Tundish slag line dry material

Abstract

The application discloses a tundish slag line dry material, and relates to the technical field of tundish refractory materials. The mass percentage of each raw material component in the tundish slag line dry material is as follows: 26-30% of 3-1mm fused magnesite, 22-28% of 1-0mm fused magnesite, 20-27% of 200-mesh fused magnesite, 1.5-2% of trisodium phosphate hexahydrate, 2-2.5% of sodium metasilicate nonahydrate, 1-1.5% of adipic acid, 4-5% of calcium carbonate, 0.3-0.5% of vermiculite, and the rest of 5-3mm fused magnesite. The application adopts a new composite binder system, solves the environmental protection problem of a traditional phenolic resin binder, and significantly improves the medium-temperature and high-temperature strength, corrosion resistance, thermal shock resistance and heat insulation performance of the magnesia dry material through the synergistic effect among the components, so that the overall optimization of the material performance is realized.

Description

Technical Field

[0001] This invention belongs to the technical field of tundish refractory materials, and specifically relates to a dry material for tundish slag lines. Background Technology

[0002] In modern steel production processes, the tundish, as a key component in continuous casting, directly impacts the purity of molten steel, production efficiency, and cost control due to the performance of its refractory materials. Tundish magnesia dry charge, a commonly used refractory material, plays a crucial role in maintaining good molten steel flow characteristics, reducing inclusions, and improving billet quality. However, traditional tundish magnesia dry charge commonly uses phenolic resin as the main binder. Although phenolic resin is widely used due to its good bonding properties and ease of application, several problems it has revealed in practical applications are increasingly attracting industry attention.

[0003] Phenolic resins release large amounts of volatile organic compounds (VOCs) during the heating and curing process. These chemicals not only have a strong, pungent odor and pose a potential threat to human health, but long-term exposure to such an environment can also lead to respiratory illnesses and other occupational health problems for employees, and in severe cases, even violate increasingly stringent environmental regulations. Therefore, finding a low-VOC or VOC-free environmentally friendly binder has become an urgent priority. Furthermore, the strength performance of phenolic resin-bonded magnesium dry charge is unsatisfactory under medium and high temperature conditions. During medium-temperature ladle baking and use, prolonged scouring by molten steel and frequent thermal shocks caused by temperature changes can lead to dry charge spalling due to its low strength, and even ladle collapse. This directly limits the service life of the tundish, reduces the operating efficiency of the continuous casting production line, and introduces certain safety risks.

[0004] Although several environmentally friendly binders have emerged on the market, such as water glass and phosphate binders, their overall performance, especially in terms of strength, corrosion resistance, and ease of application, still falls short of fully meeting the high standards required by modern continuous casting processes. Summary of the Invention

[0005] To address the environmental issues of phenolic resin binders in existing tundish magnesium dry feedstocks and the severe erosion and peeling of the dry feedstock due to insufficient strength during use, this invention provides a tundish slag line dry feedstock that overcomes the shortcomings of traditional phenolic resin binders, significantly improves the strength of the tundish dry feedstock, and ensures a green and environmentally friendly production environment.

[0006] The solution adopted by this invention to solve its technical problem is: a dry material for tundish slag lines, wherein the mass percentage of each raw material component in the dry material for tundish slag lines is as follows: 26-30% 3-1mm fused magnesia, 22-28% 1-0mm fused magnesia, 20-27% 200-mesh fused magnesia, 1.5-2% trisodium phosphate hexahydrate, 2-2.5% sodium metasilicate nonahydrate, 1-1.5% adipic acid, 4-5% calcium carbonate, 0.3-0.5% vermiculite, and the balance being 5-3mm fused magnesia.

[0007] Furthermore, the dry material of the intermediate slag line contains 28% 3-1mm fused magnesia, 25% 1-0mm fused magnesia, 24% 200-mesh fused magnesia, 1.8% trisodium phosphate hexahydrate, 2.2% sodium metasilicate nonahydrate, 1.2% adipic acid, 4.4% calcium carbonate, 0.4% vermiculite, and the balance being 5-3mm fused magnesia.

