused alumina (passing through a 200-mesh sieve); 840g of carbon raiser (particle size ≤0.7mm), 630g of Guangxi white clay (passing through a 200-mesh sieve), 1190g of 97 silicon carbide powder (passing through a 180-mesh sieve), 210g of high-temperature pitch powder (passing through a 150-mesh sieve), 70g of chromium carbide (passing through a 1000-mesh sieve), and 770g of liquid resin (a special liquid resin for taphole clay produced by Yanggu Xinmin Refractory Materials Co., Ltd.).

[0049] The above components were prepared using the same method as in Example 1 to obtain blast furnace taphole clay, which was named "FMZL-4".

[0050] Example 5

[0051] The blast furnace taphole clay in this embodiment is composed of the following components by weight: 1750g brown fused alumina (particle size 1-3mm), 840g brown fused alumina (particle size 1-0.074mm), 1400g brown fused alumina (passed through a 200-mesh sieve); 840g carbon raiser (particle size ≤0.7mm), 630g Guangxi white clay (passed through a 200-mesh sieve), 1190g 97 silicon carbide powder (passed through a 180-mesh sieve), 210g high-temperature pitch powder (passed through a 150-mesh sieve), 140g chromium carbide (passed through a 1000-mesh sieve), and 770g liquid resin (a special liquid resin for taphole clay produced by Yanggu Xinmin Refractory Materials Co., Ltd.).

[0052] The above components were prepared using the same method as in Example 1 to obtain blast furnace taphole clay, which was named "FMZL-5".

[0053] Example 6

[0054] The blast furnace taphole clay in this embodiment is composed of the following components by weight: 1750g of brown fused alumina (particle size 1-3mm), 840g of brown fused alumina (particle size 1-0.074mm), 1330g of brown fused alumina (passing through a 200-mesh sieve); 840g of carbon raiser (particle size ≤0.7mm), 630g of Guangxi white clay (passing through a 200-mesh sieve), 1190g of 97 silicon carbide powder (passing through a 180-mesh sieve), 210g of high-temperature pitch powder (passing through a 150-mesh sieve), 210g of chromium carbide (passing through a 1000-mesh sieve), and 770g of liquid resin (a special liquid resin for taphole clay produced by Yanggu Xinmin Refractory Materials Co., Ltd.).

[0055] The above components were prepared using the same method as in Example 1 to obtain blast furnace taphole clay, which was named "FMZL-6".

[0056] Example 7

[0057] The blast furnace taphole clay in this embodiment is composed of the following components by weight: 1750g brown fused alumina (particle size 1-3mm), 840g brown fused alumina (particle size 1-0.074mm), 1470g brown fused alumina (passed through a 200-mesh sieve); 840g carbon raiser (particle size ≤0.7mm), 630g Guangxi white clay (passed through a 200-mesh sieve), 1190g 97 silicon carbide powder (passed through a 180-mesh sieve), 210g high-temperature pitch powder (passed through a 150-mesh sieve), 35g vanadium carbide (passed through a 1000-mesh sieve), 35g chromium carbide (passed through a 1000-mesh sieve), and 770g liquid resin (a special liquid resin for taphole clay produced by Yanggu Xinmin Refractory Materials Co., Ltd.).

[0058] The above components were prepared using the same method as in Example 1 to obtain blast furnace taphole clay, which was named "FMZL-7".

[0059] Example 8

[0060] The blast furnace taphole clay in this embodiment is composed of the following components by weight: 1750g brown fused alumina (particle size 1-3mm), 840g brown fused alumina (particle size 1-0.074mm), 1400g brown fused alumina (passing through a 200-mesh sieve); 840g carbon raiser (particle size ≤0.7mm), 630g Guangxi white clay (passing through a 200-mesh sieve), 1190g 97 silicon carbide powder (passing through a 180-mesh sieve), 210g high-temperature pitch powder (passing through a 150-mesh sieve), 70g vanadium carbide (passing through a 1000-mesh sieve), 70g chromium carbide (passing through a 1000-mesh sieve), and 770g liquid resin (a special liquid resin for taphole clay produced by Yanggu Xinmin Refractory Materials Co., Ltd.).

[0061] The above components were prepared using the same method as in Example 1 to obtain blast furnace taphole clay, which was named "FMZL-8".

