A spherical bottom bottom-blown hot-metal ladle bottom masonry structure and a construction method thereof

Abstract

The application discloses a kind of spherical bottom bottom blowing hot metal tank bottom masonry structure and its construction method, including spherical bottom shell, tank bottom permanent layer castable, tank bottom working layer surrounding brick, tank bottom working layer castable, gas supply brick and customized grid, customized grid is fixed in spherical bottom shell inner surface and is arranged in horizontal direction;Tank bottom permanent layer castable is attached to the inner surface of spherical bottom shell, and can freely pass through and completely wrap customized grid;Two intervally arranged gas supply bricks are located on the upper surface of customized grid, and the gas supply pipes on the two gas supply bricks are vertically extended downwards, sequentially pass through customized grid and spherical bottom shell and are communicated with external air;Tank bottom working layer castable is filled in the periphery of two gas supply bricks, and tank bottom working layer surrounding brick is arranged between tank bottom working layer castable and tank bottom permanent layer castable.The application utilizes customized grid, changes the spherical bottom of hot metal tank into flat bottom, which can ensure that the bottom blowing gas can be vertically sent upwards in the narrow volume range of hot metal tank.

Description

Technical Field

[0001] This invention relates to the field of iron and steel metallurgy technology, specifically to a bottom masonry structure for a spherical bottom-blown molten iron ladle and its construction method. Background Technology

[0002] Ladle smelting is a crucial piece of equipment in the metallurgical industry for transporting and mixing molten iron. With the continuous advancement of metallurgical technology and the increasing adoption of short-process and green metallurgy, the molten iron smelting process requires the addition of large quantities of scrap steel, necessitating heating. Conventional oxygen blowing heating can only preheat the scrap steel, with limited temperature increases. LF furnace electrode heating is currently mostly used on ladles. To prevent excessively high local temperatures during electrode heating, air-supplying blocks need to be installed at the bottom for bottom blowing agitation. Currently, there are no reports in China on bottom blowing heating technology for spherical bottom molten iron ladles. The following problems exist in the construction of adding air-supplying blocks to the bottom of spherical bottom molten iron ladles: Because the gas supply bricks need to be replaced multiple times, when the gas supply bricks are installed directly on the spherical bottom of the molten iron ladle, it is impossible to ensure that the gas supply bricks are installed horizontally, and it is impossible to ensure that the bottom-blown gas flow field is vertical and horizontally upward.

[0003] When the bottom of the molten iron ladle is directly leveled with a steel plate before the air supply bricks are installed, the weight of the molten iron ladle will be greatly increased. When the bottom of the molten iron ladle is directly leveled with castable refractory before the air supply bricks are installed, the castable refractory will be damaged after use, and the installation level of the air supply bricks at the bottom of the molten iron ladle cannot be guaranteed, which will change the bottom blowing gas flow and indirectly affect the molten iron flow field.

[0004] Due to the requirements of the molten iron flow field, two gas supply bricks need to be installed. However, the horizontal cross-sectional area of ​​the spherical bottom is small, and when installing the gas supply bricks, there must be sufficient distance between the two gas supply bricks. At the same time, a certain distance must also be maintained from the working lining bricks of the molten iron ladle to prevent the bottom-blown gas from causing excessive scouring of the working lining bricks of the molten iron ladle.

[0005] Based on the above, this invention proposes a bottom masonry structure for a spherical bottom-blown molten iron ladle and its construction method, which can effectively solve the above problems. Summary of the Invention

[0006] To ensure horizontal installation of the gas supply bricks when installing a spherical bottom molten iron ladle, with the bottom-blown gas flowing vertically upwards, a reasonable layout of the gas supply bricks, a reasonable spacing between two gas supply bricks, and a reasonable spacing between the gas supply bricks and the working lining of the molten iron ladle, thus ensuring normal bottom-blown electrode heating of the molten iron ladle, this invention provides a bottom masonry structure for a spherical bottom bottom-blown molten iron ladle and its construction method.

[0007] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: On one hand, the present invention provides a bottom construction structure for a spherical bottom-blown molten iron ladle, comprising a spherical bottom shell, a permanent bottom layer castable, bottom working layer surrounding bricks, a gas supply brick, and a custom grid. The custom grid is fixed to the inner surface of the spherical bottom shell and arranged horizontally. The permanent bottom layer castable is attached to the inner surface of the spherical bottom shell and can freely pass through and completely enclose the custom grid. Two spaced gas supply bricks are located on the upper surface of the custom grid, and the gas supply pipes on the two gas supply bricks extend vertically downwards and pass through the custom grid and the spherical bottom shell in sequence to communicate with the outside air. The two gas supply bricks are surrounded by the bottom working layer castable, and the bottom working layer surrounding bricks are arranged between the bottom working layer castable and the bottom permanent layer castable.

