Refractory lining of ladle cover combined structure and preparation method

Abstract

The present invention discloses a refractory lining for a ladle cover combined structure, which includes a housing side plate and a housing panel lined at the bottom of the housing side plate. Process holes penetrating through the inner and outer surfaces are provided on the surface of the housing panel, and a process hole fence is arranged around the process holes; a circle of heavy refractory castings is arranged at intervals on the edge of the inner surface of the housing panel, and a circle of heavy refractory castings is also arranged at intervals on the inner surface of the housing panel and around the process hole fence; the parts of the inner surface of the housing panel not cast with heavy refractory castings are all cast with light refractory castings. By adopting the combined structure design of heavy refractory castings and light refractory castings, the anti-mechanical impact ability of the ladle cover refractory lining is improved through the high strength of the heavy refractory castings; by arranging the V-shaped and double-V-shaped metal anchors of the light refractory castings at staggered intervals, the anchoring force of the anchors on the light refractory castings is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of refractory materials, and particularly relates to a refractory lining for a ladle cover combined structure and a preparation method thereof. Background Art

[0002] The ladle is one of the important metallurgical equipment in steelmaking production, and is mainly used as a container for molten steel storage, transportation, secondary refining, and continuous casting. After tapping from the converter, the ladle transports the molten steel to the refining workshop and the continuous casting workshop. After pouring, the ladle is tilted with the remaining slag and waits under atmospheric conditions for the empty ladle, and then goes to the converter for tapping, completing a cycle of the ladle, and is continuously recycled. It experiences minor repairs, medium repairs, and major repairs during the ladle's single service cycle; thus, during the cyclic turnover process of the ladle, the ladle undergoes processes such as receiving molten steel, transportation, process operations, and returning the empty ladle, and heat is dissipated through the surface of the ladle wall lining of the empty ladle, forming heat storage and heat release losses of the lining. Through heat transfer of the molten steel and heat absorption and storage of the lining during the process operations, and heat dissipation from the ladle wall and the surface of the molten steel, a temperature drop at the steel-casting interface is formed. Depending on the different rhythms of molten steel transfer, operation, and empty ladle return control, the temperature drop at the steel-casting interface is also different. Usually, the temperature drop of the molten steel is ≥100°C, and in some cases, it can reach more than 200°C. Therefore, the large temperature drop at the steel-casting interface and high heat loss restrict the technical progress of molten steel smelting cost and low-carbon metallurgy. For this reason, scholars at home and abroad have carried out a large number of research and promotion applications on ladle heat preservation technology. Especially for the heat dissipation loss of the molten steel surface, due to the high temperature of the molten steel surface and large heat dissipation heat flux density, it has become a hot issue that has been first concerned by scholars and enterprises at home and abroad. Different types of ladle heat preservation covering agents have been developed to insulate the molten steel surface, and by adding the heat preservation covering agent to the molten steel surface after tapping, good results have been achieved in reducing the temperature drop during molten steel transfer. However, problems such as pollution of the molten steel by the covering agent, dust pollution during addition, and the cumbersome manual addition have restricted the continuous promotion and application of this technology. Especially with the continuous improvement of the quality requirements for steel grades after use and the continuous implementation of strict environmental protection control systems, the ladle heat preservation covering agent technology has been forced to be phased out. For this reason, the technology of covering the ladle throughout the process has emerged and has become a new energy-saving and consumption-reducing method for reducing the temperature drop during molten steel transfer. By covering the ladle for heat preservation, the temperature drop during molten steel transfer and the tapping temperature are reduced, avoiding problems such as high tapping temperature, repeated heating of the ladle when returning to the furnace, and freezing of the molten steel, achieving the purpose of energy saving, consumption reduction, and improving the quality of molten steel.

[0003] According to relevant reports, the ladle cover is composed of a steel structure and a refractory lining. Among them, the steel structure includes metal components such as the ladle cover frame body, the shell panel, the shell ring plate, and the stiffening rib plate. The refractory lining is formed by filling the inner cavity composed of the shell panel and the shell ring plate with refractory castable. Through the anchoring of the Y-shaped anchor bolts welded on the shell panel, an integral ladle cover composed of a steel structure and a refractory lining is formed. By thermally radiating and isolating and thermally insulating the refractory lining on the heating surface of the ladle cover, the service temperature of the steel structure is reduced, the strength and stiffness of the steel structure during service are improved, the high-temperature deformation and oxidation damage of the steel structure are prevented, and the purpose of extending the service life of the ladle cover and improving the heat preservation performance is achieved. Therefore, the refractory lining of the ladle cover is the key to ensuring the comprehensive service performance of the ladle cover. However, due to the frequent lid opening and closing operations during the service of the ladle cover, the service temperature of the refractory lining fluctuates violently, resulting in alternating thermal stress and thermal shock spalling; due to the mechanical impact during the lid opening and closing process, the mechanical stress spalling of the refractory lining occurs; due to the splashing and slag surging caused by the metallurgical reaction during the operation of covering the ladle, the refractory lining of the ladle cover adheres to slag and steel along the ladle, which not only intensifies the mechanical stress of the refractory lining during lid opening and closing, but also promotes the slag erosion and damage of the refractory lining. Due to the harsh service conditions of the refractory lining of the ladle cover, the refractory lining is severely damaged and the heat insulation and protection function is severely reduced, resulting in high-temperature deformation and oxidation ablation of the steel structure, which not only shortens the service life of the ladle cover, but also severely restricts the heat insulation and heat preservation effect of the ladle cover. Based on the requirements for the heat insulation and protection functions of the refractory lining of the ladle cover, the refractory castables currently used for the refractory lining of the ladle cover are mainly divided into two categories. One is the ordinary high-aluminum castable, which has good mechanical strength, thermal shock resistance, and erosion resistance, a high service life, and a long-term protection function, but has a large bulk density, a high thermal conductivity, a large weight of the ladle cover, a poor heat preservation performance, and a heavy load during lid opening and closing; the other is the lightweight heat-insulating refractory castable, which has a small thermal conductivity and a low bulk density, but has a low mechanical strength, poor resistance to mechanical damage, stress damage, and erosion resistance, a light weight of the ladle cover, a good heat preservation performance, a small load during lid opening and closing, and a service life shorter than that of the high-aluminum castable. Thus, how to improve the dual functions of heat insulation and protection of the refractory lining of the ladle cover has become the key to improving the comprehensive service performance of the ladle cover and extending its service life.

[0004] Based on the actual production requirements for the heat insulation and long service life of the ladle cover, scholars at home and abroad have carried out a large number of studies from two aspects: the structure of the ladle cover and the high-performance refractory castables used for the refractory lining. Such as:

[0005] In terms of ladle cover structure, the Chinese patent "Zhang Meijie, Wang Yao, Gu Huazhi, etc., a composite structure ladle cover capable of reversely heating the ladle lining, authorization announcement number: CN110355355B" discloses a composite structure ladle cover, which is composed of a fixing plate, a ceramic-aluminum-silicon alloy composite heat storage ball, a ladle cover plate, a ladle cover annular side plate, a ladle cover bottom box, connecting rods and bolts; the ladle cover bottom box is filled with ceramic-aluminum-silicon alloy composite heat storage balls, and the ladle cover annular side plate is mounted close to the outer wall of the ladle cover bottom box; the ladle The bottom box and the annular side plate of the ladle cover are of the same height, the top ends of the bottom box and the annular side plate of the ladle cover are covered with a ladle cover plate, and the upper plane of the ladle cover plate is provided with a fixing plate; 2 (2-4) through holes I are symmetrically provided near the edge of the fixing plate, and 2 (2-4) connecting rods are inserted into the blind holes of the annular side plate of the ladle cover through the through holes II of the bottom box of the ladle cover, and the gaps between the connecting rods (7) and the hole walls of the through holes II, the blind hole walls and the bottom of the blind holes are filled with fiber cotton; each connecting hole is fixedly connected to the corresponding through hole I of the fixing plate by bolts. The material of the bottom box of the ladle cover is high-aluminum refractory material; wherein: Al2O3 content>55wt%, compressive strength>50MPa, flexural strength>10MPa, high temperature flexural strength>10MPa; the material of the ladle cover plate and the annular side plate of the ladle cover is nano-microporous insulation board. Compared with the prior art, the material of the bottom box of the ladle cover is high-aluminum refractory material, which has high strength. It is not easy to be damaged during the frequent installation and disassembly of the ladle cover, ensuring the integrity and long life of the ladle cover; the ladle cover plate and the ladle cover annular side plate made of nano-microporous insulation board make the ladle cover have large thermal resistance and prevent the ladle cover from dissipating heat into the space; when the molten steel is stored in the ladle, the ceramic-aluminum-silicon alloy composite heat storage ball in the ladle cover and the nano-microporous insulation board can prevent heat from being lost to the environment. When the molten steel in the ladle is poured, the heat accumulated by the ceramic-aluminum-silicon alloy composite heat storage ball in the ladle cover reversely heats the ladle lining, effectively using the waste heat to prevent the ladle lining from dropping too low in temperature, which can not only increase the service life of the refractory material of the ladle lining, but also save energy consumption. At the same time, the size of the ceramic-aluminum-silicon alloy composite heat storage balls in the ladle cover, the number ratio of different ball diameters, and the silicon content of the aluminum-silicon alloy in the ceramic-aluminum-silicon alloy composite heat storage balls can be adjusted according to the situation, so that the thermal conductivity and heat storage density of the ladle cover can be adjusted. Therefore, the ladle cover of the invention has the characteristics of high strength, adjustable thermal conductivity and heat storage density, good thermal shock resistance, low heat dissipation, small heat loss during the thermal turnover of the ladle, ability to prevent the ladle lining from cracking, and long service life. However, there are shortcomings such as complex structure, difficult preparation, and high cost, which have prevented it from being actually produced and applied.

[0006] Chinese Patent "Zhang Hufei, Ladle Cover Device with Open Structure, Application Publication Number: CN104607626A". Aiming at the problems existing in the conventional prototype ladle cover, such as the ladle slag scouring the ladle cover shell and refractory materials during the ladle slag pouring process, resulting in ladle cover deformation, refractory material shedding, short service life, and even some ladle slag not being able to be smoothly poured into the slag pot, it discloses a ladle cover for the whole process of covering the ladle, mainly including: hook, lifting lug, steel structure frame, ladle cover shell, refractory material, open structure, ladle hinge seat, sand filling port; there is a lifting lug on the ladle cover, the tail end of the hook is fixed on the lifting lug through a pin shaft, and the hooked part at the other end is rotationally connected to the hinge seat through a pin shaft. There is a steel structure frame with a cross structure above the ladle cover, and the ladle cover shell is below it; there is a sand filling port above the ladle cover; there is a refractory material at the bottom layer of the ladle cover, and an open structure is provided at the front end of the refractory material, that is, at the end in the direction of the hook; during the normal operation stage, the ladle cover and the ladle rim coincide; when pouring slag, the ladle and the ladle cover rotate as a whole around the ladle trunnion; when the ladle rotates 90 degrees, the ladle cover starts to rotate with the pin shaft on the hinge seat as the rotation center, and the angle with the ladle starts to increase continuously from 0 degrees, and the liquid ladle slag flows out from the bottom of the ladle, thus realizing slag pouring with the ladle covered, which is also the common structure of the ladle cover at present. Although this patented technology solves the problem of ladle cover damage caused by slag pouring with the ladle covered, it fails to solve the problems of thermal shock damage and mechanical stress damage caused by frequent covering and uncovering of the ladle cover.

[0007] Chinese patent "Wang Chong, Chen Aijun, Zhang Qidong, etc., A ladle cover and its manufacturing method, Application Publication No.: CN110842183A". Aiming at the problem that the refractory lining near the slag-turning side of the ladle cover is easily eroded and damaged when contacting with molten steel slag, it discloses a refractory lining structure of the ladle cover with a heavy castable lining on the slag-turning side and a light castable lining on the rest. A partition board is used to separate the heavy castable lining from the light castable lining, and the width of the heavy castable lining on the slag-turning side is 0.1 - 0.4 times the width of the ladle cover. Among them, both the heavy castable and the light castable use steel fibers, and the addition amount of steel fibers is 0.5% - 10% of the weight of the castable. First, weld more than 2 anchor bolts at intervals and evenly inside the ladle cover steel structure. The anchor bolts are in a V shape. Then install a partition board in the ladle cover steel structure, and use heavy castable to fill and pour on the slag-turning side. After pouring, wait for a period of time (not exceeding 5 minutes), and remove the partition board before the castable starts to set. Because the fluidity of the castable decreases during the waiting time, it will not flow to the casting area outside the designated area; then use light castable to carry out casting and forming on the non-slag-turning side, so that the junction of the heavy castable and the light castable blends, mixes and solidifies into one body, and there will be no casting construction joints. The entire refractory material solidifies into a whole, with high strength, not easy to break or fall off. Because the fluidity of the heavy castable is generally better than that of the light castable, removing the partition board before the heavy castable starts to set will cause the casting body to collapse and flow. Due to the significant difference in the bulk density between the heavy castable and the light castable, when the light castable is cast for the second time, the light castable on the floating surface layer at the joint and the heavy castable on the sinking bottom layer will form a layered structure, further deteriorating the structural stress and thermal stress distribution of the casting body, resulting in an increase in local thermo-mechanical stress damage, which not only makes it difficult to extend the service life of the ladle cover, but also seriously affects the heat insulation effect of the ladle cover.

[0008] Chinese Patent "Yang Qingjun, Liu Ping, Luo Dingguang, etc., A Durable Steel Ladle Cover and Its Preparation Method, Authorization Announcement Number: CN113523257B". Aiming at problems such as the blockage of the nozzle seat brick and the gas-permeable seat brick caused by the easy spalling of the refractories around the bottom-blowing gas-permeable brick cleaning hole and the continuous casting temperature-measuring hole reserved in the steel ladle cover, and the easy damage in the slag-pouring scouring area, it discloses a drum-shaped steel ladle cover including a cover body and refractories. The drum-shaped structure is surrounded by circular cover side walls, a first straight cover side wall, and a second straight cover side wall located on both sides of the cover body. Only one working hole is provided on the cover body as the gas-permeable brick cleaning hole and the continuous casting temperature-measuring hole; a first reinforcement part is arranged around the working hole, including a first reinforcement edge close to the second straight cover side wall; a second reinforcement part is arranged parallel to the second straight cover side wall; a first dense refractory area is located between the second straight cover side wall and the first reinforcement edge; a second dense refractory area is located inside the first reinforcement part and outside the working hole; the first dense refractory area and the second dense refractory area include heavy castable, and the third refractory area includes light castable; studs are arranged in the first dense refractory area, the second dense refractory area, and the third refractory area. The stud is "Y"-shaped, including an upper opening, a lower part, and an upper part. The angle of the upper opening is 40° - 50°, and the ratio of the length of the upper part to the length of the lower part is 1.4 - 1.6. The Al2O3 content of the light castable is ≥ 50wt%, and the bulk density is ≥ 1.80g / cm 3 , and the heavy castable uses a castable with an Al2O3 content ≥ 70wt%, and the bulk density increases by 0.20g / cm 3 - 0.50g / cm 3 . Through the dense refractory areas of the first reinforcement part and the second reinforcement part, the anti-damage ability of the working hole and the slag-turning impact area is improved. Through the third lightweight refractory area, the stability effect is improved. Although for the damage form of the steel ladle cover proposed in this patent, the structural design of the first dense refractory area, the second dense refractory area, and the third refractory area of the steel ladle cover can achieve the suppression of the damage process in the vulnerable areas, under the condition of no partition between the first dense refractory area and the second dense refractory area, how to realize the casting of the above three areas and form a complete cast body with area division still needs to be studied. How to avoid the upper and lower stratification problems caused by the difference in the casting rheology between the heavy and light castables still needs further research; in addition, in addition to the damage forms involved in this patent during the service process of the steel ladle cover, there are also stirring thermal stress spalling, mechanical impact spalling, high-temperature stress deformation, etc.