[0008] Furthermore, the MgO content in the fused magnesia is ≥91%.

[0009] Furthermore, the trisodium phosphate hexahydrate, sodium metasilicate nonahydrate, and adipic acid are all industrial grade.

[0010] Furthermore, the calcium carbonate has a particle size of 2000 mesh and a CaCO3 content of ≥98%.

[0011] Furthermore, the vermiculite has a particle size of 325 mesh, and the vermiculite contains MgO content ≥21%, Al2O3 content ≥14%, and Fe2O3 content ≤7%.

[0012] Furthermore, the sum of the mass percentages of trisodium phosphate hexahydrate, sodium metasilicate nonahydrate, and adipic acid in the dry feed of the intermediate ballast line is 4.8% to 5.8%.

[0013] Furthermore, when the dry material of the intermediate bag slag line is used to make bags, the baking time is ≥1.5h, and the inner wall temperature of the working layer membrane is ≥280℃.

[0014] This invention utilizes trisodium phosphate hexahydrate, which, as an alkaline binder, combines with water vapor to form a stable complex at lower temperatures, providing good initial adhesion and aiding in the molding and curing of dry refractory materials. At high temperatures, phosphates can react with magnesium materials to form a glassy phase, enhancing the high-temperature structural strength and corrosion resistance of the refractory material. During heating, the phosphate ions generated from the decomposition of trisodium phosphate react with magnesium ions to form refractory magnesium phosphate salts. This reaction not only enhances the high-temperature stability of the dry refractory material but also effectively fills the pores inside, improving its density.

[0015] This invention uses sodium metasilicate nonahydrate, which has high alkalinity and good water solubility, which helps to achieve uniform mixing of dry materials and moisture evaporation during the curing process. When heated, sodium metasilicate nonahydrate gradually loses its water of crystallization and transforms into a silicon dioxide network. This network structure not only increases the refractoriness of the material, but also forms fine closed pores, improving the material's thermal insulation performance and resistance to thermal stress. At the same time, the silicon-oxygen network structure formed by the decomposition of sodium metasilicate nonahydrate at high temperatures can significantly improve the material's high-temperature strength and thermal shock resistance.

[0016] This invention uses adipic acid, an organic acid, which undergoes a condensation reaction with the alkaline components in the dry material during high-temperature heating to form a cross-linked network structure. This structure helps to disperse stress and prevent crack formation, thereby improving the overall strength and crack resistance of the dry material.

[0017] This invention uses calcium carbonate, which decomposes into calcium oxide and carbon dioxide at high temperatures. The calcium oxide further reacts with other components, which helps to form a denser structure, thereby adjusting the density and porosity of the dry material, improving its volume stability, and reducing production costs. The released carbon dioxide can act as a foaming agent to some extent, helping to form a microporous structure and enhancing the insulation effect.

[0018] This invention utilizes vermiculite. The layered structure of vermiculite expands between the hydrated layers when heated, forming numerous tiny air gaps. These gaps act as an insulation layer, effectively slowing down heat transfer and giving it excellent expansion and insulation properties. At the same time, it also increases the elasticity of the material, significantly improving the thermal shock resistance of dry materials and reducing material damage caused by rapid temperature changes.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. This invention adopts a novel composite binder system, which, compared with traditional phenolic resin binders, greatly reduces the emission of harmful gases, reduces workplace odor, significantly improves the working environment for employees, reduces occupational health risks, and meets the requirements of modern industry for green production and sustainable development.

[0021] 2. The trisodium phosphate hexahydrate and sodium metasilicate nonahydrate selected in this invention can react with fused magnesia at high temperatures to form a stable and high-strength silicate and phosphate glass phase, which effectively improves the medium and high temperature strength of the dry material, increases the service life of the dry material, and enhances the medium and high temperature strength of the dry material in the tundish slag line.