[0008] Preferably, the upper surface of the customized grille is provided with a steel plate corresponding to each of the gas supply bricks, and the gas supply bricks are placed on the steel plate.

[0009] Furthermore, the steel plate is provided with openings, and the spherical bottom shell is provided with air supply holes corresponding to the openings. A protective tube fitted outside the air supply pipe is vertically connected between the openings and the air supply holes.

[0010] Furthermore, the steel plate has a thickness of 5-10mm, a length of 500-600mm, and a width of 500-600mm; the diameter of the opening and the air supply hole are both 50-60mm; and the diameter of the protective tube is 50-60mm and the length is 120-180mm.

[0011] Preferably, the customized grating is made of steel bars with a thickness of 30-50mm and a width of 10-30mm welded into a mesh structure, with an interval of 200-300mm between adjacent steel bars; the maximum height of the customized grating from the bottom of the tank is 180-240mm.

[0012] Preferably, the gas supply brick is a slotted gas supply brick made of corundum chromium, with a height of 400~550mm, the distance between the gas supply cores of two gas supply bricks is 900~1400mm, the minimum distance between the gas supply brick and the working layer surrounding brick at the bottom of the tank is ≤100mm, and the maximum distance between the gas supply brick and the working layer surrounding brick at the bottom of the tank is ≥600mm.

[0013] Preferably, the permanent bottom layer castable is made of corundum-mullite with a chemical composition of Al2O3 ≥ 60%, a room temperature refractory strength ≥ 50 MPa, and a water-cooled thermal shock resistance of ≥ 30 cycles at 1100℃. The maximum thickness of the permanent bottom layer castable is 350~450 mm.

[0014] Preferably, the thickness of the working layer bricks at the bottom of the tank is 100mm, the length is 200~240mm, the material is aluminum silicon carbide carbon, the chemical composition content is Al2O3≥50%, SiC+C≥12%, and the room temperature refractory strength is ≥50MPa.

[0015] Preferably, the bottom working layer casting material is aluminum silicon carbide, with a chemical composition content of Al2O3≥60%, SiC+C≥8%, and a room temperature compressive strength≥40MPa.

[0016] Preferably, the spherical bottom blown molten iron ladle is used for electrode heating of molten iron, with the temperature of the molten iron before heating ≤1500℃ and the temperature of the molten iron after heating ≤1550℃.

[0017] On the other hand, the present invention provides a construction method for the bottom masonry structure of a spherical bottom-blown molten iron ladle, comprising the following steps: S1. Clean all residue from the spherical bottom shell; S2. According to the design structure, two air supply holes are opened at the corresponding parts of the spherical bottom shell; S3. Weld a custom-made grid onto the spherical bottom shell, and weld a protective pipe vertically between the custom-made grid and the air supply hole. S4. Positioning and installing the gas supply block so that the gas supply pipe extends downward through the spherical bottom shell; S5. After pouring the permanent layer of the casting material at the bottom of the casting tank, the next step can be carried out only after curing for at least 24 hours. S6. Construct the working layer brickwork at the bottom of the tank. The first layer of working layer brickwork should be 60-80mm away from the spherical bottom shell. The second to seventh layers should be set back 60-80mm from the upper working layer brickwork towards the spherical bottom shell. The seventh layer should be 60-80mm away from the spherical bottom shell. After every 2-3 rings of working layer brickwork, pour the permanent bottom layer castable into the reserved joint between the spherical bottom shell and the working layer brickwork. S7. Pour the bottom working layer of the casting tank until it is level with the height of the gas supply brick. After curing for at least 24 hours, complete the construction of the bottom of the spherical bottom shell. S8. After the construction of other parts of the molten iron ladle is completed, it can be baked and put into use after curing for at least 24 hours.

[0018] Compared with the prior art, the present invention has the following advantages: This invention welds a protective steel pipe between the opening in the steel shell and the opening in the customized grating steel plate, preventing the gas supply pipe of the gas supply brick from directly contacting the refractory materials such as the bottom casting material of the molten iron ladle, thus providing a certain degree of protection. Moreover, it allows for quick replacement of the gas supply brick during intermediate repairs.

[0019] This invention utilizes a custom-made grating with welded steel plates to transform the spherical bottom of the molten iron ladle into a flat bottom. This allows for the horizontal installation of gas supply bricks during both major and minor overhauls, ensuring that bottom-blown gas can be delivered vertically upwards within the limited volume of the molten iron ladle.