[0009] In terms of the refractory lining of the ladle cover, the Chinese patent "Cheng Wenyong, Fang Binxiang, Liu Guangping, etc., A lightweight mullite castable for ladle cover and its preparation method, Application Publication No.: CN106904981A" discloses a lightweight mullite castable composed of aggregate and matrix and its preparation method. By weight, it includes: aggregate: 30 - 70 parts of lightweight mullite balls; matrix: 0 - 15 parts of tabular corundum, 0 - 15 parts of mullite particles, 5 - 15 parts of alumina micropowder, 5 - 15 parts of mullite micropowder, 0 - 8 parts of silica fume, 5 - 15 parts of binder, and 0.1 - 0.4 parts of water reducer. Among them, the lightweight mullite balls are spherical particles with equal particle size, the particle size range is 8 - 0.1 mm, the bulk density of the balls is 1.8 - 1.2 g / cm 3 , the apparent porosity is 25 - 70%, and the water absorption rate is less than 25%; the particle size of the mullite particles is 5 - 0 mm; the particle size D50 of the mullite micropowder ≤ 5um. The binder is at least one of calcium aluminate cement, ρ - Al2O3, and silica sol. The bulk density of the lightweight mullite castable for ladle cover is 1.8 - 2.4 g / cm 3 , the apparent porosity is 30 - 50%, the thermal conductivity is 0.250 - 0.675 W / (m·K) at 500°C, the compressive strength after being treated at 110°C for 24 h is 20 - 50 MPa, and the flexural strength is 3 - 7 MPa; the compressive strength after being treated at 1550°C for 3 h is 35 - 60 MPa, the flexural strength is 8 - 14 MPa, and the residual linear change rate is -0.5 - 0.8%. By introducing lightweight mullite balls with high strength and low water absorption rate, the water addition amount of the castable is significantly reduced, overcoming the deficiencies of high water absorption rate of conventional lightweight mullite particles, large water addition amount during construction, and poor fluidity. It not only improves the construction performance of the castable, but also enhances the thermal shock resistance, mechanical strength, high - temperature volume stability, and service temperature of the castable, up to 1550°C at most.

[0010] The Chinese patent "Zou Long, Tang Shuping, Kong Yongjiang, etc., A ladle cover castable and its preparation method, Application Publication No.: CN113307613A" aims to balance properties such as high strength, low thermal conductivity, and high thermal shock resistance. It discloses a ladle cover castable composed of a main material and an admixture. Among them, the components and their mass percentages in the main material include: sintered mullite 10 - 55%, mullite hollow spheres 10 - 55%, cyanite 1 - 5%, fused magnesia powder 6 - 15%, sintered spinel particles 1 - 10%, ultrafine spinel powder 1 - 5%, activated alumina powder 3 - 10%, calcium aluminate cement 3 - 7%, silica fume 0 - 2%; the admixture includes a water reducer and explosion-proof organic fibers. The dosage of the water reducer is 0.5 - 1% of the main material dosage; the dosage of the explosion-proof organic fibers is 0.01 - 0.15% of the main material dosage. The mass percentages of various particle sizes in the sintered mullite are: 10 - 30% for 8 < particle size ≤ 15mm, 5 - 30% for 5 < particle size ≤ 8mm, 5 - 30% for 3 < particle size ≤ 5mm, 10 - 20% for 1 < particle size ≤ 3mm, 5 - 20% for 0.1 < particle size ≤ 1mm, and 5 - 30% for particle size ≤ 0.01mm. The mass percentages of various particle sizes in the mullite hollow spheres are: 10 - 40% for 3 < particle size ≤ 5mm, 10 - 40% for 2 < particle size ≤ 3mm, 10 - 40% for 1 < particle size ≤ 2mm, and 10 - 30% for 0.2 < particle size ≤ 1mm. By adding a certain amount of mullite hollow spheres, the bulk density and structural thermal stress of the castable are reduced, and the thermal shock resistance and heat insulation performance are improved; the fine fused magnesia powder introduced can react with alumina in-situ to form magnesium aluminate spinel, forming microcracks inside the castable, improving the thermal shock resistance of the castable, and controlling the total content of spinel in the castable by controlling the content of the added sintered spinel particles and ultrafine spinel powder. At the same time, part of the magnesia introduced can be solid-solved with mullite, synchronously improving the mechanical properties of the obtained castable (ensuring the anti-physical impact during the process of covering and uncovering the ladle cover, etc.); by introducing the FDN water reducer, the overall strength of the material is improved, and by introducing the explosion-proof organic fibers, the water discharge is facilitated and local explosion is prevented.

[0011] The Chinese patent "Wu Jingqiang, Luo Wei, Jin Yaodong, etc., a castable for a ladle cover and its application, authorization announcement number: CN103979949B" discloses a castable for a ladle cover composed of a main material, sodium tripolyphosphate and heat-resistant stainless steel fiber, wherein the main material comprises the following components: 45-60% alumina hollow spheres (0.2-5mm), 10-30% mullite (less than 180 mesh), 2-15% Guangxi mud (less than 180 mesh), 8-28% andalusite (≤0.5mm), 5-25% silicon carbide (≤1mm), 3-20% aluminum titanate (≤1mm), 3-15% pure calcium aluminate cement (less than 180 mesh), 1-8% silicon powder and 2-10% alpha alumina powder, sodium tripolyphosphate accounts for 0.1-0.5% of the total weight of the main material, and the heat-resistant stainless steel fiber accounts for 0.5-1.5% of the total weight of the main material. When the ladle cover is on the ladle, the heat radiated from the molten steel and slag is used to first sinter Guangxi mud, silicon micropowder, and pure calcium aluminate cement as a composite binder into a whole at high temperature. Then, the secondary mullite of garnet, the high thermal conductivity of silicon carbide, and the small expansion coefficient of aluminum titanate are used to reduce the thermal stress of the material under high temperature, reduce the spalling of the castable, and improve the thermal shock stability. The service life of the ladle cover is increased from the original 350 furnaces to 780 furnaces, and the temperature drop of the molten steel in the ladle is reduced from 0.8℃ / min to 0.3℃ / min.

[0012] The Chinese patent "Chen Hongliang, Chen Xuefei, Jiang Zhizhong, etc., Raw material formula of ladle insulation cover and preparation method of ladle insulation cover, authorization announcement number: CN101602611B" discloses a castable raw material formula composed of 40-60% brown corundum hollow balls, 10-20% brown corundum, 15-30% mullite, 1-10% alumina micropowder, 1-10% silicon micropowder, 1-5% ρ-Al2O3 powder, and 0.1-0.2% dispersant. Through the use of brown corundum hollow balls, the prepared ladle insulation cover has a small bulk density, low thermal conductivity, good thermal shock stability, corrosion resistance, good construction performance, reduced raw material costs, and increased service life. The service life is more than twice that of clay castables and high-aluminum castables, and the molten steel smelting temperature is reduced by 5-10°C.

[0013] In summary, domestic research on ladle covers mainly focuses on the improvement of the steel structure of ladle covers and the castables used for refractory linings. There is relatively little research on the comprehensive performance of ladle covers. In particular, for ladle covers composed of steel structures and refractory castable linings, there are even fewer reports on how to improve the integrity of the ladle cover composite body and give full play to the synergistic effect between components. As a result, in actual production, damage such as high-temperature deformation, oxidation and ablation of the steel structure of the ladle cover, and thermal-mechanical stress spalling and slag erosion of the refractory lining is still serious. The service life and heat insulation performance of ladle covers vary significantly, which not only affects the consumption cost of ladle covers but also the heat insulation effect of the molten steel in actual production. Therefore, further research needs to be carried out on the integrity of the composite structure of the steel structure and refractory lining of the ladle cover to achieve the comprehensive goals of extending the service life of the ladle cover, improving the heat insulation performance of the ladle cover, and reducing the temperature drop of molten steel during transfer and storage. Summary of the Invention

[0014] To overcome the deficiencies of the prior art, the purpose of the present invention is to provide a refractory lining for a ladle cover combination structure and a preparation method thereof, which have the characteristics of high integrity of the composite structure of the steel structure and refractory lining of the ladle cover, strong anti-damage ability, excellent heat insulation and heat preservation performance, etc., and achieve the purposes of extending the service life of the ladle cover, improving the heat insulation performance of the ladle cover, and reducing the temperature drop of molten steel during transfer and storage.

