High-temperature-resistant steel ladle castable and preparation method thereof

Abstract

The invention relates to the technical field of castable, and provides a high-temperature-resistant steel ladle castable and a preparation method thereof. The high-temperature-resistant steel ladle castable comprises the following components in parts by weight: 60-80 parts of high bauxite, 2-5 parts of magnesia, 10-15 parts of magnesium aluminate spinel, 4-8 parts of aluminum oxide, 2-5 parts of fused magnesia, 1-5 parts of calcium aluminate cement, 0.5-1.5 parts of silica powder, 0.2-0.5 part of a water reducing agent, 8-15 parts of silicon carbide whiskers, 2-4 parts of a dispersing agent, 1-2 parts of zirconium oxide and 0.5-1.7 parts of neodymium oxide. According to the technical scheme, the problem that the slag corrosion resistance of the castable is reduced due to the doping of magnesium aluminate spinel in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of castables, and in particular to a high-temperature resistant ladle castable and a preparation method thereof. Background Art

[0002] As the cornerstone of China's industrialization, the steel industry holds a central position in the national economy. In the iron and steelmaking processes, the ladle, a critical container for carrying high-temperature molten steel and iron, necessitates the performance of its lining material, which directly impacts production safety and efficiency. Compared to traditional shaped refractories, ladle castables offer significant advantages, including simplified production processes, manageable manufacturing costs, and excellent fluidity during construction. These unshaped refractories can be cast on-site to accommodate the complex structure of the ladle, effectively eliminating defects in brick joints, significantly reducing the risk of molten steel leakage, and significantly improving operational safety and structural integrity.

[0003] However, high-temperature service environments present severe challenges for ladle castables, with weak thermal shock resistance being a technical bottleneck restricting their application. Magnesium-aluminate spinel is currently often incorporated into refractories to improve their thermal shock resistance. However, the addition of magnesium-aluminate spinel reduces the material's resistance to slag erosion, severely impacting the ladle's service life. Therefore, a high-temperature-resistant ladle castable with excellent thermal shock and slag erosion resistance is needed. Summary of the Invention

[0004] The present invention provides a high-temperature resistant ladle castable and a preparation method thereof, which solves the problem in the prior art that the addition of magnesia-alumina spinel leads to a decrease in the slag erosion resistance of the castable.

[0005] The technical solutions of the present invention are as follows: The present invention provides a high-temperature resistant ladle castable, which comprises the following components in parts by weight: 60-80 parts of high-alumina bauxite, 2-5 parts of magnesia, 10-15 parts of magnesia-alumina spinel, 4-8 parts of aluminum oxide, 2-5 parts of fused magnesia, 1-5 parts of calcium aluminate cement, 0.5-1.5 parts of silicon micropowder, 0.2-0.5 parts of water reducer, 8-15 parts of silicon carbide whiskers, 2-4 parts of dispersant, 1-2 parts of zirconium oxide, and 0.5-1.7 parts of neodymium oxide.

[0006] As a further technical solution, the dispersant consists of sodium oleate and alkyl glycoside, and the alkyl glycoside consists of alkyl glycoside APG0810 and alkyl glycoside APG1214.

[0007] Sodium oleate, an inorganic electrolyte dispersant, can adsorb onto the surface of silicon carbide whiskers, significantly increasing the absolute value of the whisker surface potential. This generates double-layer electrostatic repulsion, allowing the whiskers to achieve a stable dispersion. Alkyl polyglycosides, non-ionic dispersants, adsorb onto the surface of silicon carbide whiskers, forming an adsorption layer of a certain thickness, utilizing steric repulsion to achieve a dispersing effect. Alkyl polyglycosides, consisting of APG0810 and APG1214, enhance dispersibility through complementary molecular structures. APG0810 is highly hydrophilic and diffuses rapidly, while APG1214 is hydrophobic and readily adsorbs particles. Together, APG0810 and APG1214 can synergistically improve the dispersion of silicon carbide whiskers and other powders in the castable, thereby enhancing the castable's thermal shock resistance.

[0008] As a further technical solution, the mass ratio of sodium oleate to alkyl glycoside is 3:5.

[0009] As a further technical solution, the mass ratio of the alkyl glycoside APG0810 to the alkyl glycoside APG1214 is 1:1~5.