[0020] This invention involves welding a custom mesh grid to the bottom of a bottom-blown molten iron ladle. When pouring the permanent layer of molten iron at the bottom of the ladle, the custom grid can freely pass through and wrap around the grid. During the middle of its use, the permanent layer can be effectively repaired, preventing the permanent layer from separating from the steel grid.

[0021] This invention customizes the positioning of the grille and the air supply brick to minimize the distance between the air supply brick and the bottom brick of the molten iron ladle, thereby maximizing the spacing between the air supply cores of the two air supply bricks and maximizing the volume of molten iron in the ladle. Attached Figure Description

[0022] Figure 1 This is a schematic cross-sectional view of the bottom construction of the spherical bottom blown iron ladle of the present invention; Figure 2 This is a top view schematic diagram of the customized grille of the present invention.

[0023] Among them, 1-permanent layer castable at the bottom of the tank; 2-protective pipe; 3-customized grating; 4-air supply brick; 5-working layer castable at the bottom of the tank; 6-working layer surrounding bricks at the bottom of the tank; 7-steel bar; 8-opening; 9-steel plate; 10-spherical bottom shell; 11-air supply pipe. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solutions of the present invention, the preferred embodiments of the present invention are described below in conjunction with specific examples, but these should not be construed as limiting the present patent.

[0025] Unless otherwise specified, the test methods or experimental methods described in the following examples are conventional methods; unless otherwise specified, the reagents and materials are obtained from conventional commercial sources or prepared by conventional methods.

[0026] Example 1: This embodiment provides a bottom construction structure for a spherical bottom-blown molten iron ladle, including: a spherical bottom shell, a permanent bottom layer castable 1, bottom working layer surrounding bricks 6, bottom working layer castable 5, air supply bricks 4, and a custom grid 3. The custom grid 3 is fixed to the inner surface of the spherical bottom shell and arranged horizontally; the permanent bottom layer castable 1 is attached to the inner surface of the spherical bottom shell and can freely pass through and completely enclose the custom grid 3; two spaced air supply bricks 4 are located on the upper surface of the custom grid 3, and the air supply pipes on the two air supply bricks 4 extend vertically downwards, passing through the custom grid 3 and the spherical bottom shell in sequence to communicate with the outside air; the two air supply bricks 4 are surrounded by bottom working layer castable 5, and bottom working layer surrounding bricks 6 are arranged between the bottom working layer castable 5 and the bottom permanent layer castable 1.

[0027] The upper surface of the custom grille 3 is provided with steel plates 9 that correspond one-to-one with the air supply bricks 4, and the air supply bricks 4 are located on the steel plates 9. The steel plates 9 are provided with openings 8, and the spherical bottom shell is provided with air supply holes that correspond one-to-one with the openings 8. A protective tube 2, which is fitted onto the outside of the air supply pipe, is vertically connected between the openings 8 and the air supply holes.

[0028] The permanent layer castable refractory at the bottom of the tank is made of corundum-mullite, with a chemical composition of Al2O3 ≥ 60%, a room temperature refractory strength ≥ 50 MPa, and a water-cooled thermal shock resistance of ≥ 30 cycles at 1100℃. The working layer lining bricks at the bottom of the tank are made of aluminosilicate carbonaceous material, with a chemical composition of Al2O3 ≥ 50%, SiC+C ≥ 12%, and a room temperature refractory strength ≥ 50 MPa. The working layer castable refractory at the bottom of the tank is also made of aluminosilicate carbonaceous material, with a chemical composition of Al2O3 ≥ 60%, SiC+C ≥ 8%, and a room temperature compressive strength ≥ 40 MPa.

[0029] This embodiment provides a construction method for the bottom of a spherical bottom-blown molten iron ladle, mainly including the following steps: The first step is to clean all the residue from the steel shell of the spherical-bottomed molten iron ladle; The second step is to open two air supply holes with a diameter of 50mm at the corresponding locations on the bottom of the steel shell, according to the design drawings. The third step involves welding a custom-made grating onto the spherical bottom steel shell. The maximum height of the custom-made grating from the bottom of the molten iron ladle is 210mm. A protective pipe for the air supply is vertically welded between the custom-made grating and the air supply hole of the steel shell. The custom-made grating is a mesh structure welded from steel bars 7, each 30mm thick and 30mm wide, with a 300mm interval between each bar 7. A steel plate, 5mm thick, 600mm long, and 600mm wide, is welded and fixed onto the grating at the grating position corresponding to the air supply hole. A hole with a diameter of 50mm is made at the corresponding position of the air supply hole. The protective pipe for the air supply is 50mm in diameter and 150mm in length. The fourth step is to position and install the slit-type gas supply block, with a height of 450mm; the distance between the cores of the two gas supply blocks is 1000mm, so that the gas supply pipe 11 extends downward through the spherical bottom shell 10. The fifth step is to pour the permanent layer of castable material at the bottom of the tank to a height of 350mm, completely covering the custom grid. After pouring, the material must be cured for at least 24 hours before proceeding to the next step. Step 6: Construct the working layer brickwork at the bottom of the tank using flat-laid bricks, 100mm thick, with a working layer length of 220mm. The first layer of working layer brickwork is 80mm away from the steel shell. The second to seventh layers are progressively recessed 60mm towards the tank shell compared to the previous layer, with the seventh layer 80mm away from the steel shell. After every 2-3 rings of working layer brickwork, pour permanent layer castable refractory into the pre-reserved joint between the tank shell and the working layer brickwork. Step 7: Pour the bottom working layer of the casting material into the tank until it is level with the height of the gas supply brick. After curing for at least 24 hours, complete the construction of the bottom of the spherical bottom blow iron tank. Step 8: After the construction of other parts of the molten iron ladle is completed, it can be baked and put into use after curing for at least 24 hours.