[0022] 3. This invention introduces adipic acid and vermiculite, which significantly enhance the toughness and thermal shock resistance of the dry material in the tundish slag line by forming a cross-linked network structure and an expanded layered structure, reducing material cracking and spalling caused by sudden temperature changes, and improving the stability and safety of the continuous casting process.

[0023] 4. The present invention uses calcium carbonate. The carbon dioxide produced by the decomposition of calcium carbonate and the interlayer expansion of vermiculite work together to form a good microporous thermal insulation structure, which effectively isolates the external high temperature, reduces the temperature fluctuation of molten steel, and improves the volume stability of dry materials.

[0024] In summary, by employing a novel composite binder system, this invention not only solves the environmental problems associated with traditional phenolic resin binders, but also significantly improves the medium- and high-temperature strength, erosion resistance, thermal shock resistance, and thermal insulation properties of magnesia dry refractory materials through the synergistic effect among the components. This achieves comprehensive optimization of material properties and brings innovation to the field of refractory materials for continuous casting tundishes. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0026] This invention provides a technical solution for dry feed in tundish slag lines:

[0027] A dry feedstock for tundish slag lines, wherein the mass percentage of each raw material component in the dry feedstock for tundish slag lines is as follows: 26-30% 3-1mm fused magnesia, 22-28% 1-0mm fused magnesia, 20-27% 200-mesh fused magnesia, 1.5-2% trisodium phosphate hexahydrate, 2-2.5% sodium metasilicate nonahydrate, 1-1.5% adipic acid, 4-5% calcium carbonate, 0.3-0.5% vermiculite, and the balance being 5-3mm fused magnesia.

[0028] In a preferred embodiment of the present invention, the dry material of the tundish slag line contains 28% 3-1mm fused magnesia, 25% 1-0mm fused magnesia, 24% 200-mesh fused magnesia, 1.8% trisodium phosphate hexahydrate, 2.2% sodium metasilicate nonahydrate, 1.2% adipic acid, 4.4% calcium carbonate, 0.4% vermiculite, and the balance being 5-3mm fused magnesia.

[0029] This invention uses 5-3mm fused magnesia. The larger-sized fused magnesia particles primarily act as a skeletal support in the dry charge of the tundish slag line, enhancing the overall strength and erosion resistance of the material. This helps reduce shrinkage caused by temperature changes during sintering or use, maintaining material stability. Appropriate particle spacing also improves permeability, facilitating the flow of molten steel and uniform temperature distribution within the tundish. Using 3-1mm fused magnesia, together with the 5-3mm particles, forms a stable skeletal system. Through reasonable particle size matching, the bulk density and uniformity of the dry charge can be improved, porosity reduced, thereby enhancing the erosion resistance and erosion resistance of the dry charge. Using 1-0mm fused magnesia... Fused magnesia, with its smaller particle size, can fill the gaps between larger particles, improving the density and compactness of the dry material. By refining the particle size distribution, it can further improve the thermal shock resistance and erosion resistance of the dry material. At the same time, the 1-0 mm small particles have a larger specific surface area, which is beneficial to the diffusion and reaction of materials during sintering, accelerating the sintering process. Using 200 mesh fused magnesia, the ultrafine fused magnesia particles can significantly refine the microstructure of the material, improving the uniformity and compactness of the dry material. The refined structure helps to improve the strength, hardness, and wear resistance of the dry material, while enhancing its resistance to penetration and erosion, and can further form a denser and more uniform sintered body.

[0030] In a preferred embodiment of the present invention, the fused magnesia contains ≥91% MgO.

[0031] This invention uses high-purity fused magnesia as raw material. High-purity fused magnesia has large crystal grains and a dense structure during the melting process. The dry tundish slag line material prepared from it also has good structural stability. Fused magnesia with high MgO content has strong resistance to slag erosion. The dry tundish slag line material prepared from it also has good refractoriness and compressive strength. It can maintain stable performance in high-temperature environments and effectively extend the service life of the tundish.

