Calcium hexaluminate refractory, nano heat insulating plate, composite refractory lining structure, method for producing same, and use thereof

Abstract

The application discloses a calcium hexaluminate refractory material, a nano heat insulation plate, a composite refractory lining structure, a preparation method and application thereof. The phase of the calcium hexaluminate refractory material comprises CA6 and one or more than two phases selected from C2M2A14, CM2A8, magnesium-aluminum spinel and corundum. The nano heat insulation plate is a micro-nano plate and a film coated micro-nano plate. The composite refractory lining structure for blocking heat conduction comprises the calcium hexaluminate refractory material and the nano heat insulation plate. The composite refractory lining structure for blocking heat conduction can effectively reduce heat loss and surface temperature, has good stability during use, can ensure the stability of a similar steel ladle refractory working lining, supports the close connection between the working layer materials of the steel ladle, avoids the leakage of molten steel of the steel ladle and the leakage of molten aluminum of a non-ferrous ladle, and practically realizes the purposes of heat preservation, energy saving and safe operation.

Description

Technical Field

[0001] This invention relates to the field of refractory materials technology, and in particular to a calcium hexaaluminate-based refractory material, a nano-insulation board, a composite refractory lining structure for blocking heat conduction, its manufacturing method, and its application. Background Technology

[0002] Ladle insulation involves not only steel refining, alloying, and continuous casting, but also converter blowing temperature and carbon-oxygen product. Controlling the carbon-oxygen product is crucial for the damage to furnace lining refractory materials, alloy usage, and refining processes. Ladle insulation has long been a focus of attention, but a truly effective solution has yet to be found.

[0003] Currently, to ensure maximum heat preservation in steel ladles, the ladle lining typically employs a three-layer structure: a working lining, a permanent lining, and an insulating lining. The working lining, in contact with the high-temperature molten metal, requires excellent high-temperature performance and good resistance to erosion from molten steel and slag. The permanent lining must combine safety and heat insulation functions. It must resist the high temperatures and erosion of molten slag and steel in the absence of the working lining, meeting the primary safety requirement. Simultaneously, it must prevent or reduce heat transfer, lowering the temperature borne by the insulating lining to achieve its heat insulation function. The permanent lining material is typically a medium-heavy ordinary low-cement castable. The insulating lining primarily reduces heat loss and the temperature borne by the steel shell, keeping the steel shell temperature below its yield temperature and ensuring minimal deformation.

[0004] Regarding thermal insulation linings, lightweight clay bricks and lightweight high-alumina bricks have high strength and good high-temperature performance, but poor thermal insulation, and their use has decreased in recent years. Alumina silicate fiberboard emerged as a thermal insulation material after lightweight clay bricks and lightweight high-alumina bricks. Its insulation effect is better than lightweight bricks, but its most critical problems are steel leakage accidents caused by crystallization and pulverization during use, and a decline in insulation performance in later stages of use; the insulation effect increases dramatically from 280℃ in the first heat to 350℃. Crystallization and pulverization of alumina silicate fiberboard cause the permanent and working linings of the ladle to lose external support, leading to cracks, lining breakage, and ultimately, serious accidents such as steel leakage. Alumina silicate fiberboard is a board material made from alumina silicate fibers. These fibers are prone to crystallization and pulverization at temperatures above 1200℃, resulting in reduced strength, decreased insulation, and increased safety hazards.

[0005] Nano-insulation boards based on nano and micro-SiO2 were applied almost simultaneously with fiberboard. These boards offer significantly better thermal insulation than aluminosilicate fiberboard, exhibiting very low thermal conductivity and excellent insulation performance. However, they suffer from the same problem as aluminosilicate fiberboard: crystallization and pulverization. Furthermore, the crystallization and pulverization temperature of nano-boards is even lower than that of aluminosilicate fiberboard, with nanoparticles typically crystallizing and pulverizing above 850℃. In existing industrial steel ladles, the temperatures subjected to nano-boards far exceed 850℃, sometimes reaching as high as 1300℃. Such temperatures are fatal to nanoparticles, causing them to crystallize rapidly and lose their original amorphous structure. Pulverization of nano-insulation boards leads to a loss of support for the working and permanent linings, resulting in large cracks and potentially causing accidents such as steel leakage. Simultaneously, the insulation function is lost. Therefore, simple nano-insulation boards cannot provide adequate thermal insulation for industrial kiln containers such as steel ladles.

[0006] Regarding permanent linings, current permanent linings for steel ladles are generally medium-heavy high-alumina castables, or aluminum-magnesium castables, or ordinary low-cement high-alumina castables, or high-alumina castables with added mullite lightweight aggregates. These materials and technologies have been used for decades, but have not been able to meet the requirements for safety and energy-saving insulation well, and there has been no significant improvement.

[0007] The permanent lining of the steel ladle can also be calcium hexaaluminate (CA6) refractory material, but the application of CA6 refractory material has four main problems: (1) CA6 material has a high impurity content. Based on CA6 as the main material, high bulk density material is achieved by adding sintering aids. Because of the lamellar structure of CA6 itself, CA6 material is difficult to sinter. Basically, sintering is promoted by adding SiO2, TiO2, etc., such as adding SiO2 to promote sintering in patent CN108947547A. Feng Gangjun et al. studied the effect of additives on the densification of CA6 by adding SiO2 (Influence of additives on the properties of calcium hexaaluminate microporous materials, Proceedings of the 15th National Conference on Unshaped Refractory Materials), etc.; (2) CA6 material contains a lot of corundum phase raw materials. Most CA6 materials are sintered, have high density, and build strength by adding a large amount (≥20%) of corundum or activated alumina micro powder, such as CN108439961A which discloses a method for preparing a dense high-purity calcium hexaaluminate-corundum multiphase material; (3) High-purity CA6 materials (Al2O3+CaO content ≥97.0%) prepared without adding sintering-promoting components generally have a bulk density of less than 2.5 g / cm³. 3 Furthermore, its strength is very low, failing to meet usage requirements. (4) Bulk density less than 2.0 g / cm³ 3 CA6 material cannot be used in steel ladles because it is not suitable for the permanent lining of the ladle, which needs to resist the erosion of molten slag and steel.

[0008] Existing permanent lining materials have the following shortcomings and defects: 1) High thermal conductivity of permanent lining materials; 2) Shrinkage and densification at high temperatures further increase the thermal conductivity of the materials; 3) Poor resistance to steel slag erosion; 4) Material shrinkage causes the working lining refractory material to expand outward, weakening the compressive force between bricks, reducing the overall integrity, and easily leading to steel leakage; 5) CA6-based materials rely on additives for sintering, resulting in a large liquid phase content, reduced high-temperature performance, and high thermal conductivity; 6) By introducing more corundum phase into CA6 materials, the thermal conductivity is greatly increased; 7) Pure CA6 materials have relatively low bulk density and strength, making it difficult to serve as a permanent lining material.

[0009] Furthermore, the current construction procedures for steel ladle refractory materials are also very unfavorable for permanent lining and insulating lining refractory materials. The construction procedure for steel ladle lining is mostly as follows: lightweight bricks are laid or insulating boards are attached to the inner wall of the ladle shell, then the formwork is installed in the core of the ladle, the permanent lining refractory material is poured and shaped, and the working lining refractory material is laid after the permanent lining dries.

[0010] Therefore, the current structure of steel ladles, which is constructed from permanent lining and insulating refractory materials, has the following defects: (1) Neither nano-insulation boards nor low thermal conductivity permanent lining refractory materials can solve the problem of heat insulation of steel ladles when used alone. Neither can effectively block heat conduction, nor can they solve the safety problem of steel ladles, nor can they form a systematic solution for the insulation and safety of steel ladles; (2) The nano-insulation boards in the existing technology all have crystallization and pulverization phenomena. Neither has solved the problem of crystallization and pulverization of nano-powders, nor has it broken through the constraints of use. After one or several furnaces in the steel ladle, they basically crystallize and pulverize, losing their heat insulation effect; (3) Neither aluminum silicate fiberboard (or felt) nor nano-insulation boards have problems such as crystallization, pulverization and structural collapse. Neither can easily lead to steel leakage accidents, and in fact, they can lead to major accidents such as excessive steel leakage and red envelopes; 4) Permanent linings, whether aluminum-magnesium castables, low-cement high-alumina castables, or medium-heavy mullite castables, all suffer from sintering shrinkage under high temperature and long-term use. This causes the supports on the periphery of the working lining refractory material to move outward, resulting in a weakening of the constraint effect and gaps between the working lining refractory materials, leading to molten steel leakage. (5) High-alumina castables and aluminum-magnesium castables have insufficient corrosion resistance. (6) CA6 materials are basically sintered by adding additives such as SiO2. The amount of high-temperature liquid phase is large, the high-temperature performance decreases, and the thermal conductivity increases. (7) The sintering difficulty of CA6 materials is compensated by introducing more corundum phase, but this leads to a significant increase in thermal conductivity. (8) The volume density and strength of high-purity CA6 materials are relatively low, making it difficult to serve as a permanent lining material. (9) The current on-site construction methods and operations make it difficult for the relevant materials to give full play to their advantages.

[0011] The defects of the existing technology are as follows: (1) Due to the high energy and instability of aluminum silicate fiber and nanoparticles, the board (or felt) and insulation board have a driving force for crystallization at high temperature. This is the nature of the material and cannot be changed. Therefore, the crystallization and pulverization of aluminum silicate fiber board and nano insulation board are inevitable. As long as the temperature it withstands is higher than its crystallization temperature, it will definitely happen; (2) The main raw material of the existing application materials is bauxite, which has a high impurity content and a large liquid phase at high temperature. For example, aluminum-magnesium castable and low-cement castable are prone to high-temperature reactions that easily sinter and densify, resulting in sintering shrinkage after use and an increase in thermal conductivity. This is due to the raw materials and properties of the materials themselves; (3) The current aluminum-magnesium castable and high-alumina castable have many impurities and a large liquid phase, and have poor resistance to erosion by slag and molten steel. This is determined by the properties of the raw materials; (4) CA6 has poor sinterability due to its own crystal structure, while steel The temperature of the permanent lining is generally 1300-1500℃. This temperature is difficult for CA6 material to sinter. Therefore, CA6 refractory material used as permanent lining must be sintered with the help of a certain liquid phase. Otherwise, the permanent lining will not form a whole and will endanger the smelting safety. (5) For CA6 material used as permanent lining, in order to form a whole and to ensure sintering, certain sintering aids or corundum must be added. This is determined by the properties of the material. If no additives or corundum are added, the volume density of pure CA6 material is generally small and cannot withstand the erosion of molten steel and slag. It cannot be used as permanent lining material. (6) No matter how the permanent lining and the heat insulation lining refractory materials are combined, they cannot effectively block heat transfer and cannot reduce the surface temperature of the steel ladle and steel shell to below 300℃ for a long time. (7) The on-site pouring, vibration construction and large amount of water added to the permanent lining cause great damage to the nano heat insulation board, which is unavoidable and difficult to solve. Summary of the Invention

[0012] To address the aforementioned problems, this invention provides a calcium hexaaluminate-based refractory material, a nano-insulation board, a composite refractory lining structure for blocking heat conduction, and its applications.

[0013] In terms of existing technology, neither a single nano-insulation board nor a single permanent lining material can achieve good thermal insulation function on its own, and both have many difficulties and defects. This invention solves the above-mentioned difficulties and defects by using a composite refractory lining structure made of calcium hexaaluminate-based refractory material and a nano-insulation board to block heat conduction. It achieves the fusion of the best-performing permanent lining material (calcium hexaaluminate-based refractory material) and the heat-insulating lining (nano-insulation board) with good thermal insulation performance. This not only leverages the performance advantages of each material but also makes the combined and superimposed performance more prominent and the effect multiplied. It not only provides sufficient support to the working lining refractory material, ensuring a tight bond between the working lining refractory materials and preventing heat loss and steel leakage, but also effectively prevents heat transfer outward, achieving systematic thermal insulation, reducing the tapping temperature and carbon-oxygen product of the converter, reducing refractory material consumption, reducing alloy usage, and resulting in significant economic and socio-economic benefits.

[0014] The specific technical solution of this invention is as follows:

[0015] 1. A calcium hexaaluminate-based refractory material, wherein the phases of the calcium hexaaluminate-based refractory material include CA6 and one or more phases selected from C2M2A14, CM2A8, magnesium aluminum spinel and corundum.

[0016] 2. The calcium hexaaluminate-based refractory material according to item 1, wherein, based on the mass percentage of CA6, C2M2A14, CM2A8, magnesium aluminum spinel and corundum in the refractory material, the total content is ≥90%, preferably 94.8-99.5%.

[0017] 3. The calcium hexaaluminate-based refractory material according to item 1 or 2, wherein, based on the mass percentage of the phase in the refractory material, the CA6 phase is 26.7-100%, preferably 31.5-99.5%, and more preferably 38.7-99.5%;

[0018] The C2M2A14 phase content is 0-72%, preferably 0-60%;

[0019] The CM2A8 phase content is 0-72%, preferably 0-59.5%;

[0020] The magnesium aluminum spinel phase is 0-10%, 0-4.60%, preferably 0%, and...

[0021] The corundum phase comprises 0-30%, preferably 0-18%, and more preferably 0-16.5%.

[0022] 4. The calcium hexaaluminate-based refractory material according to any one of items 1-3, wherein the chemical composition of the calcium hexaaluminate-based refractory material includes Al2O3, CaO and MgO, and the Al2O3 is 86.65-94.10% by mass percentage in the calcium hexaaluminate-based refractory material, preferably 87.60-94.10%, more preferably 88.07-94.10%;

[0023] The CaO content is 5.80-8.40%, preferably 6.89-8.40%; and

[0024] The MgO content is 0-6.05%, preferably 0-5.04%.

[0025] 5. The calcium hexaaluminate-based refractory material according to any one of items 1-4, wherein the bulk density of the calcium hexaaluminate-based refractory material is 2.40-2.90 g / cm³. 3 The preferred value is 2.40-2.82 g / cm³. 3 .

[0026] 6. The calcium hexaaluminate-based refractory material according to any one of items 1-5, wherein the matrix portion of the calcium hexaaluminate-based refractory material comprises CA6 and one or more phases selected from corundum, magnesium aluminum spinel, C2M2A14 and CM2A8.

[0027] 7. The calcium hexaaluminate-based refractory material according to item 6, wherein, based on the mass percentage of the phase in the matrix portion of the calcium hexaaluminate-based refractory material, the CA6 phase is 67.4-100%, preferably 78.2-100%;

[0028] The corundum phase comprises 0-30%, preferably 0-20%;

[0029] The magnesium aluminum spinel phase is 0-10% or 0-5.22%, preferably 0%.

[0030] The C2M2A14 phase comprises 0-30%, preferably 0-18.8%; and

[0031] The CM2A8 phase content is 0-30%, preferably 0-18.8%.

[0032] 8. The calcium hexaaluminate-based refractory material according to item 6 or 7, wherein the chemical composition of the matrix portion of the calcium hexaaluminate-based refractory material includes Al2O3, CaO and MgO, and the Al2O3 is 89.03-94.10% by mass percentage, preferably 90.30-93.20% in the matrix portion of the calcium hexaaluminate-based refractory material;

[0033] The CaO content is 5.80-8.40%, preferably 6.60-8.40%; and

[0034] The MgO content is 0-2.52%, preferably 0-1.68%.