[0030] Example 2: This embodiment provides a bottom construction structure for a spherical bottom-blown molten iron ladle, including: a spherical bottom shell, a permanent bottom layer castable 1, bottom working layer surrounding bricks 6, bottom working layer castable 5, air supply bricks 4, and a custom grid 3. The custom grid 3 is fixed to the inner surface of the spherical bottom shell and arranged horizontally; the permanent bottom layer castable 1 is attached to the inner surface of the spherical bottom shell and can freely pass through and completely enclose the custom grid 3; two spaced air supply bricks 4 are located on the upper surface of the custom grid 3, and the air supply pipes on the two air supply bricks 4 extend vertically downwards, passing through the custom grid 3 and the spherical bottom shell in sequence to communicate with the outside air; the two air supply bricks 4 are surrounded by bottom working layer castable 5, and bottom working layer surrounding bricks 6 are arranged between the bottom working layer castable 5 and the bottom permanent layer castable 1.

[0031] The upper surface of the custom grille 3 is provided with steel plates 9 that correspond one-to-one with the air supply bricks 4, and the air supply bricks 4 are located on the steel plates 9. The steel plates 9 are provided with openings 8, and the spherical bottom shell is provided with air supply holes that correspond one-to-one with the openings 8. A protective tube 2, which is fitted onto the outside of the air supply pipe, is vertically connected between the openings 8 and the air supply holes.

[0032] The permanent layer castable refractory at the bottom of the tank is made of corundum-mullite, with a chemical composition of Al2O3 ≥ 60%, a room temperature refractory strength ≥ 50 MPa, and a water-cooled thermal shock resistance of ≥ 30 cycles at 1100℃. The working layer lining bricks at the bottom of the tank are made of aluminosilicate carbonaceous material, with a chemical composition of Al2O3 ≥ 50%, SiC+C ≥ 12%, and a room temperature refractory strength ≥ 50 MPa. The working layer castable refractory at the bottom of the tank is also made of aluminosilicate carbonaceous material, with a chemical composition of Al2O3 ≥ 60%, SiC+C ≥ 8%, and a room temperature compressive strength ≥ 40 MPa.

[0033] This embodiment provides a construction method for the bottom of a spherical bottom-blown molten iron ladle, mainly including the following steps: The first step is to clean all the residue from the steel shell of the spherical-bottomed molten iron ladle; The second step is to open two air supply holes with a diameter of 60mm at the corresponding locations on the bottom of the steel shell, according to the design drawings. The third step involves welding a custom-made grating onto the spherical bottom steel shell. The maximum height of the custom-made grating from the bottom of the molten iron ladle is 240mm. A protective pipe for the air supply is vertically welded between the custom-made grating and the air supply port on the steel shell. The custom-made grating is a mesh structure welded from steel bars 50mm thick and 20mm wide, with each bar spaced 200mm apart. A steel plate, 10mm thick, 500mm long, and 500mm wide, is welded and fixed onto the grating at the location corresponding to the air supply port. A hole with a diameter of 60mm is drilled at the corresponding location of the air supply port. The protective pipe for the air supply is 60mm in diameter and 180mm long. The fourth step is to position and install the slit-type gas supply block, with a height of 400mm; the distance between the cores of the two gas supply blocks is 1400mm, so that the gas supply pipe 11 extends downward through the spherical bottom shell 10. The fifth step is to pour the permanent layer of castable material at the bottom of the tank to a height of 400mm, completely covering the custom grid. After pouring, the material must be cured for at least 24 hours before proceeding to the next step. Step 6: Construct the working layer brickwork at the bottom of the tank using flat-laid bricks, 100mm thick, with a working layer length of 240mm. The first layer of working layer brickwork is 60mm away from the steel shell. The second to seventh layers are progressively recessed 70mm towards the tank shell compared to the previous layer, with the seventh layer remaining 60mm away from the steel shell. After every 2-3 rings of working layer brickwork, pour permanent layer castable refractory into the pre-reserved joint between the tank shell and the working layer brickwork. Step 7: Pour the bottom working layer of the casting material into the tank until it is level with the height of the gas supply brick. After curing for at least 24 hours, complete the construction of the bottom of the spherical bottom blow iron tank. Step 8: After the construction of other parts of the molten iron ladle is completed, it can be baked and put into use after curing for at least 24 hours.