[0032] In a preferred embodiment of the present invention, the trisodium phosphate hexahydrate, sodium metasilicate nonahydrate, and adipic acid are all industrial grade.

[0033] This invention uses industrial-grade trisodium phosphate hexahydrate, sodium metasilicate nonahydrate, and adipic acid as raw materials, which possess high purity and stable chemical composition. These characteristics help reduce the impurity content in the dry feedstock of the tundish slag line, improving its overall performance and quality. During the preparation process, harmful reactions are less likely to occur, facilitating control over the performance and stability of the dry feedstock. These raw materials generate less waste and pollutants during use and are easy to process and recycle. Furthermore, the industrial-grade raw materials help reduce harm to human health and the environment.

[0034] In a preferred embodiment of the present invention, the calcium carbonate has a particle size of 2000 mesh and a CaCO3 content of ≥98%.

[0035] This invention uses high-purity calcium carbonate, which reduces the adverse effects of impurities on the performance of dry refractory materials, and helps to improve the overall quality and stability of dry refractory materials. Fine-grained calcium carbonate particles are conducive to forming a denser and more uniform microstructure in dry refractory materials. Fine particles can fill more voids and improve the density and strength of castables.

[0036] In a preferred embodiment of the present invention, the vermiculite has a particle size of 325 mesh, and the vermiculite contains MgO content ≥21%, Al2O3 content ≥14%, and Fe2O3 content ≤7%.

[0037] This invention uses 325-mesh vermiculite, which helps to achieve better mixing uniformity during the preparation process. The fine particles can also more effectively fill the pores of the dry charge, improving the density and strength of the material. The high MgO content can significantly improve the refractory performance of the dry charge of the tundish slag line, extend its service life, and enhance the thermal stability of the material, reducing cracking and spalling caused by temperature changes. An appropriate amount of Al2O3 helps to improve the overall mechanical properties of the dry charge, enhances the chemical stability of the material, and resists the erosion of molten steel and slag. A small amount of Fe2O3 can reduce the contamination of molten steel by iron generated during the use of the material, which is beneficial to maintaining the cleanliness of the molten steel. At the same time, the low Fe2O3 content helps to maintain the excellent performance of the material.

[0038] In a preferred embodiment of the present invention, the total mass percentage of trisodium phosphate hexahydrate, sodium metasilicate nonahydrate, and adipic acid in the dry feed of the tundish slag line is 4.8-5.8%.

[0039] The synergistic effect of trisodium phosphate hexahydrate, sodium metasilicate nonahydrate, and adipic acid in dry feedstock can significantly improve the material's refractoriness, erosion resistance, uniformity, and density, thereby increasing the service life and performance stability of the dry feedstock. This invention, through the rational proportioning of the three raw materials, can effectively control costs while ensuring performance, and at the same time ensure that high-quality dry feedstock for tundish slag lines can be stably obtained in actual production.

[0040] In a preferred embodiment of the present invention, the baking time of the dry material in the intermediate bag slag line is ≥1.5h, and the inner wall temperature of the working layer membrane is ≥280℃.

[0041] Extending the baking time and increasing the temperature of the inner wall of the working layer membrane helps the binder in the dry material to fully react and sinter, forming a denser and stronger structure. This not only improves the mechanical strength of the dry material but also enhances its resistance to erosion, thereby extending the service life of the tundish. Long-term baking at high temperatures allows the moisture and volatiles in the dry material to be fully removed, reducing internal stress caused by temperature changes. This helps prevent cracking and peeling of the dry material during use, improving its stability and reliability.

[0042] Specific implementation examples:

[0043] The following provides a specific embodiment of the dry feed for tundish slag lines according to the present invention.

[0044] Example 1:

[0045] This embodiment provides a dry feedstock for tundish slag lines. The percentage of each component in the dry feedstock by mass percentage is as follows: 28% 3-1mm fused magnesia, 25% 1-0mm fused magnesia, 24% 200-mesh fused magnesia, 1.8% trisodium phosphate hexahydrate, 2.2% sodium metasilicate nonahydrate, 1.2% adipic acid, 4.4% calcium carbonate, 0.4% vermiculite, and the balance being 5-3mm fused magnesia.