[0015] To achieve the above purpose, the present invention provides a refractory lining for a ladle cover combination structure, which includes a housing side plate and a housing panel lined at the bottom of the housing side plate. Process holes penetrating the inner and outer surfaces are provided on the surface of the housing panel, and a process hole fence is arranged around the process holes; a circle of heavy refractory material castings is arranged at intervals on the edge of the inner surface of the housing panel, and a circle of heavy refractory material castings is arranged at intervals on the inner surface of the housing panel and around the process hole fence. The remaining part of the inner surface of the housing panel is distributed with heavy refractory material castings at intervals along the radial and circumferential directions of the housing panel with the center of the inner surface of the housing panel as the reference point, and the center axis distance L between every two adjacent heavy refractory material castings is 3 to 5 times the diameter D of the heavy refractory material castings; the parts of the inner surface of the housing panel that are not cast with heavy refractory material castings are all cast with light refractory material castings.

[0016] Furthermore, the heavy refractory material casting is composed of a heavy refractory castable wrapping a special-shaped metal anchor, and the height hj of the heavy refractory material casting is the same as the height h of the housing side plate; the light refractory casting body is composed of a light refractory castable wrapping a V-shaped metal anchor and a double-V-shaped metal anchor, and the height of the light refractory casting body is also hj.

[0017] Furthermore, the special-shaped metal anchor includes a threaded steel bar and a number of steel bar discs evenly distributed on the outer surface of the threaded steel bar and welded obliquely, and the vertical height from the top of the steel bar disc at the top of the special-shaped metal anchor to the bottom of the threaded steel bar is 2 / 3 to 3 / 4 of the height of the heavy refractory material casting.

[0018] Furthermore, a circle of special-shaped metal anchor fittings are arranged at intervals along the edge of the inner surface of the shell panel. The threaded steel bars of the special-shaped metal anchor fittings are perpendicularly welded and fixed to the shell panel, and 1 to 4 steel wire strands on the special-shaped metal anchor fittings are welded and fixed to the shell shroud; a circle of special-shaped metal anchor fittings are arranged at intervals on the inner surface of the shell panel and around the process hole shroud. The threaded steel bars of the special-shaped metal anchor fittings are perpendicularly welded and fixed to the shell panel, and 1 to 4 steel wire strands on the special-shaped metal anchor fittings are welded and fixed to the process hole shroud; on the remaining part of the inner surface of the shell panel, special-shaped metal anchor fittings are distributed at intervals along the radial and circumferential directions of the shell panel with the center of the inner surface of the shell panel as the base point. The special-shaped metal anchor fittings are perpendicularly welded and fixed to the shell panel, and the distance between every two adjacent special-shaped metal anchor fittings is the same as the distance L between the heavy refractory castings.

[0019] Furthermore, the V-shaped metal anchor fittings are prepared by bending steel wire strands. The V-shaped angle β is 30° to 60°. The double-V-shaped metal anchor fittings are formed by welding two V-shaped anchor fittings, and the angle γ between the two V-shaped surfaces is 30° to 60°. The diameter of the steel wire strands is 4 to 6 mm.

[0020] Furthermore, V-shaped metal anchor fittings and double-V-shaped metal anchor fittings are distributed alternately at intervals on the inner surface of the shell panel at the positions where the special-shaped metal anchor fittings are not welded. V-shaped metal anchor fittings and double-V-shaped metal anchor fittings are distributed alternately at intervals on the inner surface of the shell shroud at the positions between every two adjacent special-shaped metal anchor fittings. The sharp corners of the V-shaped metal anchor fittings and the double-V-shaped metal anchor fittings are perpendicularly welded and fixed to the inner surface of the shell panel; the heights hv of the V-shaped metal anchor fittings and the double-V-shaped metal anchor fittings welded and fixed to the shell panel are all 2 / 3 to 3 / 4 of the height hj of the light refractory casting, and the alternating interval distance between the V-shaped metal anchor fittings and the double-V-shaped metal anchor fittings is 100 to 200 mm; the heights of the V-shaped metal anchor fittings and the double-V-shaped metal anchor fittings welded and fixed to the shell shroud are all 1 / 2 to 2 / 3 of the heights of the V-shaped metal anchor fittings and the double-V-shaped metal anchor fittings welded and fixed to the shell panel, and the alternating interval distance between the V-shaped metal anchor fittings and the double-V-shaped metal anchor fittings is 100 to 200 mm.

[0021] Further, the heavy refractory castable of the heavy refractory cast body includes a main material and an admixture. The raw materials of the main material include, by weight percentage: 40 - 50% of sintered mullite aggregate, 20 - 30% of fused mullite aggregate, 7 - 10% of tabular corundum powder, 5 - 7% of kyanite powder, 5 - 8% of α-Al2O3 micropowder, 4 - 6% of active SiO2 micropowder, and 4 - 6% of calcium aluminate cement; the admixture includes heat-resistant stainless steel fibers, sodium hexametaphosphate, organic explosion-proof fibers, aluminum lactate, and polyaluminum chloride, and the heat-resistant stainless steel fibers account for 1.5 - 2.5% of the weight of the main material, sodium hexametaphosphate accounts for 0.1 - 0.2% of the weight of the main material, organic explosion-proof fibers account for 0.05 - 0.15% of the weight of the main material, aluminum lactate accounts for 0.1 - 0.3% of the weight of the main material, and polyaluminum chloride accounts for 0 - 0.25% of the weight of the main material.

[0022] Further, the included angle α between the wire rod and the axis of the deformed steel bar is 22.5° - 45°, the diameter of the deformed steel bar is 8 - 15 mm, and the diameter of the wire rod is 4 - 6 mm.

[0023] Further, it further includes a reinforcing rib plate welded to the outer surface of the shell panel.

[0024] There is also provided a preparation method for the refractory lining of the ladle cover combination structure as described above, including the following steps:

[0025] 1) Use deformed steel bars and wire rods that meet the requirements of the outer diameter size, and prepare the required number of special-shaped metal anchor parts, V-shaped metal anchor parts, and double-V-shaped metal anchor parts according to the height requirements of the special-shaped metal anchor parts, V-shaped metal anchor parts, and double-V-shaped metal anchor parts.

[0026] 2) Along the edge of the inner surface of the shell panel and around the working hole apron, weld and fix the deformed steel bars perpendicular to the shell panel according to the interval distance and welding and fixing requirements of the special-shaped metal anchor parts, and weld and fix 1 - 4 wire rods to the shell apron or the working hole apron.

[0027] Weld and fix the remaining special-shaped metal anchor parts to the shell panel according to the requirements of radial and circumferential interval distribution with the center of the inner surface of the shell panel as the base point.

[0028] Weld and fix the V-shaped metal anchor parts and double-V-shaped metal anchor parts to the shell panel and the shell apron of the ladle cover steel structure according to the distribution and staggered interval distance requirements of the V-shaped metal anchor parts and double-V-shaped metal anchor parts.

[0029] 3) According to the requirements of the diameter D of the heavy refractory cast body, use serrated corrugated thin steel plates with a thickness δ of 0.25 - 0.50 mm, a wave height m of 5 - 10 mm, and a wave width n of 10 - 15 mm. Prepare axially serrated corrugated sidewall cylindrical partition plates with closed or open sides according to the quantity requirements of the heavy refractory cast body. The height hg of the partition plate is 100 - 200 mm higher than the height h of the shell enclosure plate. The top of the partition plate is reinforced by welding a steel bar coil ring, and two pull rings are symmetrically welded and fixed on the steel bar coil ring.