[0035] 9. A nano-insulation plate comprising micro-nano plates and a thin film covering the micro-nano plates, wherein the chemical composition of the micro-nano plates comprises SiO2 and ZrO2, and the weight percentage of SiO2 in the micro-nano plates is 55-100% and ZrO2 is 0-40%.

[0036] 10. The nano-insulation plate according to item 9, wherein, by weight, SiO2 is 70-100%, preferably 80-100%; and ZrO2 is 0-30%, preferably 0-15%.

[0037] 11. The nano-insulation panel according to claim 9 or 10, wherein the bulk density of the nano-insulation panel is 0.23-0.60 g / cm³. 3 The preferred value is 0.25-0.60 g / cm³. 3 More preferably, it is 0.30-0.60 g / cm³. 3 Preferably, the thermal conductivity of the nano-insulation plate at 300℃ is 0.020-0.048w / m·k, more preferably 0.025-0.048w / m·k, and even more preferably 0.025-0.045w / m·k.

[0038] 12. The nano-insulation board according to any one of items 9-11, wherein the micro / nano board further comprises fibers, preferably, the fibers are selected from one or more of glass fibers, alumina fibers, mullite fibers and aluminosilicate fibers;

[0039] The film is a metal film, an organic film, or an inorganic coating. Preferably, the metal film is aluminum foil, the organic film is a plastic film, and the inorganic coating is a silica sol coating or an aluminum dihydrogen phosphate coating.

[0040] 13. A composite refractory lining structure for blocking heat conduction, comprising a calcium hexaaluminate refractory material as described in any one of items 1-8 and a nano-insulating plate as described in any one of items 9-12, wherein the nano-insulating plate is fixedly disposed on the calcium hexaaluminate refractory material.

[0041] 14. The composite refractory lining structure according to item 13, wherein the thickness of the calcium hexaaluminate refractory material is 50-250 mm, preferably 80-116 mm; preferably, the thickness of the nano-insulation board is 10-40 mm, preferably 20-30 mm.

[0042] 15. A composite refractory lining structure forming material for blocking heat conduction, comprising the calcium hexaaluminate refractory material as described in any one of items 1-8 and the nano-insulating plate as described in any one of items 9-12, wherein the nano-insulating plate is fixedly disposed on the low-temperature side of the calcium hexaaluminate refractory material.

[0043] 16. The composite refractory lining structure forming material according to item 15, wherein the composite refractory lining structure forming material further includes high-temperature fire clay, and the nano-insulating plate is fixedly disposed on the low-temperature side of the calcium hexaaluminate refractory material by means of the high-temperature fire clay.

[0044] 17. The composite refractory lining structure forming material according to item 16, wherein the high-temperature fire mortar is selected from water glass bonded fire mortar, aluminum dihydrogen phosphate bonded fire mortar, or silica sol bonded fire mortar.

[0045] 18. The composite refractory lining structure forming material according to any one of items 15-17, wherein the thickness of the calcium hexaaluminate refractory material is 50-250 mm, preferably 80-116 mm; preferably, the thickness of the nano-insulation board is 10-40 mm, preferably 20-30 mm.

[0046] 19. A method for preparing a composite refractory lining structure as described in any one of items 13-14, comprising the following steps:

[0047] The nano-insulation board is fixed onto a calcium hexaaluminate-based refractory material using a fixative, and then cured.

[0048] 20. The method according to item 19, wherein the fixing agent is an adhesive, preferably, the adhesive is an epoxy resin adhesive, ethyl α-cyanoacrylate, methacrylate, methyl methacrylate, water glass bonded fire putty, aluminum dihydrogen phosphate bonded fire putty or silica sol bonded fire putty, and more preferably, the adhesive is an epoxy resin adhesive, ethyl α-cyanoacrylate, methacrylate or methyl methacrylate.

[0049] 21. A method for preparing a composite refractory lining structure using the composite refractory lining structure forming material according to any one of items 15-18, comprising the following steps:

[0050] The nano-insulation board was fixed to the low-temperature side of the calcium hexaaluminate refractory material using high-temperature fire mud.

[0051] 22. The method according to item 21, wherein the high-temperature fire clay is selected from water glass-bonded fire clay, aluminum dihydrogen phosphate-bonded fire clay, or silica sol-bonded fire clay.

[0052] 23. A refractory material for a permanent lining and heat insulation lining of a ladle for steel smelting, comprising the composite refractory lining structure as described in any one of items 13-14 or the composite refractory lining structure forming material as described in any one of items 15-18.

[0053] 24. A refractory material for the working lining and heat insulation lining of an aluminum molten metal smelting vessel, comprising the composite refractory lining structure as described in any one of items 13-14 or the composite refractory lining structure forming material as described in any one of items 15-18.

[0054] 25. A refractory lining for a kiln, comprising a composite refractory lining structure as described in any one of items 13-14 or a composite refractory lining structure forming material as described in any one of items 15-18.

[0055] 26. The refractory lining according to item 25, wherein the kiln is a rotary kiln.

[0056] The effects of the invention

[0057] Compared with existing technologies, the composite refractory lining structure for blocking heat conduction described in this invention has the following advantages:

[0058] (1) The composite refractory lining structure made of calcium hexaaluminate-based refractory material and nano-insulation board of this invention can effectively reduce heat loss and lower surface temperature. Taking a steel refining ladle as an example, the refractory lining structure of this invention can significantly reduce the surface temperature of the steel shell compared with the traditional structure. Furthermore, the lining structure of this invention has good stability during use, which can ensure the stability of the refractory working lining similar to that of a steel ladle, support the tight connection between the working layer materials of the steel ladle, and avoid steel leakage, aluminum leakage in colored ladles, etc., thus effectively achieving the purpose of heat preservation, energy saving and ensuring safe operation.

[0059] (2) The composite refractory lining structure of the present invention with high efficiency heat conduction barrier can give full play to the advantages of calcium hexaaluminate-based refractory material with good high temperature stability and no shrinkage under the service conditions, ensure close contact and good connection between working lining materials, and protect the safety of molten steel and other high temperature melts.

[0060] (3) The composite refractory lining structure of the present invention has the advantages of high temperature stability of calcium hexaaluminate refractory material, the structure can maintain the original structure, and the heat barrier effect.

[0061] (4) The composite refractory lining structure of the present invention with high efficiency heat conduction barrier can block high temperature in the calcium hexaaluminate refractory material by means of the high efficiency heat barrier performance of CA6, reduce the crystallization and pulverization rate of nanoparticles, ensure that the nano heat insulation board structure does not collapse or break, and ensure the performance of its excellent heat insulation performance.

[0062] (5) The safety and thermal insulation performance of the composite refractory lining structure described in this invention are far superior to those of using CA6 insulation material or nano-insulation boards alone, and are significantly better than the performance of combining mullite castables, low-cement high-alumina castables, alumina-magnesium castables, etc., with nano-insulation boards. Currently, the construction of steel ladle linings is carried out on-site. First, the nano-insulation board is attached to the steel ladle shell, then the formwork is installed inside the steel ladle, and the permanent lining castable is mixed with water on-site and poured between the formwork and the nano-insulation board, or the masonry working lining material is used as the formwork to pour the mixed permanent lining castable.

[0063] (6) The high-efficiency heat-blocking composite refractory lining structure of the present invention is widely used in permanent linings and heat insulation linings of refining ladles on steelmaking production lines. It has good integrity and heat insulation performance, which is significantly better than the effect of any combination of existing aluminum-magnesium castable permanent linings, low-cement high-alumina castable permanent linings, medium-heavy mullite castable permanent linings, etc. with aluminum silicate fiber boards, nano heat insulation boards, etc. It increases the stability and cycle of equipment operation and improves economic benefits.

[0064] (7) This invention greatly reduces the heat loss of refining ladle, enhances heat preservation performance, reduces the temperature drop of molten steel, and has significant social benefits.

[0065] (8) The composite refractory lining structure of the present invention, which has high efficiency in blocking heat conduction, can be widely used in refractory linings such as rotary kilns. It has low thermal conductivity, increases equipment operating cycle, reduces heat loss, and improves economic efficiency.

[0066] (9) The composite refractory lining structure of the present invention, which is highly efficient in blocking heat conduction, can be widely used in the construction of some industrial kilns under conditions such as high temperature, reducing atmosphere and alkaline atmosphere erosion, such as petrochemical cracking furnace. It has good erosion resistance and low thermal conductivity, and its performance is significantly better than many existing refractory materials such as corundum bricks. It increases the equipment operation cycle, reduces heat loss and improves economic benefits.

[0067] (10) The combined structure will not be damaged by mechanical forces caused by on-site construction, nor will it be corroded by acidic or alkaline slurries, thus ensuring the structure of the relevant materials and their ability to effectively block heat conduction.

[0068] Furthermore, compared to the prior art, the advantages of the present invention further include:

[0069] Taking refined steel ladles as an example, the effects and advantages obtained by combining experimental data with existing technologies are as follows:

[0070] (1) If mullite castable is used as the permanent refractory lining of steel ladle and 20mm thick ordinary aluminum silicate fiber is used as the heat insulation layer, the cladding temperature is generally 300-360℃. After several cycles of use, the aluminum silicate fiber board pulverizes and large cracks appear in the permanent lining. Not only does the steel shell temperature rise sharply, but the risk of steel leakage also increases significantly.

[0071] (2) Using mullite castable as the permanent refractory lining of the steel ladle and 20mm nano-insulation board as the thermal insulation layer, the temperature of the steel ladle shell in the first furnace was 273℃. Starting from the second furnace, the nano-board pulverized, and the steel shell temperature rose rapidly. Due to the pulverization of the nano-insulation board, the permanent lining lost its support, the permanent lining broke, and there was no thermal insulation material, which caused the cladding temperature to rise rapidly to above 350℃ or higher, and also increased the risk of steel leakage.

[0072] (3) Using the CA6 low thermal conductivity refractory material of this invention as the permanent lining of the steel ladle and ordinary aluminosilicate fiberboard as the insulation layer, the cladding temperature is 245-300℃. Due to the significant heat conduction barrier effect of CA6 refractory bricks, the hot surface temperature of ordinary aluminosilicate fiberboard is reduced to below 1100℃, avoiding the crystallization and pulverization of the fiberboard, and the overall structure and thermal insulation performance are relatively good;

[0073] (4) The permanent lining and heat insulation lining refractory material with the CA6 low thermal conductivity refractory material and nano heat insulation board of this patent invention as a combination structure will significantly reduce the shell temperature and maintain very good heat insulation performance after 5 cycles of use. There is no crystallization or pulverization phenomenon of nano heat insulation board caused by using low cement castable as permanent lining. The structural integrity and heat insulation performance are excellent. Attached Figure Description

[0074] Figure 1 These are schematic diagrams of the surfaces of CA6 refractory material and mullite castable after treatment at 1550℃ in Experiment Example 1. The left side shows the surface of CA6 refractory material, and the right side shows the surface of mullite castable.

[0075] Figure 2-1 This is a schematic diagram of the resistance of CA6 refractory material to slag erosion at 1550℃ in Experiment Example 2.

[0076] Figure 2-2 This is a schematic diagram of the mullite castable resisting slag erosion at 1550℃ in Experiment Example 2. Detailed Implementation

[0077] The present invention will now be described in detail. While specific embodiments of the invention have been shown, 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 to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0078] 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.

[0079] This invention provides a calcium hexaaluminate-based refractory material, wherein the phases of the calcium hexaaluminate-based refractory material include CA6 and one or more phases selected from C2M2A14, CM2A8, magnesium aluminum spinel and corundum.

[0080] A phase is a phase in a substance that possesses specific physicochemical properties.

[0081] C2M2A14 refers to 2CaO·2MgO·14Al2O3.

[0082] CM2A8 refers to CaO·2MgO·8Al2O3.

[0083] The phase composition of the calcium hexaaluminate-based refractory material was determined by XRD. For example, the material was ground to below 325 mesh and then scanned using an X-ray diffractometer. By analyzing the diffraction data and matching it with a standard PDF card, the relevant phases were obtained, and then the content of the relevant phases was obtained by fitting the full spectrum of the diffraction data.

[0084] In a preferred embodiment of the present invention, the total content of CA6, C2M2A14, CM2A8, corundum and magnesium aluminum spinel is ≥90%, preferably 94.8-99.5%, based on the mass percentage of the calcium hexaaluminate-based refractory material.

[0085] For example, the total content of CA6, C2M2A14, CM2A8, magnesium aluminum spinel, and corundum in the calcium hexaaluminate refractory can be 90%, 91%, 92%, 93%, 94%, 95%, 96%, 96.2%, 96.55%, 96.6%, 96.8%, 97.1%, 97.5%, 97.7%, 97.8%, 97.9%, 98%, 98.05%, 98.95%, 99.15%, 100%, or any range thereof, based on the mass percentage of the calcium hexaaluminate refractory.

[0086] In a preferred embodiment of the present invention, the CA6 phase, based on the mass percentage of the phase in the calcium hexaaluminate refractory material, is 26.7-100%, preferably 31.5-99.5%, and more preferably 38.7-99.5%.

[0087] The C2M2A14 phase content is 0-72%, preferably 0-60%;

[0088] The CM2A8 phase content is 0-72%, preferably 0-59.5%;

[0089] The magnesium aluminum spinel phase is 0-10%, 0-4.60%, preferably 0%; and

[0090] The corundum phase comprises 0-30%, preferably 0-18%, and more preferably 0-16.5%.

[0091] For example, the CA6 phase, by mass percentage in the calcium hexaaluminate-based refractory, can be 26.7%, 28%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 97.8%, 99.5%, 100%, or any range thereof.

[0092] The C2M2A14 phase can be 0%, 5%, 10%, 15%, 20%, 24.5%, 25%, 30%, 35%, 35.2%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 71%, 72%, or any range thereof.

[0093] The CM2A8 phase can be 0%, 5%, 10%, 15%, 20%, 24%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 71%, 72%, or any range thereof.

[0094] The corundum phase can be 0%, 5%, 10%, 12%, 15%, 18%, 20%, 25%, 30%, or any range thereof.

[0095] Magnesium aluminum spinel can be 0%, 1%, 2%, 3%, 4%, 4.60%, 5%, 6%, 7%, 8%, 9%, 10%, or any range thereof.

[0096] In a preferred embodiment of the present invention, the chemical composition of the calcium hexaaluminate refractory includes Al2O3, CaO and MgO, and the Al2O3 is 86.65-94.10% by mass percentage in the calcium hexaaluminate refractory material, preferably 87.6-94.10%, and more preferably 88.07-94.10%.

[0097] The CaO content is 5.80-8.40%, preferably 6.89-8.40%, and the MgO content is 0-6.05%, preferably 0-5.04%.

[0098] The Al2O3, by mass percentage in the calcium hexaaluminate refractory, can be, for example, 86.65%, 87.60%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 94.10%, or any range thereof.

[0099] The CaO content can be 5.80%, 6.0%, 7.0%, 8.0%, 8.40%, or any range thereof.

[0100] The MgO content can be 0%, 1.0%, 2.0%, 3.0%, 4.0%, 5.0%, 5.60%, 6.0%, or any range thereof.

[0101] The chemical composition of the calcium hexaaluminate refractory was determined by fluorescence XRF analysis in accordance with GB / T21114-2007.

[0102] In a preferred embodiment of the present invention, the bulk density of the calcium hexaaluminate-based refractory material is 2.40-2.90 g / cm³. 3 The preferred value is 2.40-2.82 g / cm³. 3 .