[0010] When the content of alkyl polyglycoside APG1214 in the alkyl polyglycoside in the ladle castable in the present invention is too high, the solubility of the composite alkyl polyglycoside composed of alkyl polyglycoside APG0810 and alkyl polyglycoside APG1214 will decrease, and self-polymerization will easily occur, thereby reducing the adsorption rate on the silicon carbide surface, thereby reducing the dispersion effect; when the content of alkyl polyglycoside APG1214 is too low, the composite alkyl polyglycoside composed of alkyl polyglycoside APG0810 and alkyl polyglycoside APG1214 has a weak steric hindrance effect when adsorbed on the particle surface, and has poor dispersion stability; when the mass ratio of APG0810 to APG1214 is 1:1~5, good dispersibility can be exhibited, thereby further improving the thermal shock resistance of the ladle castable.

[0011] As a further technical solution, the mass ratio of the alkyl polyglycoside APG0810 to the alkyl polyglycoside APG1214 is 1:3. When the mass ratio of the alkyl polyglycoside APG0810 to the alkyl polyglycoside APG1214 is 1:3, a stronger dispersion effect can be exhibited, thereby further improving the thermal shock resistance of the ladle castable.

[0012] As a further technical solution, the calcium aluminate cement has an alumina content of 73.5% to 75.5% by weight. When used as a castable, calcium aluminate cement with an alumina content of 73.5% to 75.5% by weight exhibits high refractoriness, excellent high-temperature strength retention, superior thermal shock resistance, strong resistance to alkaline slag corrosion, and excellent sintered volume stability, making it suitable for harsh high-temperature operating conditions.

[0013] As a further technical solution, the water reducer is a lignin sulfonate water reducer, including one or more of sodium lignin sulfonate, calcium lignin sulfonate, and magnesium lignin sulfonate. When used in castables, lignin sulfonate water reducers can reduce water consumption, improve fluidity, and enhance workability; they can also delay setting time and facilitate handling; they can also reduce the water-cement ratio and enhance structural density, thereby improving the strength and corrosion resistance of the castable, and are relatively low in cost.

[0014] As a further technical solution, the alumina powder has a particle size of 2-3 μm. When used in ladle castables, alumina powder with a particle size of 2-3 μm can fill intergranular spaces, reduce porosity, and increase density and strength; improve matrix fluidity and enhance workability; promote sintering at high temperatures, and improve the ladle castable's resistance to thermal shock and slag erosion. The moderate particle size also balances filling efficiency with cost advantages.

[0015] As a further technical solution, the silicon carbide whiskers have a diameter of 100-500nm and a length of 10-50μm. When added to the ladle castable, they form a bridging toughening network through a nanoscale one-dimensional structure, significantly improving the thermal shock resistance of the ladle castable through crack deflection, pinning, and pullout mechanisms. Their high thermal conductivity reduces thermal stress concentration, and their chemical stability enhances resistance to slag erosion. They also improve the material's wear resistance and structural toughness, enhancing the ladle castable's slag erosion resistance, wear resistance, and toughness.

[0016] The present invention also provides a method for preparing a high-temperature resistant ladle castable, comprising the following steps: S1, mixing the components of the high temperature resistant ladle castable uniformly to obtain a mixture; S2. After the mixture and water are evenly mixed, the mixture is put into a mold, vibrated into shape, and demoulded and dried to obtain a high-temperature resistant ladle castable.

[0017] As a further technical solution, the mass ratio of the mixture to water is 1:10.

[0018] The working principle and beneficial effects of the present invention are: The high-temperature resistant ladle castable prepared by the present invention using high-alumina bauxite, magnesia, magnesia spinel, alumina powder, fused magnesia, calcium aluminate cement, silicon powder, water reducer, silicon carbide whisker, dispersant, zirconium oxide, and neodymium oxide as raw materials has strong thermal shock resistance and slag erosion resistance. The reason is that: on the one hand, the addition of zirconium oxide to the ladle castable can play a phase transformation toughening effect, absorb crack propagation energy, inhibit the propagation of corrosive cracks, and thus improve the erosion resistance of the ladle castable; on the other hand, the simultaneous addition of magnesia spinel, zirconium oxide, and neodymium oxide can be sintered at high temperature to form neodymium zirconate, which is added to the castable as a second phase and can play a heterogeneous nucleation role during the sintering process, increase nucleation sites, promote matrix grain refinement, thereby reducing the thermal expansion difference within a single grain and reducing stress concentration; at the same time, the number of grain boundaries is increased, which hinders crack propagation and disperses stress, thereby improving the thermal shock resistance of the castable. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0020] In the following embodiments and comparative examples, high-alumina bauxite (particle size of 74 μm, alumina content of 88%), magnesia (particle size of 3-5 mm), magnesia-alumina spinel (particle size of 0.6-0.12 mm), alumina (particle size of 3 μm, purity of 99.6%), fused magnesia (particle size of 74 μm), calcium aluminate cement CA75 (purchased from Zhengzhou Jinghua Special Cement Co., Ltd.), silica powder (particle size of 44 μm, purity of 97%), silicon carbide whiskers (diameter of 100-500 nm, length of 10-50 μm), zirconium oxide (particle size of 1 μm, purity of 99.9%), and neodymium oxide (particle size of 40 nm, purity of 99.9%).

