Corrosion resistant refractory, method of making and use thereof

Abstract

The application discloses a kind of corrosion-resistant refractory material, preparation method and its application.The phase of the corrosion-resistant refractory material includes corundum and one or more than two phases selected from CA6, C2M2A14, CM2A8 and ZrO2.The high-temperature liquid phase amount of the refractory material is less, the pore structure is uniform, the thermal shock stability is good, and the refractory material can be widely used in steelmaking production line, and can also be widely used in rotary kiln refractory lining, has good corrosion resistance, low thermal conductivity, and the performance is obviously superior to many existing silicon-magnesia brick, magnesium-aluminum spinel brick and other refractory materials.

Description

Technical Field

[0001] This invention relates to the field of refractory materials technology, and in particular to a highly corrosion-resistant refractory material, its preparation method, and its application. Background Technology

[0002] After molten iron is smelted in a converter, it contains a large amount of oxygen, so the molten steel must undergo a refining process, mainly deoxidation, desulfurization, and removal of non-metallic inclusions. This process generally requires high temperatures and high slag basicity. The damage to refractory materials during refining is very severe, mainly due to the high temperature and high basicity of the slag.

[0003] High temperatures cause the molten slag to erode refractory materials at a very fast rate. Therefore, the working linings used for refining steel ladles are generally made of high-quality refractory materials with high purity and good corrosion resistance. For example, the main raw material of currently used corundum-spinel castables and corundum-MgO-SiO2 castables is corundum.

[0004] Refined slag generally has high basicity and low viscosity, primarily for desulfurization and altering inclusion properties. However, this also leads to deeper penetration of the slag into the refractory material, which in turn means deterioration and corrosion. The significant differences in expansion coefficients and high-temperature performance between the altered layer and the original brick layer cause spalling and damage to the refractory material, a highly detrimental form of destruction.

[0005] Unlike ceramics, refractory materials generally experience significant temperature variations and thermal stress during application. Therefore, to prevent stress cracking and breakage during use, refractory materials need to retain a certain degree of porosity to buffer expansion stress; for example, corundum-spinel castables retain 15-19% porosity. While these pores buffer expansion stress, they also facilitate the infiltration of low-viscosity slag, leading to penetration and spalling damage. For current refractory material preparation technologies and research concepts, retaining a certain degree of porosity is essential, fundamentally to prevent stress damage and ensure thermal shock stability.

[0006] Therefore, refractory materials used for steel ladles need to meet three requirements: corrosion resistance, impermeability, and thermal shock resistance. However, thermal shock resistance is contradictory to impermeability and corrosion resistance.

[0007] Currently, the primary category of steel ladle lining materials used in industrial applications are magnesia-carbon bricks and alumina-magnesia-carbon bricks. These are made by adding graphite to magnesia and corundum, which have good corrosion resistance. Graphite's low wettability prevents slag and molten steel from penetrating into the refractory material. Simultaneously, graphite's high thermal conductivity reduces the internal temperature gradient of the refractory material, mitigating thermal stress caused by sudden temperature changes and improving the refractory material's thermal shock resistance. However, graphite materials introduce carbon into the steel, especially noticeable in the smelting of ultra-low carbon steel. Furthermore, graphite oxidation accelerates the material's deterioration, as it effectively increases porosity. Carbon-free refining of ladle refractory materials is a crucial development direction.

[0008] Corundum-spinel or corundum-MgO-SiO2 system castables are currently the most industrially used carbon-free refractory materials. The aggregates are tabular corundum and spinel particles, and the fine powders are tabular corundum, spinel, activated alumina micro powder and pure aluminate cement, etc. The raw materials of this type of castable are all high-purity and highly corrosion-resistant raw materials, but the refractory materials constructed together have a contradiction between thermal shock stability and impermeability and erosion resistance.

[0009] For carbon-free refractories, improved thermal shock resistance is typically achieved by maintaining a certain level of porosity, but the presence of porosity reduces impermeability. Erosion resistance is achieved through high purification and corrosion resistance of raw materials, but this presents challenges in sintering and addressing the impermeability issue. Impermeability is primarily improved by enhancing the sinterability and density of the refractory material. To achieve density, besides adjusting particle size distribution, densification is achieved through the sintering process, which typically requires a liquid phase.

[0010] Since refractory materials are aggregates of large particles and fine powders, the densification between particles requires a large force, while the surface tension and solid solution driving force of the liquid phase are very limited. Therefore, liquid phase sintering may change the local morphology, but it cannot change the overall structure, nor can it effectively prevent slag penetration unless a large amount of liquid phase is present, which is not feasible under the high temperature and harsh conditions of steel refining. In addition, the presence of a large amount of liquid phase also leads to a significant decrease in the thermal shock stability of the material. Therefore, the contradiction between thermal shock stability and impermeability and corrosion resistance has not been resolved.

[0011] Calcium hexaaluminate has the structural formula CaO·6Al₂O₃ (abbreviated CA₆), a melting point of 1875℃, and a theoretical density of 3.79 g / cm³. 3The characteristics of this material are: (1) good stability under low oxygen partial pressure; (2) calcium hexaaluminate has a layered stacked structure, crystal growth is anisotropic, the growth rate along the C-axis is slow, and it is difficult to sinter; (3) when CA6 reacts with slag, it generates CA2 (abbreviation of CaO·2Al2O3), CA (abbreviation of CaO·Al2O3), etc. At the steelmaking temperature, CA2 is solid and CA is liquid, so the solid-liquid mixed phase blocks the pores and inhibits slag penetration.

[0012] The ability to suppress slag penetration is well-suited for use in refractory materials at the contact points with the melt. However, the lamellar structure and anisotropic growth result in poor sintering properties and difficulty in densification, making it challenging to produce materials with a bulk density greater than 3.0 g / cm³. 3 The above raw materials have a bulk density greater than 2.90 g / cm³. 3 The above are examples of calcium hexaaluminate refractories. Without densified CA6 raw materials, it is impossible to produce high-density CA6 refractories.

[0013] Currently, to achieve densification of calcium hexaaluminate raw materials, most methods involve adding additives such as SiO2 and TiO2, which then induce a liquid phase at high temperatures, promoting densification and sintering. For example, Chen Zhaoyou and Chai Junlan, in their article "Calcium Hexaaluminate Materials and Their Application in Aluminum Industrial Furnaces" (Chen Zhaoyou et al., Calcium Hexaaluminate Materials and Their Application in Aluminum Industrial Furnaces [J]. Refractory Materials, 2011, 45(2): 122-125.), discuss the physicochemical properties of Bonate (the trade name for calcium hexaaluminate), in which the chemical composition SiO2 is 0.9%. For example, "A method for preparing dense calcium hexaaluminate refractory clinker" (CN110171980A) and "A method for preparing dense calcium hexaaluminate refractory clinker" (CN105585314A) use TiO2 and MnO as sintering agents, respectively. However, this method cannot achieve densification by controlling the stacking of atoms in the mirror layer; it merely uses the liquid phase to bring the grains closer together, but this densification is limited. Moreover, methods that use sintering aids to increase density always come at the cost of sacrificing the high-temperature performance of the material, significantly reducing its high-temperature performance (even though the amount added is less than 1%, the amount of liquid phase generated at high temperatures is several times greater).

[0014] Refractory materials based on calcium hexaaluminate raw materials with added sintering aids, in addition to the defects inherent in the raw material, also suffer from high apparent porosity (typically 15-23%) and poor erosion resistance. Calcium hexaaluminate refractories will experience rapid damage under conditions of high porosity and high levels of added sintering aids.

[0015] Since both CaO·2MgO·8Al2O3 and 2CaO·2MgO·14Al2O3 are formed by stacking CA6 structural units with MgO·Al2O3 along the C-axis, their properties are similar to CA6. For ease of description, we will refer to them as CA6 below, and will uniformly abbreviate CaO·2MgO·8Al2O3 and 2CaO·2MgO·14Al2O3 as CMA. In addition, CA6 and CMA will be collectively referred to as calcium hexaaluminate phases.

[0016] Therefore, given the advantages of calcium hexaaluminate in terms of chemical composition, it is crucial to significantly improve the density of the material, reduce apparent porosity, reduce the penetration of molten steel and slag, reduce the altered and damaged layers, and improve its service life. Furthermore, improving the purity of calcium hexaaluminate materials, enhancing their resistance to slag erosion, and extending their service life are all critical considerations for refractory linings of refining steel ladles and refractory materials for containers used in molten aluminum smelting.

[0017] Based on the above analysis, the problems and defects of the existing technology are as follows: (1) In order to balance thermal shock stability and slag penetration resistance, refractory materials must retain a certain porosity, which will lead to slag penetrating deeper into the refractory material, resulting in a thicker modified layer, and subsequently corrosion and spalling damage; (2) In order to ensure corrosion resistance, most raw materials are of high purity, but they are difficult to sinter. In order to achieve sintering and densification of the green body, sintering aids must be introduced to lower the melting point and increase the liquid phase, which in turn reduces the material's resistance to slag corrosion; (3) Adding sintering aids to promote sintering and densification only changes the local microstructure, and the overall structure will not change much. Although the material is densified, the porosity is still high. (4) There is currently no large-scale production of dense CA6 refractory raw materials. Although a small amount of dense CA6 raw materials are produced, the raw materials contain sintering aids such as SiO2. (5) The presence of more sintering-aiding liquid phases will lead to a significant decrease in the thermal shock stability of the material. (6) The contradiction between thermal shock stability and impermeability and corrosion resistance has not yet been resolved.

[0018] The difficulties in solving the above problems and defects are: (1) The existing refractory material development concept determines that the pore distribution of both castables and refractory bricks is uneven. In order to alleviate the stress damage caused by temperature changes, a large amount of porosity is required to offset the uneven pore distribution, which inevitably leads to slag penetration and is difficult to control. (2) In order to enhance the resistance to slag erosion, the purity of raw materials can only be increased. However, high-purity raw materials are difficult to sinter by particle diffusion alone, and the strength cannot be guaranteed. (3) High-purity refractory material systems can only achieve sintering and obtain strength by adding sintering aids to achieve liquid phase sintering. However, the appearance of low-melting-point liquid phase leads to a decrease in erosion resistance. (4) Due to its own structural characteristics, CA6 material is difficult to sinter. Although adding sintering aids can achieve densification, the high-temperature performance is reduced, the resistance to slag erosion is greatly reduced, and the thermal shock resistance is reduced. (5) The existing refractory material development concept determines that it is difficult to achieve high density based on the densest particle packing and the surface tension of the liquid phase.