[0046] Example 2:

[0047] This embodiment provides a dry feedstock for tundish slag lines. The percentage of each component in the dry feedstock by mass percentage is as follows: 30% fused magnesia of 3-1mm, 22% fused magnesia of 1-0mm, 25% fused magnesia of 200 mesh, 1.6% trisodium phosphate hexahydrate, 2.3% sodium metasilicate nonahydrate, 1.5% adipic acid, 4.6% calcium carbonate, 0.5% vermiculite, and the balance being fused magnesia of 5-3mm.

[0048] Example 3:

[0049] This embodiment provides a dry feedstock for tundish slag lines. The percentage of each component in the dry feedstock by mass percentage is as follows: 26% 3-1mm fused magnesia, 26% 1-0mm fused magnesia, 20% 200-mesh fused magnesia, 1.9% trisodium phosphate hexahydrate, 2.5% sodium metasilicate nonahydrate, 1.4% adipic acid, 4.2% calcium carbonate, 0.3% vermiculite, and the balance being 5-3mm fused magnesia.

[0050] Example 4:

[0051] This embodiment provides a dry feedstock for tundish slag lines. The percentage of each component in the dry feedstock by mass percentage is as follows: 27% 3-1mm fused magnesia, 28% 1-0mm fused magnesia, 22% 200-mesh fused magnesia, 1.7% trisodium phosphate hexahydrate, 2% sodium metasilicate nonahydrate, 1.1% adipic acid, 5% calcium carbonate, 0.4% vermiculite, and the balance being 5-3mm fused magnesia.

[0052] Example 5:

[0053] This embodiment provides a dry feedstock for tundish slag lines. The percentage of each component in the dry feedstock by mass percentage is as follows: 26% 3-1mm fused magnesia, 24% 1-0mm fused magnesia, 27% 200-mesh fused magnesia, 1.5% trisodium phosphate hexahydrate, 2.4% sodium metasilicate nonahydrate, 1.3% adipic acid, 4.8% calcium carbonate, 0.5% vermiculite, and the balance being 5-3mm fused magnesia.

[0054] Example 6:

[0055] This embodiment provides a dry feedstock for tundish slag lines. The percentage of each component in the dry feedstock by mass percentage is as follows: 28% 3-1mm fused magnesia, 25% 1-0mm fused magnesia, 23% 200-mesh fused magnesia, 2% trisodium phosphate hexahydrate, 2.1% sodium metasilicate nonahydrate, 1% adipic acid, 4% calcium carbonate, 0.4% vermiculite, and the balance being 5-3mm fused magnesia.

[0056] Comparative Example 1:

[0057] This comparative example provides a dry feedstock for tundish slag lines. The percentages of each component in this dry feedstock by mass are as follows: 30% 3-1mm fused magnesia, 22% 1-0mm fused magnesia, 25% 200-mesh fused magnesia, 0.5% trisodium phosphate hexahydrate, 2.3% sodium metasilicate nonahydrate, 1.5% adipic acid, 4.6% calcium carbonate, 0.5% vermiculite, and the balance being 5-3mm fused magnesia. In this comparative example, the content of trisodium phosphate hexahydrate is relatively low, only 0.5%.

[0058] Comparative Example 2:

[0059] This comparative example provides a dry feedstock for tundish slag lines. The percentages of each component in this dry feedstock by mass percentage are as follows: 26% 3-1mm fused magnesia, 26% 1-0mm fused magnesia, 20% 200-mesh fused magnesia, 1.9% trisodium phosphate hexahydrate, 2.5% sodium metasilicate nonahydrate, 0.4% adipic acid, 4.2% calcium carbonate, 0.3% vermiculite, and the balance being 5-3mm fused magnesia. In this comparative example, the adipic acid content is relatively low, at only 0.4%.