[0021] Example 1 A high-temperature resistant ladle castable comprises the following components in parts by weight: 60 parts of high-alumina bauxite, 2 parts of magnesia, 10 parts of magnesia-alumina spinel, 4 parts of alumina, 2 parts of fused magnesia, 1 part of calcium aluminate cement, 0.5 parts of silica powder, 0.2 parts of sodium lignin sulfonate, 8 parts of silicon carbide whiskers, 2 parts of a dispersant, 1 part of zirconium oxide, and 0.5 parts of neodymium oxide, wherein the dispersant is sodium oleate; A method for preparing a high-temperature resistant ladle castable comprises the following steps: S1. Evenly mix the components of the high-temperature resistant ladle castable to obtain a mixture; S2. After the mixture and water are evenly mixed, the mixture is placed in a mold, vibrated into shape, and demoulded and dried to obtain a high-temperature resistant ladle castable; wherein the mass ratio of water to the mixture is 1:10.

[0022] Example 2 Compared with Example 1, the only difference between Example 2 is that a high-temperature resistant ladle castable in this embodiment includes the following components in parts by weight: 70 parts of high-alumina bauxite, 4 parts of magnesia, 12 parts of magnesia-alumina spinel, 6 parts of alumina, 4 parts of fused magnesia, 3 parts of calcium aluminate cement, 1 part of silicon micropowder, 0.4 parts of calcium lignin sulfonate, 10 parts of silicon carbide whiskers, 3 parts of dispersant, 1.5 parts of zirconium oxide, and 1.3 parts of neodymium oxide, wherein the dispersant is sodium oleate.

[0023] Example 3 Compared with Example 1, the only difference of Example 3 is that a high-temperature resistant ladle castable in this embodiment includes the following components in parts by weight: 80 parts of high-alumina bauxite, 5 parts of magnesia, 15 parts of magnesia-alumina spinel, 8 parts of alumina, 5 parts of fused magnesia, 5 parts of calcium aluminate cement, 1.5 parts of silicon micropowder, 0.5 parts of magnesium lignin sulfonate, 15 parts of silicon carbide whiskers, 4 parts of dispersant, 2 parts of zirconium oxide, and 1.7 parts of neodymium oxide, wherein the dispersant is sodium oleate.

[0024] Example 4 Compared with Example 2, the only difference of Example 4 is that, in this example, the dispersant consists of sodium oleate and alkyl glycoside in a mass ratio of 3:5, and the alkyl glycoside consists of alkyl glycoside APG0810 and alkyl glycoside APG1214 in a mass ratio of 1:1.

[0025] Example 5 Compared with Example 2, the only difference of Example 5 is that the dispersant in this example consists of sodium oleate and alkyl glycoside in a mass ratio of 3:5, and the alkyl glycoside consists of alkyl glycoside APG0810 and alkyl glycoside APG1214 in a mass ratio of 1:3.

[0026] Example 6 Compared with Example 2, the only difference of Example 6 is that the dispersant in this example consists of sodium oleate and alkyl glycoside in a mass ratio of 3:5, and the alkyl glycoside consists of alkyl glycoside APG0810 and alkyl glycoside APG1214 in a mass ratio of 1:5.

[0027] Example 7 Compared with Example 2, the only difference of Example 7 is that the dispersant in this example is only alkyl glycoside, wherein the alkyl glycoside is composed of alkyl glycoside APG0810 and alkyl glycoside APG1214 in a mass ratio of 1:3.

[0028] Comparative Example 1 The only difference between this comparative example and Example 1 is that in this comparative example, zirconium oxide is replaced by an equal amount of neodymium oxide.