[0034] Example 3: This embodiment provides a bottom construction structure for a spherical bottom-blown molten iron ladle, including: a spherical bottom shell, a permanent bottom layer castable 1, bottom working layer surrounding bricks 6, bottom working layer castable 5, air supply bricks 4, and a custom grid 3. The custom grid 3 is fixed to the inner surface of the spherical bottom shell and arranged horizontally; the permanent bottom layer castable 1 is attached to the inner surface of the spherical bottom shell and can freely pass through and completely enclose the custom grid 3; two spaced air supply bricks 4 are located on the upper surface of the custom grid 3, and the air supply pipes on the two air supply bricks 4 extend vertically downwards, passing through the custom grid 3 and the spherical bottom shell in sequence to communicate with the outside air; the two air supply bricks 4 are surrounded by bottom working layer castable 5, and bottom working layer surrounding bricks 6 are arranged between the bottom working layer castable 5 and the bottom permanent layer castable 1.

[0035] The upper surface of the custom grille 3 is provided with steel plates 9 that correspond one-to-one with the air supply bricks 4, and the air supply bricks 4 are located on the steel plates 9. The steel plates 9 are provided with openings 8, and the spherical bottom shell is provided with air supply holes that correspond one-to-one with the openings 8. A protective tube 2, which is fitted onto the outside of the air supply pipe, is vertically connected between the openings 8 and the air supply holes.

[0036] The permanent layer castable refractory at the bottom of the tank is made of corundum-mullite, with a chemical composition of Al2O3 ≥ 60%, a room temperature refractory strength ≥ 50 MPa, and a water-cooled thermal shock resistance of ≥ 30 cycles at 1100℃. The working layer lining bricks at the bottom of the tank are made of aluminosilicate carbonaceous material, with a chemical composition of Al2O3 ≥ 50%, SiC+C ≥ 12%, and a room temperature refractory strength ≥ 50 MPa. The working layer castable refractory at the bottom of the tank is also made of aluminosilicate carbonaceous material, with a chemical composition of Al2O3 ≥ 60%, SiC+C ≥ 8%, and a room temperature compressive strength ≥ 40 MPa.

[0037] This embodiment provides a construction method for the bottom of a spherical bottom-blown molten iron ladle, mainly including the following steps: The first step is to clean all the residue from the steel shell of the spherical-bottomed molten iron ladle; The second step is to drill two air supply holes with a diameter of 55mm at the corresponding locations on the bottom of the steel shell, according to the design drawings. The third step involves welding a custom-made grating onto the spherical bottom steel shell. The maximum height of the custom-made grating from the bottom of the molten iron ladle is 180mm. A protective pipe for the air supply is vertically welded between the custom-made grating and the air supply hole on the steel shell. The custom-made grating is a mesh structure welded from steel bars 40mm thick and 20mm wide, with each bar spaced 250mm apart. A steel plate, 10mm thick, 550mm long, and 550mm wide, is welded and fixed to the grating at the location corresponding to the air supply hole. An opening with a diameter of 55mm is made at the corresponding location of the air supply hole. The protective pipe for the air supply is 55mm in diameter and 150mm long. The fourth step is to position and install the slit-type gas supply block, with a height of 550mm; the distance between the cores of the two gas supply blocks is 900mm, so that the gas supply pipe 11 extends downward through the spherical bottom shell 10. The fifth step is to pour the permanent layer of castable material at the bottom of the tank to a height of 400mm, completely covering the custom grid. After pouring, the material must be cured for at least 24 hours before proceeding to the next step. Step 6: Construct the working layer brickwork at the bottom of the tank using flat-laid bricks, 100mm thick, with a working layer length of 200mm. The first layer of working layer brickwork is 60mm away from the steel shell. The second to seventh layers are progressively recessed 70mm towards the tank shell compared to the previous layer, with the seventh layer 60mm away from the steel shell. After every 2-3 rings of working layer brickwork, pour permanent layer castable refractory into the pre-reserved joint between the tank shell and the working layer brickwork. Step 7: Pour the bottom working layer of the casting material into the tank until it is level with the height of the gas supply brick. After curing for at least 24 hours, complete the construction of the bottom of the spherical bottom blow iron tank. Step 8: After the construction of other parts of the molten iron ladle is completed, it can be baked and put into use after curing for at least 24 hours.