[0030] 4) According to the formulations of the heavy refractory castable and the light refractory castable, weigh and proportion the raw materials. Adopt the refractory castable stirring and mixing process to prepare the heavy refractory castable and the light refractory castable with the required weights, and bag them for standby.

[0031] 5) Sleeve and buckle the axially serrated corrugated sidewall cylindrical partition plate with an open side to the special-shaped metal anchor fittings welded and fixed on the inner side of the shell enclosure plate and the outer side of the working hole enclosure plate. The open side of the sidewall is closely attached to the shell enclosure plate and the working hole enclosure plate, and 1 - 4 steel bar coils welded and fixed to the shell enclosure plate or the working hole enclosure plate pass through the open side of the sidewall. Sleeve and buckle the axially serrated corrugated sidewall cylindrical partition plate with a closed side to other special-shaped metal anchor fittings. All axially serrated corrugated sidewall cylindrical partition plates with open or closed sides are fixed by wire bundling through the pull rings with the casting construction steel pipe grid platform.

[0032] 6) According to the conventional refractory castable water - adding stirring and mixing process, use two mixers to separately add water to stir and mix the prepared heavy refractory castable and light refractory castable evenly to obtain the heavy refractory castable mixture and the light refractory castable mixture.

[0033] 7) Pour the heavy refractory castable mixture into the axially serrated corrugated sidewall cylindrical partition plate, and at the same time add the light refractory castable mixture outside the partition plate to the same height as the internal heavy refractory castable mixture. Use a vibrating rod to vibrate and form the heavy and light refractory castables, and according to the requirement that the heights of the inner and outer cylinders of the cylindrical partition plate increase simultaneously, supplement and vibrate and form the heavy and light refractory castable mixtures until the heights of the heavy refractory cast body and the light refractory cast body are the same as the height of the shell enclosure plate of the ladle cover steel structure. Through the pull rings of the cylindrical partition plate, timely remove the cylindrical partition plate, turn on the vibrating rod to vibrate on the surface layer of the heavy refractory castable area, and supplement the heavy refractory castable mixture to the height of the shell enclosure plate.

[0034] 8) After the ladle cover combined refractory lining is cast and formed, first cure it naturally for 48 - 72 h, and then conduct a baking treatment for 48 - 72 h. The maximum baking temperature is 800 - 1000 °C.

[0035] Compared with the prior art, the advantages of the present invention are as follows:

[0036] For the refractory lining of the ladle cover combined structure of the present invention, a combined structure design of a heavy refractory cast body and a light refractory cast body is adopted. Through the high strength of the heavy refractory cast body, the anti-mechanical impact ability of the refractory lining of the ladle cover is improved; through the structural design of the heavy refractory cast body in which the heavy refractory castable wraps the special-shaped metal anchor, the strength, stiffness and anti-mechanical damage ability of the cast body are further improved; by arranging the heavy refractory cast body closely on the inner side of the ring plate of the steel structure shell of the ladle cover and at intervals on the outer side of the apron of the working hole, the high-temperature protection effect of the cast body on the steel structure shell apron and the working hole apron and its anchoring effect on the refractory lining in this area are strengthened, the anti-destruction ability of the refractory lining in the vulnerable area is improved, and the direct contact between the steel structure shell apron and the working hole apron and the high-temperature oxidizing gas, molten slag and molten steel is avoided, and high-temperature oxidation, high-temperature corrosion and deformation are inhibited; by arranging the heavy refractory cast body at intervals along the radial and circumferential directions of the ladle cover with the center of the inner surface of the panel of the steel structure shell of the ladle cover as the base point, the riveting effect on the light refractory cast body is enhanced, and the anti-mechanical impact and spalling ability is improved; by arranging the V-shaped and double-V-shaped metal anchor of the light refractory cast body at staggered intervals, the anchoring force of the anchor on the light refractory cast body is improved, the anchoring action area of the anchor is expanded, and the anchor combination state, structural integrity and anti-destruction ability between the light refractory cast body and the ladle shell are improved; through the structural design of the heavy refractory cast body with an initial shape of a cylindrical body with an axially serrated corrugated side wall surface, a dog-tooth type infiltration and inlay combination is realized between the heavy refractory cast body and the light refractory cast body, the bonding strength between the heavy refractory cast body and the light refractory cast body and the integrity of the combined structure refractory lining are improved, and the anti-mechanical stress, thermal stress damage and erosion and damage ability of molten slag and molten steel are further enhanced.

[0037] The heavy refractory castable of the present invention effectively utilizes the characteristic of small expansion coefficient of mullite by adopting sintered mullite aggregate to improve thermal shock stability. By utilizing the thermal shock crack arrest and stress absorption characteristics of the microporous structure of the sintered material, the thermal shock stability is further improved. By using tabular corundum powder, the high-temperature mechanical properties and slag and steel erosion resistance of the heavy refractory castable are improved. By introducing kyanite, the high-temperature sintering shrinkage of the castable is inhibited, and the volume and structural stability under the service conditions of the cast body are improved. By the composite addition of α-Al2O3 micropowder, active SiO2 micropowder and calcium aluminate cement and their sol-gel and hydration composite bonding mechanisms, the mechanical properties of the cast body at normal temperature, medium temperature and high temperature are improved, and the ability to resist thermal mechanical stress damage during the whole service process of the cast body is strengthened. By adding heat-resistant stainless steel fibers, the fracture toughness of the cast body is improved, and the impact damage of thermal mechanical stress is inhibited. By the compound addition of organic explosion-proof fibers and aluminum lactate, the anti-explosion stability of the cast body and the adaptability to the baking process are improved, and the adverse effects of a single explosion-proof mechanism on the cast body are compensated. By adding sodium hexametaphosphate, the water addition amount of the castable is reduced, and the fluidity of the castable is improved. By adding polyaluminum chloride, the initial setting time of the castable is adjusted, the curing time of the cast body is shortened, and the turnover efficiency of the ladle cover is improved.

[0038] The light refractory castable of the present invention adopts the light high-strength refractory castable for ladle covers disclosed in "Light High-Strength Refractory Castable for Ladle Covers, Its Preparation Method and Application, Application Publication No.: CN115159996A", which not only enhances the heat insulation performance but also improves the ability of the cast body to resist thermal mechanical stress damage.

[0039] The preparation method of the refractory lining of the ladle cover combined structure of the present invention ensures that the outer shape structure and dimensional parameters of the ladle cover meet the actual production requirements through the complete repair of the ladle cover steel structure or the preparation of a new steel structure; through the preparation of special-shaped metal anchors, V-shaped and double-V-shaped metal anchors and their welding and fixing in the ladle cover steel structure shell as required, it ensures the reasonable distribution of various anchors and their firm welding in the steel structure shell; through the processing and preparation of the axially serrated corrugated sidewall cylindrical partition plate and the installation and fixing of the special-shaped metal anchors with sleeve buckles, it ensures the serrated corrugated structure of the sidewall of the heavy refractory cast body, realizing the effective isolation between the heavy refractory castable and the light refractory castable during the casting construction process; through the processing and preparation of the heavy and light refractory castables according to the formula and stirring and mixing process requirements, it ensures the product quality of the castables; through the simultaneous casting of the heavy and light refractory castables, the static pressure of the castables inside and outside the axially serrated corrugated sidewall cylindrical partition plate is balanced, preventing the extrusion deformation and damage of the partition plate, facilitating the removal and reuse of the partition plate, ensuring the structural integrity of the heavy and light refractory material cast bodies, and through the vibration of the surface layer of the heavy refractory castable after the partition plate is removed, promoting the dog-tooth type infiltration and embedding combination between the heavy and light refractory castables, improving the interface bonding strength and the structural integrity and stability of the ladle cover combined refractory lining, and improving the anti-damage ability of the combined refractory lining. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic structural diagram of the refractory lining of the ladle cover combined structure of the present invention;