[0103] For example, the bulk density of the calcium hexaaluminate-based refractory material can be 2.40 g / cm³. 3 2.50g / cm 3 2.55g / cm 3 2.60g / cm 3 2.70 g / cm 3 2.80g / cm 3 2.90g / cm 3 or any range thereof.

[0104] The bulk density of the calcium hexaaluminate refractory was determined according to GB / T2997-2000.

[0105] In a preferred embodiment of the present invention, the phases of the matrix portion of the calcium hexaaluminate refractory material include CA6 and one or more phases selected from corundum, magnesium aluminum spinel, C2M2A14 and CM2A8.

[0106] The matrix portion of the calcium hexaaluminate refractory material refers to the portion of the calcium hexaaluminate refractory material excluding granular materials.

[0107] The phase composition of the matrix portion of the calcium hexaaluminate refractory material was determined by micro-area diffraction using XRD.

[0108] For example, the procedure can involve selecting seven different samples and cutting out seven specimens from them. Each specimen undergoes micro-area diffraction, and the spectra are then fitted to the full spectrum to determine the content of each phase. Two data points with significant deviations are removed, and the average of the phase contents of the remaining five specimens is taken as the phase content of the thermal insulation and refractory material matrix. To ensure accurate analysis and minimize deviations, the selected matrix area should be maximized during sample preparation and scanning.

[0109] In a preferred embodiment of the present invention, the CA6 phase is 67.4-100% by mass percentage in the matrix portion of the calcium hexaaluminate refractory material, preferably 78.2-100%.

[0110] The corundum phase comprises 0-30%, preferably 0-20%;

[0111] The magnesium aluminum spinel phase is 0-10% or 0-5.22%, preferably 0%.

[0112] The C2M2A14 phase comprises 0-30%, preferably 0-18.8%; and

[0113] The CM2A8 phase content is 0-30%, preferably 0-18.8%.

[0114] For example, the CA6 phase can be any range from 67.4%, 70%, 75%, 80%, 85%, 90%, 95%, 98.5%, 100% or between, based on the mass percentage of the phase in the matrix portion of the calcium hexaaluminate refractory material.

[0115] The corundum phase can be 0%, 5%, 10%, 15%, 20%, 25%, 30%, or any range thereof;

[0116] The magnesium aluminum spinel phase can be 0%, 1%, 2%, 3%, 4%, 4.85%, 5.22%, 6%, 7%, 8%, 9%, 10%, or any range thereof;

[0117] The C2M2A14 phase can be 0%, 5%, 10%, 15%, 20%, 25%, 30%, or any range thereof;

[0118] The CM2A8 phase can be 0%, 5%, 10%, 15%, 20%, 25%, 28.4%, 30%, or any range thereof.

[0119] In a preferred embodiment of the present invention, the chemical composition of the calcium hexaaluminate refractory matrix includes Al2O3, CaO and MgO, and the Al2O3 is 89.03-94.10% by mass percentage in the calcium hexaaluminate refractory matrix portion, preferably 90.3-93.2%.

[0120] The CaO content is 5.80-8.40%, preferably 6.60-8.4%, and

[0121] The MgO content is 0-2.52%, preferably 0-1.68%.

[0122] For example, based on the mass percentage of the matrix portion of the calcium hexaaluminate-based refractory material, the Al₂O₃ can be 89.03%, 90.55%, 91.00%, 91.10%, 91.20%, 91.30%, 91.40%, 91.50%, 91.60%, 91.70%, 91.80%, 91.90%, 92.00%, 92.10%, or 92.20%. %, 92.30%, 92.40%, 92.50%, 92.60%, 92.70%, 92.80%, 92.90%, 93.00%, 93.10%, 93.20%, 93.30%, 93.40%, 93.50%, 93.60%, 93.70%, 93.80%, 93.90%, 94.00%, 94.10%, or any range thereof;

[0123] The CaO can be 5.80%, 5.85%, 5.90%, 6.00%, 6.10%, 6.20%, 6.30%, 6.40%, 6.50%, 6.60%, 6.70%, 6.80%, 6.90%, 7.00%, 7.10%, 7.20%, 7.30%, 7.40%, 7.50%, 7.60%, 7.70%, 7.80%, 7.90%, 8.00%, 8.10%, 8.20%, 8.30%, 8.40%, or any range thereof.

[0124] The MgO can be 0, 1.00%, 1.10%, 1.20%, 1.30%, 1.40%, 1.48%, 1.50%, 1.60%, 1.70%, 1.80%, 1.90%, 2.00%, 2.10%, 2.20%, 2.30%, 2.52%, or any range thereof.

[0125] The chemical composition of the calcium hexaaluminate-based refractory matrix was determined by elemental analysis of the matrix portion of the sample under an electron microscope, i.e., EDS analysis.

[0126] Preferably, the method includes the following steps: selecting 10 different samples, and cutting out at least 12 specimens from them, and surface-cutting them. Each cut specimen is placed under an electron microscope, the matrix portion is selected, and a rectangular area of ​​appropriate size is chosen for elemental analysis; the elemental content is converted into oxides, and the chemical composition is calculated, i.e., converted to Al2O3, CaO, and MgO content. Two data points with large deviations are removed, and then the average of the Al2O3, CaO, and MgO contents of the 10 samples is taken as the chemical composition of the calcium hexaaluminate-based refractory matrix. To ensure accurate chemical composition and small deviation, the selected rectangular area should be maximized during elemental analysis.

[0127] In a preferred embodiment of the present invention, the calcium hexaaluminate-based refractory material is prepared by a method comprising the following steps:

[0128] The mixture is obtained by mixing granular material and fine powder, and then sintering.

[0129] The sintering can be atmospheric pressure sintering or hot pressing sintering.

[0130] Atmospheric pressure sintering refers to a sintering method that does not require the application of pressure at high temperatures.

[0131] The granular material refers to the portion that cannot be screened through a 180-mesh square-hole sieve (Xinxiang Zhongtuo Machinery Equipment Co., Ltd.), i.e., the portion located on the 180-mesh square-hole sieve. The particle size of the granular material is 180 mesh - 8mm, i.e., the particle size is 0.088-8mm. For example, the particle size of the granular material can be 0.088mm, 0.090mm, 0.095mm, 0.10mm, 0.15mm, 0.20mm, 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 or any range between them.

[0132] 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 of ≤180 mesh, that is, a particle size of ≤0.088mm.

[0133] Hot pressing sintering refers to a method of sintering materials under the combined action of pressure and temperature.

[0134] In a preferred embodiment of the present invention, the fine powder is selected from one or more of the following: fine powder containing CaO, fine powder containing Al2O3, and fine powder containing MgO.

[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 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, sub-white corundum powder, dense corundum powder, sintered corundum powder, and tabular corundum powder.

[0137] Preferably, the MgO-containing fine powder is selected from one or more of magnesite, light-burned magnesia, brucite, magnesium hydroxide, magnesium chloride, high-purity magnesia, and fused magnesia.

[0138] Among them, 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.

[0139] Fine powder containing Al2O3 refers to alumina-based fine powder whose main chemical component is Al2O3.

[0140] Fine powder containing MgO refers to fine powder whose main chemical component is MgO.

[0141] 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).

[0142] 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℃.

[0143] 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℃.

[0144] ρ-Al2O3 powder is an alumina powder with certain hydration bonding properties obtained by rapidly processing aluminum hydroxide at high temperatures of 600-900℃.

[0145] Industrial alumina is a mineral whose main component is α-Al2O3. It is prepared by calcining aluminum hydroxide at 900-1250℃.

[0146] 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.

[0147] Sub-white fused alumina powder is produced from bauxite. Because its chemical composition and physical properties are similar to those of white fused alumina, it is 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.

[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%. It has a plate-like 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] High-purity magnesia is a sintered magnesia raw material with an MgO content of ≥96.5%, which is produced by pressing lightly calcined magnesia into balls and calcining 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] Pure aluminate cement is a hydraulic inorganic binder with CA, or CA2, or a mixture of CA and CA2 as the main phases.

[0155] In a preferred embodiment of the present invention, when using one or more of the following CaO-containing fine powders (which cannot form CA6 or CMA phases by relying solely on these CaO-containing fine powders) as the source of CaO in the matrix and failing to meet the phase and chemical composition requirements of the product matrix, the fine powder may further include Al2O3-containing fine powder or Al2O3-containing fine powder and MgO-containing fine powder, depending on the phase and chemical composition of the product.

[0156] When using fine powder containing MgO (which alone cannot form phases such as CA6 or CMA), if the phase and chemical composition of the product matrix cannot be satisfied by relying solely on the fine powder containing MgO, the fine powder may also include fine powder containing Al2O3 or fine powder containing Al2O3 and fine powder containing CaO, depending on the phase and chemical composition of the product.

[0157] When using fine powder containing Al2O3, if using these fine powders containing Al2O3 alone cannot meet the phase and chemical composition requirements of the product matrix, the fine powder may also include fine powder containing CaO or fine powder containing MgO, or fine powder containing both CaO and MgO, depending on the phase and chemical composition of the product.

[0158] In a preferred embodiment of the present invention, the granular material is selected from one or more of CA6, C2M2A14 and CM2A8, preferably CA6.

[0159] In a preferred embodiment of the present invention, the mass ratio of the granules to the fine powder is 0-60:40-100.

[0160] For example, the mass ratio of the granules to the fine powder (i.e., the granules / fine powder) can be 0, 1 / 99, 2 / 98, 3 / 97, 4 / 96, 5 / 95, 6 / 94, 7 / 93, 8 / 92, 9 / 91, 10 / 90, 11 / 89, 12 / 88, 13 / 87, 14 / 86, 15 / 85, 16 / 84, 17 / 83, 18 / 82, 19 / 81, 20 / 80, 21 / 79, 22 / 78, 23 / 77, 24 / 76, 25 / 75, 26 / 74, 27 / 73, 28 / 72, 29 / 71, 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, or any range thereof.

[0161] In a preferred embodiment of the present invention, the mixture is placed in a mold of a high-temperature device for hot pressing and sintering, or the mixture is formed at room temperature and then placed in a mold of a high-temperature device for hot pressing and sintering, or the mixture is formed at room temperature and pre-sintered at low temperature before hot pressing and sintering.

[0162] 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.

[0163] The process of hot pressing and sintering the mixture after it has been formed at room temperature refers to pressing the mixture into a blank at room temperature or pre-forming it into a blank at room temperature, drying it, and then hot pressing and sintering it. The hot pressing and sintering method is the same as above.

[0164] The process of forming the mixture at room temperature and pre-sintering at low temperature followed by hot pressing and sintering refers to the process of forming or pre-forming the mixture at low temperature and pre-sintering it at 1350-1500℃ before placing it into a mold in a high-temperature device for hot pressing and sintering.

[0165] In a preferred embodiment of the present invention, the hot pressing sintering temperature is 1550-1750℃, and preferably, the hot pressing strength is 0.5-10MPa. For example, the temperature can be 1550℃, 1600℃, 1650℃, 1700℃, 1750℃ or any range therebetween.

[0166] The hot-pressing strength can be, for example, 0.5MPa, 1MPa, 1.5MPa, 2MPa, 2.5MPa, 3MPa, 3.5MPa, 4MPa, 4.5MPa, 5MPa, 5.5MPa, 6MPa, 6.5MPa, 7MPa, 7.5MPa, 8MPa, 8.5MPa, 9MPa, 9.5MPa, 10MPa or any range thereof.

[0167] In a preferred embodiment of the present invention, the heat-insulating and refractory material is prepared by a method comprising the following steps:

[0168] The granular material and fine powder are mixed to obtain a mixture. After adding an appropriate binder to the mixture, it is pressed, dried, and fired at a temperature of 1550-1800℃.

[0169] The granules and fine powders are the same as those described above.

[0170] The binder can be, for example, an inorganic binder or an organic binder, wherein the inorganic binder includes pure aluminate cement, aluminum dihydrogen phosphate, aluminum chloride, aluminum sulfate, etc., and the organic binder includes carboxymethyl cellulose, dextrin, glucose, cellulose, etc.

[0171] In a preferred embodiment of the present invention, the calcium hexaaluminate-based refractory material is prepared by a method comprising the following steps:

[0172] The mixture is prepared by mixing granular material and fine powder, adding appropriate amount of water to the mixture, stirring, vibrating and molding, curing and drying.

[0173] The particles are selected from one or more of CA6, C2M2A14 and CM2A8, with CA6 being preferred.

[0174] The fine powder includes pure aluminate cement, active α-Al2O3 powder, and one or more of the following: CA6, C2M2A14, CM2A8, and Al2O3-containing fine powder; preferably, the Al2O3-containing fine powder is selected from one or more of the following: γ-Al2O3 powder, p-Al2O3 powder, aluminum hydroxide, industrial alumina, white corundum powder, sub-white corundum powder, dense corundum powder, sintered corundum powder, and tabular corundum powder.

[0175] The present invention provides a nano heat insulation plate, which includes a micro-nano plate and a film covering the micro-nano plate, wherein the chemical composition of the micro-nano plate includes SiO2 and ZrO2, and the weight percentage of SiO2 in the micro-nano plate is 55-100% and ZrO2 is 0-40%.

[0176] The micro / nanoplates are mainly composed of nano- and micron-sized SiO2.

[0177] The amount of SiO2, by weight in the micro / nanoplate, can be, for example, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, or any range thereof.

[0178] The amount of ZrO2, by weight in the micro / nanoplate, can be, for example, 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or any range thereof.

[0179] The micro / nanoplate was treated in air at 1000℃ for 6 hours to obtain the components described above.

[0180] The micro / nano powder also contains other components, such as SiC, Al2O3, TiO2, etc.

[0181] In a preferred embodiment of the present invention, the bulk density of the nano-insulation plate is 0.23-0.60 g / cm³. 3 The preferred value is 0.25-0.60 g / cm³. 3 More preferably, it is 0.30-0.60 g / cm³. 3 Preferably, the thermal conductivity of the nano-insulation plate at 300℃ is 0.020-0.048w / m·k, more preferably 0.025-0.048w / m·k, and even more preferably 0.025-0.045w / m·k.

[0182] For example, the bulk density of the nano-insulation plate is 0.23 g / cm³. 3 0.24g / cm 3 0.25g / cm 3 0.26g / cm 3 0.27g / cm3 0.28g / cm 3 0.29g / cm 3 0.30g / cm 3 0.31g / cm 3 0.32g / cm 3 0.33g / cm 3 0.34g / cm 3 0.35g / cm 3 0.36g / cm 3 0.37g / cm 3 0.38g / cm 3 0.39g / cm 3 0.40 g / cm 3 0.41 g / cm 3 0.42g / cm 3 0.43g / cm 3 0.44 g / cm 3 0.45g / cm 3 0.46 g / cm 3 0.47g / cm 3 0.48g / cm 3 0.49g / cm 3 0.50g / cm 3 0.51g / cm 3 0.52g / cm 3 0.53g / cm 3 0.54g / cm 3 0.55g / cm 3 0.56g / cm 3 0.57g / cm 3 0.58g / cm 3 0.59g / cm 3 0.60 g / cm 3 0.70g / cm 3 Or any range between them.

[0183] For example, the thermal conductivity of the nano-insulation plate at 300°C can be 0.020 W / m·K, 0.025 W / m·K, 0.030 W / m·K, 0.035 W / m·K, 0.040 W / m·K, 0.045 W / m·K, 0.048 W / m·K, or any range thereof.