[0062] Example 9

[0063] The blast furnace taphole clay in this embodiment is composed of the following components by weight: 1750g brown fused alumina (particle size 1-3mm), 840g brown fused alumina (particle size 1-0.074mm), 1330g brown fused alumina (passed through a 200-mesh sieve); 840g carbon raiser (particle size ≤0.7mm), 630g Guangxi white clay (passed through a 200-mesh sieve), 1190g 97 silicon carbide powder (passed through a 180-mesh sieve), 210g high-temperature pitch powder (passed through a 150-mesh sieve), 105g vanadium carbide (passed through a 1000-mesh sieve), 105g chromium carbide (passed through a 1000-mesh sieve), and 770g liquid resin (a special liquid resin for taphole clay produced by Yanggu Xinmin Refractory Materials Co., Ltd.).

[0064] The above components were prepared using the same method as in Example 1 to obtain blast furnace taphole clay, which was named "FMZL-9".

[0065] Example 10

[0066] The blast furnace taphole clay in this embodiment is composed of the following components by weight: 1750g brown fused alumina (particle size 1-3mm), 840g brown fused alumina (particle size 1-0.074mm), 1330g brown fused alumina (passing through a 200-mesh sieve); 840g carbon raiser (particle size ≤0.7mm), 630g Guangxi white clay (passing through a 200-mesh sieve), 1190g 97 silicon carbide powder (passing through a 180-mesh sieve), 210g high-temperature pitch powder (passing through a 150-mesh sieve), 210g pore-forming chromium vanadium carbide (passing through a 1000-mesh sieve), and 770g liquid resin (a special liquid resin for taphole clay produced by Yanggu Xinmin Refractory Materials Co., Ltd.).

[0067] In this embodiment, the method for preparing pore-forming chromium vanadium carbide is as follows:

[0068] Step A: Weigh carbon powder, chromium powder, vanadium powder and aluminum powder according to the molar ratio of carbon, chromium, vanadium and aluminum of 1:1:1:1.5 and mix them to obtain mixed raw material powder.

[0069] Step B: Mix 500g of the mixed raw material powder with 1500mL of methanol and ball mill for 3 hours, then place it in a vacuum drying oven and vacuum dry at 65℃ for 3 hours to obtain the pretreated raw material powder.

[0070] Step C: Sinter the pretreated raw material powder in an inert gas atmosphere at a temperature of 1800℃ for 1 hour. After sintering, allow it to cool naturally to room temperature, then pulverize it through a 1000-mesh sieve and take the sieve-passing material, which is the pore-forming chromium vanadium carbide intermediate powder.

[0071] Step D: Soak the pore-forming chromium vanadium carbide intermediate powder in a 30wt% hydrofluoric acid solution for 10 days at a solid-liquid ratio of 1g:10mL. After soaking, perform solid-liquid separation. Wash the solid product obtained from the solid-liquid separation with water until the washing liquid is neutral, and then place it in a vacuum drying oven and vacuum dry at 105℃ for 8 hours. After drying, pore-forming chromium vanadium carbide is obtained.

[0072] The above components were prepared using the same method as in Example 1 to obtain blast furnace taphole clay, which was named "FMZL-10".

[0073] Comparative Example

[0074] This comparative example of blast furnace taphole clay consists of the following components by weight: 1750g brown fused alumina (particle size 1-3mm), 840g brown fused alumina (particle size 1-0.074mm), 1540g brown fused alumina (passed through a 200-mesh sieve); 840g carburizing agent (particle size ≤0.7mm), 630g Guangxi white clay (passed through a 200-mesh sieve), 1190g 97 silicon carbide powder (passed through a 180-mesh sieve), 210g high-temperature pitch powder (passed through a 150-mesh sieve), and 770g liquid resin (a special liquid resin for taphole clay produced by Yanggu Xinmin Refractory Materials Co., Ltd.).

[0075] The above components were prepared using the same method as in Example 1 to obtain blast furnace taphole clay, which was named "FMZL-0".

[0076] Table 1 shows the composition of blast furnace taphole clay in Examples 1 to 10 and the comparative examples.

[0077] Table 1

[0078]

[0079] Sample preparation and firing: Seven cylindrical and eleven strip samples of blast furnace taphole clay from Examples 1 to 10 and the comparative example were prepared respectively, and fired at 1200℃ / 1400℃ / 1500℃ respectively. The compressive strength / flexural strength / apparent porosity / bulk density / linear change rate, and high-temperature flexural strength at 1200℃ and 1450℃ were tested after firing. The test results are shown in Table 2.