[0041] Figure 2 is Figure 1 the schematic A-A cross-sectional view of;

[0042] Figure 3 It is a schematic structural diagram of the special-shaped metal anchor;

[0043] Figure 4 It is a schematic structural diagram of the V-shaped metal anchor;

[0044] Figure 5 It is a schematic structural diagram of the double-V-shaped metal anchor;

[0045] Figure 6 It is a schematic structural diagram of the serrated corrugated steel plate;

[0046] Figure 7 It is the front view of the closed axially serrated corrugated sidewall cylindrical partition plate;

[0047] Figure 8 is Figure 7 the top view schematic of;

[0048] Figure 9 It is the front view of the open axially serrated corrugated sidewall cylindrical partition plate;

[0049] Figure 10 is Figure 9 a top view schematic diagram;

[0050] Figure 11 is a distribution schematic diagram of special-shaped metal anchor bolts, cylindrical partition plates, V-shaped and double-V-shaped metal anchor bolts;

[0051] Figure 12 is Figure 11 an enlarged schematic diagram of part C;

[0052] Figure 13 is Figure 12 a B-B sectional view schematic diagram of

[0053] The reference numerals of each component in the figure are as follows:

[0054] heavy refractory cast body 1, light refractory cast body 2, shell enclosure plate 3, shell panel 4, process hole enclosure plate 5, stiffening rib plate 6, special-shaped metal anchor bolt 7, V-shaped metal anchor bolt 8, double-V-shaped metal anchor bolt 9, threaded steel bar 10, partition plate 11, steel wire rod ring 12, pull ring 13, serrated corrugated steel sheet 14, process hole 15, steel wire rod 16. Specific embodiments

[0055] The present invention will be specifically described below in conjunction with the accompanying drawings and specific embodiments.

[0056] As shown in Figure 1 , Figure 2 , Figure 11 The refractory lining of the ladle cover composite structure includes a shell enclosure plate 3, a shell panel 4 lined at the bottom of the shell enclosure plate 3, and a stiffening rib plate 6 welded to the outer surface of the shell panel 4. A process hole 15 penetrating through the inner and outer surfaces is provided on the surface of the shell panel 4, and a process hole enclosure plate 5 is arranged around the process hole 15; a ring of heavy refractory cast bodies 1 is arranged at intervals on the edge of the inner surface of the shell panel 4, and a ring of heavy refractory cast bodies 1 is arranged at intervals on the inner surface of the shell panel 4 and around the process hole enclosure plate 5. At the same time, the remaining parts of the inner surface of the shell panel 4 are distributed with heavy refractory cast bodies 1 at intervals along the radial and circumferential directions of the shell panel 4 with the center of the inner surface of the shell panel 4 as the base point, and the center axis distance L between every two adjacent heavy refractory cast bodies 1 is 3 to 5 times the diameter D of the heavy refractory cast body 1; the parts of the inner surface of the shell panel 4 not cast with heavy refractory cast bodies 1 are all cast with light refractory cast bodies 2.

[0057] Combined with Figure 3 , Figure 4 , Figure 5As shown in the figure, the heavy refractory cast body 1 is composed of a heavy refractory castable wrapping the special-shaped metal anchor 7, and the height hj of the heavy refractory cast body 1 is the same as the height h of the shell enclosing plate 3; the light refractory cast body 2 is composed of a light refractory castable wrapping the V-shaped metal anchor 8 and the double-V-shaped metal anchor 9, and the height of the light refractory cast body 2 is also hj.

[0058] The special-shaped metal anchor 7 includes a threaded steel bar 10 and a number of steel bar strips 16 that are evenly distributed on the outer surface of the threaded steel bar 10 and are inclined and welded. The included angle α between the steel bar strip 16 and the axis of the threaded steel bar 10 is 22.5° to 45°. The diameter of the threaded steel bar 10 is 8 to 15 mm, and the diameter of the steel bar strip 16 is 4 to 6 mm. And the vertical height from the top end of the steel bar strip 16 at the top of the special-shaped metal anchor 7 to the bottom of the threaded steel bar 10 is 2 / 3 to 3 / 4 of the height of the heavy refractory cast body 1. A circle of special-shaped metal anchors 7 is arranged at intervals on the inner surface of the shell panel 4. The threaded steel bar 10 of the special-shaped metal anchor 7 is vertically welded and fixed to the shell panel 4, and 1 to 4 steel bar strips 16 on the special-shaped metal anchor 7 are welded and fixed to the shell enclosing plate 3; a circle of special-shaped metal anchors 7 is arranged at intervals on the inner surface of the shell panel 4 and around the process hole enclosing plate 5. The threaded steel bar 10 of the special-shaped metal anchor 7 is vertically welded and fixed to the shell panel 4, and 1 to 4 steel bar strips 16 on the special-shaped metal anchor 7 are welded and fixed to the process hole enclosing plate 5; the remaining parts of the inner surface of the shell panel 4 are distributed with special-shaped metal anchors 7 at intervals along the radial and circumferential directions of the inner surface of the shell panel 4 with the center of the inner surface of the shell panel 4 as the reference point. The special-shaped metal anchor 7 is vertically welded and fixed to the shell panel 4. And the distance between every two adjacent special-shaped metal anchors 7 is the same as the distance L of the heavy refractory cast body 1.

[0059] The V-shaped metal anchor 8 is prepared by bending a steel wire rod. The V-shaped angle β is 30° to 60°. The double-V-shaped metal anchor 9 is formed by welding two V-shaped anchors, and the included angle γ between the two V-shaped surfaces is 30° to 60°. The diameter of the steel wire rod is 4 to 6 mm. The V-shaped metal anchors 8 and the double-V-shaped metal anchors 9 are alternately and spaced apart on the inner surface of the shell panel 4 at the positions where the special-shaped metal anchors 7 are not welded. The V-shaped metal anchors 8 and the double-V-shaped metal anchors 9 are alternately and spaced apart on the inner surface of the shell gusset 3 at the positions between every two adjacent special-shaped metal anchors 7. The sharp corners of the V-shaped metal anchors 8 and the double-V-shaped metal anchors 9 are perpendicularly welded and fixed to the inner surface of the shell panel 4. The heights hv of the V-shaped metal anchors 8 and the double-V-shaped metal anchors 9 welded and fixed to the shell panel 4 are both 2 / 3 to 3 / 4 of the height hj of the light refractory castable 2, and the staggered spacing between the V-shaped metal anchors 8 and the double-V-shaped metal anchors 9 is 100 to 200 mm; the heights of the V-shaped metal anchors 8 and the double-V-shaped metal anchors 9 welded and fixed to the shell gusset 3 are both 1 / 2 to 2 / 3 of the heights of the V-shaped metal anchors 8 and the double-V-shaped metal anchors 9 welded and fixed to the shell panel 4, and the staggered spacing between the V-shaped metal anchors 8 and the double-V-shaped metal anchors 9 is 100 to 200 mm.

[0060] The heavy refractory castable of the heavy refractory castable body includes a main material and an admixture. The raw materials of the main material include, by weight percentage: sintered mullite aggregate (1 - 8 mm) 40 - 50%, fused mullite aggregate (1 - 0.1 mm) 20 - 30%, tabular corundum powder (325 mesh) 7 - 10%, kyanite powder (particle size 120 mesh) 5 - 7%, α-Al2O3 micropowder 5 - 8%, active SiO2 micropowder 4 - 6%, and calcium aluminate cement 4 - 6%; the admixture includes heat-resistant stainless steel fiber, sodium hexametaphosphate, organic explosion-proof fiber, aluminum lactate, and polyaluminum chloride. The heat-resistant stainless steel fiber accounts for 1.5 - 2.5% of the weight of the main material, sodium hexametaphosphate accounts for 0.1 - 0.2% of the weight of the main material, organic explosion-proof fiber accounts for 0.05 - 0.15% of the weight of the main material, aluminum lactate accounts for 0.1 - 0.3% of the weight of the main material, and polyaluminum chloride accounts for 0 - 0.25% of the weight of the main material.