[0038] Example 4: This embodiment provides a bottom construction structure for a spherical bottom-blown molten iron ladle, including: a spherical bottom shell, a permanent bottom layer castable 1, bottom working layer surrounding bricks 6, bottom working layer castable 5, air supply bricks 4, and a custom grid 3. The custom grid 3 is fixed to the inner surface of the spherical bottom shell and arranged horizontally; the permanent bottom layer castable 1 is attached to the inner surface of the spherical bottom shell and can freely pass through and completely enclose the custom grid 3; two spaced air supply bricks 4 are located on the upper surface of the custom grid 3, and the air supply pipes on the two air supply bricks 4 extend vertically downwards, passing through the custom grid 3 and the spherical bottom shell in sequence to communicate with the outside air; the two air supply bricks 4 are surrounded by bottom working layer castable 5, and bottom working layer surrounding bricks 6 are arranged between the bottom working layer castable 5 and the bottom permanent layer castable 1.

[0039] The upper surface of the custom grille 3 is provided with steel plates 9 that correspond one-to-one with the air supply bricks 4, and the air supply bricks 4 are located on the steel plates 9. The steel plates 9 are provided with openings 8, and the spherical bottom shell is provided with air supply holes that correspond one-to-one with the openings 8. A protective tube 2, which is fitted onto the outside of the air supply pipe, is vertically connected between the openings 8 and the air supply holes.

[0040] The permanent layer castable refractory at the bottom of the tank is made of corundum-mullite, with a chemical composition of Al2O3 ≥ 60%, a room temperature refractory strength ≥ 50 MPa, and a water-cooled thermal shock resistance of ≥ 30 cycles at 1100℃. The working layer lining bricks at the bottom of the tank are made of aluminosilicate carbonaceous material, with a chemical composition of Al2O3 ≥ 50%, SiC+C ≥ 12%, and a room temperature refractory strength ≥ 50 MPa. The working layer castable refractory at the bottom of the tank is also made of aluminosilicate carbonaceous material, with a chemical composition of Al2O3 ≥ 60%, SiC+C ≥ 8%, and a room temperature compressive strength ≥ 40 MPa.

[0041] This embodiment provides a construction method for the bottom of a spherical bottom-blown molten iron ladle, mainly including the following steps: The first step is to clean all the residue from the steel shell of the spherical-bottomed molten iron ladle; The second step is to open two air supply holes with a diameter of 50mm at the corresponding locations on the bottom of the steel shell, according to the design drawings. The third step involves welding a custom-made grating onto the spherical bottom steel shell. The maximum height of the custom-made grating from the bottom of the molten iron ladle is 240mm. A protective pipe for the air supply is vertically welded between the custom-made grating and the air supply hole on the steel shell. The custom-made grating is a mesh structure welded from steel bars 50mm thick and 15mm wide, with each bar spaced 220mm apart. A steel plate, 5mm thick, 450mm long, and 450mm wide, is welded and fixed to the grating at the grating position corresponding to the air supply hole. An opening with a diameter of 50mm is made at the corresponding position of the air supply hole. The protective pipe for the air supply is 50mm in diameter and 120mm long. The fourth step is to position and install the slit-type gas supply block, with a height of 550mm; the distance between the cores of the two gas supply blocks is 1200mm, so that the gas supply pipe 11 extends downward through the spherical bottom shell 10. The fifth step is to pour the permanent layer of castable material at the bottom of the tank to a height of 450mm, completely covering the custom grid. After pouring, the material must be cured for at least 24 hours before proceeding to the next step. Step 6: Construct the working layer brickwork at the bottom of the tank using flat-laid bricks, 100mm thick, with a working layer length of 200mm. The first layer of working layer brickwork is 70mm away from the steel shell. The second to seventh layers are progressively recessed 60mm towards the tank shell compared to the previous layer, with the seventh layer 60mm away from the steel shell. After every 2-3 rings of working layer brickwork, pour permanent layer castable refractory into the pre-reserved joint between the tank shell and the working layer brickwork. Step 7: Pour the bottom working layer of the casting material into the tank until it is level with the height of the gas supply brick. After curing for at least 24 hours, complete the construction of the bottom of the spherical bottom blow iron tank. Step 8: After the construction of other parts of the molten iron ladle is completed, it can be baked and put into use after curing for at least 24 hours.