[0080] Table 2

[0081]

[0082] Examples 1 to 10 are blast furnace taphole clay prepared with vanadium carbide, chromium carbide, vanadium carbide and chromium carbide, or porous vanadium carbide. The comparative examples are taphole clay prepared without vanadium carbide and / or chromium carbide, and with porous vanadium carbide. Table 2 shows that, compared to the comparative examples, for vanadium carbide alone, the two samples with vanadium carbide additions of 1 wt% and 2 wt% showed improved high-temperature flexural strength at 1200℃ and 1450℃, and improved room-temperature compressive strength after firing at 1200℃. For taphole clay with chromium carbide alone, the high-temperature flexural strength tested at 1200℃ for 1 hour and the room-temperature compressive strength after firing at 1200℃ were improved. For taphole clay with combined vanadium carbide and chromium carbide additions, the high-temperature flexural strength tested at 1200℃ and 1450℃ was significantly improved. For the pore-forming chromium vanadium carbide added to the taphole clay, its high-temperature flexural strength, as well as its room-temperature compressive strength and room-temperature flexural strength after firing under different temperature conditions, are all improved to varying degrees, and the taphole clay has the best overall performance.

[0083] Crucible Test: Crucibles were prepared for five samples (FMZL-0, FMZL-3, FMZL-6, and FMZL-9), and blast furnace slag erosion tests were conducted at 1550℃ for comparison. Experimental results are shown below. Figures 1 to 4 .

[0084] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. Blast furnace taphole clay, characterized in that, It is composed of the following components in parts by weight: 380-420 parts by weight of brown fused alumina, 70-90 parts by weight of carbon refining agent, 50-70 parts by weight of Guangxi white clay, 110-150 parts by weight of silicon carbide, 15-30 parts by weight of pitch powder, and 50-100 parts by weight of liquid resin; or it is composed of the following components in parts by weight: 380-420 parts by weight of brown fused alumina, 70-90 parts by weight of carbon refining agent, 50-70 parts by weight of Guangxi white clay, 110-150 parts by weight of silicon carbide, 15-30 parts by weight of pitch powder, 5-30 parts by weight of vanadium carbide or chromium carbide or a mixture of vanadium carbide and chromium carbide or pore-forming chromium vanadium carbide, and 50-100 parts by weight of liquid resin.

2. The blast furnace taphole clay according to claim 1, characterized in that, It is composed of the following components in parts by weight: 390-410 parts by weight of brown corundum, 80-85 parts by weight of carbon raiser, 60-65 parts by weight of Guangxi white clay, 110-120 parts by weight of silicon carbide, 20-25 parts by weight of pitch powder, 7-21 parts by weight of vanadium carbide or chromium carbide or a mixture of vanadium carbide and chromium carbide or pore-forming chromium vanadium carbide, and 70-80 parts by weight of liquid resin.

3. The blast furnace taphole clay according to claim 2, characterized in that, It is composed of the following components in parts by weight: 392-406 parts by weight of brown corundum, 84 parts by weight of carbon raiser, 63 parts by weight of Guangxi white clay, 119 parts by weight of silicon carbide, 21 parts by weight of pitch powder, 7-21 parts by weight of vanadium carbide or chromium carbide, and 77 parts by weight of liquid resin.

4. The blast furnace taphole clay according to claim 2, characterized in that, It is composed of the following components in parts by weight: 392-406 parts by weight of brown corundum, 84 parts by weight of carbon raiser, 63 parts by weight of Guangxi white clay, 119 parts by weight of silicon carbide, 21 parts by weight of pitch powder, 7-21 parts by weight of pore-forming chromium vanadium carbide, and 77 parts by weight of liquid resin; the preparation method of pore-forming chromium vanadium carbide is as follows: Step A: Weigh carbon powder, chromium powder, vanadium powder and aluminum powder respectively according to the molar ratio of carbon, chromium, vanadium and aluminum of 1:1:1:(1~1.5) and mix them to obtain mixed raw material powder. Step B: Mix the mixed raw material powder with methanol at a solid-liquid ratio of 1g:(2-4)mL and ball mill for 2-3 hours. Then, place the mixture in a vacuum drying oven and vacuum dry at 50-65℃ for 2-3 hours to obtain the pretreated raw material powder. Step C: Sinter the pretreated raw material powder in an inert gas atmosphere at a temperature of 1600-1800℃ for 1-2 hours. After sintering, allow it to cool naturally to room temperature, then pulverize it through a 1000-mesh sieve and take the sieve-passing material, which is the pore-forming chromium vanadium carbide intermediate powder. Step D: Soak the pore-forming chromium vanadium carbide intermediate powder in a 20-30 wt% hydrofluoric acid solution for 5-10 days at a solid-liquid ratio of 1 g: (5-10) mL. After soaking, perform solid-liquid separation. Wash the solid product obtained from the solid-liquid separation with water until the washing liquid is neutral, and then place it in a vacuum drying oven at 90-105℃ for 8-10 hours. After drying, pore-forming chromium vanadium carbide is obtained.