[0019] The significance of solving the above problems and defects is as follows: Based on high-purity, highly corrosion-resistant raw materials, high-purity, corrosion-resistant refractory materials can be produced without adding any sintering aids, generating a low-melting-point liquid phase, or relying on liquid-phase sintering. This fully leverages the corrosion resistance advantages of high-purity raw materials; it constructs refractory materials with uniform microstructure, which not only solves the structural stress of refractory materials as a whole but also addresses the resistance to slag penetration, achieving a harmonious balance between penetration resistance and thermal shock resistance. This not only fully utilizes the excellent corrosion resistance of high-purity raw materials but also addresses the contradiction between thermal shock resistance and slag penetration resistance, and solves the problem of rapid damage to ladle working lining refractory materials under harsh refining conditions. The economic and socio-economic benefits are very significant. Summary of the Invention

[0020] To address the above problems, this invention provides a highly corrosion-resistant refractory material, its preparation method, and its application.

[0021] The high corrosion-resistant refractory material of the present invention does not require the addition of any sintering aids during the preparation process. It adopts a hot-pressing sintering process to prepare refractory material products with high purity, good erosion resistance, resistance to molten slag penetration and high thermal shock stability.

[0022] The specific technical solution of this invention is as follows:

[0023] 1. A corrosion-resistant refractory material, wherein the phases of the refractory material include corundum and one or more phases selected from CA6, C2M2A14, CM2A8 and ZrO2.

[0024] 2. The refractory material according to item 1, wherein, based on the mass percentage of the phases in the refractory material, the sum of corundum and one or more phases selected from CA6, C2M2A14, CM2A8 and ZrO2 is ≥90%;

[0025] Preferably, the corundum phase content is 26.5-89.5%, more preferably 32-89.5%, and even more preferably 32.0-88.0%.

[0026] The total content of the CA6+C2M2A14+CM2A8 phases is 5.25-66.5%, preferably 5.25-62.0%, and more preferably 6.0-62.0%; and

[0027] The ZrO2 phase comprises 0-35%, preferably 0-30%.

[0028] 3. The refractory material according to item 1 or 2, wherein, based on the mass percentage of the refractory material, the content of the sintering-promoting impurity component is ≤1.5%, preferably ≤1.0%.

[0029] 4. The refractory material according to any one of claims 1-3, wherein the chemical composition of the refractory material comprises Al2O3, CaO, MgO and ZrO2, and the Al2O3 is 59.5-98.99%, preferably 59.5-98.99%, more preferably 64.57-98.99% by mass percentage in the refractory material; the CaO is 0.30-5.58%, preferably 0.35-5.58%, more preferably 0.35-5.20%; the MgO is 0-5.58% and the ZrO2 is 0-35%.

[0030] 5. The refractory material according to any one of items 1-4, wherein the bulk density of the refractory material is 2.90-3.65 g / cm³. 3 The preferred value is 2.95-3.45 g / cm³. 3 Further preferred values ​​are 2.95-3.30 g / cm³. 3 .

[0031] 6. The refractory material according to any one of items 1-5, wherein the refractory material is prepared by a method comprising the steps of:

[0032] The mixture is obtained by mixing granular material and fine powder, and then hot-pressing and sintering the mixture.

[0033] 7. The refractory material according to item 6, wherein the mass ratio of the granules to the fine powder is 30-65:35-70.

[0034] 8. The refractory material according to item 6 or 7, wherein the granular material comprises corundum granules and mixed granules, preferably, the corundum granules constitute 65-100% and the mixed granules constitute 0-35% by mass percentage in the granules;

[0035] Preferably, the mixed granules are selected from one or more of CA6 granules, C2M2A14 granules and CM2A8 granules;

[0036] Preferably, the corundum particles are selected from one or more of tabular corundum particles, sintered corundum particles, white corundum particles, dense corundum particles, and sub-white corundum particles.

[0037] 9. The refractory material according to any one of items 6-8, wherein the fine powder comprises Al2O3-CaO-MgO fine powder and ZrO2-containing fine powder, preferably, the Al2O3-CaO-MgO fine powder is 50-100% and the ZrO2-containing fine powder is 0-50% by mass percentage in the fine powder;

[0038] Preferably, the Al2O3-CaO-MgO fine powder includes fine powder containing Al2O3 and one or more fine powders selected from CA6, C2M2A14, CM2A8 and MgO-CaO fine powders.

[0039] Preferably, the MgO-CaO fine powder is a fine powder containing MgO and / or a fine powder containing CaO;

[0040] Preferably, the fine powder containing Al2O3 is selected from one or more of the following: active α-Al2O3 powder, γ-Al2O3 powder, ρ-Al2O3 powder, aluminum hydroxide, industrial alumina, white corundum powder, sintered corundum powder, and tabular corundum powder.

[0041] Preferably, the MgO-containing fine powder is selected from one or more of the following: magnesium carbonate, lightly calcined magnesium oxide, brucite, magnesium hydroxide, magnesium chloride, high-purity magnesium oxide, and fused magnesium oxide.

[0042] Preferably, the CaO-containing fine powder is selected from one or more of quicklime, limestone, calcium hydroxide, CaO·Al2O3, CaO·2Al2O3, 12CaO·7Al2O3, CA6, C2M2A14 and CM2A8;

[0043] Preferably, the ZrO2-containing fine powder is selected from one or more of monoclinic zirconium oxide, tetragonal zirconium oxide, desilicationized zirconium oxide, and fused zirconium oxide.

[0044] 10. The refractory material according to any one of items 6-9, wherein the particle size of the fine powder is ≤0.088mm; preferably, the particle size of the granules is 0.088-10mm, more preferably 0.088-8mm.

[0045] 11. The refractory material according to any one of items 6-10, wherein the hot pressing sintering is performed by placing the mixture into a mold of a high-temperature device for hot pressing sintering, or by forming the mixture at room temperature and then placing it into a mold of a high-temperature device for hot pressing sintering, or by forming the mixture at room temperature and pre-sintering it at low temperature before hot pressing sintering.

[0046] 12. The refractory material according to item 11, wherein the hot-pressing sintering temperature is 1550-1800℃, preferably, the hot-pressing strength is 0.5-30MPa.

[0047] 13. A method for preparing a refractory material, comprising the following steps:

[0048] The mixture is obtained by mixing granular material and fine powder, and then hot-pressing and sintering the mixture.

[0049] 14. The preparation method according to item 13, wherein the mass ratio of the granules to the fine powder is 30-65:35-70.

[0050] 15. The preparation method according to item 13 or 14, wherein the granules comprise corundum granules and mixed granules, preferably, the corundum granules comprise 65-100% and the mixed granules comprise 0-35% by mass percentage in the granules;

[0051] Preferably, the mixed granular material is one or more of CA6 granular material, C2M2A14 granular material and CM2A8 granular material;

[0052] Preferably, the corundum particles are selected from one or more of tabular corundum, sintered corundum, white corundum, dense corundum, and sub-white corundum.

[0053] 16. The preparation method according to any one of items 13-15, wherein the fine powder comprises Al2O3-CaO-MgO fine powder and ZrO2-containing fine powder, preferably, the Al2O3-CaO-MgO fine powder accounts for 50-100% of the fine powder by mass percentage, and the ZrO2-containing fine powder accounts for 0-50%;

[0054] Preferably, the Al2O3-CaO-MgO fine powder includes fine powder containing Al2O3 and one or more fine powders selected from CA6, C2M2A14, CM2A8 and MgO-CaO fine powders.

[0055] Preferably, the MgO-CaO fine powder is a fine powder containing MgO and / or a fine powder containing CaO;

[0056] Preferably, the fine powder containing Al2O3 is selected from one or more of the following: active α-Al2O3 powder, γ-Al2O3 powder, ρ-Al2O3 powder, aluminum hydroxide, industrial alumina, white corundum powder, sintered corundum powder, and tabular corundum powder.

[0057] Preferably, the MgO-containing fine powder is selected from one or more of the following: magnesium carbonate, lightly calcined magnesium oxide, brucite, magnesium hydroxide, magnesium chloride, sintered magnesium oxide, and fused magnesium oxide.

[0058] Preferably, the CaO-containing fine powder is selected from one or more of quicklime, limestone, calcium hydroxide, CaO·Al2O3, CaO·2Al2O3, 12CaO·7Al2O3, CA6, C2M2A14 and CM2A8;

[0059] Preferably, the ZrO2-containing fine powder is selected from one or more of monoclinic zirconium oxide, tetragonal zirconium oxide, desilicationized zirconium oxide, and fused zirconium oxide.

[0060] 17. The preparation method according to any one of items 13-16, wherein the particle size of the fine powder is ≤0.088 mm; preferably, the particle size of the granules is 0.088-10 mm, more preferably 0.088-8 mm.

[0061] 18. The preparation method according to any one of items 13-17, wherein the hot pressing sintering is to place the mixture into a mold of a high-temperature device for hot pressing sintering, or to form the mixture at room temperature and then place it into a mold of a high-temperature device for hot pressing sintering, or to form the mixture at room temperature and pre-sinter at low temperature and then place it into a mold of a high-temperature device for hot pressing sintering.

[0062] 19. The preparation method according to item 18, wherein the hot pressing sintering temperature is 1550-1800℃, preferably, the hot pressing strength is 0.5-30MPa.

[0063] 20. A working lining for a steel ladle used in steelmaking, comprising the refractory material described in any one of items 1-12 or the refractory material prepared by any one of items 13-19.

[0064] 21. A working lining for an aluminum molten metal smelting and conveying ladle, comprising the refractory material described in any one of items 1-12 or the refractory material prepared by any one of items 13-19.

[0065] 22. A refractory lining for an industrial kiln, comprising the refractory material described in any one of items 1-12 or the refractory material prepared by any one of items 13-19.

[0066] The effects of the invention

[0067] (1) The refractory material described in this invention does not use any sintering-promoting components during the preparation process. It does not achieve sintering by means of liquid phase, but promotes particle rearrangement and particle diffusion by means of high temperature and high pressure. Therefore, the refractory material provided by this invention has a small amount of high temperature liquid phase, uniform pore structure and good thermal shock stability.

