Blast furnace hearth structure for smelting vanadium titano-magnetite and cooling regulation method

Abstract

The present application relates to iron-making technology field, propose a kind of for vanadium-titanium magnetite smelting blast furnace hearth structure and cooling control method, the blast furnace structure includes furnace bottom brick lining, hearth side wall brick lining and be located in the hearth side wall brick lining below furnace base;Furnace bottom brick lining and the outside of the hearth side wall brick lining is provided with smooth cast iron cooling wall, the inside of the furnace base is provided with cooling device;The furnace bottom brick lining is successively provided with heat preservation brick layer and heat-conducting brick layer from hearth bottom to furnace base direction, heat preservation brick layer includes dense clay brick and composite mullite brick, the heat-conducting brick layer is semi-graphite carbon brick;Hearth side wall brick lining is built with the composite mullite brick, and in the corner of hearth and furnace bottom, hearth side wall brick lining extends to form brick lining reinforcing structure in the direction of furnace in.The present application solves the problem of excessive deposition of titanium carbonitride caused by improper temperature gradient when smelting vanadium-titanium magnetite, inhibits the accumulation of hearth center and edge bonding, maintains the hearth active and blast furnace smooth.

Description

Technical Field

[0001] This invention relates to the field of ironmaking technology, and in particular to a blast furnace hearth structure and cooling control method for vanadium-titanium magnetite smelting. Background Technology

[0002] Currently, blast furnaces generally adopt a hearth structure composed of carbon bricks and ceramic pads. This structure relies on the high thermal conductivity of the carbon bricks for rapid heat transfer, while the ceramic pads provide insulation and corrosion resistance. Combined with a strong cooling system, this design aims to form a stable solidification protective layer within the hearth.

[0003] However, this traditional structure proved severely unsuitable for smelting vanadium-titanium magnetite. Titanium dioxide in the slag readily reduced to form high-melting-point titanium carbonitride, and its excessive precipitation within the hearth leads to central accumulation and edge adhesion, worsening the gas and liquid permeability of the charge column and causing fluctuations in furnace conditions. The large temperature gradient created by the traditional high-thermal-conductivity carbon bricks and strong cooling actually accelerated the formation and deposition of titanium carbonitride. Simultaneously, the rapid increase in viscosity of high-titanium slag at low temperatures further exacerbated accumulation and adhesion.

[0004] Therefore, the existing structure is difficult to balance maintaining the activity of the hearth and inhibiting harmful deposition, and there is an urgent need for a new hearth structure that is adapted to the smelting characteristics of vanadium-titanium magnetite. Summary of the Invention

[0005] In view of the problem that the existing blast furnace hearth structure relies on high thermal conductivity carbon bricks and strong cooling system, which creates a large temperature gradient, promotes the excessive generation and deposition of titanium carbonitride during the smelting of vanadium-titanium magnetite, and leads to accumulation in the hearth center and adhesion at the edge, which seriously restricts the smooth operation of the blast furnace and the optimization of indicators, the first aspect of the present invention proposes a blast furnace hearth structure for vanadium-titanium magnetite smelting, including a bottom brick lining, a hearth sidewall brick lining, and a furnace base located below the hearth sidewall brick lining; Among them, the outer side of the furnace bottom brick lining and the furnace hearth side wall brick lining is provided with a smooth cast iron cooling wall, and the furnace base is provided with a cooling device; The furnace bottom lining is provided with a heat-insulating brick layer and a heat-conducting brick layer in sequence from the bottom of the furnace hearth to the furnace base. The heat-insulating brick layer includes dense clay bricks and composite mullite bricks, and the heat-conducting brick layer is semi-graphite carbon bricks. The furnace hearth sidewall brick lining is constructed using the composite mullite bricks, and at the corner between the furnace hearth and the furnace bottom, the furnace hearth sidewall brick lining extends inward to form a brick lining reinforcement structure.

[0006] In some embodiments, the material properties of the smooth cast iron cooling wall are superior to those of QT400-18 ductile iron.

[0007] In some embodiments, the smooth cast iron cooling wall is connected to a soft water closed-loop cooling system.

[0008] In some embodiments, the furnace bottom brick lining is constructed using a vertical masonry method.

[0009] In some embodiments, the brick lining reinforcement structure is formed by laying at least three layers of composite mullite bricks laterally from the cooling wall of the furnace hearth into the furnace, and the brick lining reinforcement structure extends to a depth of 1.4 to 1.6 meters into the furnace.