[0184] In a preferred embodiment of the present invention, the micro / nano plate further includes fibers, preferably one or more of glass fibers, alumina fibers, mullite fibers and aluminum silicate fibers.

[0185] In a preferred embodiment of the present invention, the film includes a metal film, an organic film, and an inorganic coating. Preferably, the metal film is aluminum foil, the organic film is a plastic film, and the inorganic coating is a silica sol coating or an aluminum dihydrogen phosphate film.

[0186] The metal film can be, for example, aluminum foil or steel film;

[0187] The inorganic coating refers to silica sol or aluminum dihydrogen phosphate covering the surface of micro / nano plates, or silica sol filling and distributing between inorganic nanoparticles, or aluminum dihydrogen phosphate filling and distributing between inorganic nanoparticles.

[0188] In a preferred embodiment of the present invention, the nano-insulation plate is prepared by a method comprising the following steps:

[0189] Micro-nano SiO2 powder, ZrO2 powder and fibers are mixed evenly, and an appropriate amount of binder is added. The mixture can be formed by flow forming, suction filtration forming, vibration forming, scraping forming or pressing forming, and then dried to form micro-nano plates. A thin film is coated on the surface of the micro-nano plates to obtain a nano heat insulation plate. The film can be an inorganic film, a metal film or an organic film.

[0190] The binder may be, for example, silica sol, aluminum dihydrogen phosphate, water glass, sodium hexametaphosphate, etc.

[0191] The present invention provides a composite refractory lining structure for blocking heat conduction, which includes the calcium hexaaluminate refractory material and the nano heat insulation board described above, wherein the nano heat insulation board is fixedly disposed on the calcium hexaaluminate refractory material.

[0192] Because calcium hexaaluminate-based refractory materials have good thermal insulation properties, high temperatures are trapped within them, reducing the temperature of the nano-insulation board and lowering it below the crystallization temperature, thus ensuring the performance of the nano-insulation board.

[0193] In a preferred embodiment of the present invention, the thickness of the calcium hexaaluminate refractory material is 50-250 mm, preferably 80-116 mm, and the thickness of the nano-insulation board is preferably 10-40 mm, preferably 20-30 mm.

[0194] For example, the thickness of the calcium hexaaluminate refractory material can be 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, 210mm, 220mm, 230mm, 240mm, 250mm or any range thereof.

[0195] The thickness of the nano-insulation plate can be 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm or any range thereof.

[0196] The aforementioned composite refractory lining structure that blocks heat conduction is used after being assembled and then constructed on-site.

[0197] This invention provides a method for preparing the composite refractory lining structure described above, comprising the following steps:

[0198] The nano-insulation board is obtained by fixing it onto a calcium hexaaluminate-based refractory material using a fixative and then curing it.

[0199] The fixative is an adhesive used to fix the nano-insulation board onto the calcium hexaaluminate refractory material.

[0200] The adhesive may be, for example, epoxy resin, ethyl α-cyanoacrylate, methacrylate, methyl methacrylate, water glass bonded fire putty, aluminum dihydrogen phosphate bonded fire putty, or silica sol bonded fire putty, preferably epoxy resin, ethyl α-cyanoacrylate, methacrylate, or methyl methacrylate.

[0201] For example, a block can be constructed by fixing a nano-insulation board onto a calcium hexaaluminate refractory material using an adhesive or other means, and then the block can be laid on site after bonding or drying.

[0202] The present invention provides a composite refractory lining structure forming material for blocking heat conduction, which includes the calcium hexaaluminate refractory material and the nano heat insulation board mentioned above, wherein the nano heat insulation board is fixedly disposed on the low-temperature side of the calcium hexaaluminate refractory material.

[0203] In a preferred embodiment of the present invention, the composite refractory lining structure forming material further includes high-temperature fire mud, and the nano-insulation board is fixedly disposed on the low-temperature side of the calcium hexaaluminate refractory material by the high-temperature fire mud.

[0204] Preferably, the high-temperature fire clay can be, for example, water glass-bonded fire clay, aluminum dihydrogen phosphate-bonded fire clay, or silica sol-bonded fire clay.

[0205] In a preferred embodiment of the present invention, the thickness of the calcium hexaaluminate refractory material is 50-250 mm, preferably 80-116 mm; preferably, the thickness of the nano-insulation board is 10-40 mm, preferably 20-30 mm.

[0206] By using high-temperature fire clay to fix the nano-insulation plate on the low-temperature side of the calcium hexaaluminate refractory material, the high temperature is trapped within the calcium hexaaluminate refractory material due to its good thermal insulation performance. This reduces the temperature of the nano-insulation plate, lowering it below the crystallization temperature and ensuring the performance of the nano-insulation plate.

[0207] The composite refractory lining structure that blocks heat conduction is obtained by combining the aforementioned composite refractory lining structure forming materials on site.

[0208] This invention provides a method for preparing a composite refractory lining structure using the aforementioned heat-conducting composite refractory lining structure forming material, comprising the following steps:

[0209] The nano-insulation board was fixed to the low-temperature side of the calcium hexaaluminate refractory material using high-temperature fire mud.

[0210] For example, a nano-insulation board can be attached tightly to the inner surface of the steel shell of a smelting container such as a ladle, and then a calcium hexaaluminate refractory material can be built on the inner side (high temperature side). The nano-insulation board and the calcium hexaaluminate refractory material can be dry-bonded, or high-temperature mortar can be used.

[0211] The composite refractory lining structure that blocks heat conduction described in this invention can be used as a permanent lining and heat insulation lining for steel ladles used in steel smelting, a working lining and heat insulation lining for aluminum molten metal smelting containers, a refractory lining for rotary kilns, and refractory linings for other kilns, etc.

[0212] 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. All listed chemical compositions are those of samples treated at 1000°C. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0213] Example 1-1 Preparation of calcium hexaaluminate-based refractory materials

[0214] (1) Mix 500g of CA6 granules (maximum particle size 5mm) and 500g of CA6 fine powder evenly to obtain a mixture.

[0215] (2) The mixture is placed in a mold of a high-temperature device for direct hot pressing and sintering. When the temperature rises to the maximum temperature of 1630°C, a hot pressing pressure of 5MPa is applied at this temperature to obtain a calcium hexaaluminate refractory material.

[0216] The phase analysis of the refractory material was performed using XRD analysis. The 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 full spectrum of the diffraction data, revealing that the main phase was CA6. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 99.5%.

[0217] The chemical composition of the refractory material was analyzed by fluorescence XRF analysis in accordance with GB / T21114-2007. The chemical composition, based on the mass percentage of the refractory material, contains 91.04% Al2O3 and 8.40% CaO.

[0218] The phase analysis of the matrix portion of the refractory material was performed using XRD micro-area diffraction. Twelve different refractory materials were selected, and twelve samples were cut from each. Within each sample, a matrix region with relatively uniform color and microstructure was selected for micro-area diffraction, and the diffraction patterns were fully fitted to determine the content of each phase. Two data points with significant deviations were removed, and the average of the phase contents of the remaining ten samples was taken as the phase content of the refractory material matrix. The matrix portion of the refractory material was found to primarily contain CA6, with the CA6 phase accounting for 99.2% of the matrix portion by mass.

[0219] The chemical composition of the matrix portion of the refractory material was determined using the EDS method. Twelve different refractory materials were selected, and twelve samples were cut and polished. Each polished sample was placed under an electron microscope, and a region with a relatively uniform microstructure was selected within the matrix. A rectangular sampling area of ​​appropriate size was then chosen within this region for elemental analysis. The collected elemental contents were converted into oxides, and the chemical composition was calculated, specifically the contents of Al₂O₃, CaO, and MgO. Two data points with significant deviations were discarded, and the average value of the Al₂O₃, CaO, and MgO contents from the ten samples was taken as the chemical composition of the refractory material matrix. Based on the mass percentage of the matrix portion, the chemical composition of the refractory material matrix consisted of 91.20% Al₂O₃ and 8.40% CaO.

[0220] The calcium hexaaluminate-based refractory material was tested according to GB / T2997-2000, and the determined bulk density was 2.54 g / cm³. 3 .

[0221] According to the national standard GB / T 5990-2006, the thermal conductivity of the refractory material obtained in Example 1 at 350℃ is 1.36 W / mK.

[0222] The prepared material was made into a crucible, steel slag was placed in the crucible, the temperature was raised to 1500℃ and held for 3 hours, and then the cooled sample was cut open along the middle. The depth of steel slag erosion on the sample was measured to be 2.41 mm.

[0223] Example 1-2 Preparation of calcium hexaaluminate-based refractory materials

[0224] (1) Mix 450g of CA6 granules (maximum particle size 3mm), 440g of CA6 fine powder, and 110g of tabular corundum powder evenly to obtain a mixture.

[0225] (2) The mixture is placed in the mold of the high-temperature device and hot-pressed and sintered directly. When the temperature rises to the maximum temperature of 1580℃, a pressure of 3MPa is applied at this temperature to obtain calcium hexaaluminate refractory material.

[0226] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and corundum. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 86.5%, and the content of the corundum phase was 11%.

[0227] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 91.3% Al2O3 and 7.28% CaO.

[0228] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and corundum. The content of the CA6 phase is 77.2% and the content of the corundum phase is 20% by mass percentage of the phases in the matrix portion of the refractory material.

[0229] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, comprises 93.2% Al2O3 and 6.60% CaO.

[0230] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.41 g / cm³. 3 .

[0231] The analysis was performed using the same method as in Examples 1-1, and the obtained refractory material had a thermal conductivity of 1.33 W / mK at 350°C.

[0232] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 2.61 mm.

[0233] Examples 1-3: Preparation of calcium hexaaluminate-based refractory materials

[0234] (1) Mix 500g of CA6 granules (maximum particle size 3mm), 400g of CA6 fine powder, and 100g of C2M2A14 powder evenly to obtain a mixture.

[0235] (2) The mixture is placed in the mold of the high-temperature device and hot-pressed and sintered directly. When the temperature rises to the maximum temperature of 1630°C, a hot-pressing pressure of 3MPa is applied at this temperature to obtain calcium hexaaluminate refractory material.

[0236] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and C2M2A14. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 89.12%, and the content of the C2M2A14 phase was 9.4%.

[0237] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 91.03% Al2O3, 0.43% MgO, and 8.02% CaO.

[0238] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and C2M2A14, wherein, based on the mass percentage of the phases in the matrix portion of the refractory material, the content of the CA6 phase is 78.2% and the content of the C2M2A14 phase is 18.8%.

[0239] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, expressed as a percentage by mass of 90.8% Al2O3, 0.8% MgO, and 8.0% CaO, was determined.

[0240] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.55 g / cm³. 3 .

[0241] The analysis was performed using the same method as in Example 1-1, and the obtained refractory material had a thermal conductivity of 1.38 W / mK at 350°C.

[0242] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 2.52 mm.

[0243] Examples 1-4: Preparation of calcium hexaaluminate-based refractory materials

[0244] (1) Mix 500g of CA6 granules (maximum particle size 3mm), 400g of CA6 fine powder, 85.8g of industrial alumina powder, 8.6g of high-purity magnesia powder and 7.8g of calcium hydroxide powder evenly to obtain a mixture.

[0245] (2) The mixture is placed in the mold of the high temperature device and hot-pressed and sintered directly. When the temperature rises to the maximum temperature of 1650℃, a hot-pressing pressure of 8MPa is applied at this temperature to obtain calcium hexaaluminate refractory material.

[0246] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and CM2A8. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 89.04%, and the content of the CM2A8 phase was 9.4%.

[0247] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 90.34% Al2O3, 0.78% MgO, and 7.86% CaO.

[0248] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and CM2A8, wherein, based on the mass percentage of the phases in the matrix portion of the refractory material, the content of the CA6 phase is 78.2% and the content of the CM2A8 phase is 18.8%.

[0249] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, expressed as a percentage by mass, comprises 90.30% Al2O3, 1.68% MgO, and 7.81% CaO.

[0250] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.53 g / cm³. 3 .

[0251] The analysis was performed using the same method as in Example 1-1, and the obtained refractory material had a thermal conductivity of 1.40 W / mK at 350°C.

[0252] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 2.64 mm.

[0253] Examples 1-5: Preparation of calcium hexaaluminate-based refractory materials

[0254] (1) Mix 450g of CA6 granules (maximum particle size 3mm), 40g of CA6 fine powder, 69g of 12CaO·7Al2O3 fine powder, 331g of active α-Al2O3 micro powder, and 110g of white corundum powder evenly to obtain a mixture.

[0255] (2) The mixture is placed in a mold of a high-temperature device for direct hot pressing and sintering. Pressure is applied when the temperature rises to 1350°C and gradually increased as the temperature rises. The maximum temperature reaches 1750°C and the maximum hot pressing strength is 0.5 MPa, thus obtaining a calcium hexaaluminate refractory material.

[0256] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and corundum. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 84.1% and the content of the corundum phase was 10.7%.

[0257] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 92.01% Al2O3 and 7.21% CaO.

[0258] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and corundum. The content of the CA6 phase is 73.9% and the content of the corundum phase is 19.5% by mass percentage of the phases in the matrix portion of the refractory material.

[0259] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, comprises 93.20% Al2O3 and 6.61% CaO.

[0260] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.61 g / cm³. 3 .

[0261] The analysis was performed using the same method as in Example 1-1, and the obtained refractory material had a thermal conductivity of 1.58 W / mK at 350°C.

[0262] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 2.40 mm.

[0263] Examples 1-6: Preparation of calcium hexaaluminate-based refractory materials

[0264] (1) Mix 400g of CA6 granules (maximum particle size 3mm), 280g of CA6 fine powder, 184g of γ-Al2O3 powder, 120g of tabular corundum powder, and 22.2g of Ca(OH)2 fine powder evenly to obtain a mixture.

[0265] (2) The mixture is pressed at room temperature and lightly calcined at 1500°C, and then placed in the mold of a high-temperature device. Pressure is gradually applied starting from the temperature of 1550°C, with the highest temperature reaching 1720°C and the maximum hot-pressing strength being 1MPa, to obtain calcium hexaaluminate refractory material.

[0266] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and corundum. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 85.5%, and the content of the corundum phase was 11.8%.

[0267] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 92.03% Al2O3 and 7.18% CaO.

[0268] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and corundum. The content of the CA6 phase is 77.2% and the content of the corundum phase is 20% by mass percentage of the phases in the matrix portion of the refractory material.

[0269] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, comprises 93.2% Al2O3 and 6.61% CaO.

[0270] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.60 g / cm³. 3 .

[0271] The analysis was performed using the same method as in Example 1-1, and the obtained refractory material had a thermal conductivity of 1.56 W / mK at 350°C.

[0272] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 2.43 mm.

[0273] Examples 1-7: Preparation of calcium hexaaluminate-based refractory materials

[0274] (1) Mix 835g of CA6 fine powder, 60g of tabular corundum fine powder and 110g of ρ-Al2O3 fine powder evenly to obtain a mixture.

[0275] (2) The mixture is pre-formed with water and dried, and then placed in a mold of a high-temperature device for heating. The temperature is raised to a maximum of 1650°C. At this temperature, a hot-pressing pressure of 6 MPa is applied to obtain a calcium hexaaluminate refractory material based on CA6.

[0276] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and corundum. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 82.0%, and the content of the corundum phase was 16.5%.

[0277] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 91.6% Al2O3 and 6.92% CaO.