[0068] (2) The refractory material provided by the present invention has a total content of sintering-promoting components such as SiO2, TiO2, Fe2O3, and R2O (a general term for K2O and Na2O) introduced from the raw materials of ≤1.5%. The chemical composition purity of the material system is high, which is higher than that of the refractory materials containing calcium hexaaluminate phase prepared by the existing technology. It has less high-temperature liquid phase, which can give full play to the performance advantages of high-purity raw materials and has outstanding resistance to slag erosion.

[0069] (3) The refractory material provided by the present invention includes corundum and one or more of CA6, C2M2A14, CM2A8 and ZrO2. The total phase content is ≥90% based on the mass percentage of the phases in the refractory material. The phase purity is high. When the CA6 phase component reacts with the molten slag, it generates solid and liquid components containing CA2, CA, etc., which block the pores and enhance the material's resistance to molten slag erosion.

[0070] (4) The bulk density of the refractory material provided by this invention is 2.90–3.65 g / cm³. 3 It is significantly superior to refractory materials containing calcium hexaaluminate phase prepared by existing technologies; while maintaining the high purity of the material system, the high-density material of this invention has greatly enhanced resistance to mechanical erosion by molten steel and slag, improved resistance to slag penetration, and significantly increased service life.

[0071] (5) The refractory material provided by the present invention has a uniform structure and no large pore concentration, and will not have local premature damage. During use, the material will be corroded evenly and slowly, and will not have peeling layer-like falling or large block damage. Therefore, the service life will be greatly increased.

[0072] (6) The refractory material provided by the present invention is based on high-purity raw materials, has high density, and has a uniform pore structure and low high oxygen potential components (SiO2, TiO2, Fe2O3, etc.). Therefore, the material has excellent resistance to slag erosion, impermeability and thermal shock stability, which solves the contradiction between the three, gives full play to the performance advantages of high-purity raw materials, greatly improves the service life of the material, and can be widely used in the metallurgical industry. It can also be widely used in the transition zone of cement rotary kilns and the construction of other industrial kilns, increasing the equipment operating cycle, reducing production costs, and saving energy and reducing emissions.

[0073] (7) The preparation method provided by the present invention uses simple raw materials. Without using any sintering-promoting components, it can achieve good sintering of high-purity refractory materials containing calcium hexaaluminate phase by means of hot pressing sintering process. The method is scientific and reasonable.

[0074] (8) The corrosion-resistant refractory material provided by the present invention can be widely used in steelmaking production lines, such as ladle working liners for ladle refining. It has good corrosion resistance, which greatly reduces the damage of refractory materials and the impact on molten steel during the smelting of high-end special steel, improves the overall quality of high-end special steel in my country's metallurgical industry, increases equipment operating cycle, improves economic benefits, and has significant social benefits.

[0075] (9) The corrosion-resistant refractory material of the present invention can also be widely used in the refractory lining of rotary kilns, such as the transition zone of cement rotary kilns. It has good erosion resistance and low thermal conductivity, and its performance is significantly better than many existing refractory materials such as silicon-mullite bricks and magnesium-aluminate spinel bricks. It can increase the equipment operating cycle, reduce heat loss, and improve economic benefits.

[0076] (10) The corrosion-resistant refractory material of the present invention has very low sensitivity to atmosphere and can be widely used in the construction of industrial kilns under conditions of high temperature, reducing atmosphere and alkaline atmosphere erosion, such as petrochemical cracking furnace. It has good stability, low thermal conductivity and good erosion resistance. Its performance is significantly better than many existing corundum bricks and other refractory materials. It can increase the equipment operation cycle, reduce heat loss and improve economic benefits. Attached Figure Description

[0077] Figure 1-1 This is a schematic diagram showing the effect of corundum-spinel castable after dynamic rotating slag erosion.

[0078] Figure 1-2 This is a schematic diagram of the effect of the refractory material described in Example 1 after being eroded by dynamic rotating slag.

[0079] Figure 2-1 This is a schematic diagram of the static crucible method for steel smelting in Experiment Example 2, where 1 is slag, 2 is an alumina crucible, 3 is steel, 4 is aluminum, and 5 is a refractory material crucible.

[0080] Figure 2-2 The images show the erosion effects of corundum-spinel castable and the refractory material described in Example 1 after steelmaking by static crucible method over different time periods. a, b, and c are the outline structures of the refractory material obtained in Example 1 at 30 min, 40 min, and 50 min, respectively, while d, e, and f are the outline structures of the corundum-spinel castable at 30 min, 40 min, and 50 min, respectively.

[0081] Figure 2-3 This is a schematic diagram showing the comparison of the microstructure of corundum-spinel castable and the refractory material described in Example 1. Detailed Implementation

[0082] The present invention will now be described in detail with reference to the accompanying drawings, wherein the same numerals in all the drawings denote the same features. While specific embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0083] It should be noted that certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that different terms may be used to refer to the same component. This specification and claims do not distinguish components based on differences in terminology, but rather on differences in function. The terms "comprising" or "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising but not limited to." The following descriptions are preferred embodiments for carrying out the invention; however, these descriptions are for the purpose of understanding the general principles of the specification and are not intended to limit the scope of the invention. The scope of protection of this invention is determined by the appended claims.

[0084] The present invention provides a corrosion-resistant refractory material, wherein the phases of the refractory material include corundum and one or more phases selected from CA6, C2M2A14, CM2A8 and ZrO2.

[0085] The phase composition of the refractory material is determined by XRD, for example, by grinding the material to below 325 mesh and then scanning it using an X-ray diffractometer. By analyzing the diffraction data and matching it with a standard PDF card, the relevant phases are obtained, and then the content of the relevant phases is obtained by fitting the diffraction data.

[0086] Regarding the ZrO2 phase, because H f O2 and ZrO2 coexist, are difficult to separate, and have similar crystal forms, therefore,

[0087] ①H f O2 phase is included in ZrO2;

[0088] ② Due to differences in temperature, process, and other factors, and because the composition distribution is not perfectly uniform (absolute uniformity is impossible), the final product may contain ZrO2-CaO solid solution, ZrO2-MgO solid solution, CaO·ZrO2, MgO·ZrO2, and other phases. In the presence of these phases, the ZrO2 content is first corrected based on XRF results. Then, this ZrO2 content is converted to zirconia phase. The CaO and MgO that are dissolved or combined in the form of CaO·ZrO2, MgO·ZrO2, etc., are converted to CA6 and CMA (first, the CaO and MgO content is converted to CA6 and MA, then based on temperature or the composition of the CaO-MgO-Al2O3 system, etc., it is converted to CA6 and CMA, etc.). Finally, all these phases are normalized to 100%, and the percentage content of each phase is calculated.

[0089] Regarding the content of ZrO2 in its chemical composition, due to H f O2 and ZrO2 coexist and are difficult to separate, so in the XRF of this patent, the HfO2 content is calculated in the ZrO2 content.

[0090] In a preferred embodiment of the present invention, the sum of corundum and one or more phases selected from CA6, C2M2A14, CM2A8 and ZrO2 is ≥90% based on the mass percentage of the phases in the refractory material.

[0091] Preferably, the corundum phase content is 26.5-89.5%, more preferably 32-89.5%, and even more preferably 32.0-88.0%.

[0092] The total content of the CA6+C2M2A14+CM2A8 phases is 5.25-66.5%, preferably 5.25-62.0%, more preferably 6.0-62.0%; and

[0093] The ZrO2 phase comprises 0-35%, preferably 0-30%.

[0094] For example, the total percentage of phases in the refractory material can be 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, etc., based on the mass percentage of the phases in the refractory material.

[0095] The corundum phase comprises 26.5%, 32%, 34.75%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 88%, 89.5%, etc.

[0096] The total amount of the CA6+C2M2A14+CM2A8 phase can be 5.25%, 6%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 66.5%, etc.

[0097] The ZrO2 phase can be 0%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, etc.

[0098] The sum of the total amounts of the CA6+C2M2A14+CM2A8 phases refers to the content of CA6 when only CA6 is present in the phases, and the content of C2M2A14 or CM2A8 when only C2M2A14 or CM2A8 is present, respectively.

[0099] When CA6 and C2M2A14 are present in a phase, it refers to the sum of their contents; when C2M2A14 and CM2A8 are present in a phase, it refers to the sum of the contents of both phases; when CA6 and CM2A8 are present in a phase, it refers to the sum of the contents of those two phases.

[0100] When CA6, C2M2A14 and CM2A8 phases are present in a material, it refers to the sum of the contents of the three phases.

[0101] In a preferred embodiment of the present invention, the content of the sintering-promoting impurity component is ≤1.5%, preferably ≤1.0%, based on its mass percentage in the refractory material.

[0102] For example, the content of the sintering-promoting impurity component, by mass percentage in the refractory material, is 1.5%, 1.4%, 1.3%, 1.2%, 1.1%, 1.0%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1%, 0, or any range thereof.

[0103] The impurity components that promote sintering are SiO2, TiO2, Fe2O3, and R2O. Due to the low content of the sintering-promoting components, the chemical purity of the material system is high. Among them, R2O refers to alkali metal oxides.

[0104] In a preferred embodiment of the present invention, the chemical composition of the refractory material includes Al2O3, CaO, MgO, and ZrO2. Based on the mass percentage of the refractory material, the Al2O3 is 59.5-98.99%, preferably 59.5-98.99%, more preferably 64.57-98.99%; the CaO is 0.30-5.58%, preferably 0.35-5.58%, more preferably 0.35-5.20%; the MgO is 0-5.58%; and the ZrO2 is 0-35%.

[0105] For example, the Al2O3 can be 59.5%, 61.45%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98.5%, 98.99% or any range thereof, based on its mass percentage in the refractory material.

[0106] The CaO can be 0.30%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.58%, or any range thereof;

[0107] The MgO can be 0%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.58%, or any range thereof;

[0108] The ZrO2 can be 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, or any range thereof.

[0109] The chemical composition of the refractory material was determined by fluorescence XRF analysis, i.e., in accordance with GB / T21114-2007.

[0110] In a preferred embodiment of the present invention, the bulk density of the refractory material is 2.90-3.65 g / cm³. 3 The preferred value is 2.95-3.45 g / cm³. 3 Further preferred values ​​are 2.95-3.30 g / cm³. 3 .