[0010] In some embodiments, the cooling device is a water-cooled pipe embedded in the concrete structure of the furnace base.

[0011] In some embodiments, the blast furnace hearth structure is suitable for smelting vanadium-titanium magnetite with a TiO2 content greater than 15% in the slag, and the effective volume of the blast furnace to which the blast furnace hearth structure is applied is 1000~2000 cubic meters.

[0012] In some embodiments, the layer sequence of the furnace bottom brick lining from the bottom of the hearth to the furnace base includes: layers 1 to 3 being dense clay bricks, layers 4 to 5 being composite mullite bricks, layers 6 to 8 being the dense clay bricks, and layers 9 to 10 being semi-graphite carbon bricks.

[0013] A second aspect of the present invention also provides a cooling control method applied to the blast furnace hearth structure for vanadium-titanium magnetite smelting according to any of the foregoing embodiments, comprising the following steps: Based on the utilization coefficient and service stage of the blast furnace, the smooth cast iron cooling wall is dynamically controlled in zones. When the blast furnace utilization coefficient is ≥2.5t / (m³•d) or in the later stage of furnace service, the heat flow intensity of the first and second cooling walls at the bottom of the hearth is controlled at 1200~1500kcal / (m²•h), and the heat flow intensity of the third and fourth cooling walls at the top of the hearth is controlled at 2800~3500kcal / (m²•h). When the blast furnace utilization coefficient is <2.5t / (m³•d) or when it is in the middle of the furnace operation from start-up, the heat flux intensity of the first and second cooling walls at the bottom of the hearth should be controlled at 900~1200kcal / (m²•h), and the heat flux intensity of the third and fourth cooling walls at the top of the hearth should be controlled at 2000~2800kcal / (m²•h).

[0014] In some embodiments, during the control process, the temperature difference between the cooling water of the first cooling wall and the second cooling wall is controlled within the range of 0.4~0.8℃, and the temperature difference between the cooling water of the third cooling wall and the fourth cooling wall is controlled within the range of 1.2~2.5℃.

[0015] This invention has at least the following beneficial effects: It proposes a blast furnace hearth structure and cooling control method for vanadium-titanium magnetite smelting, effectively solving the problem of excessive titanium carbonitride deposition caused by improper temperature gradients during vanadium-titanium magnetite smelting. This suppresses accumulation in the hearth center and adhesion at the edges, maintaining hearth activity and smooth blast furnace operation. Specifically, the insulating brick layer composed of dense clay bricks and composite mullite bricks utilizes their low thermal conductivity to achieve hearth insulation, reducing the temperature gradient and suppressing the rapid formation of titanium carbonitride from the root. The semi-graphite carbon brick thermally conductive layer at the bottom of the furnace can efficiently transfer heat to the cooling device in the later stages of furnace operation, protecting the furnace base and promoting the formation of a stable furnace bottom protective layer. The hearth sidewall uses composite mullite bricks and extends at the corners to form a reinforced structure, enhancing the area's resistance to erosion and adhesion. The smooth cast iron cooling wall on the outer side, together with the furnace base cooling device, constitutes an adjustable cooling system, providing precise thermal management for the aforementioned brick lining structure and achieving a dynamic balance between suppressing harmful deposition and maintaining smelting activity. The cooling control method, which works in conjunction with the furnace hearth structure of this invention, achieves proactive optimization of the furnace hearth thermal state through zoned and dynamic refined management. This, in turn, works synergistically with the structural design to jointly solve the problem of titanium carbonitride deposition control. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of a blast furnace hearth structure for vanadium-titanium magnetite smelting, provided as an embodiment of the present invention. The attached figures are labeled as follows: 1. Furnace base; 2. First cooling wall; 3. Second cooling wall; 4. Third cooling wall; 5. Fourth cooling wall; 6. Semi-graphite carbon brick; 7. Dense clay bricks in layers 6-7; 8. Composite mullite brick; 9. Dense clay bricks in layers 1-3; 10. Taphole centerline; 11. Brick lining of hearth sidewalls; 12. Brick lining reinforcement structure; 13. Bottom of hearth; 21. Dense clay brick; 31. Insulating brick layer; 41. Brick lining of hearth bottom; 51. Smooth cast iron cooling wall; 100. Blast furnace hearth structure. Detailed Implementation

[0018] The following describes embodiments of the present invention. However, it should be understood that the disclosed embodiments are merely examples, and other embodiments may take various alternative forms.