[0061] The light refractory castable of the light refractory castable body is the light high-strength refractory castable for ladle covers disclosed in "Light High-Strength Refractory Castable for Ladle Covers, Its Preparation Method and Application, Application Publication No.: CN115159996A".

[0062] The present invention also provides a preparation method for the refractory lining of the ladle cover combination structure, including the following steps:

[0063] 1) Use threaded steel bars and steel wire rods that meet the requirements of the outer diameter size, and prepare the required number of special-shaped metal anchors, V-shaped metal anchors, and double-V-shaped metal anchors according to the height requirements of the special-shaped metal anchors, V-shaped metal anchors, and double-V-shaped metal anchors.

[0064] 2) Along the edge of the inner surface of the shell panel and around the working hole apron, weld and fix the threaded steel bars perpendicular to the shell panel according to the spacing distance and welding fixation requirements of the special-shaped metal anchors, and weld and fix 1 to 4 steel wire rods to the shell apron or the working hole apron;

[0065] Weld and fix the remaining special-shaped metal anchors to the shell panel according to the requirements of radial and circumferential spaced distribution with the center of the inner surface of the shell panel as the base point;

[0066] Weld and fix the V-shaped metal anchors and double-V-shaped metal anchors to the shell panel and the shell apron of the ladle cover steel structure according to the distribution and staggered spacing distance requirements of the V-shaped metal anchors and double-V-shaped metal anchors.

[0067] 3) As Figure 7 、 8 、9、10、12、13 shown, according to the requirements of the diameter D of the heavy refractory castable, use serrated corrugated thin steel plates 14 with a thickness δ of 0.25 - 0.50 mm, a wave height m of 5 - 10 mm, and a wave width n of 10 - 15 mm, and prepare an axially serrated corrugated sidewall cylindrical partition board 11 with a closed or open sidewall according to the requirements of the number of heavy refractory castables. The height hg of the partition board 11 is 100 - 200 mm higher than the height h of the shell apron 3; the top of the partition board 11 is welded and reinforced with a steel wire rod ring 12, and two pull rings 13 are symmetrically welded and fixed on the steel wire rod ring.

[0068] 4) Weigh and proportion the raw materials according to the heavy refractory castable formula and the light refractory castable formula; use the conventional refractory castable mixing process to prepare the required weight of heavy refractory castable; use the preparation process disclosed in "Lightweight and High-Strength Refractory Castable for Ladle Cover, Its Preparation Method and Application, Application Publication No.: CN115159996A" to prepare the light refractory castable, and bag it for standby.

[0069] 5) Place the axially serrated corrugated sidewall cylindrical partition plate 11 with sidewall openings over the special-shaped metal anchor 7 which is welded and fixed along the inner side of the shell skirt 3 and the outer side of the working hole skirt 5. The sidewall openings are closely attached to the shell skirt and the working hole skirt, and 1 - 4 steel wire strands welded and fixed to the shell skirt or the working hole skirt pass through the sidewall openings. Place the axially serrated corrugated sidewall cylindrical partition plate 11 with closed sidewalls over other special-shaped metal anchors. All axially serrated corrugated sidewall cylindrical partition plates with open or closed sidewalls are fixed to the casting construction steel pipe grid platform through wire bundling by means of pull rings.

[0070] 6) According to the conventional process of adding water and mixing refractory castables, use two mixers to separately add water and mix the prepared heavy refractory castable and light refractory castable evenly to obtain a heavy refractory castable mixture and a light refractory castable mixture.

[0071] 7) Pour the heavy refractory castable mixture into the axially serrated corrugated sidewall cylindrical partition plate 11. At the same time, pour the light refractory castable mixture outside the partition plate 11 to the same height as the internal heavy refractory castable mixture. Use a vibrating rod to vibrate and form the heavy and light refractory castables. According to the requirement that the heights of the inner and outer cylinders of the cylindrical partition plate increase simultaneously, supplement and vibrate and form the heavy and light refractory castable mixtures until the heights of the heavy refractory material casting and the light refractory material casting are the same as the height of the shell skirt of the ladle cover steel structure. Through the pull ring of the cylindrical partition plate, timely remove the cylindrical partition plate, turn on the vibrating rod to vibrate the surface layer of the heavy refractory castable area, and supplement the heavy refractory castable mixture to the height of the shell skirt. Thus, the casting and forming of the combined refractory lining composed of the heavy refractory material casting and the light refractory material casting of the ladle cover are completed.

[0072] 8) After the casting and forming of the ladle cover combined refractory lining, according to the conventional process, first perform natural curing for 48 - 72 h, and then conduct baking treatment for 48 - 72 h. The maximum baking temperature is 800 - 1000 °C. After baking, the ladle cover is put into normal production service.

[0073] Using the ladle cover combined structure refractory lining of the present invention and its preparation method, the preparation and industrial test of ladle covers for 200 t and 300 t ladles were carried out. The test results show that compared with the conventional ladle cover, the service life of the ladle cover is extended by 1 time, and the average surface temperature during the whole service process of the ladle cover is reduced by 15 °C, achieving the expected goal of extending the service life of the ladle cover and improving the heat insulation performance of the ladle cover.

Claims

1. A refractory lining for a ladle cover combined structure, characterized in that: It includes a housing enclosure plate (3) and a housing panel (4) lined at the bottom of the housing enclosure plate (3). Process holes (15) penetrating through the inner and outer surfaces are formed on the surface of the housing panel (4), and a process hole enclosure plate (5) is arranged around the process holes (15); a circle of heavy refractory cast bodies (1) is arranged at intervals on the edge of the inner surface of the housing panel (4), a circle of heavy refractory cast bodies (1) is arranged at intervals on the inner surface of the housing panel (4) and around the process hole enclosure plate (5), and the remaining part of the inner surface of the housing panel (4) is distributed with heavy refractory cast bodies (1) at intervals along the radial and circumferential directions of the housing panel with the center of the inner surface of the housing panel (4) as the reference point. The center axis distance L between every two adjacent heavy refractory cast bodies (1) is 3 to 5 times the diameter D of the heavy refractory cast body (1); the part of the inner surface of the housing panel (4) not cast with the heavy refractory cast body (1) is all cast with a light refractory cast body (2).

2. The refractory lining of the ladle cover combined structure according to claim 1, wherein: The heavy refractory cast body (1) is composed of a heavy refractory castable wrapping a special-shaped metal anchor (7), and the height hj of the heavy refractory cast body (1) is the same as the height h of the housing enclosure plate (3); the light refractory cast body (2) is composed of a light refractory castable wrapping a V-shaped metal anchor (8) and a double-V-shaped metal anchor (9), and the height of the light refractory cast body (2) is also hj.

3. The refractory lining of the ladle cover combination structure according to claim 2, characterized in that: The special-shaped metal anchor (7) includes a threaded steel bar (10) and a number of steel bar strips (16) evenly distributed on the outer surface of the threaded steel bar (10) and welded obliquely, and the vertical height from the top end of the steel bar strip (16) at the top of the special-shaped metal anchor (7) to the bottom of the threaded steel bar (10) is 2 / 3 to 3 / 4 of the height of the heavy refractory cast body (1).

4. The refractory lining of the ladle cover combined structure according to claim 3, characterized in that: A circle of special-shaped metal anchors (7) is arranged at intervals on the edge of the inner surface of the housing panel (4). The threaded steel bar (10) of the special-shaped metal anchor (7) is vertically welded and fixed to the housing panel (4), and 1 to 4 steel bar strips (16) on the special-shaped metal anchor (7) are welded and fixed to the housing enclosure plate (3); a circle of special-shaped metal anchors (7) is arranged at intervals on the inner surface of the housing panel (4) and around the process hole enclosure plate (5). The threaded steel bar (10) of the special-shaped metal anchor (7) is vertically welded and fixed to the housing panel (4), and 1 to 4 steel bar strips (16) on the special-shaped metal anchor (7) are welded and fixed to the process hole enclosure plate (5); the remaining part of the inner surface of the housing panel (4) is distributed with special-shaped metal anchors (7) at intervals along the radial and circumferential directions of the housing panel (4) with the center of the inner surface of the housing panel (4) as the reference point. The special-shaped metal anchor (7) is vertically welded and fixed to the housing panel (4), and the distance between every two adjacent special-shaped metal anchors (7) is the same as the distance L between the heavy refractory cast bodies (1).