[0111] For example, the bulk density of the refractory material can be 2.90 g / cm³. 3 2.91 g / cm 3 2.92g / cm 3 2.93g / cm 3 2.94 g / cm 3 2.95g / cm 3 2.96 g / cm 32.97g / cm 3 2.98g / cm 3 2.99g / cm 3 3.00g / cm 3 3.05g / cm 3 3.10 g / cm 3 3.15g / cm 3 3.20g / cm 3 3.25g / cm 3 3.30g / cm 3 3.35g / cm 3 3.40 g / cm 3 3.45g / cm 3 3.50g / cm 3 3.55g / cm 3 3.60g / cm 3 3.65g / cm 3 or any range thereof.

[0112] The bulk density of the refractory material was determined according to GB / T2997-2000.

[0113] In a preferred embodiment of the present invention, the refractory material is prepared by a method comprising the following steps:

[0114] The mixture is obtained by mixing granular material and fine powder, and then hot-pressing and sintering the mixture.

[0115] The granular material refers to the portion that cannot be sieved through a 180-mesh square-hole sieve (Xinxiang Zhongtuo Machinery Equipment Co., Ltd.), i.e., the portion that remains on the 180-mesh square-hole sieve. The particle size of the granular material is 180 mesh - 10 mm, i.e., 0.088-10 mm, preferably 0.088-8 mm. For example, the particle size can be 0.088 mm, 0.090 mm, 0.095 mm, 0.10 mm, 0.15 mm, 0.20 mm, etc. The range is m, 0.25mm, 0.30mm, 0.35mm, 0.40mm, 0.45mm, 0.50mm, 0.55mm, 0.60mm, 0.65mm, 0.70mm, 0.75mm, 0.80mm, 0.85mm, 0.90mm, 0.95mm, 1mm, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, or any range between them.

[0116] The fine powder refers to the portion that passes through a 180-mesh square-hole sieve, that is, the portion located below the 180-mesh square-hole sieve, with a particle size ≤180 mesh, that is, a particle size ≤0.088mm.

[0117] Hot pressing sintering refers to a method of sintering and preparing materials under the combined action of pressure and temperature.

[0118] In a preferred embodiment of the present invention, the mass ratio of the granules to the fine powder is 30-65:35-70.

[0119] For example, the mass ratio of the granules to the fine powder (i.e., the mass ratio of granules to fine powder) is 30 / 70, 31 / 69, 32 / 68, 33 / 67, 34 / 66, 35 / 65, 36 / 64, 37 / 63, 38 / 62, 39 / 61, 40 / 60, 41 / 59, 42 / 58, 43 / 57, 44 / 56, 45 / 55, 46 / 54, 47 / 53, 48 / 52, 49 / 51, 50 / 50, 51 / 49, 52 / 48, 53 / 47, 54 / 46, 55 / 45, 56 / 44, 57 / 43, 58 / 42, 59 / 41, 60 / 40, 61 / 39, 62 / 38, 63 / 37, 64 / 36, 65 / 35, or any range between them.

[0120] In a preferred embodiment of the present invention, the granular material includes corundum granules and mixed granules. Preferably, the corundum granules account for 65-100% of the granules by mass percentage, and the mixed granules account for 0-35%.

[0121] Preferably, the mixed granules are selected from one or more of CA6 granules, C2M2A14 granules and CM2A8 granules;

[0122] Preferably, the corundum particles are selected from one or more of tabular corundum particles, sintered corundum particles, white corundum particles, dense corundum particles, and sub-white corundum particles.

[0123] The corundum granules, by mass percentage, may be, for example, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, or any range thereof.

[0124] The mixed granular material can be 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, or any range thereof.

[0125] The C2M2A14 granules refer to 2CaO·2MgO·14Al2O3 granules, and the CM2A8 granules refer to CaO·2MgO·8Al2O3 granules.

[0126] The plate-shaped corundum particles have a coarse-grained, well-developed α-Al2O3 crystal structure with an Al2O3 content of over 97.0%. They have a plate-like crystal structure with small pores and a large number of closed pores.

[0127] The sintered corundum granules refer to refractory clinker made from industrial alumina as raw material, which is ground into pellets or blanks and sintered at a high temperature of 1750-1900℃. It has high bulk density, low porosity, and excellent thermal shock resistance and slag erosion resistance at high temperatures.

[0128] The white corundum granules are aluminum oxide raw materials prepared by electro-melting of industrial alumina. The aluminum oxide (Al2O3) content is above 97.5%, and it contains a small amount of iron oxide, silicon oxide and other components. It is white in color.

[0129] The aforementioned sub-white fused alumina granules are produced from bauxite. Because their chemical composition and physical properties are similar to those of white fused alumina, they are called sub-white fused alumina. This product possesses the hardness of white fused alumina while also having the toughness of brown fused alumina, making it an ideal high-grade refractory and abrasive material.

[0130] In a preferred embodiment of the present invention, the fine powder includes Al2O3-CaO-MgO fine powder and ZrO2-containing fine powder. Preferably, the Al2O3-CaO-MgO fine powder accounts for 50-100% of the fine powder by mass percentage, and the ZrO2-containing fine powder accounts for 0-50%.

[0131] Preferably, the Al2O3-CaO-MgO fine powder includes fine powder containing Al2O3 and one or more fine powders selected from CA6, C2M2A14, CM2A8 and MgO-CaO fine powders.

[0132] Preferably, the MgO-CaO fine powder is a fine powder containing MgO and / or a fine powder containing CaO;

[0133] Preferably, the fine powder containing Al2O3 is selected from one or more of the following: active α-Al2O3 powder, γ-Al2O3 powder, ρ-Al2O3 powder, aluminum hydroxide, industrial alumina, white corundum powder, sintered corundum powder, and tabular corundum powder.

[0134] Preferably, the MgO-containing fine powder is selected from one or more of magnesium carbonate, lightly calcined magnesium oxide, brucite, magnesium hydroxide, magnesium chloride, high-purity magnesium oxide, and fused magnesium oxide.

[0135] Preferably, the CaO-containing fine powder is selected from one or more of quicklime, limestone, calcium hydroxide, CaO·Al2O3, CaO·2Al2O3 (CA2), 12CaO·7Al2O3 (C12A7), CA6, C2M2A14 and CM2A8;

[0136] Preferably, the ZrO2-containing fine powder is selected from one or more of monoclinic zirconium oxide, tetragonal zirconium oxide, desilicationized zirconium oxide, and fused zirconium oxide.

[0137] Given that the phases of Al2O3-CaO-MgO fine powder after high-temperature hot pressing and sintering include corundum phase and one or more of CA6, CM2A8, and C2M2A14, the corundum phase can be derived from Al2O3-containing fine powder through high-temperature conversion. CA6 can be obtained by reacting CaO-containing fine powder and / or Al2O3-containing fine powder with quicklime, limestone, calcium hydroxide, CaO·Al2O3, CaO·2Al2O3, 12CaO·7Al2O3, and other CaO-containing raw materials. C2M2A14 can be obtained by reacting C2M2A14 fine powder and / or Al2O3-containing fine powder, MgO-containing fine powder, and CaO-containing fine powder (except C2M2A14). CM2A8 can be obtained by reacting CM2A8 fine powder with / or fine powder containing Al2O3, fine powder containing MgO, or fine powder containing CaO (other than CM2A8).

[0138] The Al2O3-CaO-MgO fine powder, by mass percentage, can be, for example, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, or any range thereof;

[0139] The ZrO2-containing fine powder can be 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, or any range thereof.

[0140] The fine powder containing Al2O3 refers to fine powder whose main chemical component is Al2O3 or Al(OH)3. The fine powder containing MgO refers to fine powder whose main chemical component is MgO.

[0141] Fine powder containing CaO refers to fine powder whose chemical composition includes CaO, or fine powder containing CaO and Al2O3, or fine powder containing CaO, MgO and Al2O3.

[0142] The ZrO2-containing fine powder refers to fine powder whose main chemical component is ZrO2.

[0143] Activated α-Al2O3 powder is an alumina powder with high activity, mainly composed of α-Al2O3, obtained by treating industrial alumina or aluminum hydroxide as raw materials at 1250-1450℃.

[0144] γ-Al2O3 powder is an alumina powder with a high specific surface area and good adsorption properties, obtained by treating aluminum hydroxide as raw material at 140-150℃.

[0145] ρ-Al2O3 powder is an alumina powder with certain hydration bonding properties obtained by rapidly processing aluminum hydroxide at high temperatures of 600-900℃.

[0146] Industrial alumina is a mineral whose main component is α-Al2O3. It is prepared by calcining aluminum hydroxide at 900-1250℃.

[0147] White corundum powder is an alumina raw material with an aluminum oxide (Al2O3) content of over 97.5% prepared by electro-melting of industrial alumina. It also contains small amounts of iron oxide, silicon oxide, and other components, and is white in color.

[0148] Sintered corundum powder refers to refractory clinker made from alumina as raw material, which is ground into pellets or blanks and sintered at a high temperature of 1750-1900℃. It has high bulk density, low porosity, and excellent thermal shock resistance and slag erosion resistance at high temperatures.

[0149] The tabular corundum powder has a coarse-grained, well-developed α-Al2O3 crystal structure with an Al2O3 content of over 97.0%. It has a tabular crystal structure with small pores and a large number of closed pores.

[0150] Lightly calcined magnesia is a magnesia-based raw material with high activity and periclase phase, prepared by calcining magnesite (mainly composed of magnesium carbonate) at 800-1000℃.

[0151] Brussels crystal is a raw material with Mg(OH)2 as its main component.

[0152] Sintered magnesium oxide is a dense magnesium oxide raw material with an MgO content of ≥94.5%, which is produced by calcining lightly burned magnesium oxide at high temperature.

[0153] Fused magnesia is a dense magnesia raw material with an MgO content of ≥96.5% prepared by electric arc melting of lightly calcined magnesia or magnesite as raw materials.

[0154] Quicklime, also known as calcined lime, is mainly composed of calcium oxide. It is usually produced by calcining natural rocks, whose main component is calcium carbonate, at high temperatures, which decomposes them into carbon dioxide and calcium oxide (chemical formula: CaO, i.e., quicklime, also known as marble).

[0155] Monoclinic zirconia is a room-temperature stable zirconia crystal form, and it exists in the monoclinic form.

[0156] Tetragonal zirconia is zirconia that is stable in a tetragonal phase.

[0157] Desilicon zirconium is zirconium oxide prepared by removing SiO2 and other substances from zircon.