[0278] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and corundum. The content of the CA6 phase is 82.0% and the content of the corundum phase is 16.5% by mass percentage of the phases in the matrix portion of the refractory material.

[0279] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, comprises 91.6% Al2O3 and 6.92% CaO.

[0280] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.52 g / cm³.3 .

[0281] The analysis was performed using the same method as in Examples 1-1, and the obtained refractory material had a thermal conductivity of 1.31 W / mK at 350°C.

[0282] The erosion depth of the refractory material was measured using the same method as in Example 1, and the result was 3.20 mm.

[0283] Examples 1-8: Preparation of calcium hexaaluminate-based refractory materials

[0284] (1) Mix 800g of CA6 fine powder, 100g of tabular corundum fine powder and 105g of ρ-Al2O3 fine powder evenly to obtain a mixture.

[0285] (2) The mixture is pre-formed with water and dried, and then placed in a mold of a high-temperature device for heating. The temperature is raised to a maximum of 1600℃. At this temperature, a hot-pressing pressure of 8MPa is applied to obtain a calcium hexaaluminate refractory material based on CA6.

[0286] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and corundum. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 78.6%, and the content of the corundum phase was 20%.

[0287] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 92.4% Al2O3 and 6.52% CaO.

[0288] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and corundum. The content of the CA6 phase is 78.6% and the content of the corundum phase is 20% by mass percentage of the phases in the matrix portion of the refractory material.

[0289] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, comprises 92.4% Al2O3 and 6.52% CaO.

[0290] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.52 g / cm³. 3 .

[0291] The analysis was performed using the same method as in Examples 1-1, and the obtained refractory material had a thermal conductivity of 1.34 W / mK at 350°C.

[0292] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 3.10 mm.

[0293] Examples 1-9: Preparation of calcium hexaaluminate-based refractory materials

[0294] (1) Mix 700g of CA6 fine powder, 100g of sintered corundum powder, 174.8g of γ-Al2O3 fine powder and 45g of limestone fine powder evenly.

[0295] (2) The mixture is pressed at room temperature and then placed in the mold of a high-temperature device. Pressure is gradually applied starting from the temperature of 1450°C, and the maximum temperature is 1600°C with a maximum hot-pressing strength of 1MPa to obtain calcium hexaaluminate refractory material.

[0296] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6, and the content of the CA6 phase was 97.5% by mass percentage of the phases in the refractory material.

[0297] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 90.1% Al2O3 and 8.40% CaO.

[0298] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phase of the matrix portion of the refractory material includes CA6, wherein the content of the CA6 phase is 97.5% by mass percentage of the phase in the matrix portion of the refractory material.

[0299] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, comprises 90.1% Al2O3 and 8.40% CaO.

[0300] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.40 g / cm³. 3 .

[0301] The analysis was performed using the same method as in Examples 1-1, and the obtained refractory material had a thermal conductivity of 1.31 W / mK at 350°C.

[0302] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 3.30 mm.

[0303] Examples 1-10: Preparation of calcium hexaaluminate-based refractory materials

[0304] (1) Mix 200g of CA6 granules (maximum particle size 3mm), 200g of C2M2A14 aggregate (maximum particle size 3mm), 540g of CA6 fine powder, 4.3g of quicklime powder, 3.0g of fused magnesium oxide, and 52.9g of white corundum fine powder evenly to obtain a mixture.

[0305] (2) The mixture is pressed and shaped and then placed in a mold of a high-temperature device for hot pressing and sintering. When the maximum temperature rises to 1550°C, a pressure of 4MPa is applied at this temperature to obtain a calcium hexaaluminate refractory material.

[0306] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and C2M2A14. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 71.3%, and the content of the C2M2A14 phase was 23.5%.

[0307] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 90.04% Al2O3, 1.22% MgO, and 7.56% CaO.

[0308] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and C2M2A14. The content of the CA6 phase is 88.6% and the content of the C2M2A14 phase is 9.74% by mass percentage of the phases in the matrix portion of the refractory material.

[0309] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, expressed as a percentage by mass, comprises 90.37% Al2O3, 0.42% MgO, and 8.18% CaO.

[0310] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.43 g / cm³. 3 .

[0311] The analysis was performed using the same method as in Example 1-1, and the obtained refractory material had a thermal conductivity of 1.42 W / mK at 350°C.

[0312] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 2.67 mm.

[0313] Examples 1-11: Preparation of calcium hexaaluminate-based refractory materials

[0314] (1) Mix 600g of CM2A8 granules (maximum particle size 3mm), 200g of CA6 fine powder, 280.2g of aluminum hydroxide fine powder, and 22.2g of calcium hydroxide fine powder evenly to obtain a mixture;

[0315] (2) The mixture is pressed into shape at room temperature and then placed in the mold of a high-temperature device. Pressure is gradually applied from room temperature. When the maximum temperature reaches 1700℃, the maximum hot-pressing strength is 2MPa, thus obtaining calcium hexaaluminate refractory material.

[0316] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and CM2A8. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 38.7%, and the content of the CM2A8 phase was 59.5%.

[0317] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 88.07% Al2O3, 5.04% MgO, and 6.89% CaO.

[0318] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phase of the matrix portion of the refractory material includes CA6, wherein the content of the CA6 phase is 98.7% by mass percentage of the phase in the matrix portion of the refractory material.

[0319] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, expressed as a percentage by mass, comprises 90.5% Al2O3 and 8.40% CaO.

[0320] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.65 g / cm³. 3 .

[0321] The analysis was performed using the same method as in Examples 1-1, and the obtained refractory material had a thermal conductivity of 1.62 W / mK at 350°C.

[0322] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 2.62 mm.

[0323] Examples 1-12: Preparation of calcium hexaaluminate-based refractory materials

[0324] (1) Mix 600g of C2M2A14 granules (maximum particle size 3mm) and 400g of CA6 fine powder evenly to obtain a mixture.

[0325] (2) The mixture is placed in a mold of a high-temperature device for hot pressing and sintering. When the temperature rises to 1400°C, pressure is gradually applied. When the temperature rises to 1720°C, the maximum hot pressing strength is 10 MPa, and calcium hexaaluminate refractory material is obtained.

[0326] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and C2M2A14. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 38.7%, and the content of the C2M2A14 phase was 60%.

[0327] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 89.32% Al2O3, 2.74% MgO, and 7.41% CaO.

[0328] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phase of the matrix portion of the refractory material includes CA6, wherein the content of the CA6 phase is 100% based on the mass percentage of the phase in the matrix portion of the refractory material.

[0329] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, expressed as a percentage by mass, comprises 90.8% Al2O3 and 8.40% CaO.

[0330] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.82 g / cm³. 3 .

[0331] The analysis was performed using the same method as in Example 1-1, and the obtained refractory material had a thermal conductivity of 2.25 W / mK at 350°C.

[0332] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 2.2 mm.

[0333] Examples 1-13: Preparation of calcium hexaaluminate-based refractory materials

[0334] (1) Mix 600g of CM2A8 granules (maximum particle size 3mm), 320g of CA6 fine powder, and 80g of dense corundum fine powder evenly to obtain a mixture.

[0335] (2) The mixture is placed in a mold of a high-temperature device and hot-pressed and sintered directly. When the temperature rises to a maximum of 1700°C, a hot-pressing pressure of 5MPa is applied at this temperature to obtain a calcium hexaaluminate refractory material.

[0336] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory included CA6, CM2A8, and corundum. Based on the mass percentage of the phases in the refractory, the content of the CA6 phase was 31.5%, the content of the CM2A8 phase was 58.3%, and the content of the corundum phase was 7.4%.

[0337] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 88.41% Al2O3, 5.04% MgO, and 7.43% CaO.

[0338] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and corundum, wherein, based on the mass percentage of the phases in the matrix portion of the refractory material, the content of the CA6 phase is 78.2% and the content of the corundum phase is 18.6%.

[0339] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, comprises 93.2% Al2O3 and 6.60% CaO.

[0340] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.72 g / cm³. 3 .

[0341] The analysis was performed using the same method as in Examples 1-1, and the obtained refractory material had a thermal conductivity of 2.13 W / mK at 350°C.

[0342] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 2.52 mm.

[0343] Examples 1-14: Preparation of calcium hexaaluminate-based refractory materials

[0344] (1) Mix 600g of CM2A8 granules (maximum particle size 3mm), 320g of CA6 fine powder, and 80g of CM2A8 fine powder evenly to obtain a mixture.

[0345] (2) The mixture is pressed into shape at room temperature and then placed in a mold of a high-temperature device for hot pressing and sintering. When the temperature rises to a maximum of 1670°C, pressure is applied at this temperature and the hot pressing strength is 0.5 MPa, thus obtaining calcium hexaaluminate refractory material.

[0346] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and CM2A8. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 31.5%, and the content of the CM2A8 phase was 67.1%.

[0347] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 87.60% Al2O3, 5.62% MgO, and 6.43% CaO.

[0348] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and CM2A8, wherein, based on the mass percentage of the phases in the matrix portion of the refractory material, the content of the CA6 phase is 78.2% and the content of the CM2A8 phase is 19.2%.

[0349] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, comprises 90.30% Al2O3, 1.68% MgO, and 7.82% CaO.

[0350] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.63 g / cm³. 3 .

[0351] The analysis was performed using the same method as in Examples 1-1, and the obtained refractory material had a thermal conductivity of 1.87 W / mK at 350°C.

[0352] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 2.9 mm.

[0353] Examples 1-15: Preparation of calcium hexaaluminate-based refractory materials

[0354] (1) Mix 947.4g of CA6 fine powder, 15g of fused magnesia fine powder and 38g of active α-Al2O3 fine powder evenly to obtain a mixture.

[0355] (2) The mixture is pressed into shape at room temperature and lightly calcined at 1350°C before being placed in a mold of a high-temperature device. Pressure is applied starting from the temperature of 1500°C, with the temperature reaching a maximum of 1580°C and the maximum hot-pressing strength being 5MPa, to obtain calcium hexaaluminate refractory material.

[0356] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and C2M2A14. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 67.4%, and the content of the C2M2A14 phase was 30%.

[0357] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 89.32% Al2O3, 1.38% MgO, and 7.81% CaO.

[0358] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.48 g / cm³. 3 .

[0359] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phase of the matrix portion of the refractory material includes CA6, wherein the content of the CA6 phase is 98.5% by mass percentage of the phase in the matrix portion of the refractory material.

[0360] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, includes 89.32% Al2O3, 1.38% MgO, and 7.81% CaO.

[0361] The analysis was performed using the same method as in Example 1-1, and the obtained refractory material had a thermal conductivity of 1.46 W / mK at 350°C.

[0362] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 4.0 mm.

[0363] Examples 1-16: Preparation of calcium hexaaluminate-based refractory materials

[0364] (1) Mix 600g of CM2A8 granules (maximum particle size 8mm), 80g of CA6 fine powder, 281g of aluminum hydroxide fine powder, 17.5g of lime fine powder and 120g of CM2A8 fine powder evenly to obtain a mixture.

[0365] (2) The mixture is pressed into shape at room temperature and lightly sintered at 1400°C, and then placed in a mold of a high-temperature device for hot pressing and sintering. When the temperature rises to 1500°C, pressure is applied and gradually increased as the temperature rises. When the temperature reaches a maximum of 1750°C, the maximum hot pressing strength is 0.5 MPa, thus obtaining a calcium hexaaluminate refractory material.

[0366] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and CM2A8. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 26.7%, and the content of the CM2A8 phase was 72%.

[0367] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 86.65% Al2O3, 6.05% MgO, and 6.22% CaO.

[0368] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and CM2A8, wherein, based on the mass percentage of the phases in the matrix portion of the refractory material, the content of the CA6 phase is 68% and the content of the corundum phase is 30%.

[0369] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, expressed as a percentage by mass, includes 89.03% Al2O3, 2.52% MgO, and 7.60% CaO.

[0370] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.90 g / cm³. 3 .

[0371] The analysis was performed using the same method as in Example 1-1, and the obtained refractory material had a thermal conductivity of 2.48 W / mK at 350°C.

[0372] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 2.10 mm.

[0373] Examples 1-17 Preparation of calcium hexaaluminate-based refractory materials

[0374] (1) Mix 100g of C2M2A14 granules (maximum particle size 1mm), 630g of CA6 fine powder, 18.7g of quicklime fine powder, 13.4g of high-purity magnesia powder, 180g of white corundum fine powder and 58g of active α-Al2O3 powder evenly to obtain a mixture.

[0375] (2) The mixture is pressed into shape at room temperature and lightly sintered at 1450°C, and then placed into the mold of a high-temperature device for hot pressing and sintering. When the temperature rises to 1500°C, pressure is gradually applied. The temperature rises to a maximum of 1620°C, and the maximum hot pressing strength is 8MPa, thus obtaining calcium hexaaluminate refractory material.

[0376] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6, C2M2A14, and MgO·Al2O3. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 84.2%, the content of the C2M2A14 phase was 9.28%, and the content of the MgO·Al2O3 phase was 4.60%.

[0377] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 89.14% Al2O3, 1.71% MgO, and 7.65% CaO.

[0378] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and MgO·Al2O3, wherein, based on the mass percentage of the phases in the matrix portion of the refractory material, the content of the CA6 phase is 93.5% and the content of the MgO·Al2O3 phase is 5.22%.

[0379] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, expressed as a percentage by mass, comprises 90.07% Al2O3, 1.32% MgO, and 7.67% CaO.

[0380] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.57 g / cm³. 3 .

[0381] The analysis was performed using the same method as in Example 1-1, and the obtained refractory material had a thermal conductivity of 1.67 W / mK at 350°C.

[0382] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 3.6 mm.

[0383] Examples 1-18: Preparation of calcium hexaaluminate-based refractory materials

[0384] (1) Mix 700g of CA6 fine powder, 150g of tabular corundum fine powder and 155g of ρ-Al2O3 fine powder evenly to obtain a mixture.

[0385] (2) The mixture is pre-formed with water and dried, and then placed in a mold of a high-temperature device for heating. The temperature is raised to a maximum of 1550°C. At this temperature, a hot-pressing pressure of 10 MPa is applied to obtain a calcium hexaaluminate refractory material based on CA6.

[0386] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and corundum. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 66.4%, and the content of the corundum phase was 30%.

[0387] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 94.10% Al2O3 and 5.80% CaO.

[0388] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and corundum. The content of the CA6 phase is 66.4% and the content of the corundum phase is 30% by mass percentage of the phases in the matrix portion of the refractory material.

[0389] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, comprises 94.10% Al2O3 and 5.80% CaO.

[0390] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.52 g / cm³. 3 .

[0391] The analysis was performed using the same method as in Example 1-1, and the obtained refractory material had a thermal conductivity of 1.48 W / mK at 350°C.

[0392] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 3.10 mm.

[0393] Examples 1-19: Preparation of calcium hexaaluminate-based refractory materials

[0394] (1) Mix 600g of C2M2A14 granules (maximum particle size 10mm), 280g of CA6 fine powder, and 120g of C2M2A14 fine powder evenly to obtain a mixture.

[0395] (2) The mixture is placed in a mold of a high-temperature device for hot pressing and sintering. Pressure is gradually applied from room temperature, and the temperature rises to a maximum of 1610℃. The maximum hot pressing strength is 6MPa, thus obtaining calcium hexaaluminate refractory material.

[0396] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and C2M2A14. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 26.7%, and the content of the C2M2A14 phase was 72%.