[0019] Furthermore, it should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or apparatus that comprises a list of elements may include not only those elements but also elements not expressly listed or inherent to such process, method, article, or apparatus.

[0020] One or more embodiments of this application will now be described with reference to the accompanying drawings.

[0021] To achieve the above objectives, the present invention provides an embodiment of a blast furnace hearth structure for vanadium-titanium magnetite smelting. Please refer to [reference needed]. Figure 1 A blast furnace hearth structure 100 for vanadium-titanium magnetite smelting includes a bottom brick lining 41, a hearth sidewall brick lining 11, and a furnace base 1. The bottom brick lining 41 is a multi-layer composite structure, with a heat-insulating brick layer 31 and a heat-conducting brick layer arranged sequentially from the bottom 13 of the hearth to the furnace base 1. The heat-insulating brick layer 31 includes dense clay bricks 21 and composite mullite bricks 8, and the heat-conducting brick layer is semi-graphite carbon bricks 6. The hearth sidewall brick lining 11 is constructed with composite mullite bricks 8, and at the corner between the hearth and the bottom, the hearth sidewall brick lining 11 extends inward to form a brick lining reinforcement structure 12. The bottom brick lining 41 and the hearth sidewall brick lining 11 are provided with smooth cast iron cooling walls 51 on their outer sides. The furnace base 1 is located below the bottom brick lining 41 and has a cooling device inside.

[0022] In some embodiments, the furnace bottom brick lining 41 and the hearth sidewall brick lining 11 together constitute the working lining that directly faces the high-temperature molten slag and iron inside the furnace, while the furnace base 1 serves as the supporting foundation for the entire hearth and the carrier for part of the cooling system.

[0023] In some embodiments, a smooth cast iron cooling wall 51 is provided on the outer side (i.e., the side facing away from the furnace) of the furnace bottom brick lining 41 and the hearth sidewall brick lining 11. The smooth cast iron cooling wall 51 is a cast iron component with internally cast cooling water channels and a smooth working surface. It is installed in close contact with the brick lining to absorb the heat transferred by the brick lining and remove it through internal circulating cooling water. The furnace base 1 is located below the furnace bottom brick lining 41 and is usually a reinforced concrete structure. A cooling device, such as embedded cooling water pipes, is provided inside to cool the furnace bottom foundation and prevent overheating.

[0024] In some embodiments, the hearth sidewall lining 11 is constructed using composite mullite bricks 8. Composite mullite bricks 8 possess good resistance to slag and iron erosion and moderate thermal conductivity, making them suitable as the hearth sidewall lining 11. At the corner between the hearth and the furnace bottom, i.e., the junction area between the sidewall and the bottom, where stress is complex and erosion is severe, the construction method of the hearth sidewall lining 11 changes, extending inwards towards the furnace, i.e., towards the taphole centerline 10, forming a brick lining reinforcement structure 12. This brick lining reinforcement structure 12 is essentially a thickening and special construction of the sidewall lining in the corner area, used to enhance mechanical strength and erosion resistance.

[0025] In some embodiments, the furnace bottom lining 41 is a multi-layered composite structure. Starting from the bottom 13 of the hearth in contact with molten iron and extending downwards towards the furnace base 1, this structure sequentially comprises an insulating brick layer 31 and a heat-conducting brick layer. The insulating brick layer 31 refers to the brick layer region composed of a low thermal conductivity material, primarily serving to insulate and maintain the hearth temperature; the heat-conducting brick layer refers to the brick layer region composed of a high thermal conductivity material, primarily serving to efficiently transfer heat. The insulating brick layer 31 includes dense clay bricks 21 and composite mullite bricks 8. The dense clay bricks 21 are high-quality clay refractory bricks prepared using a special process, exhibiting extremely low porosity and high bulk density, possessing excellent erosion resistance and low thermal conductivity. In a specific embodiment of the present invention, the dense clay bricks 21 are preferably ultra-dense clay bricks, prepared using a special process, possessing superior densification, higher bulk density, and lower apparent porosity, thereby exhibiting better erosion resistance and lower thermal conductivity. Composite mullite brick 8 is a high-performance refractory material with mullite (3Al2O3·2SiO2) as its main crystalline phase. It has good thermal shock resistance, high high-temperature strength, and low thermal conductivity. The combination of these two types of bricks forms an effective heat preservation zone in the upper part of the furnace bottom, significantly reducing downward heat loss and helping to maintain the temperature uniformity of the hearth, especially above the dead iron layer, thereby weakening the temperature gradient that promotes titanium carbonitride precipitation. Semi-graphite carbon brick 6 is a carbonaceous refractory brick containing a certain amount of graphite. Its graphitization degree is between that of microporous carbon bricks and fully graphite carbon bricks. It has a much higher thermal conductivity than the aforementioned dense clay brick 21 and composite mullite brick 8, but its oxidation resistance is better than that of fully graphite carbon bricks. Arranging semi-graphite carbon brick 6 at the bottom layer of the furnace bottom can quickly conduct heat downwards in the later stages of furnace operation when the upper brick lining is eroded and thinned.