5. The blast furnace taphole clay according to claim 2, characterized in that, It is composed of the following components in parts by weight: 392-406 parts by weight of brown corundum, 84 parts by weight of carbon raiser, 63 parts by weight of Guangxi white clay, 119 parts by weight of silicon carbide, 21 parts by weight of pitch powder, 3.5-10.5 parts by weight of vanadium carbide, 3.5-10.5 parts by weight of chromium carbide, and 77 parts by weight of liquid resin.

6. The blast furnace taphole clay according to any one of claims 1-5, characterized in that, The particle size distribution of brown fused alumina is as follows: 160-180 parts by weight of brown fused alumina particles with a particle size greater than 1 mm and less than or equal to 3 mm, 80-90 parts by weight of brown fused alumina powder with a particle size greater than 0.074 mm and less than or equal to 1 mm, and 120-160 parts by weight of brown fused alumina fine powder with a particle size less than or equal to 0.074 mm.

7. The blast furnace taphole clay according to claim 6, characterized in that, The particle size distribution of brown fused alumina is as follows: 175 parts by weight of brown fused alumina particles with a particle size greater than 1 mm and less than or equal to 3 mm, 84 parts by weight of brown fused alumina powder with a particle size greater than 0.074 mm and less than or equal to 1 mm, and 133 to 147 parts by weight of brown fused alumina fine powder with a particle size less than or equal to 0.074 mm.

8. The blast furnace taphole clay according to claim 6, characterized in that, The carbon raiser is a coal-based carbon raiser with a particle size of 0.7 mm or less, a fixed carbon content of 91% or more, an ash content of 6.0–8.5 wt%, a volatile matter content of 1.3 wt% or less, a moisture content of 0.5 wt% or less, and a bulk density of 1.6 g / cm³ or more. 3 The Guangxi white clay is sieved through a 200-mesh sieve; the silicon carbide powder is sieved through a 180-mesh sieve, with a silicon carbide mass fraction greater than or equal to 97 wt%; the asphalt powder is high-temperature asphalt powder, sieved through a 150-mesh sieve, with a softening point of 160–200℃, an ash content less than or equal to 1.5 wt%, and a fixed carbon content greater than or equal to 50 wt%; the liquid resin is a special liquid resin for gunning clay produced by Yanggu Xinmin Refractory Materials Co., Ltd.; vanadium carbide is sieved through a 1000-mesh sieve, chromium carbide is sieved through a 1000-mesh sieve, and the pore-forming chromium vanadium carbide is sieved through a 1000-mesh sieve.

9. A method for preparing blast furnace taphole clay, characterized in that, Includes the following steps: Step (1): Prepare raw materials according to the composition ratio of blast furnace taphole clay as described in claim 1, and perform raw material pretreatment; Step (2): Add the carbon raiser and brown corundum with a particle size greater than 0.074 mm to a preheated mixer and stir. Then add liquid resin and continue stirring. Then add Guangxi white mud, silicon carbide, asphalt powder, vanadium carbide or chromium carbide or a mixture of vanadium carbide and chromium carbide or pore-forming chromium vanadium carbide and crush and stir. After stirring, the gunning mud material is obtained. Step (3): Press the blast furnace clay into blocks, cut them into pieces, and package them into shapes to obtain blast furnace clay.

10. The method for preparing blast furnace taphole clay according to claim 9, characterized in that, In step (1), the raw material pretreatment includes drying and dehydrating Guangxi white clay. The drying and dehydration conditions are as follows: Guangxi white clay is spread in a thickness of 8-12 cm and dried at a temperature of 100-110℃ for 6-12 hours. In step (2), the preheating temperature of the mixer is 40-50℃; the mixing time of the carbon raiser and brown corundum is 2-3 min, and the mixing time after adding the liquid resin is 3-5 min; the rolling and mixing time is 55-65 min, and the material temperature in the mixer is controlled at 60-70℃ during the rolling and mixing process; the mixing speed of the mixer is 5-10 rpm throughout the mixing process. In step (3), the pressure of the clay material during the molding process is 5-10 MPa, and the holding time is 3-5 s.

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