[0042] Example 5: This embodiment provides a bottom construction structure for a spherical bottom-blown molten iron ladle, including: a spherical bottom shell, a permanent bottom layer castable 1, bottom working layer surrounding bricks 6, bottom working layer castable 5, air supply bricks 4, and a custom grid 3. The custom grid 3 is fixed to the inner surface of the spherical bottom shell and arranged horizontally; the permanent bottom layer castable 1 is attached to the inner surface of the spherical bottom shell and can freely pass through and completely enclose the custom grid 3; two spaced air supply bricks 4 are located on the upper surface of the custom grid 3, and the air supply pipes on the two air supply bricks 4 extend vertically downwards, passing through the custom grid 3 and the spherical bottom shell in sequence to communicate with the outside air; the two air supply bricks 4 are surrounded by bottom working layer castable 5, and bottom working layer surrounding bricks 6 are arranged between the bottom working layer castable 5 and the bottom permanent layer castable 1.

[0043] The upper surface of the custom grille 3 is provided with steel plates 9 that correspond one-to-one with the air supply bricks 4, and the air supply bricks 4 are located on the steel plates 9. The steel plates 9 are provided with openings 8, and the spherical bottom shell is provided with air supply holes that correspond one-to-one with the openings 8. A protective tube 2, which is fitted onto the outside of the air supply pipe, is vertically connected between the openings 8 and the air supply holes.

[0044] The permanent layer castable refractory at the bottom of the tank is made of corundum-mullite, with a chemical composition of Al2O3 ≥ 60%, a room temperature refractory strength ≥ 50 MPa, and a water-cooled thermal shock resistance of ≥ 30 cycles at 1100℃. The working layer lining bricks at the bottom of the tank are made of aluminosilicate carbonaceous material, with a chemical composition of Al2O3 ≥ 50%, SiC+C ≥ 12%, and a room temperature refractory strength ≥ 50 MPa. The working layer castable refractory at the bottom of the tank is also made of aluminosilicate carbonaceous material, with a chemical composition of Al2O3 ≥ 60%, SiC+C ≥ 8%, and a room temperature compressive strength ≥ 40 MPa.

[0045] This embodiment provides a construction method for the bottom of a spherical bottom-blown molten iron ladle, mainly including the following steps: The first step is to clean all the residue from the steel shell of the spherical-bottomed molten iron ladle; The second step is to open two air supply holes with a diameter of 50mm at the corresponding locations on the bottom of the steel shell, according to the design drawings. The third step involves welding a custom-made grating onto the spherical bottom steel shell. The maximum height of the custom-made grating from the bottom of the molten iron ladle is 200mm. A protective pipe for the air supply is vertically welded between the custom-made grating and the air supply hole on the steel shell. The custom-made grating is a mesh structure welded from steel bars 50mm thick and 10mm wide, with each bar spaced 220mm apart. A steel plate, 5mm thick, 450mm long, and 450mm wide, is welded and fixed to the grating at the grating position corresponding to the air supply hole. An opening with a diameter of 50mm is made at the corresponding position of the air supply hole. The protective pipe for the air supply is 50mm in diameter and 120mm long. The fourth step is to position and install the slit-type gas supply block, with a height of 520mm; the distance between the cores of the two gas supply blocks is 1000mm, so that the gas supply pipe 11 extends downward through the spherical bottom shell 10. The fifth step is to pour the permanent layer of castable material at the bottom of the tank to a height of 400mm, completely covering the custom grid. After pouring, the material must be cured for at least 24 hours before proceeding to the next step. Step 6: Construct the working layer brickwork at the bottom of the tank using flat-laid bricks, 100mm thick, with a working layer length of 200mm. The first layer of working layer brickwork is 70mm away from the steel shell. The second to seventh layers are progressively recessed 60mm towards the tank shell compared to the previous layer, with the seventh layer 60mm away from the steel shell. After every 2-3 rings of working layer brickwork, pour permanent layer castable refractory into the pre-reserved joint between the tank shell and the working layer brickwork. Step 7: Pour the bottom working layer of the casting material into the tank until it is level with the height of the gas supply brick. After curing for at least 24 hours, complete the construction of the bottom of the spherical bottom blow iron tank. Step 8: After the construction of other parts of the molten iron ladle is completed, it can be baked and put into use after curing for at least 24 hours.

[0046] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A bottom masonry structure for a spherical bottom-blown molten iron ladle, characterized in that: The tank includes a permanent bottom layer castable (1), a custom grid (3), an air supply brick (4), a tank bottom working layer castable (5), a tank bottom working layer surrounding brick (6), and a spherical bottom shell (10). The custom grid (3) is fixed to the inner surface of the spherical bottom shell and arranged horizontally. The permanent bottom layer castable (1) is attached to the inner surface of the spherical bottom shell and can freely pass through and completely enclose the custom grid (3). Two spaced air supply bricks (4) are located on the upper surface of the custom grid (3). The air supply pipes (11) on the two air supply bricks (4) extend vertically downward and pass through the custom grid (3) and the spherical bottom shell in sequence to communicate with the outside air. The tank bottom working layer castable (5) is filled around the two air supply bricks (4). The tank bottom working layer surrounding brick (6) is set between the tank bottom working layer castable (5) and the tank bottom permanent layer castable (1).