[0158] Fused zirconia is zirconia prepared by melting zirconia powder with an electric arc.

[0159] In a preferred embodiment of the present invention, the hot pressing sintering is performed by placing the mixture into a mold of a high-temperature device for hot pressing sintering, or by forming the mixture at room temperature and then placing it into a mold of a high-temperature device for hot pressing sintering, or by forming the mixture at room temperature and firing it in a low-temperature device and then placing it into a mold of a high-temperature device for hot pressing sintering.

[0160] For example, hot pressing sintering of the mixture in a mold of a high-temperature device refers to placing the mixed material in the mold of the high-temperature device and heating it. When the temperature reaches the maximum temperature, pressure is applied to achieve sintering, or the temperature and pressure are maintained for a certain period of time to complete the hot pressing sintering of the material; or placing the mixture in the mold of the high-temperature device and heating it to a certain temperature while applying pressure, then gradually increasing the temperature and simultaneously increasing the applied pressure until the temperature reaches the maximum temperature and the pressure reaches the maximum value to complete the hot pressing sintering of the material, or maintaining the temperature and pressure for a certain period of time to complete the hot pressing sintering of the material; or placing the mixture in the mold of the high-temperature device and gradually increasing the pressure applied to the mixture while heating it until the temperature reaches the maximum temperature and the pressure reaches the maximum value to complete the hot pressing sintering of the material, or maintaining the temperature and pressure for a certain period of time to complete the hot pressing sintering of the material.

[0161] The process of forming the mixture at room temperature and then placing it into a mold in a high-temperature device for hot pressing and sintering refers to pressing the mixture into a blank at room temperature, drying it, and then hot pressing and sintering it. Alternatively, the blank can be heated to its maximum temperature and pressure applied to achieve sintering, or the temperature and pressure can be maintained continuously for a certain time to complete the hot pressing and sintering of the material; or the blank can be placed in a mold in a high-temperature device and heated to a certain temperature while applying pressure, then the temperature is gradually increased while the applied pressure is simultaneously increased until the maximum temperature and pressure are reached, completing the hot pressing and sintering of the material, or the temperature and pressure can be maintained continuously for a certain time to complete the hot pressing and sintering of the material; or the blank can be placed in a mold in a high-temperature device, and the pressure applied to the mixture is gradually increased while the temperature is increased until the maximum temperature and pressure are reached, completing the hot pressing and sintering of the material, or the temperature and pressure can be maintained continuously for a certain time to complete the hot pressing and sintering of the material.

[0162] The high-temperature device is a commonly used high-temperature device in the field of art, such as a high-temperature furnace.

[0163] The process of forming the mixture at room temperature and pre-sintering it at low temperature before placing it into a mold in a high-temperature device for hot pressing and sintering refers to pressing the mixture at room temperature and pre-sintering it at 1350-1500℃ before placing it into a mold in a high-temperature device for hot pressing and sintering. The hot pressing and sintering operation is the same as above.

[0164] In a preferred embodiment of the present invention, the hot pressing sintering temperature is 1550-1800℃, and preferably, the hot pressing strength is 0.5-30MPa.

[0165] The hot-pressing strength is the pressure value applied to a unit area of ​​the sample.

[0166] For example, the temperature can be 1550℃, 1600℃, 1650℃, 1700℃, 1750℃, 1800℃ or any range therebetween;

[0167] The hot-pressing strength can be, for example, 0.5 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, 4.5 MPa, 5 MPa, 5.5 MPa, 6 MPa, 6.5 MPa, 7 MPa, 7.5 MPa, 8 MPa, 8.5 MPa, 9 MPa, 9.5 MPa, 10 MPa, 10.5 MPa, 11 MPa, 11.5 MPa, 12 MPa, 12.5 MPa, 13 MPa, 13.5 MPa, 14 MPa, 14.5 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, or any range thereof.

[0168] This invention provides a method for preparing a refractory material, comprising the following steps:

[0169] The mixture is obtained by mixing granular material and fine powder, and then hot-pressing and sintering the mixture.

[0170] In a preferred embodiment of the present invention, the mass ratio of the granules to the fine powder is 30-65:35-70.

[0171] In a preferred embodiment of the present invention, the particle size of the fine powder is ≤0.088mm; preferably, the particle size of the granules is 0.088-10mm, and more preferably 0.088-8mm.

[0172] In a preferred embodiment of the present invention, the hot pressing sintering is performed by placing the mixture into a mold of a high-temperature device for hot pressing sintering, or by forming the mixture at room temperature and then placing it into a mold of a high-temperature device for hot pressing sintering, or by forming the mixture at room temperature and firing it in a low-temperature device and then placing it into a mold of a high-temperature device for hot pressing sintering.

[0173] The refractory material obtained by the present invention through high temperature and high pressure to promote particle rearrangement and particle diffusion has a low amount of high temperature liquid phase, uniform microstructure and good thermal shock stability.

[0174] The present invention provides a working lining for a steel ladle used in steelmaking, comprising the refractory material described above or the refractory material prepared by the preparation method described above.

[0175] The present invention provides a working lining for an aluminum molten metal smelting and conveying ladle, which includes the refractory material described above or the refractory material prepared by the preparation method described above.

[0176] The present invention provides a refractory lining for an industrial kiln, comprising the refractory material described above or the refractory material prepared by the preparation method described above.

[0177] Example

[0178] This invention provides a general and / or specific description of the materials and methods used in the experiments. In the following examples, unless otherwise specified, % represents wt%, i.e., weight percentage. Reagents or instruments used, unless otherwise specified, are all commercially available conventional reagent products. Table 1 shows the sources of the raw materials used in the examples.

[0179] Table 1 shows the sources of the raw materials used in the embodiments.

[0180]

[0181]

[0182] Example 1

[0183] (1) Mix 600g of white corundum particles, 40g of active α-Al2O3 fine powder, 100g of industrial alumina fine powder, 60g of CM2A8 fine powder and 200g of fused zirconia fine powder evenly, and the maximum particle size is 5mm.

[0184] (2) The mixture is placed in the mold of the high-temperature device for hot pressing and sintering. When the temperature rises to the maximum temperature of 1640℃, pressure is applied and the maximum hot pressing strength is 6MPa to obtain corrosion-resistant refractory material.

[0185] The obtained refractory material was subjected to powder XRD analysis. The refractory material was ground to below 325 mesh and then scanned using an X-ray diffractometer (Bruker: D8 ADVANCE). By analyzing the diffraction data and matching it with a standard PDF card, the relevant phases were obtained. The content of these phases was then determined by fitting the diffraction data, revealing that the main phases were corundum, CM2A8, and zirconium oxide. Based on the mass percentage of the phases in the refractory material, the total amount of corundum, CM2A8, and zirconium oxide was 99.1%, with corundum accounting for 73.1%, CM2A8 for 6.0%, and zirconium oxide for 20.0%.

[0186] The refractory material was subjected to XRF analysis according to the standard, and the determination was carried out in accordance with GB / T21114-2007. The refractory material was found to contain 78.17% Al2O3, 0.43% MgO, 0.35% CaO, and 20.0% ZrO2 by mass percentage.

[0187] The refractory material of this embodiment was tested according to GB / T2997-2000, and the bulk density was found to be 3.30 g / cm³. 3 .

[0188] Example 2

[0189] (1) Mix 300g of dense corundum particles, 200g of tabular corundum particles, 140g of CA6 fine powder, 92g of industrial alumina fine powder, 15g of 8.4g CaCO3 fine powder, 160g of white corundum powder, and 100g of desiliconized zirconium oxide fine powder evenly. The maximum particle size is 5mm.

[0190] (2) The mixture is placed in the mold of the high-temperature device for hot pressing and sintering; when the temperature rises to 1500℃, pressure is applied and the pressure is increased while the temperature rises. The temperature rises to a maximum of 1760℃ and the maximum hot pressing strength is 2MPa, thus obtaining a corrosion-resistant refractory material.

[0191] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum, CA6, and zirconium oxide. The total amount of corundum, CA6, and zirconium oxide in the measured refractory material was 98.18% by mass percentage, with corundum phase accounting for 65.1%, CA6 phase accounting for 23.4%, and zirconium oxide phase accounting for 9.68%.

[0192] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 87.12% Al2O3, 1.93% CaO, and 9.65% ZrO2 by mass percentage.

[0193] The bulk density was determined using the same method as in Example 1, and was found to be 3.12 g / cm³. 3 .

[0194] Example 3

[0195] (1) Mix 260g of sub-white fused alumina particles, 140g of CM2A8 particles, 60g of white fused alumina powder, 100g of CM2A8 powder, 17g of C12A7 fine powder, 17.5g of magnesium hydroxide powder, 113g of active α-Al2O3 powder, and 300g of fused zirconium oxide powder evenly. The maximum particle size is 8mm.

[0196] (2) The mixture is pressed and dried and then placed in a mold of a high-temperature device for hot pressing and sintering. The temperature rises to a maximum of 1780℃ and the maximum hot pressing strength is 0.5MPa, thus obtaining a corrosion-resistant refractory material.

[0197] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum, CM2A8, and zirconium oxide. Based on the mass percentage of the phases in the tested refractory material, the total amount of corundum, CM2A8, and zirconium oxide was 98.5%, with corundum phase accounting for 32.0%, CM2A8 phase accounting for 36.5%, and zirconium oxide phase accounting for 30%.

[0198] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 64.57% Al2O3, 2.94% MgO, 2.01% CaO, and 30% ZrO2 by mass percentage.

[0199] The bulk density was determined using the same method as in Example 1, and was found to be 3.30 g / cm³. 3 .

[0200] Example 4

[0201] (1) Stir 300g of sintered corundum particles, 300g of dense corundum particles, 280g of white corundum fine powder, 110g of active α-Al2O3 powder and 13.5g of calcium hydroxide fine powder evenly, and the maximum particle size is 5mm.

[0202] (2) The mixture is placed in the mold of the high-temperature device for hot pressing and sintering. Pressure is gradually applied from the temperature when it rises to 1400℃. The temperature rises to a maximum of 1680℃. The maximum hot pressing strength is 1MPa, and corrosion-resistant refractory material is obtained.

[0203] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum and CA6. The total amount of corundum and CA6 in the phases of the tested refractory material was 98.6%, with corundum phase accounting for 88.0% and CA6 phase accounting for 10.6%.

[0204] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 98.99% Al2O3 and 0.89% CaO by mass percentage.