[0397] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 88.87% Al2O3, 3.36% MgO, and 7.16% CaO.

[0398] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and C2M2A14, wherein, based on the mass percentage of the phases in the matrix portion of the refractory material, the content of the CA6 phase is 68.1% and the content of the C2M2A14 phase is 30%.

[0399] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, comprises 90.46% Al2O3, 1.31% MgO, and 7.82% CaO.

[0400] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.60 g / cm³. 3 .

[0401] The analysis was performed using the same method as in Example 1-1, and the obtained refractory material had a thermal conductivity of 1.75 W / mK at 350 °C.

[0402] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 3.5 mm.

[0403] Examples 1-20: Preparation of calcium hexaaluminate-based refractory materials

[0404] (1) Mix 400g of CA6 granules (maximum particle size 3mm), 280g of CA6 fine powder, 184g of γ-Al2O3 powder, 120g of tabular corundum powder, and 22.2g of Ca(OH)2 fine powder evenly to obtain a mixture.

[0405] (2) The mixture is pressed at room temperature and lightly calcined at 1500°C, and then placed in the mold of a high-temperature device. Pressure is gradually applied starting from the temperature of 1550°C, with the highest temperature reaching 1750°C and the maximum hot-pressing strength being 6MPa, to obtain calcium hexaaluminate refractory material.

[0406] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and corundum. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 85.5%, and the content of the corundum phase was 11.8%.

[0407] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 92.03% Al2O3 and 7.18% CaO.

[0408] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and corundum. The content of the CA6 phase is 77.2% and the content of the corundum phase is 20% by mass percentage of the phases in the matrix portion of the refractory material.

[0409] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, comprises 93.2% Al2O3 and 6.61% CaO.

[0410] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.90 g / cm³. 3 .

[0411] The analysis was performed using the same method as in Examples 1-1, and the obtained refractory material had a thermal conductivity of 2.42 W / mK at 350°C.

[0412] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 1.95 mm.

[0413] Examples 1-21: Preparation of calcium hexaaluminate-based refractory materials

[0414] (1) Mix 100g of C2M2A14 granules (maximum particle size 1mm), 324g of CA6 fine powder, 53g of quicklime fine powder, 28.5g of high-purity magnesia powder, 400g of white corundum fine powder and 108g of active α-Al2O3 powder evenly to obtain a mixture.

[0415] (2) The mixture is pressed into shape at room temperature and lightly sintered at 1450°C, and then placed into the mold of a high-temperature device for hot pressing and sintering. When the temperature rises to 1500°C, pressure is gradually applied. The temperature rises to a maximum of 1550°C, and the maximum hot pressing strength is 1MPa, thus obtaining calcium hexaaluminate refractory material.

[0416] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6, C2M2A14, and MgO·Al2O3. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 70.7%, the content of the C2M2A14 phase was 9.28%, and the content of the MgO·Al2O3 phase was 10.0%.

[0417] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 88.5% Al2O3, 3.02% MgO, and 7.21% CaO.

[0418] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and MgO·Al2O3, wherein, based on the mass percentage of the phases in the matrix portion of the refractory material, the content of the CA6 phase is 78.6% and the content of the MgO·Al2O3 phase is 11.2%.

[0419] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, expressed as a percentage by mass of 89.3% Al2O3, 2.95% MgO, and 7.20% CaO, was determined.

[0420] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the medium-density refractory material was 2.85 g / cm³. 3 .

[0421] The analysis was performed using the same method as in Example 1-1, and the obtained refractory material had a thermal conductivity of 2.54 W / mK at 350°C.

[0422] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 3.45 mm.

[0423] Examples 1-22: Preparation of calcium hexaaluminate-based refractory materials

[0424] A calcium hexaaluminate refractory material was prepared by using 55% CA6 aggregate with a particle size of 0.088 mm, 33% CA6 fine powder with a particle size of less than 325 mesh and 12% activated alumina micro powder as raw materials, adding aluminum dihydrogen phosphate binder and mixing evenly, and then pressing and firing at 1600℃.

[0425] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and corundum. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 86.3%, and the content of the corundum phase was 11.2%.

[0426] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 92.57% Al2O3 and 7.28% CaO.

[0427] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and corundum, wherein, based on the mass percentage of the phases in the matrix portion of the refractory material, the content of the CA6 phase is 72.4% and the content of the corundum phase is 25.1%.

[0428] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, comprises 91.6% Al2O3 and 5.92% CaO.

[0429] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the calcium hexaaluminate-based refractory was 2.70 g / cm³. 3 .

[0430] The analysis was performed using the same method as in Example 1-1, and the obtained refractory material had a thermal conductivity of 2.31 W / mK at 350°C.

[0431] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 4.45 mm.

[0432] Examples 1-23: Preparation of calcium hexaaluminate-based refractory materials

[0433] CA6-based refractory materials were prepared by mixing 60% of 0.088mm C2M2A14 aggregate, 26% of CA6 fine powder with a particle size of less than 325 mesh, 4% of pure aluminate cement, 5% of white corundum fine powder with a particle size of less than 325 mesh, and 5% of activated alumina micro powder, adding water and stirring, then pressing and drying the mixture.

[0434] Phase and chemical composition tests were conducted after the prepared CA6-based refractory material was treated at 1600℃ for 6 hours.

[0435] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and C2M2A14. Based on the mass percentage of the phases in the refractory material, the content of the C2M2A14 phase was 59.1%, and the content of the CA6 phase was 38.5%.

[0436] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 87.6% Al2O3, 2.84% MgO, and 7.28% CaO.

[0437] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phase of the matrix portion of the refractory material includes CA6, wherein the content of the CA6 phase is 97.3% by mass percentage of the phase in the matrix portion of the refractory material.

[0438] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, comprises 91.4% Al2O3 and 8.29% CaO.

[0439] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the calcium hexaaluminate-based refractory was 2.55 g / cm³. 3 .

[0440] The analysis was performed using the same method as in Examples 1-1, and the obtained refractory material had a thermal conductivity of 2.21 W / mK at 350°C.

[0441] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 5.28 mm.

[0442] Examples 1-24: Preparation of calcium hexaaluminate-based refractory materials

[0443] CA6-based refractory materials were prepared by using 50% CA6 aggregate with a particle size of 0.088 mm, 40% CA6 fine powder with a particle size of less than 325 mesh, 0.84% ​​limestone powder and 9.16% activated alumina micro powder as raw materials, adding a suitable carboxymethyl cellulose binder and stirring evenly, and then pressing and firing at 1750℃.

[0444] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6 and corundum. Based on the mass percentage of the phases in the refractory material, the content of the CA6 phase was 94.3%, and the content of the corundum phase was 3.42%.

[0445] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 90.9% Al2O3 and 7.25% CaO.

[0446] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phases of the matrix portion of the refractory material include CA6 and corundum, wherein, based on the mass percentage of the phases in the matrix portion of the refractory material, the content of the CA6 phase is 90.3% and the content of the corundum phase is 7.22%.

[0447] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, as a percentage by mass of the matrix portion, comprises 92.2% Al2O3 and 7.38% CaO.

[0448] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the calcium hexaaluminate-based refractory was 2.65 g / cm³. 3 .

[0449] The analysis was performed using the same method as in Examples 1-1, and the obtained refractory material had a thermal conductivity of 2.74 W / mK at 350°C.

[0450] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 4.22 mm.

[0451] Examples 1-25: Preparation of calcium hexaaluminate-based refractory materials

[0452] CA6-based refractory materials are prepared by adding water-reducing agent and mixing them evenly, using 65% CA6 aggregate with a particle size of less than 325 mesh, 25% CA6 fine powder, 4% pure aluminate cement and 6% activated alumina micro powder as raw materials, and then preforming them.

[0453] Phase and chemical composition tests were conducted after the prepared CA6-based refractory material was treated at 1600℃ for 6 hours.

[0454] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6, and the content of the CA6 phase was 97.5% by mass percentage of the phases in the refractory material.

[0455] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 90.4% Al2O3 and 8.05% CaO.

[0456] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phase of the matrix portion of the refractory material includes CA6, wherein the content of the CA6 phase is 97.3% by mass percentage of the phase in the matrix portion of the refractory material.

[0457] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, expressed as a percentage by mass, includes 89.7% Al2O3 and 8.06% CaO.

[0458] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the calcium hexaaluminate-based refractory was 2.76 g / cm³. 3 .

[0459] The analysis was performed using the same method as in Examples 1-1, and the obtained refractory material had a thermal conductivity of 2.32 W / mK at 350°C.

[0460] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 5.19 mm.

[0461] Examples 1-26: Preparation of calcium hexaaluminate-based refractory materials

[0462] Using 65% CM2A8 aggregate (0.088mm), 25% CA6 fine powder (particle size less than 325 mesh), 4% pure aluminate cement, and 6% activated alumina powder as raw materials, a water-reducing agent is added and the mixture is stirred evenly. After preforming, CA6-based refractory materials are obtained.

[0463] Phase and chemical composition tests were conducted after the prepared CA6-based refractory material was treated at 1600℃ for 6 hours.

[0464] Phase analysis was performed using the same method as in Examples 1-1. The phases of the calcium hexaaluminate refractory material included CA6. The content of the CM2A8 phase was 64.1% and the content of the CA6 phase was 33.5% by mass percentage of the phases in the refractory material.

[0465] Chemical composition analysis was performed using the same method as in Examples 1-1. The chemical composition of the obtained calcium hexaaluminate refractory material, based on the mass percentage of the refractory material, included 86.3% Al2O3, 5.12% MgO, and 6.14% CaO.

[0466] The phase analysis of the matrix portion was performed using the same method as in Examples 1-1. The phase of the matrix portion of the refractory material includes CA6, wherein the content of the CA6 phase is 97.4% by mass percentage of the phase in the matrix portion of the refractory material.

[0467] The chemical composition of the matrix portion was analyzed using the same method as in Examples 1-1. The chemical composition of the matrix portion of the refractory material, expressed as a percentage by mass, includes 89.7% Al2O3 and 8.06% CaO.

[0468] The bulk density was analyzed using the same method as in Examples 1-1, and the bulk density of the calcium hexaaluminate refractory was 2.75 g / cm³. 3 .

[0469] The analysis was performed using the same method as in Example 1-1, and the obtained refractory material had a thermal conductivity of 2.37 W / mK at 350°C.

[0470] The erosion depth of the refractory material was measured using the same method as in Example 1-1, and the result was 5.26 mm.

[0471] Table 1. Relevant data from Examples 1-1 to 1-26

[0472]

[0473]

[0474]

[0475] Example 2-1 Preparation of Nanoscale Heat Insulation Plate

[0476] According to the mass percentage, 83% of the micro-nano SiO2 powder coated with TiO2, 15% of ZrO2 powder and 2% of aluminum silicate fiber are mixed evenly, an appropriate amount of silica sol binder is added and stirred evenly, the mixture is placed in a mold, pressed into shape using a press, dried and wrapped and sealed with aluminum foil to obtain a nano heat insulation board.

[0477] The chemical composition of the micro / nanoplate was analyzed by fluorescence XRF analysis in accordance with GB / T21114-2007. The chemical composition of the micro / nanoplate after treatment at 1000℃ for 6 hours included 80.05% SiO2, 14.62% ZrO2, and the remainder being Al2O3, TiO2, CaO, Fe2O3, K2O and Na2O.

[0478] The micro / nanoplate was tested according to GB / T2997-2000, and the measured bulk density was 0.35 g / cm³. 3 .

[0479] The thermal conductivity of the micro / nano plate at 350℃ was measured to be 0.028 W / mK according to the ferrous metallurgical industry standard YB / T 4130-2005.

[0480] Example 2-2 Preparation of Nanoscale Insulation Plate

[0481] According to the mass percentage, 74% of the micro-nano SiO2 powder coated with ZrO2 was mixed evenly with 24% of ZrO2 powder and 2% of aluminum silicate fiber. An appropriate amount of white glue binder was added and stirred evenly. The mixture was then pressed into shape by a press, dried, wrapped with aluminum foil, and sealed with plastic film to obtain a micro-nano heat insulation board.

[0482] Chemical composition analysis was performed using the same method as in Example 2-1. The chemical composition of the micro / nanoplate after treatment at 1000℃ for 6 hours included 72.40% SiO2, 23.76% ZrO2, and the remainder being Al2O3, Fe2O3, CaO, K2O, and Na2O.

[0483] The bulk density was analyzed using the same method as in Example 2-1, and the bulk density of the micro / nanoplate was 0.59 g / cm³. 3 .

[0484] The micro / nanoplate was analyzed using the same method as in Example 2-1, and the thermal conductivity at 350°C was 0.034 W / mK.

[0485] Preparation of Nanoscale Heat Insulation Plates in Examples 2-3

[0486] According to the mass percentage, 99.5% of micro-nano SiO2 powder, 0.5% of glass fiber, and an appropriate amount of aluminum dihydrogen phosphate binder are added and stirred evenly. The mixture is then pressed into shape using a press, dried, wrapped in aluminum foil, and sealed with plastic film to obtain a nano heat insulation board.

[0487] Chemical composition analysis was performed using the same method as in Example 2-1. The chemical composition of the micro / nanoplate after treatment at 1000℃ for 6 hours included 99.5% SiO2, with the remainder being Al2O3, Fe2O3, K2O, and Na2O.

[0488] The bulk density was analyzed using the same method as in Example 2-1, and the bulk density of the micro / nanoplate was 0.40 g / cm³. 3 .

[0489] The micro / nanoplate was analyzed using the same method as in Example 2-1, and the thermal conductivity at 350°C was 0.025 W / mK.

[0490] Preparation of Nanoscale Insulation Plates in Examples 2-4

[0491] According to the mass percentage, 71% of ZrO2-doped micro / nano SiO2 powder, 23% of ZrO2 powder, and 6% of SiC fiber are mixed evenly, an appropriate amount of dextrin is added as a binder, and after stirring evenly, the mixture is scraped and pressed into shape using a scraper. After drying, it is wrapped with aluminum foil to obtain a nano heat insulation board.

[0492] Chemical composition analysis was performed using the same method as in Example 2-1. The chemical composition of the micro / nano powder after treatment at 1000℃ for 6 hours included 76.40% SiO2, 22.88% ZrO2, and the remainder being Al2O3, K2O, and Na2O.

[0493] The bulk density was analyzed using the same method as in Example 2-1, and the bulk density of the micro / nanoplate was 0.38 g / cm³. 3 .

[0494] The micro / nanoplate was analyzed using the same method as in Example 2-1, and the thermal conductivity at 350°C was 0.030 W / mK.

[0495] Preparation of Nanoscale Insulation Plates in Examples 2-5

[0496] According to the mass percentage, 90% of micro-nano SiO2 powder, 6% of SiC micro powder, and 4% of mullite fiber are mixed evenly, an appropriate amount of water glass binder is added and stirred evenly, pressed into shape by a press, dried and coated with silica sol to obtain a nano heat insulation board.

[0497] Chemical composition analysis was performed using the same method as in Example 2-1. The chemical composition of the micro / nanoplate after treatment at 1000℃ for 6 hours included 95.47% SiO2, with the remainder being Al2O3, TiO2, Fe2O3, K2O, and Na2O.

[0498] The bulk density was analyzed using the same method as in Example 2-1, and the bulk density of the micro / nanoplate was 0.23 g / cm³. 3 .