2. The bottom masonry structure of the spherical bottom blown iron ladle according to claim 1, characterized in that: The upper surface of the custom grille (3) is provided with a steel plate (9) that corresponds one-to-one with the gas supply brick (4), and the gas supply brick (4) is located on the steel plate (9).

3. The bottom masonry structure of the spherical bottom blown iron ladle according to claim 2, characterized in that: The steel plate (9) is provided with an opening (8), and the spherical bottom shell is provided with an air supply hole corresponding to the opening (8). A protective tube (2) fitted outside the air supply pipe is vertically connected between the opening (8) and the air supply hole.

4. The bottom masonry structure of the spherical bottom blown iron ladle according to claim 3, characterized in that: The steel plate (9) has a thickness of 5~10mm, a length of 500~600mm, and a width of 500~600mm. The diameter of the opening (8) and the air supply hole is 50~60mm. The diameter of the protective tube (2) is 50~60mm and the length is 120~180mm.

5. The bottom masonry structure of the spherical bottom blown iron ladle according to claim 1, characterized in that: The customized grille (3) is made of steel bars (7) with a thickness of 30~50mm and a width of 10~30mm welded into a mesh structure, with a spacing of 200~300mm between adjacent steel bars (7); the customized grille (3) is 180~240mm above the bottom of the tank.

6. The bottom masonry structure of the spherical bottom blown iron ladle according to claim 1, characterized in that: The gas supply brick (4) is a slit-type gas supply brick (4) made of corundum chromium, with a height of 400~550mm. The distance between the gas supply cores of two gas supply bricks (4) is 900~1400mm. The minimum distance between the gas supply brick (4) and the bottom brick of the molten iron ladle is ≤100mm, and the distance between the gas supply brick (4) and the wall brick of the molten iron ladle is ≥600mm.

7. The bottom masonry structure of the spherical bottom blown iron ladle according to claim 1, characterized in that: The permanent layer castable material (1) at the bottom of the tank is made of corundum mullite, with a chemical composition content of Al2O3≥60%, a room temperature refractory strength≥50MPa, and a water-cooled thermal shock resistance of ≥30 times at 1100℃.

8. The bottom masonry structure of the spherical bottom blown iron ladle according to claim 1, characterized in that: The thickness of the working layer brick (6) at the bottom of the tank is 100mm, the length is 200~240mm, the material is aluminum silicon carbide carbon, the chemical composition content is Al2O3≥50%, SiC+C≥12%, and the refractory strength at room temperature is ≥50MPa.

9. The bottom masonry structure of the spherical bottom blown iron ladle according to claim 1, characterized in that: The bottom working layer casting material (5) is made of aluminum silicon carbide, with a chemical composition content of Al2O3≥60%, SiC+C≥8%, and room temperature pressure resistance ≥40MPa.

10. A construction method for the bottom masonry structure of a spherical bottom-blown molten iron ladle as described in claim 1, characterized in that, Includes the following steps: S1. Clean all residue from the spherical bottom shell; S2. According to the design structure, two air supply holes are opened at the corresponding parts of the spherical bottom shell; S3. Weld a custom grid (3) onto the spherical bottom shell, and weld a protective tube (2) vertically between the custom grid (3) and the air supply hole. S4. The gas supply block (4) is positioned and installed so that the gas supply pipe (11) passes downward through the spherical bottom shell (10). S5. Casting material for the permanent layer at the bottom of the casting tank (1). After casting, the next step can be carried out only after curing for at least 24 hours. S6. Construct the working layer bricks (6) at the bottom of the tank. The first working layer bricks are 60-80mm away from the spherical bottom shell. The second to seventh layers are 60-80mm away from the upper working layer bricks and are respectively moved back towards the spherical bottom shell. The seventh layer bricks are 60-80mm away from the spherical bottom shell. After every 2-3 rings of working layer bricks (6) are constructed, pour the permanent layer casting material (1) into the reserved joint between the spherical bottom shell and the working layer bricks. S7. Pour the bottom working layer of the casting material (5) until it is level with the height of the gas supply brick (4). After curing for at least 24 hours, complete the construction of the bottom of the spherical bottom shell. S8. After the construction of other parts of the molten iron ladle is completed, it can be baked and put into use after curing for at least 24 hours.

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