[0205] The bulk density was determined using the same method as in Example 1, and was found to be 2.95 g / cm³. 3 .

[0206] Example 5

[0207] (1) Mix 500g of sub-white fused alumina particles, 73g of CA6 fine powder, 100g of white fused alumina powder, 28g of ρ-Al2O3 powder, and 40g of CaO·Al2O3 fine powder evenly. The maximum particle size is 5mm.

[0208] (2) Add appropriate water to the mixture and stir evenly. After casting and drying, it is pre-fired at 1500℃ and then placed in a mold of a high-temperature device for hot pressing and sintering. When the temperature rises to 1770℃, pressure is applied. The maximum hot pressing strength is 2MPa, and corrosion-resistant refractory material is obtained.

[0209] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum and CA6. Based on the mass percentage of the phases in the measured refractory material, the total amount of corundum and CA6 was 96.9%, with corundum phase accounting for 74.5% and CA6 phase accounting for 22.4%.

[0210] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 96.6% Al2O3 and 1.95% CaO by mass percentage.

[0211] The bulk density was determined using the same method as in Example 1, and was found to be 3.12 g / cm³. 3 .

[0212] Example 6

[0213] (1) Mix 650g of plate-shaped corundum particles, 105g of CA6 fine powder, 100g of white corundum powder, and 223g of aluminum hydroxide powder evenly. The maximum particle size is 5mm.

[0214] (2) The mixture is placed in the mold of the high-temperature device for hot pressing and sintering. The temperature is increased and the pressure is increased at the same time. The temperature is increased to a maximum of 1700℃ and the maximum hot pressing strength is 14MPa, thus obtaining a corrosion-resistant refractory material.

[0215] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum and CA6. Based on the mass percentage of the phases in the tested refractory material, the total amount of corundum and CA6 was 98.1%, the corundum phase was 88.0%, and the CA6 phase was 10.1%.

[0216] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 98.99% Al2O3 and 0.75% CaO by mass percentage.

[0217] The bulk density was determined using the same method as in Example 1, and was found to be 3.28 g / cm³. 3 .

[0218] Example 7

[0219] (1) Mix 500g of sub-white fused alumina particles, 100g of C2M2A14 fine powder, 45g of CA2 fine powder, 7g of fused magnesia powder, 89g of ρ-Al2O3 powder and 260g of white fused alumina powder evenly. The maximum particle size is 5mm.

[0220] (2) Add appropriate water to the mixture and stir evenly. After vibration molding and drying, it is pre-fired at 1350℃ and then placed in the mold of a high-temperature device for hot pressing and sintering. When the temperature rises to 1750℃, pressure is applied. The maximum hot pressing strength is 1MPa, and corrosion-resistant refractory material is obtained.

[0221] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum and C2M2A14. Based on the mass percentage of the phases in the measured refractory material, the total amount of corundum and C2M2A14 was 96.2%, with corundum phase accounting for 75.0% and C2M2A14 phase accounting for 21.2%.

[0222] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 96.3% Al2O3, 1.0% MgO, and 1.20% CaO by mass percentage.

[0223] The bulk density was determined using the same method as in Example 1, and was found to be 3.12 g / cm³. 3 .

[0224] Example 8

[0225] (1) Mix 300g of sub-white fused alumina particles, 90g of CA6 fine powder, 17g of calcium hydroxide fine powder, 138g of active α-Al2O3 powder, 265g of ρ-Al2O3 powder and 460g of white fused alumina powder evenly. The maximum particle size is 5mm.

[0226] (2) The mixture is dried after being pressure molded, and then placed in a high-temperature device for treatment at 1450℃; the treated sample is placed in the mold of the high-temperature device for hot pressing and sintering. When the temperature rises to 1600℃, pressure is applied while the temperature is increased. The maximum temperature rises to 1770℃ and the maximum hot pressing strength is 3MPa, thus obtaining a corrosion-resistant refractory material.

[0227] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum and CA6. Based on the mass percentage of the phases in the measured refractory material, the total amount of corundum and CA6 was 97.1%, the corundum phase was 74.7%, and the CA6 phase was 22.4%.

[0228] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 96.4% Al2O3 and 1.91% CaO by mass percentage.

[0229] The bulk density was determined using the same method as in Example 1, and was found to be 3.12 g / cm³. 3 .

[0230] Example 9

[0231] (1) Mix 500g of tabular corundum particles, 100g of CM2A8 fine powder, 11g of calcium hydroxide fine powder, 17.5g of high-purity magnesia powder, 122g of industrial alumina fine powder, and 260g of tabular corundum powder evenly. The maximum particle size is 5mm.

[0232] (2) After the mixture is formed and dried at room temperature, it is placed in the mold of a high-temperature device for hot pressing and sintering. When the temperature rises to 1550℃, pressure is applied. The pressure is increased while the temperature rises. The maximum temperature rises to 1740℃. The maximum hot pressing strength is 4MPa, and corrosion-resistant refractory material is obtained.

[0233] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum and CM2A8. Based on the mass percentage of the phases in the measured refractory material, the total amount of corundum and CM2A8 was 95.42%, the corundum phase was 73.1%, and the CM2A8 phase was 22.32%.

[0234] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 95.7% Al2O3, 1.97% MgO, and 1.02% CaO by mass percentage.

[0235] The bulk density was determined using the same method as in Example 1, and was found to be 3.12 g / cm³. 3 .

[0236] Example 10

[0237] (1) Stir 260g of sintered corundum particles, 140g of CA6 particles, 120g of off-white corundum fine powder, 55g of Ca(OH)2 fine powder, 200g of tabular corundum powder, and 245g of ρ-Al2O3 fine powder evenly, with a maximum particle size of 6mm.

[0238] (2) The mixture is pressed into shape at room temperature and pre-fired at 1500°C. Then it is placed in the mold of a high-temperature device and pressure is applied while heating. The temperature rises to a maximum of 1750°C and the maximum hot-pressing strength is 7MPa, thus obtaining a corrosion-resistant refractory material.

[0239] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum and CA6. Based on the mass percentage of the phases in the tested refractory material, the total amount of corundum and CA6 was 98.8%, with corundum phase accounting for 36.8% and CA6 phase accounting for 62.0%.

[0240] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 93.7% Al2O3 and 5.20% CaO by mass percentage.

[0241] The bulk density was determined using the same method as in Example 1, and was found to be 3.25 g / cm³. 3 .

[0242] Example 11

[0243] (1) Mix 195g of tabular corundum particles, 105g of CM2A8 particles, 70g of active α-Al2O3 powder, 280g of CM2A8 fine powder, 100g of tetragonal zirconia fine powder, and 250g of fused zirconia fine powder evenly. The maximum particle size is 5mm.

[0244] (2) After the mixture is formed at room temperature, it is placed in the mold of a high-temperature device for hot pressing and sintering. The temperature is increased while the pressure is applied. The maximum temperature is 1550℃ and the maximum hot pressing strength is 30MPa, thus obtaining a corrosion-resistant refractory material.

[0245] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum, CM2A8, and zirconium oxide. Based on the mass percentage of the phases in the tested refractory material, the total amount of corundum, CM2A8, and zirconium oxide was 99.6%, with corundum phase accounting for 26.5%, CM2A8 phase accounting for 38.1%, and zirconium oxide phase accounting for 35%.

[0246] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 59.5% Al2O3, 3.01% MgO, 2.03% CaO, and 35% ZrO2 by mass percentage.

[0247] The bulk density was determined using the same method as in Example 1, and was found to be 3.45 g / cm³. 3 .

[0248] Example 12

[0249] (1) Mix 350g of white corundum particles, 300g of sintered corundum particles, 175g of monoclinic zirconia fine powder, 52.5g of CM2A8 fine powder, and 188g of aluminum hydroxide powder evenly. The maximum particle size is 3mm.

[0250] (2) The mixture is placed in the mold of the high-temperature furnace device for hot pressing and sintering. When the temperature rises to 1350℃, pressure is applied. The pressure is increased while the temperature rises. The temperature rises to a maximum of 1600℃ and the maximum hot pressing strength is 15MPa, thus obtaining a corrosion-resistant refractory material.

[0251] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum, CM2A8, and zirconium oxide. The total amount of corundum, CA6, and zirconium oxide was 97.15% by mass percentage in the phases of the tested refractory material, with corundum phase accounting for 75.4%, CM2A8 phase accounting for 5.25%, and zirconium oxide phase accounting for 16.5%.

[0252] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 80.8% Al2O3, 0.30% CaO, 0.43% MgO, and 16.9% ZrO2 by mass percentage.

[0253] The bulk density was determined using the same method as in Example 1, and was found to be 3.26 g / cm³. 3 .

[0254] Example 13

[0255] (1) Stir 195g of sintered corundum particles, 105g of CA6 particles, 100g of industrial alumina fine powder, 138.5g of ρ-Al2O3 powder, 460g of CA6 fine powder and 11.5g of calcium hydroxide powder evenly. The maximum particle size is 8mm.

[0256] (2) The mixture is molded and dried at room temperature, and after being treated at 1500℃, it is placed in a mold of a high-temperature furnace for hot pressing and sintering. The temperature rises to a maximum of 1700℃, and the maximum hot pressing strength is 21MPa, thus obtaining a corrosion-resistant refractory material.

[0257] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum and CA6. The total amount of corundum and CA6 in the phases of the tested refractory material was 97.7%, with corundum phase accounting for 31.2% and CA6 phase accounting for 66.5%.

[0258] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 93.1% Al2O3 and 5.58% CaO by mass percentage.

[0259] The bulk density was determined using the same method as in Example 1, and was found to be 3.25 g / cm³. 3 .

[0260] Example 14

[0261] (1) Mix 300g of sintered corundum particles, 460g of industrial alumina fine powder, 140g of CA6 fine powder, 11.5g of calcium hydroxide powder, and 93g of γ-Al2O3 powder evenly. The maximum particle size is 5mm.

[0262] (2) The mixture is placed in a mold of a high-temperature device for hot pressing and sintering. The temperature rises to a maximum of 1650℃ and the maximum hot pressing strength is 8MPa, thus obtaining a corrosion-resistant refractory material.

[0263] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum and CA6. Based on the mass percentage of the phases in the measured refractory material, the total amount of corundum and CA6 was 95.4%, the corundum phase was 75.1%, and the CA6 phase was 20.3%.