[0060] Comparative Example 3:

[0061] This comparative example provides a dry feedstock for tundish slag lines. The percentages of each component in this dry feedstock by mass percentage are as follows: 27% 3-1mm fused magnesia, 28% 1-0mm fused magnesia, 22% 200-mesh fused magnesia, 1.7% trisodium phosphate hexahydrate, 1% sodium metasilicate nonahydrate, 1.1% adipic acid, 5% calcium carbonate, 0.4% vermiculite, and the balance being 5-3mm fused magnesia. In this comparative example, the sodium metasilicate nonahydrate content is relatively low, at only 1%.

[0062] Comparative Example 4:

[0063] This comparative example provides a dry feedstock for tundish slag lines. The percentage of each component in the dry feedstock by mass percentage is as follows: 26% 3-1mm fused magnesia, 24% 1-0mm fused magnesia, 27% 200-mesh fused magnesia, 1.5% trisodium phosphate hexahydrate, 2.4% sodium metasilicate nonahydrate, 1.3% adipic acid, 4.8% calcium carbonate, and the balance being 5-3mm fused magnesia. This comparative example does not contain vermiculite.

[0064] Comparative Example 5:

[0065] This comparative example provides a dry feedstock for tundish slag lines. The percentages of each component in this dry feedstock by mass percentage are as follows: 28% 3-1mm fused magnesia, 25% 1-0mm fused magnesia, 23% 200-mesh fused magnesia, 2% trisodium phosphate hexahydrate, 2.1% sodium metasilicate nonahydrate, 1% adipic acid, 2.5% calcium carbonate, 0.4% vermiculite, and the balance being 5-3mm fused magnesia. In this comparative example, the calcium carbonate content is relatively low, only 2.5%.

[0066] In this invention, samples of the dry refractory material from intermediate ladle slag lines of Examples 1-6 and Comparative Examples 1-5 were prepared according to GB / T4513.5-2017 "Unshaped Refractory Materials - Part 5: Sample Preparation and Pretreatment". The bulk density, linear shrinkage rate, flexural strength, and compressive strength were tested according to GB / T... The test methods in 4513.6-2017 "Unshaped Refractory Materials - Part 6: Determination of Physical Properties" were used. The qualified product test index ranges are as follows: the sum of the mass percentages of trisodium phosphate hexahydrate, sodium metasilicate nonahydrate, and adipic acid is 4.8-5.8%; linear shrinkage rate (1100℃ / 3h) is 0-0.3%, and linear shrinkage rate (1550℃ / 3h) is -1.5-0%; flexural strength (220℃ / 2h) is ≥1.6MPa, flexural strength (1100℃ / 3h) is ≥1.1MPa, and flexural strength (1550℃ / 3h) is ≥3MPa; compressive strength (220℃ / 2h) is ≥6MPa, compressive strength (1100℃ / 3h) is ≥2.2MPa, and compressive strength (1550℃ / 3h) is ≥9MPa. The test results are shown in Table 1.

[0067] Table 1. Test results of Examples 1-6 and Comparative Examples 1-5

[0068]

[0069] Comparative Example 1 is based on Example 2, but with a reduction in the amount of trisodium phosphate hexahydrate added (below the limit of the present invention), and a corresponding increase of 5-3 mm of fused magnesia. As can be seen from Table 1, compared with Example 2, the flexural strength and compressive strength of Comparative Example 1 are significantly reduced, and the test results are unqualified. The test effect of Comparative Example 1 is significantly lower than that of Example 2.

[0070] Comparative Example 2 is based on Example 3, but with a reduction in the amount of adipic acid added (below the limit of the present invention) and a corresponding increase in fused magnesia by 5-3 mm. As can be seen from Table 1, compared with Example 3, the flexural strength and compressive strength of Comparative Example 2 are significantly reduced. Although the test results are qualified, the test effect of Comparative Example 2 is significantly lower than that of Example 3.