[0026] According to several embodiments of the present invention, the material properties of the smooth cast iron cooling wall 51 are superior to those of QT400-18 ductile iron. The smooth cast iron cooling wall 51 is connected to a soft water closed-loop cooling system. QT400-18 is a common grade of ductile iron with a tensile strength of not less than 400 MPa and an elongation after fracture of not less than 18%. The cast iron material selected in this invention exceeds the level of QT400-18 in one or more key indicators such as thermal conductivity, high-temperature strength, and thermal fatigue resistance, ensuring the reliability and efficient heat transfer capacity of the cooling wall under long-term high-temperature and thermal cycling conditions. Soft water is treated purified water with extremely low hardness, effectively preventing scaling within the cooling channels. Closed-loop circulation means that the cooling water is circulated within a closed system without direct exchange with the external environment. This helps maintain stable water quality, improves cooling efficiency and service life, and facilitates precise cooling control.

[0027] According to several embodiments of the present invention, the brick-lined reinforcing structure 12 is formed by laying at least three layers of composite mullite bricks 8 laterally from the cooling wall of the hearth sidewall into the furnace, and the brick-lined reinforcing structure 13 extends into the furnace to a depth of 1.4 to 1.6 meters. The fact that the brick-lined reinforcing structure 13 is formed by laying at least three layers of composite mullite bricks 8 laterally from the cooling wall of the hearth sidewall into the furnace indicates that at the corner, the bricklaying direction changes from vertical or circumferential to approximately horizontal (lateral), like laying a floor, layer by layer inward to form a dense, thickened structure. The brick-lined reinforcing structure 13 extends into the furnace to a depth of 1.4 to 1.6 meters, for example, about 1.5 meters. This depth is sufficient to cross the stress concentration zone at the corner, providing solid support and protection for the lower part of the sidewall.

[0028] According to several embodiments of the present invention, the cooling device is a water-cooled pipe embedded in the concrete structure of the furnace base 1. These water-cooled pipes are usually arranged in a certain pattern in the concrete of the furnace base 1. After cooling water is introduced, they can effectively remove the heat conducted down from the 6 layers of semi-graphite carbon bricks at the bottom of the furnace, prevent the concrete of the furnace base 1 from being damaged due to excessive temperature, and help to form a reasonable temperature field at the bottom of the furnace.

[0029] According to several embodiments of the present invention, the blast furnace hearth structure 100 is suitable for smelting vanadium-titanium magnetite with a TiO2 content greater than 15% in the slag, and the effective volume of the blast furnace to which the blast furnace hearth structure 100 is applied is 1000~2000 cubic meters.

[0030] According to several embodiments of the present invention, the furnace bottom brick lining 41 has a total of 10 layers, and its layer sequence from the bottom of the hearth 13 to the furnace base 1 includes: layers 1-3 are dense clay bricks 9, layers 4-5 are composite mullite bricks 8, layers 6-8 are the aforementioned dense clay bricks, and layers 9-10 are semi-graphite carbon bricks. According to several embodiments of the present invention, the furnace bottom brick lining 41 adopts a vertical masonry method. For example, in a 10-layer structure, the basic layer sequence of clay brick-mullite brick-clay brick-carbon brick is maintained, so that the insulation layer (clay bricks and mullite bricks) occupies the main thickness, and the highly thermally conductive semi-graphite carbon bricks 6 are placed at the bottom, achieving the purpose of upper insulation and lower conductivity. Vertical masonry means that the long side of the bricks is laid perpendicular to the plane of the furnace bottom, which is beneficial to enhance the integrity of the brick lining, reduce circumferential joints, and improve the resistance to molten iron penetration.