5. The refractory lining of the ladle cover combination structure according to claim 2, characterized in that: The V-shaped metal anchor (8) is prepared by bending a steel wire rod. The V-shaped angle β is 30° to 60°. The double-V-shaped metal anchor (9) is formed by welding two V-shaped anchors, and the included angle γ between the two V-shaped surfaces is 30° to 60°. The diameter of the steel wire rod is 4 to 6 mm.

6. The refractory lining of the ladle cover combined structure according to claim 5, characterized in that: On the inner surface of the shell panel (4) and at the positions where the non-welded special-shaped metal anchors (7) are not located, the V-shaped metal anchors (8) and the double-V-shaped metal anchors (9) are distributed at staggered intervals. On the inner surface of the shell enclosing plate (3) and at the positions between every two adjacent special-shaped metal anchors (7), the V-shaped metal anchors (8) and the double-V-shaped metal anchors (9) are distributed at staggered intervals. The sharp corners of the V-shaped metal anchors (8) and the double-V-shaped metal anchors (9) are perpendicularly welded and fixed to the inner surface of the shell panel (4). The heights hv of the V-shaped metal anchors (8) and the double-V-shaped metal anchors (9) welded and fixed to the shell panel (4) are all 2 / 3 to 3 / 4 of the height hj of the light refractory cast body (2), and the staggered interval between the V-shaped metal anchors (8) and the double-V-shaped metal anchors (9) is 100 to 200 mm. The heights of the V-shaped metal anchors (8) and the double-V-shaped metal anchors (9) welded and fixed to the shell enclosing plate (3) are all 1 / 2 to 2 / 3 of the heights of the V-shaped metal anchors (8) and the double-V-shaped metal anchors (9) welded and fixed to the shell panel (4), and the staggered interval between the V-shaped metal anchors (8) and the double-V-shaped metal anchors (9) is 100 to 200 mm.

7. The refractory lining of the ladle cover combination structure according to claim 2, characterized in that: The heavy refractory cast material of the heavy refractory cast body includes a main material and an admixture. The raw materials of the main material include, by weight percentage: 40 to 50% of sintered mullite aggregate, 20 to 30% of fused mullite aggregate, 7 to 10% of tabular corundum powder, 5 to 7% of kyanite powder, 5 to 8% of α-Al2O3 micropowder, 4 to 6% of active SiO2 micropowder, and 4 to 6% of calcium aluminate cement. The admixture includes heat-resistant stainless steel fibers, sodium hexametaphosphate, organic explosion-proof fibers, aluminum lactate, and polyaluminum chloride. The heat-resistant stainless steel fibers account for 1.5 to 2.5% of the weight of the main material, sodium hexametaphosphate accounts for 0.1 to 0.2% of the weight of the main material, organic explosion-proof fibers account for 0.05 to 0.15% of the weight of the main material, aluminum lactate accounts for 0.1 to 0.3% of the weight of the main material, and polyaluminum chloride accounts for 0 to 0.25% of the weight of the main material.

8. The refractory lining of the ladle cover combination structure according to claim 3, characterized in that: The included angle α between the axis of the steel wire rod (16) and the threaded steel bar (10) is 22.5° to 45°. The diameter of the threaded steel bar (10) is 8 to 15 mm, and the diameter of the steel wire rod (16) is 4 to 6 mm.

9. The refractory lining of the ladle cover combined structure according to claim 1, wherein: It also includes a reinforcing rib plate (6) welded to the outer surface of the shell panel (4).

10. A preparation method of the refractory lining of the ladle cover combined structure as described in claim 2, characterized in that: It includes the following steps: 1) Use threaded steel bars and steel wire rods that meet the outer diameter size requirements, and prepare the required number of special-shaped metal anchors, V-shaped metal anchors, and double-V-shaped metal anchors according to the height requirements of the special-shaped metal anchors, V-shaped metal anchors, and double-V-shaped metal anchors. 2) Along the edges of the inner surface of the shell panel and around the working hole apron, in accordance with the spacing distance of the special-shaped metal anchors and the requirements for welding fixation, perpendicularly weld the threaded steel bars to the shell panel. Weld 1 to 4 steel bar coils to the shell apron or the working hole apron; In accordance with the requirements of radially and circumferentially spaced distribution with the center of the inner surface of the shell panel as the base point, weld the remaining special-shaped metal anchors to the shell panel; In accordance with the distribution and staggered spacing distance requirements of the V-shaped metal anchors and double-V-shaped metal anchors, weld the V-shaped metal anchors and double-V-shaped metal anchors to the shell panel and the shell apron of the ladle cover steel structure; 3) In accordance with the requirements of the diameter D of the heavy refractory castable, use a serrated corrugated thin steel plate (14) with a thickness δ of 0.25 - 0.50 mm, a wave height m of 5 - 10 mm, and a wave width n of 10 - 15 mm. Prepare an axially serrated corrugated sidewall cylindrical partition board (11) with a closed or open sidewall according to the quantity requirements of the heavy refractory castable. The height hg of the partition board (11) is 100 - 200 mm higher than the height h of the shell apron (3); Reinforce the top of the partition board (11) by welding a steel bar coil ring (12), and symmetrically weld and fix two pull rings (13) on the steel bar coil ring; 4) According to the heavy refractory castable formula and the light refractory castable formula, weigh and proportion the raw materials; Adopt the refractory castable stirring and mixing process to prepare the required weight of heavy refractory castable and light refractory castable, and bag them for standby; 5) Slip-fit the axially serrated corrugated sidewall cylindrical partition board (11) with an open sidewall onto the special-shaped metal anchors (7) welded and fixed along the inner side of the shell apron (3) and the outer side of the process hole apron (5). The open sidewall of the partition board closely adheres to the shell apron and the working hole apron, and make 1 to 4 steel bar coils welded and fixed to the shell apron or the working hole apron pass through the open sidewall; Slip-fit the axially serrated corrugated sidewall cylindrical partition board (11) with a closed sidewall onto other special-shaped metal anchors; Fix all axially serrated corrugated sidewall cylindrical partition boards with open or closed sidewalls to the casting construction steel pipe grid platform through the pull rings by wire bundling; 6) According to the conventional refractory castable water-adding stirring and mixing process, use two mixers to separately add water to stir and mix the prepared heavy refractory castable and light refractory castable evenly to obtain a heavy refractory castable mixture and a light refractory castable mixture; 7) Add heavy refractory castable mixture into the axially serrated corrugated sidewall cylindrical partition board (11), and at the same time add lightweight refractory castable mixture outside the partition board (11) to the same height as the internal heavy refractory castable mixture; use a vibrating rod to vibrate and form the heavy and lightweight refractory castables, and according to the requirement that the heights of the inner and outer cylinders of the cylindrical partition board increase simultaneously, supplement and vibrate and form the heavy and lightweight refractory castable mixtures until the heights of the heavy refractory material casting body and the lightweight refractory material casting body are the same as the height of the ladle cover steel structure shell partition board; through the pull ring of the cylindrical partition board, take out the cylindrical partition board in time, turn on the vibrating rod to vibrate on the surface layer of the heavy refractory castable area, and supplement the heavy refractory castable mixture to the height of the shell partition board; 8) After the ladle cover combined refractory lining is cast and formed, first cure it naturally for 48 - 72h, and then carry out a baking treatment for 48 - 72h, and the maximum baking temperature is 800 - 1000°C.

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