[0264] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 96.1% Al2O3 and 1.94% CaO by mass percentage.

[0265] The bulk density was determined using the same method as in Example 1, and was found to be 2.90 g / cm³. 3 .

[0266] Example 15

[0267] (1) Stir 260g of sintered corundum particles, 140g of CM2A8 particles, 40g of industrial alumina fine powder, 83g of ρ-Al2O3 powder, and 480g of CM2A8 fine powder evenly. The maximum particle size is 10mm.

[0268] (2) The mixture is placed in a mold of a high-temperature furnace for hot pressing and sintering. The temperature rises to a maximum of 1650℃ and the maximum hot pressing strength is 4MPa, thus obtaining a corrosion-resistant refractory material.

[0269] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum and CM2A8. Based on the mass percentage of the phases in the measured refractory material, the total amount of corundum and CM2A8 was 98.8%, the corundum phase was 36.8%, and the CM2A8 phase was 62%.

[0270] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 90.1% Al2O3, 5.20% MgO, and 3.60% CaO by mass percentage.

[0271] The bulk density was determined using the same method as in Example 1, and was found to be 2.90 g / cm³. 3 .

[0272] Example 16

[0273] (1) Mix 195g of sintered corundum particles, 105g of CM2A8 particles, 100g of industrial alumina fine powder, 40g of ρ-Al2O3 fine powder and 560g of CM2A8 fine powder evenly. The maximum particle size is 1mm.

[0274] (2) The mixture is placed in the mold of a high-temperature furnace and hot-pressed and sintered directly. The maximum temperature is 1800℃ and the hot-pressing strength is 2MPa to obtain corrosion-resistant refractory material.

[0275] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum and CM2A8. Based on the mass percentage of the phases in the measured refractory material, the total amount of corundum and CM2A8 was 98.3%, with corundum phase accounting for 31.8% and CM2A8 phase accounting for 66.5%.

[0276] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 89.3% Al2O3, 5.58% MgO, and 3.88% CaO by mass percentage.

[0277] The bulk density was determined using the same method as in Example 1, and was found to be 3.65 g / cm³. 3 .

[0278] Example 17

[0279] (1) Stir 300g of sintered corundum particles, 585g of industrial alumina fine powder, 40g of ρ-Al2O3 fine powder, 45g of calcium hydroxide fine powder, and 48g of fused magnesia evenly. The maximum particle size is 1mm.

[0280] (2) The mixture is molded and dried at room temperature, and after being treated at 1450℃, it is placed in a mold of a high-temperature device for hot pressing and sintering. The maximum temperature is 1720℃ and the hot pressing strength is 3MPa, thus obtaining a corrosion-resistant refractory material.

[0281] The analysis was performed using the same method as in Example 1, and the main phases were found to be corundum, CM2A8, and CA6. Based on the mass percentage of the phases in the tested refractory material, the total amount of corundum and CM2A8 was 90.0%, the corundum phase was 44.0%, the CM2A8 phase was 22.6%, and the CA6 phase was 23.4%.

[0282] The analysis was performed using the same method as in Example 1, and the refractory material was found to contain 90.8% Al2O3, 4.28% MgO, and 3.13% CaO by mass percentage.

[0283] The bulk density was determined using the same method as in Example 1, and was found to be 2.93 g / cm³. 3 .

[0284] Comparative Example 1

[0285] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 uses a conventional preparation method, namely, the method of Example 1 in Chinese Patent Application CN107500747A to obtain the refractory material.

[0286] The analysis was performed using the same method as in Example 1. The chemical composition of the obtained refractory material, based on its mass percentage in the refractory material, included 92.11% Al2O3 and 7.02% CaO.

[0287] The analysis was performed using the same method as in Example 1. The main phases of Comparative Example 1 were CA6, corundum, CaO·Al2O3, and CaO·2Al2O3. Based on the mass percentage of the phases in the refractory material, the CA6 phase accounted for 69.1%, the corundum phase for 24.2%, the CaO·Al2O3 phase for 2.30%, and the CaO·2Al2O3 phase for 2.31%.

[0288] The analysis was performed using the same method as in Example 1, and the bulk density of Comparative Example 1 was 3.05 g / cm³. 3 .

[0289] Table 2. Raw materials used in the examples and comparative examples and the resulting refractory materials.

[0290]

[0291]

[0292] Experiment Example 1: Dynamic Slag Erosion Experiment

[0293] The dynamic slag erosion experiment compared the refractory material samples obtained in Example 1 and Comparative Example 1.

[0294] The specimens for dynamic slag erosion require a relatively long length to be fixed on the rotating shaft. Given the high bulk density, high corundum phase content, and high hardness of the refractory material obtained in Example 1, it is difficult to drill into φ15mm cylindrical specimens; instead, they are cut into square strips. Since the erosion rate is measured based on the dimensions of opposite sides, cutting the specimens into square strips does not affect the accuracy of the final results. For comparison, the castable from Comparative Example 1 was cast into specimens of the same size.

[0295] The conditions for the dynamic slag erosion experiment were as follows: deoxidation was performed using metallic aluminum, the experimental temperature was 1600℃, the atmosphere was argon, the slag system was CaO-Al2O3-SiO2, the steel slag composition was CaO 51%, Al2O3 30%, SiO2 11%, MgO 8%, and the CaO / SiO2 ratio was 4.6.

[0296] The castable refractory of Comparative Example 1 and the refractory material described in Example 1 were respectively bonded to the electric motor using a high-temperature adhesive, with the rotation speed controlled at 10 revolutions per minute. The experimental results are as follows: Figure 1-1 and Figure 1-2 As shown.

[0297] from Figure 1-1 and Figure 1-2 It can be seen that after 8 minutes of rotation, the castable sample of Comparative Example 1, immersed in steel slag, had already disintegrated, while the refractory material of Example 1 showed little change, with its roundness remaining very obvious and essentially unchanged. Cutting open the sample and measuring the width of the unreacted interface with vernier calipers showed that it was damaged by 0.2–0.5 mm, indicating that the refractory material obtained in Example 1 has excellent erosion resistance.

[0298] Experiment Example 2: Static Slag Erosion Experiment

[0299] The static slag erosion experiment used the crucible method, in which... Figure 2-1 A schematic diagram of the static crucible method for smelting molten steel.

[0300] The sample in Example 1 was first hot-pressed into a φ45mm sample, and then a φ30mm×40mm recess was drilled from it. The castable refractory from Comparative Example 1 was also cast into a φ45mm sample, with an internal recess size of φ30mm×40mm. The experimental conditions were 1600℃, argon atmosphere, and deoxidation using metallic aluminum. The slag system was CaO-Al2O3-SiO2, with a steel slag composition of CaO 51%, Al2O3 30%, SiO2 11%, MgO 8%, and a CaO / SiO2 ratio of 4.6. The static slag erosion results are as follows... Figure 2-3 As shown, a, b, and c are the contour structures of the castable material of Comparative Example 1 at 30 min, 40 min, and 50 min, respectively, and d, e, and f are the contour structures of the sample of Example 1 at 30 min, 40 min, and 50 min, respectively.

[0301] from Figure 2-3 As can be seen, for the castable of Comparative Example 1, some parts were completely penetrated and eroded by molten slag after 40 minutes, and the sample collapsed. Although the erosion thickness in some parts showed 270 μm, the molten slag had completely penetrated, which is due to the structure and properties of traditional refractory materials. Due to the non-uniformity of the structure of traditional materials, they are often good overall, but some parts can no longer withstand the load. In contrast, the sample of Example 1 of this invention showed very good uniformity and a very intact structure.

[0302] also, Figure 2-3 To compare the microstructure of the castable refractory of Comparative Example 1 and the sample of Example 1 of this patent, a, b, and c show the microstructures of the castable refractory of Comparative Example 1 at 30 min, 40 min, and 50 min, respectively, while d, e, and f show the microstructures of the sample of Example 1 at 30 min, 40 min, and 50 min, respectively. The microstructures also show that the structure of the castable refractory of Comparative Example 1 is very non-uniform, with slag penetrating deeply along areas with more pores. In contrast, the penetration and erosion layer of Example 1 of this patent is very thin and uniform. This demonstrates the superior performance of the sample of this invention.

[0303] Experiment Example 3: Experiments on slag erosion, total penetration depth, and thermal shock stability

[0304] The refractory materials obtained in Examples 1-17 and Comparative Example 1 were subjected to experiments on slag erosion, total penetration depth, and thermal shock stability. Regarding the determination of slag erosion and penetration depth: firstly, the crucible after the experiment was cut along its mid-face; then, samples were cut along the direction of slag penetration and erosion for electron microscopy observation and measurement, thereby determining the slag erosion and penetration depth. Thermal shock stability experiments were conducted according to GB / T 30873-2014, and the results are shown in Table 3.

[0305] Table 3 Experimental Data

[0306] Total depth of slag erosion and penetration, μm / 40min Thermal shock stability, secondary Example 1 100μm 10 Example 2 130μm 16 Example 3 136μm 14 Example 4 155μm 12 Example 5 142μm 13 Example 6 134μm 12 Example 7 147μm 10 Example 8 160μm 11 Example 9 158μm 10 Example 10 154μm 13 Example 11 133μm 10 Example 12 107μm 8 Example 13 165μm 12 Example 14 170μm 17 Example 15 183μm 16 Example 16 138μm 5 Example 17 210μm 15 Comparative Example 1 7.5mm 15

[0307] For refractory materials, their applicability and performance evaluation are not only related to their resistance to slag erosion, but also need to consider the thermal shock stability of the refractory material under rapid temperature cooling and heating conditions; if the thermal shock stability is poor, cracks may appear during use, affecting the performance of the material.

[0308] Regarding corrosion resistance, the addition of ZrO2 is advantageous at the same bulk density; corundum exhibits better corrosion resistance compared to CA6, C2M2A8, and CM2A8. For the same composition, refractory materials with higher bulk density generally have better corrosion resistance.

[0309] The addition of ZrO2 is beneficial for thermal shock stability. The addition of CA6 results in better thermal shock stability than the addition of the same mass of corundum, C2M2A8, and CM2A8. Under the same composition, a lower bulk density results in better thermal shock stability.

[0310] In addition, the cost-effectiveness of refractory materials must also be considered. For example, refractory materials with added zirconium oxide have good resistance to slag erosion and thermal shock stability, and their performance is also excellent when the amount added is large. However, zirconium oxide is relatively expensive. Therefore, the performance of the embodiments of the present invention is the result of a comprehensive comparison.