[0031] The aforementioned blast furnace hearth structure 100 for vanadium-titanium magnetite smelting effectively solves the problem of excessive titanium carbonitride deposition caused by improper temperature gradients during vanadium-titanium magnetite smelting, thereby inhibiting accumulation in the hearth center and adhesion at the edges, maintaining hearth activity and smooth blast furnace operation. Specifically, the insulating brick layer 31, composed of dense clay bricks 21 and composite mullite bricks 8, utilizes its low thermal conductivity to achieve hearth insulation, reduce temperature gradients, and inhibit the excessively rapid formation of titanium carbonitride from the source; the semi-graphite carbon brick 6 thermally conductive brick layer at the bottom of the furnace can efficiently conduct heat to the cooling device in the later stages of furnace operation, protecting the furnace base 1 and promoting the formation of a stable furnace bottom protective layer; the hearth sidewall uses composite mullite bricks 8 and extends at the corners to form a reinforced structure, enhancing the erosion resistance and adhesion resistance of this area; the smooth cast iron cooling wall 51 set on the outside and the cooling device of the furnace base 1 together constitute an adjustable cooling system, providing precise thermal management for the aforementioned brick lining structure, achieving a dynamic balance between inhibiting harmful deposition and maintaining smelting activity.

[0032] A second aspect of the present invention also provides a cooling control method applied to the blast furnace hearth structure 100 for vanadium-titanium magnetite smelting according to any of the foregoing, comprising the following steps: dynamically controlling the smooth cast iron cooling wall 51 by partition according to the utilization coefficient and furnace service stage of the blast furnace; dividing the smooth cast iron cooling wall 51 from the furnace base 1 to the bottom of the hearth 13 into a first cooling wall 2, a second cooling wall 3, a third cooling wall 4 and a fourth cooling wall 5 in sequence. When the blast furnace utilization coefficient is ≥2.5t / (m³·d) or in the later stage of furnace operation, the heat flux intensity of the first cooling wall 2 and the second cooling wall 3 should be controlled at 1200~1500kcal / (m²·h), and the heat flux intensity of the third cooling wall 4 and the fourth cooling wall 5 should be controlled at 2800~3500kcal / (m²•h). When the blast furnace utilization coefficient is <2.5t / (m³•d) or in the period from start-up to mid-stage of furnace operation, the heat flux intensity of the first cooling wall 2 and the second cooling wall 3 should be controlled at 900~1200kcal / (m²•h), and the heat flux intensity of the third cooling wall 4 and the fourth cooling wall 5 should be controlled at 2000~2800kcal / (m²•h).

[0033] As a specific embodiment, the cooling wall is divided into two key areas for differentiated control: the first cooling wall 2 and the second cooling wall 3 correspond to the outer side of the furnace bottom brick lining 41 to the bottom of the dead iron layer, and the heat load is relatively low; the third cooling wall 4 and the fourth cooling wall 5 correspond to the dead iron layer to below the tuyeres, which are areas where slag and iron accumulate and flow actively, with high heat load and direct contact with molten slag and iron. (1) When the blast furnace utilization coefficient is ≥2.5t / (m³•d) (high smelting intensity) or in the later stage of furnace service: the slag and iron flow rate in the hearth is large and the temperature is high, or the brick lining may have become thin. At this time, in order to enhance cooling to protect the furnace lining, resist erosion and stabilize the furnace shape, a higher heat flow intensity should be adopted. The heat flow intensity of the first cooling wall 2 and the second cooling wall 3 area is controlled at 1200~1500kcal / (m²•h), and the heat flow intensity of the third cooling wall 4 and the fourth cooling wall 5 area is controlled at 2800~3500kcal / (m²•h). (2) When the blast furnace utilization coefficient is <2.5t / (m³•d) (low smelting intensity) or is in the middle of the furnace operation period: the amount of slag and iron in the hearth is relatively small, or the brick lining is thick and the risk of erosion is low. At this time, in order to reduce unnecessary heat loss, maintain sufficient hearth temperature to maintain its chemical and physical activity, and avoid excessive cooling leading to edge adhesion, a lower heat flux intensity should be adopted. The heat flux intensity of the first cooling wall 2 and the second cooling wall 3 should be controlled at 900~1200kcal / (m²•h), and the heat flux intensity of the third cooling wall 4 and the fourth cooling wall 5 should be controlled at 2000~2800kcal / (m²•h).