[0499] The micro / nanoplate was analyzed using the same method as in Example 2-1, and the thermal conductivity at 350°C was 0.048 W / mK.

[0500] Preparation of Nanoscale Insulation Plates in Examples 2-6

[0501] According to the mass percentage, 94% of the micro-nano SiO2 powder coated with TiO2 was mixed evenly with 6% of aluminum silicate fiber, an appropriate amount of cellulose was added as a binder, the mixture was stirred evenly, filtered and shaped, dried, wrapped with aluminum foil, and sealed with plastic film to obtain a nano heat insulation board.

[0502] Chemical composition analysis was performed using the same method as in Example 2-1. The chemical composition of the micro / nano powder after treatment at 1000℃ for 6 hours included 93.20% SiO2, with the remainder being Al2O3, TiO2, Fe2O3, K2O, and Na2O.

[0503] The bulk density was analyzed using the same method as in Example 2-1, and the bulk density of the micro / nanoplate was 0.25 g / cm³. 3 .

[0504] The micro / nanoplate was analyzed using the same method as in Example 2-1, and the thermal conductivity at 350°C was 0.020 W / mK.

[0505] Preparation of Nanoscale Heat Insulation Plates in Examples 2-7

[0506] According to the mass percentage, 70% of micro-nano SiO2 powder and 30% of ZrO2 powder are mixed evenly, an appropriate amount of sodium tripolyphosphate binder is added, water is added and stirred evenly, the mixture is poured and shaped, dried and then coated with aluminum dihydrogen phosphate to obtain a nano heat insulation board.

[0507] Chemical composition analysis was performed using the same method as in Example 2-1. The chemical composition of the micro / nano powder after treatment at 1000℃ for 6 hours included 68.31% SiO2, 29.3% ZrO2, and the remainder being Al2O3 and TiO2.

[0508] The bulk density was analyzed using the same method as in Example 2-1, and the bulk density of the micro / nanoplate was 0.52 g / cm³.3 .

[0509] The micro / nanoplate was analyzed using the same method as in Example 2-1, and the thermal conductivity at 350°C was 0.048 W / mK.

[0510] Preparation of Nanoscale Insulation Plates in Examples 2-8

[0511] According to the mass percentage, 56% of micro-nano SiO2 powder coated with ZrO2 is mixed evenly with 40% ZrO2 powder and 4% Al2O3 fiber. An appropriate amount of sodium hexametaphosphate binder is added, water is added and stirred evenly, vibrated and shaped, dried, wrapped with aluminum foil, and sealed with plastic film to obtain a nano heat insulation board.

[0512] Chemical composition analysis was performed using the same method as in Example 2-1. The chemical composition of the micro / nano powder after treatment at 1000℃ for 6 hours included 55.00% SiO2, 39.98% ZrO2, and the remainder was Al2O3, MgO, Fe2O3, K2O and Na2O.

[0513] The bulk density was analyzed using the same method as in Example 2-1, and the bulk density of the micro / nanoplate was 0.70 g / cm³. 3 .

[0514] The micro / nanoplate was analyzed using the same method as in Example 2-1, and the thermal conductivity at 350°C was 0.043 W / mK.

[0515] Table 2. Raw material composition of nano-insulation panels in Examples 2-1 to 2-8

[0516]

[0517]

[0518] Example 3-1: Preparation of a composite refractory lining structure for blocking heat conduction (assembled and constructed on-site).

[0519] The nano-insulation board with a thickness of 20 mm prepared in Example 2-1 was bonded to the low-temperature side of the CA6 refractory material with a thickness of 90 mm prepared in Example 1-1 using water glass combined with fire cement, and then cured.

[0520] The obtained composite refractory lining structure was constructed on site to obtain the permanent lining and heat insulation refractory lining for the steel ladle refining ladle.

[0521] Example 3-2 Preparation of composite refractory lining structure for blocking heat conduction (on-site assembly): The nano-insulation board obtained in Examples 2-6 with a thickness of 30 mm was attached to the shell;

[0522] The CA6 refractory material prepared by wet construction of 80mm layer using silica sol combined with fine aluminum silicate powder in Examples 1-2, and the gap between the CA6 refractory material and the nano-insulation board filled with fire mortar, is used to obtain the permanent lining and heat insulation lining refractory material for steel ladle refining ladle.

[0523] Example 3-3 Preparation of composite refractory lining structure for blocking heat conduction (on-site assembly): The nano-insulation board obtained in Example 2-2 with a thickness of 25 mm was attached to the shell;

[0524] The CA6 refractory material obtained in Examples 1-5 was constructed by wet-laying 110mm of water glass combined with fine aluminum silicate powder, and the gap between the CA6 refractory material and the nano-insulation board was filled with fire mortar to obtain the permanent lining and heat insulation lining refractory material for steel ladle refining ladle.

[0525] Examples 3-4: Preparation of composite refractory lining structures for blocking heat conduction (assembled and constructed on-site).

[0526] The nano-insulation panels prepared in Examples 2-7 with a thickness of 23 mm were bonded to the low-temperature side of the CA6 refractory material prepared in Examples 1-11 with a thickness of 112 mm using methacrylate adhesive, and then cured.

[0527] The obtained composite refractory lining structure was constructed on site to obtain the permanent lining and heat insulation refractory lining for the steel ladle refining ladle.

[0528] Example 3-5: Preparation of composite refractory lining structure for blocking heat conduction (assembled and constructed on site).

[0529] The nano-insulation board with a thickness of 20 mm described in Examples 2-4 was bonded to the low-temperature side of the CA6 refractory material with a thickness of 100 mm obtained in Examples 1-11 using aluminum dihydrogen phosphate combined with aluminum silicate fine powder, and then dried.

[0530] The obtained composite refractory lining structure was constructed on site to obtain the permanent lining and heat insulation refractory lining for the steel ladle refining ladle.

[0531] Examples 3-6 Preparation of composite refractory lining structure for blocking heat conduction (on-site assembly): The nano-insulation board obtained in Examples 2-6 with a thickness of 30 mm was attached to the shell;

[0532] The CA6 refractory material obtained in Examples 1-12 was constructed by wet mortar bonding aluminosilicate fine powder with silica sol to form a 100mm layer. The gap between the CA6 refractory material and the nano-insulation board was filled with fire mortar to obtain the permanent lining and heat insulation lining refractory material for steel ladle refining ladle.

[0533] Example 3-7 Preparation of composite refractory lining structure for blocking heat conduction (on-site assembly): The nano-insulation board obtained in Example 2-5 with a thickness of 10 mm was attached to the shell;

[0534] The CA6 refractory material obtained in Examples 1-12 was constructed by wet lining of 250mm using aluminum dihydrogen phosphate combined with aluminum silicate fine powder. The gap between the CA6 refractory material and the nano heat insulation board was filled with fire mortar to obtain the permanent lining and heat insulation lining refractory material for steel ladle refining ladle.

[0535] Example 3-8: Preparation of composite refractory lining structure for blocking heat conduction (assembled and constructed on site).

[0536] The nano-insulation board with a thickness of 23 mm described in Examples 2-7 was bonded to the low-temperature side of the CA6 refractory material with a thickness of 80 mm obtained in Examples 1-14 using silica sol and aluminum silicate fine powder, and then dried.

[0537] The obtained composite refractory lining structure was constructed on site to obtain the permanent lining and heat insulation refractory lining for the steel ladle refining ladle.

[0538] Examples 3-9: Preparation of composite refractory lining structures for blocking heat conduction (on-site assembly)

[0539] The nano-insulation plate of Examples 2-3 with a thickness of 25 mm was attached to the casing;

[0540] The CA6 refractory material obtained in Examples 1-19 was constructed by wet construction of 80mm layer using water glass combined with aluminosilicate powder, and the gap between the CA6 refractory material and the nano-insulation board was filled with fire mortar to obtain the permanent lining and heat insulation lining refractory material for steel ladle refining ladle.

[0541] Example 3-10: Preparation of composite refractory lining structure for blocking heat conduction (assembled and constructed on site).

[0542] The nano-insulation panels described in Examples 2-4 with a thickness of 20 mm were bonded to the low-temperature side of the CA6 refractory material obtained in Examples 1-22 with a thickness of 250 mm using ethyl cyanoacrylate adhesive, and then dried.

[0543] The obtained composite refractory lining structure was constructed on site to obtain the permanent lining and heat insulation refractory lining for the steel ladle refining ladle.

[0544] Example 3-11: Preparation of a composite refractory lining structure for blocking heat conduction (on-site assembly)

[0545] The nano-insulation plate of Examples 2-3 with a thickness of 25 mm was attached to the casing;

[0546] The CA6 refractory material obtained in Examples 1-24 was constructed by wet construction of 110mm layer using water glass combined with aluminosilicate powder, and the gap between the CA6 refractory material and the nano-insulation board was filled with fire mortar to obtain the permanent lining and heat insulation lining refractory material for steel ladle refining ladle.

[0547] Example 3-12: Preparation of a composite refractory lining structure for blocking heat conduction (assembled and constructed on-site).

[0548] The 20mm thick nano-insulation board of Example 2-1 was bonded to the low-temperature side of the 100mm thick CA6 refractory material described in Examples 1-25 using epoxy resin adhesive, and then cured.

[0549] The obtained composite refractory lining structure was constructed on site to obtain the permanent lining and heat insulation refractory lining for the steel ladle refining ladle.

[0550] Example 3-13: Preparation of a composite refractory lining structure for blocking heat conduction (on-site assembly)

[0551] The 25mm thick nano-insulation plate from Example 2-2 was attached to the casing;

[0552] The CA6 precast blocks obtained in Examples 1-26 were constructed using a wet method with aluminum dihydrogen phosphate combined with aluminum silicate powder, with a thickness of 80 mm. The gaps between the CA6 precast blocks and the nano-insulation board were filled with fire mortar to obtain permanent lining and heat insulation refractory materials for steel ladle refining ladles.

[0553] Table 3. Thickness of CA6 refractory material and nano-insulation board used in composite refractory materials

[0554]

[0555]

[0556] Experimental Example 1: High-Temperature Sintering Stability of the CA6 Refractory Material as Described in Examples 1-1 of the Present Invention

[0557] Mullite castable is a high-performance permanent lining material used in industry. Its aggregate is lightweight mullite, and the fine powder is bauxite powder, pure aluminate cement, activated alumina powder and silica powder, etc. It is prepared by adding water, mixing, pouring and vibration construction.

[0558] The CA6 refractory material obtained in Example 1-1 and the mullite casting were placed in a high-temperature furnace and heated to 1550°C, and then held for 3 hours. The morphology after treatment is as follows. Figure 1 As shown.

[0559] from Figure 1It can be seen that the surface of the CA6 sample after sintering is very clean, with no cracks and virtually no sintering shrinkage. In contrast, the mullite castable sample showed network cracks on its surface after sintering, indicating that it exhibited sintering shrinkage. These micro-cracks may develop into larger cracks after repeated thermal cycles, even leading to sample fracture. This fully demonstrates that the high-temperature stability of the sample obtained by this invention is excellent.

[0560] The CA6 refractory materials obtained in Examples 1-2 to 1-26 have similar technical effects.

[0561] Experimental Example 2: Resistance of the CA6 refractory material described in Examples 1-1 of this invention to slag corrosion.

[0562] The CA6 refractory material and mullite castable obtained in Examples 1-1 of this invention were respectively prepared as follows: Figure 2-1 , 2-2 A crucible was filled with steel slag and placed in a high-temperature furnace. The temperature was raised to 1550℃ and held for 3 hours. After holding, the crucible was cooled with the furnace and then cut open along the middle to observe the penetration and erosion of the steel slag. The steel slag composition was: CaO 51%, Al₂O₃ 30%, SiO₂ 11%, MgO 8%, with a CaO / SiO₂ ratio of 4.6. The experimental results are as follows: Figure 2-1 as well as Figure 2-2 As shown.

[0563] Figure 2-1 This is the result of the CA6 refractory material described in Example 1-1 resisting slag erosion, and Figure 2-2 This is a result of the mullite castable resisting slag erosion, from Figure 2-1 as well as Figure 2-2 It can be seen that the mullite castable has poor resistance to slag erosion, as the slag has penetrated to the outside, meaning it has completely entered the outside of the sample. In contrast, the CA6 sample described in Example 1-1 of this invention shows a much shallower slag penetration depth, indicating that the sample described in Example 1-1 of this invention has very good resistance to slag erosion.

[0564] The CA6 refractory materials obtained in Examples 1-2 to 1-26 have similar effects.

[0565] Experiment Example 3: Experiment on the temperature change and difference of the ladle shell in the refining process.

[0566] The composite refractory lining structure with heat-blocking properties obtained in Examples 3-1 to 3-13, mullite castable and fiberboard, mullite castable and nanoboard described in Example 2-1, and CA6 refractory material and fiberboard described in Example 1-1 were tested to determine the on-site cladding temperature change of the refining ladle. The test results are shown in Table 4.

[0567] Table 4 shows the steel shell temperatures after using composite refractory lining structures, mullite castables and fiberboards, mullite castables and nanoboards as described in Example 2-1, and CA6 refractory materials and fiberboards as described in Example 1-1.

[0568]

[0569]

[0570] As can be seen from the table above, although the steel shell temperature of the ladle lining structure composed of mullite castable and 20mm nano-insulation board was reduced to 273℃, a significant temperature rise was observed after the first heat, indicating that the nano-insulation board had crystallized and powdered, and subsequently lost its heat insulation effect.

[0571] Based on the ladle lining structure of this invention, CA6 low thermal conductivity refractory material not only has excellent heat conduction blocking performance but also resists erosion by molten steel and slag, significantly outperforming mullite castables and ensuring smelting safety. For both permanent and insulating linings of the ladle, heat insulation is crucial; however, resistance to slag erosion and prevention of molten steel leakage are essential. Therefore, for the permanent lining, resistance to slag and molten steel erosion must be guaranteed.

[0572] In addition, due to the heat conduction barrier properties of CA6 material, the high temperature of smelting is blocked in CA6 material, which reduces the crystallization and pulverization rate of nanomaterials and ensures the integrity of nanostructure. Therefore, the refractory lining based on the composite structure of this patent can be used in steel ladles to maintain the steel shell temperature at 100-200℃, with very obvious effect.

[0573] 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 composite refractory lining masonry structure for blocking heat conduction, comprising a thermally insulating calcium hexaaluminate refractory and a nano-insulation board, wherein the nano-insulation board is fixedly disposed on the low-temperature side of the calcium hexaaluminate refractory. The phases of the calcium hexaaluminate-based refractory material include CA6 and one or more phases selected from C2M2A14, CM2A8, magnesium aluminum spinel and corundum. The total content of CA6, C2M2A14, CM2A8, magnesium aluminum spinel and corundum is ≥90% by mass percentage in the refractory material; The proportions of CA6 phases range from 26.7% to 99.5%. The C2M2A14 phase content is 0-72%; The phase composition of CM2A8 is 0-72%; The magnesium aluminum spinel phase is 0-10%, and The corundum phase content is 0-11.8%; The matrix phase of the calcium hexaaluminate refractory material includes CA6 and one or more phases selected from corundum, magnesium aluminum spinel, C2M2A14 and CM2A8. The CA6 phase comprises 67.4-100% by mass percentage in the matrix portion of the calcium hexaaluminate refractory material. The corundum phase comprises 0-30%; The magnesium aluminum spinel phase is 0-10%; The C2M2A14 phase content is 0-30%; and The phase composition of CM2A8 is 0-30%; The bulk density of the calcium hexaaluminate-based refractory material is 2.40-2.90 g / cm³. 3 ; The nano-insulation plate comprises micro-nano plates and a thin film coating the micro-nano plates, wherein, The chemical composition of the micro / nanoplate includes SiO2 and ZrO2, with SiO2 accounting for 55-100% and ZrO2 accounting for 0-40% by weight in the micro / nanoplate.