[0071] Comparative Example 3 is based on Example 4, but with a reduction in the amount of sodium metasilicate nonahydrate added (below the limit of the present invention), and a corresponding increase in fused magnesia by 5-3 mm. As can be seen from Table 1, compared with Example 4, the flexural strength and compressive strength of Comparative Example 3 are significantly reduced, and the test results are unqualified. The test effect of Comparative Example 3 is significantly lower than that of Example 4.

[0072] Comparative Example 4 is based on Example 5, but the introduction of vermiculite is removed and 5-3mm of fused magnesia is added accordingly. As can be seen from Table 1, compared with Example 5, the flexural strength and compressive strength of Comparative Example 4 are significantly reduced. Although the test results are qualified, the test effect of Comparative Example 4 is significantly lower than that of Example 5.

[0073] Comparative Example 5 is based on Example 6, but with a reduction in the amount of calcium carbonate added (below the limit of the present invention) and a corresponding increase in fused magnesia by 5-3 mm. As can be seen from Table 1, compared with Example 6, the flexural strength and compressive strength of Comparative Example 5 are significantly reduced. Although the test results are qualified, the test effect of Comparative Example 5 is significantly lower than that of Example 6.

[0074] In summary, this invention effectively improves the flexural and compressive strength of dry tundish slag line feedstock by adding trisodium phosphate hexahydrate, sodium metasilicate nonahydrate, adipic acid, vermiculite, and calcium carbonate. Through their synergistic effect in the dry feedstock, their refractoriness, erosion resistance, uniformity, and density are significantly enhanced, thereby improving the service life and performance stability of the dry feedstock. By rationally proportioning trisodium phosphate hexahydrate, sodium metasilicate nonahydrate, and adipic acid, this invention can effectively control costs while ensuring performance, and simultaneously ensure the stable production of high-quality dry tundish slag line feedstock in actual production.

[0075] The above description is only a preferred embodiment of the present invention and does not limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dry feed for tundish slag lines, characterized in that: The mass percentage of each raw material component in the dry feed of the intermediate slag line is as follows: 26-30% fused magnesia of 3-1mm, 22-28% fused magnesia of 1-0mm, 20-27% fused magnesia of 200 mesh, 1.5-2% trisodium phosphate hexahydrate, 2-2.5% sodium metasilicate nonahydrate, 1-1.5% adipic acid, 4-5% calcium carbonate, 0.3-0.5% vermiculite, and the balance being fused magnesia of 5-3mm.

2. The dry feed for tundish slag lines according to claim 1, characterized in that: The dry material of the intermediate slag line contains 28% fused magnesia of 3-1mm, 25% fused magnesia of 1-0mm, 24% fused magnesia of 200 mesh, 1.8% trisodium phosphate hexahydrate, 2.2% sodium metasilicate nonahydrate, 1.2% adipic acid, 4.4% calcium carbonate, 0.4% vermiculite, and the balance being fused magnesia of 5-3mm.

3. The dry feed for tundish slag lines according to claim 1, characterized in that: The fused magnesia contains ≥91% MgO.

4. The dry feed for tundish slag lines according to claim 1, characterized in that: The trisodium phosphate hexahydrate, sodium metasilicate nonahydrate, and adipic acid are all industrial grade.

5. The dry feed for tundish slag lines according to claim 1, characterized in that: The calcium carbonate has a particle size of 2000 mesh and a CaCO3 content of ≥98%.

6. The dry feed for tundish slag lines according to claim 1, characterized in that: The vermiculite has a particle size of 325 mesh, and the vermiculite contains MgO content ≥21%, Al2O3 content ≥14%, and Fe2O3 content ≤7%.

7. The dry feed for tundish slag lines according to claim 1, characterized in that: The total mass percentage of trisodium phosphate hexahydrate, sodium metasilicate nonahydrate, and adipic acid in the dry feed of the intermediate ballast slag line is 4.8% to 5.8%.

8. A dry feed line for tundish slag production according to claim 1, characterized in that: When the dry material of the intermediate bag slag line is used to make bags, the baking time is ≥1.5h, and the inner wall temperature of the working layer membrane is ≥280℃.

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