[0034] As a specific embodiment, while implementing the above-mentioned heat flux intensity regulation, the temperature difference between the inlet and outlet cooling water can also be monitored and controlled as a reference for judging whether the cooling intensity is appropriate. For example, during the regulation process, the temperature difference between the cooling water of the first cooling wall 2 and the second cooling wall 3 is controlled within the range of 0.4~0.8℃, and the temperature difference between the cooling water of the third cooling wall 4 and the fourth cooling wall 5 is controlled within the range of 1.2~2.5℃. Controlling the temperature difference within a reasonable range that matches the heat flux intensity helps to achieve more stable and balanced cooling.

[0035] The following describes the practical application of the blast furnace hearth structure 100 and cooling control method based on the present invention, in order to further understand the blast furnace hearth structure 100 and cooling control method for vanadium-titanium magnetite smelting of the present invention.

[0036] Example 1 (A 1750m³ blast furnace A) The blast furnace slag Ti O2 The content is 20.0%~22.0%, and its hearth adopts a 10-layer structure. The layer sequence from the bottom 13 of the hearth to the furnace base 1 includes: layers 1-3 are dense clay bricks 9, layers 4-5 are composite mullite bricks 8, layers 6-8 are the aforementioned dense clay bricks 7, and layers 9-10 are semi-graphite carbon bricks 6. Initially, under a low utilization coefficient, for example 2.20t / (m³•d), excessive cooling intensity was used. The heat flux intensity of the third cooling wall 4 and the fourth cooling wall 5 reached 5000kcal / (m²•h), resulting in severe edge adhesion and center accumulation in the hearth. Subsequently, according to the cooling control method of the present invention, the heat flux intensity of the third cooling wall 4 and the fourth cooling wall 5 was adjusted to a reasonable lower limit range of 2200~2500kcal / (m²•h), and the working condition of the hearth quickly improved, and the production indicators returned to normal.

[0037] Example 2 (A 1750m³ blast furnace B) The blast furnace slag has a TiO2 content of 20.0-22.5%, and the hearth structure is the same as in Example 1. As production progresses, the utilization coefficient increases from 2.30 to 2.80 t / (m³•d), and the furnace enters its later service life. The original cooling intensity is insufficient; the first and second cooling walls have an intensity of approximately 1000 kcal / (m²•h), and the third and fourth cooling walls have an intensity of approximately 2600 kcal / (m²•h), causing the hearth temperature to rise continuously. According to the cooling control method of this invention, the cooling intensity is increased to near the upper limit, i.e., the first and second cooling walls have an intensity of approximately 1400 kcal / (m²•h), and the third and fourth cooling walls have an intensity of approximately 3500 kcal / (m²•h), achieving stable control of the hearth temperature and ensuring the safe and smooth operation of the blast furnace under high-production conditions.

[0038] The aforementioned cooling control method, in conjunction with the aforementioned hearth structure, achieves proactive optimization of the hearth's thermal state through zoned and dynamic refined management. This, in synergy with the structural design, jointly solves the challenge of controlling titanium carbonitride deposition. Specifically, by clearly dividing the hearth cooling wall into two independent regions—the lower part (the first cooling wall 2 and the second cooling wall 3) and the upper part (the third cooling wall 4 and the fourth cooling wall 5)—the essential differences in heat load and function at different heights of the hearth are identified. This allows for precise matching of cooling intensity with the actual operating conditions of each region, avoiding overcooling or undercooling caused by traditional single cooling regimes. Using the blast furnace utilization coefficient and furnace service stage as the core criteria for control, a dynamic correlation is established between cooling intensity, smelting intensity, and furnace age. During high smelting intensity or the later stages of furnace service, the upper limit heat flux intensity is used to enhance cooling, resist erosion, and stabilize the furnace shape; during low smelting intensity or the early to mid-stages of furnace service, the lower limit heat flux intensity is used to reduce cooling, minimize heat loss, and maintain the hearth temperature. This dynamic strategy breaks the vicious cycle of strong cooling, large gradient cooling, and precipitation promotion, transforming the cooling regime from a passive heat removal tool into an active temperature field management tool. Through its coordination with a specific hearth structure, it achieves an optimal balance between protecting the furnace lining, preventing erosion, and inhibiting the harmful precipitation of titanium carbonitride, effectively reducing center buildup and edge adhesion, and ensuring the long-term stable operation and optimized performance of the blast furnace.