[0029] Comparative Example 2 The only difference between this comparative example and Example 1 is that in this comparative example, neodymium oxide is replaced by an equal amount of zirconium oxide.

[0030] Comparative Example 3 The only difference between this comparative example and Example 1 is that zirconium oxide and neodymium oxide are not added in this comparative example.

[0031] Comparative Example 4 The only difference between this comparative example and Example 1 is that in this comparative example, neodymium oxide is replaced by an equal amount of lanthanum oxide (with a particle size of 40 nm and a purity of 99.9%).

[0032] The ladle castables prepared in Examples 1 to 7 and Comparative Examples 1 to 4 were tested according to the following method: 1. Thermal shock resistance: Test the thermal shock resistance of the sample in accordance with Method 1: Water quenching method - straight brick specimen method specified in GB / T 30873-2014 "Test method for thermal shock resistance of refractory materials"; 2. Slag erosion resistance: According to the provisions of GB / T8931-2007 "Test method for slag resistance of refractory materials", the slag erosion rate of the sample is tested by the static sample slag immersion and ventilation method; The measurement results are shown in Tables 1 and 2.

[0033] Table 1 Performance measurement results of ladle castables in Examples 1 to 3 and Comparative Examples 1 to 4

[0034] Table 2 Performance measurement results of ladle castables in Example 2 and Examples 4 to 7

[0035] The data in Tables 1-2 demonstrate that the high-temperature-resistant ladle castable prepared by the present invention exhibits high thermal shock resistance and good slag erosion resistance. A comparison of Example 1 with Comparative Examples 1-4 demonstrates that the addition of zirconium oxide and neodymium oxide significantly improves the thermal shock resistance and slag erosion resistance of the ladle castable. A comparison of Example 2 with Examples 4-7 demonstrates that the thermal shock resistance of the ladle castable is further enhanced when the alkyl polyglycoside comprises APG0810 and APG1214 in a mass ratio of 1:3.

[0036] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, 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 high temperature resistant ladle castable, characterized in that: The invention comprises the following components in parts by weight: 60-80 parts of high-alumina bauxite, 2-5 parts of magnesia, 10-15 parts of magnesia-alumina spinel, 4-8 parts of alumina, 2-5 parts of fused magnesia, 1-5 parts of calcium aluminate cement, 0.5-1.5 parts of silicon micropowder, 0.2-0.5 parts of water reducer, 8-15 parts of silicon carbide whiskers, 2-4 parts of dispersant, 1-2 parts of zirconium oxide, and 0.5-1.7 parts of neodymium oxide.

2. A high temperature resistant ladle castable according to claim 1, characterized in that: The dispersant consists of sodium oleate and alkyl glycoside, and the alkyl glycoside consists of alkyl glycoside APG0810 and alkyl glycoside APG1214.

3. A high temperature resistant ladle castable according to claim 2, characterized in that: The mass ratio of the sodium oleate to the alkyl glycoside is 3:5-6.

4. A high temperature resistant ladle castable according to claim 2, characterized in that: The mass ratio of the alkyl glycoside APG0810 to the alkyl glycoside APG1214 is 1:1-5.

5. The high temperature resistant ladle castable according to claim 3, characterized in that: The mass ratio of the alkyl glycoside APG0810 to the alkyl glycoside APG1214 is 1:

3.

6. The high temperature resistant ladle castable according to claim 1, characterized in that: The alumina content in the calcium aluminate cement is 73.5 wt% to 75.5 wt%.

7. The high temperature resistant ladle castable according to claim 1, characterized in that: The water reducer is a lignin sulfonate water reducer, and the lignin sulfonate water reducer includes one or more of sodium lignin sulfonate, calcium lignin sulfonate, and magnesium lignin sulfonate.

8. The high temperature resistant ladle castable according to claim 1, characterized in that: The particle size of the aluminum oxide is 2-3 μm.

9. The high temperature resistant ladle castable according to claim 1, characterized in that: The silicon carbide whisker has a diameter of 100-500 nm and a length of 10-50 μm.

10. A method for preparing a high temperature resistant ladle castable, for preparing the high temperature resistant ladle castable according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, mixing the components of the high temperature resistant ladle castable uniformly to obtain a mixture; S2. After the mixture and water are evenly mixed, the mixture is put into a mold, vibrated into shape, and demoulded and dried to obtain a high-temperature resistant ladle castable.

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