2. The composite refractory lining masonry structure according to claim 1, wherein, The total content of CA6, C2M2A14, CM2A8, magnesium aluminum spinel and corundum is 94.8-99.5% by mass percentage in refractory materials.

3. The composite refractory lining masonry structure according to claim 1, wherein, Based on the mass percentage of the phases in refractory materials, CA6 phase comprises 31.5-99.5%; The C2M2A14 phase content is 0-60%; The phase composition of CM2A8 is 0-59.5%; The magnesium aluminum spinel phase comprises 0-4.60%, and The corundum phase content is 0-16.5%.

4. The composite refractory lining masonry structure according to claim 1, wherein, Based on the mass percentage of the phases in refractory materials, CA6 phase accounts for 38.7-99.5%; The magnesium aluminum spinel phase is 0.

5. The composite refractory lining masonry structure according to claim 1, wherein, The chemical composition of the calcium hexaaluminate-based refractory material includes Al2O3, CaO, and MgO, and the Al2O3 accounts for 86.65-94.10% of the total mass of the calcium hexaaluminate-based refractory material. The CaO content is 5.80-8.40%; and The MgO content is 0-6.05%.

6. The composite refractory lining masonry structure according to claim 5, wherein, The Al2O3 comprises 87.60-94.10% by mass percentage in the calcium hexaaluminate refractory material. The CaO content is 6.89-8.40%; and The MgO content is 0-5.04%.

7. The composite refractory lining masonry structure according to claim 5, wherein, The Al2O3 is 88.07-94.10% by mass percentage in the calcium hexaaluminate refractory material.

8. The composite refractory lining masonry structure according to claim 1, wherein, The bulk density of the calcium hexaaluminate-based refractory material is 2.40-2.82 g / cm³. 3 .

9. The composite refractory lining masonry structure according to claim 1, wherein, The CA6 phase comprises 78.2-100% by mass percentage in the matrix portion of the calcium hexaaluminate refractory material. The corundum phase is 0-20%; The magnesium aluminum spinel phase comprises 0-5.22%; The C2M2A14 phase composition is 0-18.8%; and The phase composition of CM2A8 is 0-18.8%.

10. The composite refractory lining masonry structure according to claim 1, wherein, The magnesium aluminum spinel phase is 0% by mass percentage of the phase in the matrix portion of the calcium hexaaluminate refractory material.

11. The composite refractory lining masonry structure according to claim 1, wherein, The chemical composition of the matrix portion of the calcium hexaaluminate refractory material includes Al2O3, CaO, and MgO, and the Al2O3 accounts for 89.03-94.10% of the matrix portion by mass. The CaO content is 5.80-8.40%; and The MgO content is 0-2.52%.

12. The composite refractory lining masonry structure according to claim 11, wherein, The Al2O3 comprises 90.30-93.20% of the matrix portion of the calcium hexaaluminate refractory material by mass percentage. The CaO content is 6.60-8.40%; and The MgO content is 0-1.68%.

13. The composite refractory lining masonry structure according to claim 1, wherein, By weight, SiO2 accounts for 70-100% of the total content in the micro / nanoplates; ZrO2 accounts for 0-30%.

14. The composite refractory lining masonry structure according to claim 1, wherein, By weight, SiO2 accounts for 80-100% of the total content in the micro / nanoplates; ZrO2 accounts for 0-15%.

15. The composite refractory lining masonry structure according to claim 1, wherein, The bulk density of the nano-insulation panel is 0.23-0.60 g / cm³. 3 .

16. The composite refractory lining masonry structure according to claim 1, wherein, The bulk density of the nano-insulation panel is 0.25-0.60 g / cm³. 3 .

17. The composite refractory lining masonry structure according to claim 1, wherein, The bulk density of the nano-insulation panel is 0.30-0.60 g / cm³. 3 .

18. The composite refractory lining masonry structure according to claim 1, wherein, The thermal conductivity of the nano-insulation plate at 300℃ is 0.020-0.048w / m•k.

19. The composite refractory lining masonry structure according to claim 1, wherein, The thermal conductivity of the nano-insulation plate at 300℃ is 0.025-0.048w / m•k.

20. The composite refractory lining masonry structure according to claim 1, wherein, The thermal conductivity of the nano-insulation plate at 300℃ is 0.025-0.045w / m•k.

21. The composite refractory lining masonry structure according to claim 1, wherein, The micro / nanoplate also includes fibers.

22. The composite refractory lining masonry structure according to claim 21, wherein, The fiber is selected from one or more of glass fiber, alumina fiber, mullite fiber and aluminosilicate fiber.

23. The composite refractory lining masonry structure according to claim 1, wherein, The film is a metal film, an organic film, or an inorganic coating.

24. The composite refractory lining masonry structure according to claim 23, wherein, The metal film is aluminum foil, the organic film is a plastic film, and the inorganic coating is a silica sol coating or an aluminum dihydrogen phosphate coating.

25. The composite refractory lining masonry structure according to any one of claims 1-24, wherein, The thickness of the calcium hexaaluminate-based refractory material is 50-250 mm.

26. The composite refractory lining masonry structure according to any one of claims 1-24, wherein, The thickness of the calcium hexaaluminate-based refractory material is 80-116 mm.

27. The composite refractory lining masonry structure according to any one of claims 1-24, wherein, The thickness of the nano-insulation board is 10-40mm.

28. The composite refractory lining masonry structure according to any one of claims 1-24, wherein, The thickness of the nano-insulation board is 20-30mm.

29. A composite refractory lining masonry structure forming material for blocking heat conduction, comprising a thermally insulating calcium hexaaluminate refractory and a nano-insulating plate, wherein the nano-insulating plate is fixedly disposed on the low-temperature side of the calcium hexaaluminate refractory. The phases of the calcium hexaaluminate-based refractory material include CA6 and one or more phases selected from C2M2A14, CM2A8, magnesium aluminum spinel and corundum. The total content of CA6, C2M2A14, CM2A8, magnesium aluminum spinel and corundum is ≥90% by mass percentage in the refractory material; The proportions of CA6 phases range from 26.7% to 99.5%. The C2M2A14 phase content is 0-72%; The phase composition of CM2A8 is 0-72%; The magnesium aluminum spinel phase is 0-10%, and The corundum phase content is 0-11.8%; The matrix phase of the calcium hexaaluminate refractory material includes CA6 and one or more phases selected from corundum, magnesium aluminum spinel, C2M2A14 and CM2A8. The CA6 phase comprises 67.4-100% by mass percentage in the matrix portion of the calcium hexaaluminate refractory material. The corundum phase comprises 0-30%; The magnesium aluminum spinel phase is 0-10%; The C2M2A14 phase content is 0-30%; and The phase composition of CM2A8 is 0-30%; The bulk density of the calcium hexaaluminate-based refractory material is 2.40-2.90 g / cm³. 3 ; The nano-insulation plate comprises micro-nano plates and a thin film coating the micro-nano plates, wherein, The chemical composition of the micro / nanoplate includes SiO2 and ZrO2, with SiO2 accounting for 55-100% and ZrO2 accounting for 0-40% by weight in the micro / nanoplate.

30. The composite refractory lining masonry structure forming material according to claim 29, wherein, The total content of CA6, C2M2A14, CM2A8, magnesium aluminum spinel and corundum is 94.8-99.5% by mass percentage in refractory materials.

31. The composite refractory lining masonry structure forming material according to claim 29, wherein, Based on the mass percentage of the phases in refractory materials, CA6 phase comprises 31.5-99.5%; The C2M2A14 phase content is 0-60%; The phase composition of CM2A8 is 0-59.5%; The magnesium aluminum spinel phase comprises 0-4.60%, and The corundum phase content is 0-16.5%.

32. The composite refractory lining masonry structure forming material according to claim 29, wherein, Based on the mass percentage of the phases in refractory materials, CA6 phase accounts for 38.7-99.5%; The magnesium aluminum spinel phase is 0.

33. The composite refractory lining masonry structure forming material according to claim 29, wherein, The chemical composition of the calcium hexaaluminate-based refractory material includes Al2O3, CaO, and MgO, and the Al2O3 accounts for 86.65-94.10% of the total mass of the calcium hexaaluminate-based refractory material. The CaO content is 5.80-8.40%; and The MgO content is 0-6.05%.

34. The composite refractory lining masonry structure forming material according to claim 33, wherein, The Al2O3 comprises 87.60-94.10% by mass percentage in the calcium hexaaluminate refractory material. The CaO content is 6.89-8.40%; and The MgO content is 0-5.04%.

35. The composite refractory lining masonry structure forming material according to claim 33, wherein, The Al2O3 is 88.07-94.10% by mass percentage in the calcium hexaaluminate refractory material.

36. The composite refractory lining masonry structure forming material according to claim 29, wherein, The bulk density of the calcium hexaaluminate-based refractory material is 2.40-2.82 g / cm³. 3 .

37. The composite refractory lining masonry structure forming material according to claim 29, wherein, The CA6 phase comprises 78.2-100% by mass percentage in the matrix portion of the calcium hexaaluminate refractory material. The corundum phase is 0-20%; The magnesium aluminum spinel phase comprises 0-5.22%; The C2M2A14 phase composition is 0-18.8%; and The phase composition of CM2A8 is 0-18.8%.

38. The composite refractory lining masonry structure forming material according to claim 29, wherein, The magnesium aluminum spinel phase is 0% by mass percentage of the phase in the matrix portion of the calcium hexaaluminate refractory material.

39. The composite refractory lining masonry structure forming material according to claim 29, wherein, The chemical composition of the matrix portion of the calcium hexaaluminate refractory material includes Al2O3, CaO, and MgO, and the Al2O3 accounts for 89.03-94.10% of the matrix portion by mass. The CaO content is 5.80-8.40%; and The MgO content is 0-2.52%.

40. The composite refractory lining masonry structure forming material according to claim 39, wherein, The Al2O3 comprises 90.30-93.20% of the matrix portion of the calcium hexaaluminate refractory material by mass percentage. The CaO content is 6.60-8.40%; and The MgO content is 0-1.68%.

41. The composite refractory lining masonry structure forming material according to claim 29, wherein, By weight, SiO2 accounts for 70-100% of the total content in the micro / nanoplates; ZrO2 accounts for 0-30%.

42. The composite refractory lining masonry structure forming material according to claim 29, wherein, By weight, SiO2 accounts for 80-100% of the total content in the micro / nanoplates; ZrO2 accounts for 0-15%.

43. The composite refractory lining masonry structure forming material according to claim 29, wherein, The bulk density of the nano-insulation panel is 0.23-0.60 g / cm³. 3 .

44. The composite refractory lining masonry structure forming material according to claim 29, wherein, The bulk density of the nano-insulation panel is 0.25-0.60 g / cm³. 3 .

45. The composite refractory lining masonry structure forming material according to claim 29, wherein, The bulk density of the nano-insulation panel is 0.30-0.60 g / cm³. 3 .

46. ​​The composite refractory lining masonry structure forming material according to claim 29, wherein, The thermal conductivity of the nano-insulation plate at 300℃ is 0.020-0.048w / m•k.

47. The composite refractory lining masonry structure forming material according to claim 29, wherein, The thermal conductivity of the nano-insulation plate at 300℃ is 0.025-0.048w / m•k.

48. The composite refractory lining masonry structure forming material according to claim 29, wherein, The thermal conductivity of the nano-insulation plate at 300℃ is 0.025-0.045w / m•k.

49. The composite refractory lining masonry structure forming material according to claim 29, wherein, The micro / nanoplate also includes fibers.

50. The composite refractory lining masonry structure forming material according to claim 49, wherein, The fiber is selected from one or more of glass fiber, alumina fiber, mullite fiber and aluminosilicate fiber.

51. The composite refractory lining masonry structure forming material according to claim 29, wherein, The film is a metal film, an organic film, or an inorganic coating.

52. The composite refractory lining masonry structure forming material according to claim 51, wherein, The metal film is aluminum foil, the organic film is a plastic film, and the inorganic coating is a silica sol coating or an aluminum dihydrogen phosphate coating.

53. The composite refractory lining masonry structure forming material according to any one of claims 29-52, wherein, The thickness of the calcium hexaaluminate-based refractory material is 50-250 mm.

54. The composite refractory lining masonry structure forming material according to any one of claims 29-52, wherein, The thickness of the calcium hexaaluminate-based refractory material is 80-116 mm.

55. The composite refractory lining masonry structure forming material according to any one of claims 29-52, wherein, The thickness of the nano-insulation board is 10-40mm.

56. The composite refractory lining masonry structure forming material according to any one of claims 29-52, wherein, The thickness of the nano-insulation board is 20-30mm.

57. The composite refractory lining masonry structure forming material according to any one of claims 29-52, wherein, The composite refractory lining masonry structure forming material also includes high-temperature fire mud, and the nano heat insulation board is fixedly installed on the low-temperature side of the calcium hexaaluminate refractory material through the high-temperature fire mud.

58. The composite refractory lining masonry structure forming material according to claim 57, wherein, The high-temperature fire clay is selected from water glass-bonded fire clay, aluminum dihydrogen phosphate-bonded fire clay, or silica sol-bonded fire clay.

59. A method for preparing a composite refractory lining masonry structure according to any one of claims 1-28, comprising the following steps: The nano-insulation board is fixed to the low-temperature side of the calcium hexaaluminate refractory material using a fixative, and then cured.

60. The method according to claim 59, wherein, The fixative is an adhesive.

61. The method according to claim 60, wherein, The adhesive is epoxy resin, ethyl α-cyanoacrylate, methacrylate, methyl methacrylate, water glass bonded fire putty, aluminum dihydrogen phosphate bonded fire putty, or silica sol bonded fire putty.

62. The method according to claim 60, wherein, The adhesive is epoxy resin, ethyl α-cyanoacrylate, methacrylate, or methyl methacrylate.

63. A method for preparing a composite refractory lining masonry structure using the composite refractory lining masonry structure forming material according to any one of claims 29-58, comprising the following steps: The nano-insulation board was fixed to the low-temperature side of the calcium hexaaluminate refractory material using high-temperature fire mud.

64. The method according to claim 63, wherein, The high-temperature fire clay is selected from water glass-bonded fire clay, aluminum dihydrogen phosphate-bonded fire clay, or silica sol-bonded fire clay.

65. A refractory material for a permanent lining and heat-insulating lining of a steel ladle for molten steel smelting, comprising a composite refractory lining masonry structure as described in any one of claims 1-28 or a composite refractory lining masonry structure forming material as described in any one of claims 29-58.

66. A refractory material for the working lining and heat insulation lining of an aluminum molten metal smelting vessel, comprising a composite refractory lining masonry structure as described in any one of claims 1-28 or a composite refractory lining masonry structure forming material as described in any one of claims 29-58.

67. A refractory lining for a kiln, comprising a composite refractory lining masonry structure as described in any one of claims 1-28 or a composite refractory lining masonry structure forming material as described in any one of claims 29-58.

68. The refractory lining according to claim 67, wherein, The kiln is a rotary kiln.

Images