[0311] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A corrosion-resistant refractory material, wherein the phases of the refractory material include corundum and one or more phases selected from CA6, C2M2A14, CM2A8 and ZrO2; Based on the mass percentage of the phases in the refractory material, the sum of corundum and one or more phases selected from CA6, C2M2A14, CM2A8 and ZrO2 is ≥90%; The corundum phase comprises 26.5-89.5%; The total amount of the CA6+C2M2A14+CM2A8 phases is 5.25-66.5%; The ZrO2 phase content is 0-35%; The bulk density of the refractory material is 2.95-3.45 g / cm³. 3 ; The chemical composition of the refractory material includes Al2O3, CaO, MgO and ZrO2, and the Al2O3 is 59.5-98.99% by mass percentage; the CaO is 0.30-5.58%; the MgO is 0-5.58% and the ZrO2 is 0-35%.

2. The refractory material according to claim 1, wherein, The corundum phase comprises 32-89.5% by mass percentage of the phases in the refractory material. The total amount of the CA6+C2M2A14+CM2A8 phases is 5.25-62.0%; and The ZrO2 phase is 0-30%.

3. The refractory material according to claim 1, wherein, The corundum phase comprises 32.0-88.0% by mass percentage of the phases in the refractory material. The total amount of the CA6+C2M2A14+CM2A8 phases is 6.0-62.0%.

4. The refractory material according to claim 1, wherein, The content of sintering-promoting impurity components is ≤1.5% by mass percentage in the refractory material.

5. The refractory material according to claim 1, wherein, The content of sintering-promoting impurity components is ≤1.0% by mass percentage in the refractory material.

6. The refractory material according to claim 1, wherein, The Al2O3 comprises 59.5-98.99% and the CaO comprises 0.35-5.58% by mass percentage in the refractory material.

7. The refractory material according to claim 1, wherein, The Al2O3 comprises 64.57-98.99% and the CaO comprises 0.35-5.20% by mass percentage in the refractory material.

8. The refractory material according to claim 1, wherein, The bulk density of the refractory material is 2.95-3.30 g / cm³. 3 .

9. The refractory material according to any one of claims 1-8, wherein, The refractory material is prepared by a method comprising the following steps: The mixture is obtained by mixing granular material and fine powder, and then hot-pressing and sintering the mixture.

10. The refractory material according to claim 9, wherein, The mass ratio of the granules to the fine powder is 30-65:35-70.

11. The refractory material according to claim 9, wherein, The granular material includes corundum granules and mixed granules.

12. The refractory material according to claim 11, wherein, The corundum granules comprise 65-100% of the granules by mass percentage, and the mixed granules comprise 0-35%.

13. The refractory material according to claim 12, wherein, The mixed granules are selected from one or more of CA6 granules, C2M2A14 granules and CM2A8 granules.

14. The refractory material according to claim 12, wherein, The corundum particles are selected from one or more of tabular corundum particles, sintered corundum particles, white corundum particles, dense corundum particles, and sub-white corundum particles.

15. The refractory material according to claim 9, wherein, The fine powder includes Al2O3-CaO-MgO series fine powder and ZrO2-containing fine powder.

16. The refractory material according to claim 15, wherein, The Al2O3-CaO-MgO fine powder accounts for 50-100% of the total fine powder by mass percentage, and the ZrO2-containing fine powder accounts for 0-50%.

17. The refractory material according to claim 15, wherein, The Al2O3-CaO-MgO fine powder includes fine powder containing Al2O3 and one or more fine powders selected from CA6, C2M2A14, CM2A8 and MgO-CaO fine powders.

18. The refractory material according to claim 17, wherein, The MgO-CaO fine powder is a fine powder containing MgO and / or a fine powder containing CaO.

19. The refractory material according to claim 17, wherein, The Al2O3-containing fine powder is selected from one or more of the following: active α-Al2O3 powder, γ-Al2O3 powder, ρ-Al2O3 powder, aluminum hydroxide, industrial alumina, white corundum powder, sintered corundum powder, and tabular corundum powder.

20. The refractory material according to claim 18, wherein, The MgO-containing fine powder is selected from one or more of the following: magnesium carbonate, lightly calcined magnesium oxide, brucite, magnesium hydroxide, magnesium chloride, high-purity magnesium oxide, and fused magnesium oxide.

21. The refractory material according to claim 18, wherein, The CaO-containing fine powder is selected from one or more of quicklime, limestone, calcium hydroxide, CaO·Al2O3, CaO·2Al2O3, 12CaO·7Al2O3, CA6, C2M2A14 and CM2A8.

22. The refractory material according to claim 15, wherein, The ZrO2-containing fine powder is selected from one or more of monoclinic zirconium oxide, tetragonal zirconium oxide, desilicationized zirconium, and fused zirconium oxide.

23. The refractory material according to claim 9, wherein, The particle size of the fine powder is ≤0.088mm.

24. The refractory material according to claim 9, wherein, The particle size of the granules is 0.088-10 mm.

25. The refractory material according to claim 9, wherein the particle size of the granules is 0.088-8 mm.

26. The refractory material according to claim 9, wherein, The hot pressing sintering is performed by placing the mixture into a mold of a high-temperature device for hot pressing sintering, or by forming the mixture at room temperature and then placing it into a mold of a high-temperature device for hot pressing sintering, or by forming the mixture at room temperature and pre-sintering it at low temperature before hot pressing sintering.

27. The refractory material according to claim 26, wherein, The hot pressing sintering temperature is 1550-1800℃.

28. The refractory material according to claim 26, wherein, The hot-pressing strength is 0.5-30 MPa.

29. A method for preparing a refractory material, comprising the following steps: The mixture is obtained by mixing granular material and fine powder, and then hot-pressing and sintering the mixture. The refractory material includes corundum and one or more phases selected from CA6, C2M2A14, CM2A8 and ZrO2; Based on the mass percentage of the phases in the refractory material, the sum of corundum and one or more phases selected from CA6, C2M2A14, CM2A8 and ZrO2 is ≥90%; The corundum phase comprises 26.5-89.5%; The total amount of the CA6+C2M2A14+CM2A8 phases is 5.25-66.5%; The ZrO2 phase content is 0-35%; The bulk density of the refractory material is 2.95-3.45 g / cm³. 3 ; The chemical composition of the refractory material includes Al2O3, CaO, MgO and ZrO2, and the Al2O3 is 59.5-98.99% by mass percentage; the CaO is 0.30-5.58%; the MgO is 0-5.58% and the ZrO2 is 0-35%.

30. The preparation method according to claim 29, wherein, The mass ratio of the granules to the fine powder is 30-65:35-70.

31. The preparation method according to claim 29, wherein, The granular material includes corundum granules and mixed granules.

32. The preparation method according to claim 31, wherein, The corundum granules comprise 65-100% of the granules by mass percentage, and the mixed granules comprise 0-35%.

33. The preparation method according to claim 31, wherein, The mixed granular material is one or more of CA6 granular material, C2M2A14 granular material and CM2A8 granular material.

34. The preparation method according to claim 31, wherein, The corundum particles are selected from one or more of tabular corundum, sintered corundum, white corundum, dense corundum, and sub-white corundum.

35. The preparation method according to claim 29, wherein, The fine powder includes Al2O3-CaO-MgO series fine powder and ZrO2-containing fine powder.

36. The preparation method according to claim 35, wherein, The Al2O3-CaO-MgO fine powder accounts for 50-100% of the total fine powder by mass percentage, and the ZrO2-containing fine powder accounts for 0-50%.

37. The preparation method according to claim 35, wherein, The Al2O3-CaO-MgO fine powder includes fine powder containing Al2O3 and one or more fine powders selected from CA6, C2M2A14, CM2A8 and MgO-CaO fine powders.

38. The preparation method according to claim 37, wherein, The MgO-CaO fine powder is a fine powder containing MgO and / or a fine powder containing CaO.

39. The preparation method according to claim 37, wherein, The Al2O3-containing fine powder is selected from one or more of the following: active α-Al2O3 powder, γ-Al2O3 powder, ρ-Al2O3 powder, aluminum hydroxide, industrial alumina, white corundum powder, sintered corundum powder, and tabular corundum powder.

40. The preparation method according to claim 38, wherein, The MgO-containing fine powder is selected from one or more of the following: magnesium carbonate, lightly calcined magnesium oxide, brucite, magnesium hydroxide, magnesium chloride, sintered magnesium oxide, and fused magnesium oxide.

41. The preparation method according to claim 38, wherein, The CaO-containing fine powder is selected from one or more of quicklime, limestone, calcium hydroxide, CaO·Al2O3, CaO·2Al2O3, 12CaO·7Al2O3, CA6, C2M2A14 and CM2A8.

42. The preparation method according to claim 35, wherein, The ZrO2-containing fine powder is selected from one or more of monoclinic zirconium oxide, tetragonal zirconium oxide, desilicationized zirconium, and fused zirconium oxide.

43. The preparation method according to claim 29, wherein, The particle size of the fine powder is ≤0.088mm.

44. The preparation method according to claim 29, wherein, The particle size of the granules is 0.088-10 mm.

45. The preparation method according to claim 29, wherein the particle size of the granules is 0.088-8 mm.

46. ​​The preparation method according to any one of claims 29-45, wherein, The hot pressing sintering is performed by placing the mixture into a mold of a high-temperature device for hot pressing sintering, or by forming the mixture at room temperature and then placing it into a mold of a high-temperature device for hot pressing sintering, or by forming the mixture at room temperature and pre-sintering it at low temperature and then placing it into a mold of a high-temperature device for hot pressing sintering.

47. The preparation method according to claim 46, wherein, The hot pressing sintering temperature is 1550-1800℃.

48. The preparation method according to claim 46, wherein, The hot-pressing strength is 0.5-30 MPa.

49. A working lining for a steel ladle used in steelmaking, comprising the refractory material according to any one of claims 1-28 or the refractory material prepared by the preparation method according to any one of claims 29-48.

50. A working lining for an aluminum molten metal smelting and conveying ladle, comprising the refractory material according to any one of claims 1-28 or the refractory material prepared by the preparation method according to any one of claims 29-48.

51. A refractory lining for an industrial kiln, comprising the refractory material according to any one of claims 1-28 or the refractory material prepared by the preparation method according to any one of claims 29-48.

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