[0039] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the embodiments of this invention as defined by the claims. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0040] It should be understood that, as used herein, the singular form “a” is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, “and / or” refers to any and all possible combinations of one or more of the associated listed items.

[0041] The embodiment numbers disclosed in the above embodiments of the present invention are merely for description and do not represent the superiority or inferiority of the embodiments.

[0042] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A blast furnace hearth structure for vanadium-titanium magnetite smelting, characterized in that, It includes the furnace bottom brick lining, the furnace hearth sidewall brick lining, and the furnace base located below the furnace hearth sidewall brick lining; Among them, the outer side of the furnace bottom brick lining and the furnace hearth side wall brick lining is provided with a smooth cast iron cooling wall, and the furnace base is provided with a cooling device; The furnace bottom lining is provided with a heat-insulating brick layer and a heat-conducting brick layer in sequence from the bottom of the furnace hearth to the furnace base. The heat-insulating brick layer includes dense clay bricks and composite mullite bricks, and the heat-conducting brick layer is semi-graphite carbon bricks. The furnace hearth sidewall brick lining is constructed using the composite mullite bricks, and at the corner between the furnace hearth and the furnace bottom, the furnace hearth sidewall brick lining extends inward to form a brick lining reinforcement structure.

2. The blast furnace hearth structure for vanadium-titanium magnetite smelting according to claim 1, characterized in that, The material properties of the smooth cast iron cooling wall are superior to those of QT400-18 ductile iron.

3. The blast furnace hearth structure for vanadium-titanium magnetite smelting according to claim 2, characterized in that, The smooth cast iron cooling wall is connected to a soft water closed-loop cooling system.

4. The blast furnace hearth structure for vanadium-titanium magnetite smelting according to claim 1, characterized in that, The furnace bottom brick lining is constructed using a vertical masonry method.

5. The blast furnace hearth structure for vanadium-titanium magnetite smelting according to claim 1, characterized in that, The brick lining reinforcement structure is formed by laying at least 3 layers of composite mullite bricks laterally from the cooling wall of the furnace hearth into the furnace, and the extension depth of the brick lining reinforcement structure into the furnace is 1.4 to 1.6 meters.

6. The blast furnace hearth structure for vanadium-titanium magnetite smelting according to claim 1, characterized in that, The cooling device is a water-cooled pipe embedded in the concrete structure of the furnace base.

7. The blast furnace hearth structure for vanadium-titanium magnetite smelting according to claim 1, characterized in that, The blast furnace hearth structure is suitable for smelting vanadium-titanium magnetite with a TiO2 content greater than 15% in the slag, and the effective volume of the blast furnace to which the blast furnace hearth structure is applied is 1000~2000 cubic meters.

8. The blast furnace hearth structure for vanadium-titanium magnetite smelting according to claim 1, characterized in that, The layer sequence of the furnace bottom brick lining from the bottom of the hearth to the furnace base includes: layers 1-3 are dense clay bricks, layers 4-5 are composite mullite bricks, layers 6-8 are the aforementioned dense clay bricks, and layers 9-10 are semi-graphite carbon bricks.

9. A cooling regulation method, characterized in that, The blast furnace hearth structure for vanadium-titanium magnetite smelting as described in any one of claims 1-7 includes the following steps: Based on the utilization coefficient and service stage of the blast furnace, the smooth cast iron cooling wall is dynamically controlled in zones. When the blast furnace utilization coefficient is ≥2.5t / (m³·d) or in the later stage of furnace service, the heat flow intensity of the first and second cooling walls at the bottom of the hearth is controlled at 1200~1500kcal / (m²·h), and the heat flow intensity of the third and fourth cooling walls at the top of the hearth is controlled at 2800~3500kcal / (m²·h). When the blast furnace utilization coefficient is <2.5t / (m³•d) or when it is in the middle of the furnace operation from start-up, the heat flux intensity of the first and second cooling walls at the bottom of the hearth should be controlled at 900~1200 kcal / (m²•h), and the heat flux intensity of the third and fourth cooling walls at the top of the hearth should be controlled at 2000~2800 kcal / (m²•h).

10. The cooling regulation method according to claim 9, characterized in that, During the control process, the temperature difference between the cooling water of the first cooling wall and the second cooling wall is controlled within the range of 0.4~0.8℃, and the temperature difference between the cooling water of the third cooling wall and the fourth cooling wall is controlled within the range of 1.2~2.5℃.

Images