Gradient sintering method and equipment for light high-strength magnesia carbon brick

Abstract

The invention provides a gradient sintering method and equipment for a light high-strength magnesia carbon brick, belongs to the technical field of brick making equipment, and solves the technical problem that the composition, the structure and the performance of the existing magnesia carbon brick cannot be continuously or quasi-continuously changed in the material thickness or length direction. The invention discloses a gradient sintering method and equipment for light high-strength magnesia carbon bricks. Comprising the following steps: S1, proportioning raw materials, wherein the raw materials of the light high-strength magnesia carbon brick are prepared from the following substances in parts by weight: 50-70 parts of high-purity fused magnesite, 10-15 parts of flaky graphite, 3-5 parts of phenolic resin, 5-9 parts of an antioxidant, 5-7 parts of silicon carbide, 1-3 parts of aluminum oxide, 5-9 parts of graphite, 2-4 parts of coal ash, 8-10 parts of quartz powder and 9-12 parts of clay; s2, mixing the materials: pouring the proportioned materials into a grinding and mixing machine for grinding and mixing, wherein the speed of the grinding and mixing machine is 150-300 r / min in the mixing process; the method has the advantage of realizing continuous or quasi-continuous change of composition, structure and performance in the thickness or length direction of the material.

Description

Technical Field

[0001] This invention belongs to the technical field of brick-making equipment, and relates to a sintering method and equipment, particularly a gradient sintering method and equipment for lightweight high-strength magnesia-carbon bricks. Background Technology

[0002] Magnesia-carbon bricks are non-burning carbon composite refractory materials made from high-melting-point alkaline oxide magnesium oxide (melting point 2800°C) and high-melting-point carbon materials that are difficult to be wetted by slag, with the addition of various non-oxide additives. They are bonded together with carbonaceous binders. Magnesia-carbon bricks are mainly used as linings in converters, AC electric arc furnaces, and DC electric arc furnaces, as well as in slag lines of steel ladles. As a composite refractory material, magnesia-carbon bricks effectively utilize the strong slag erosion resistance of magnesia and the high thermal conductivity and low expansion of carbon, compensating for the major drawback of poor spalling resistance of magnesia.

[0003] A search revealed a Chinese patent document that discloses a sintering device for magnesia-carbon bricks [Application No.: 202021547977.2; Publication No.: CN 212645374 U]. A sintering device for magnesia-carbon bricks includes a combustion chamber, a sintering box at the top of the combustion chamber, and a placement assembly rotatably connected to the upper end face of the combustion chamber and inside the sintering box. A heat-conducting column, penetrating the placement assembly and rotatably connected to it, is provided on the upper end face of the combustion chamber. Multiple vent holes are evenly distributed on the circumference of the heat-conducting column. This sintering device for magnesia-carbon bricks allows for the even and spaced placement of multiple magnesia-carbon brick blanks via the placement assembly, facilitating uniform heating of the blanks and increasing the heating area for rapid firing. The high-temperature gas from the combustion chamber is quickly delivered to each magnesia-carbon brick blank within the sintering box via gas distribution pipes, gas pipes, heat-conducting columns, and vent holes, further ensuring uniform heating and improving production efficiency. Multiple exhaust channels facilitate the rapid removal of water vapor, making the device highly practical.

[0004] Although this patent improves production efficiency and facilitates rapid water vapor discharge by setting multiple emission channels, making it highly practical, it cannot achieve gradient sintering capability. This means that the magnesia-carbon bricks prepared by this application cannot have continuous or quasi-continuous variations in composition, structure, and properties in the material thickness or length direction. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a gradient sintering method and equipment for lightweight, high-strength magnesia-carbon bricks. The technical problem this invention aims to solve is: how to achieve continuous or quasi-continuous changes in composition, structure, and properties in the thickness or length direction of the material.

[0006] The objective of this invention can be achieved through the following technical solutions: A gradient sintering method and equipment for lightweight, high-strength magnesia-carbon bricks, comprising the following steps: S1. Raw Material Proportioning: The raw materials for this lightweight, high-strength magnesia-carbon brick are prepared from the following parts by weight: 50-70 parts high-purity fused magnesia, 10-15 parts flake graphite, 3-5 parts phenolic resin, 5-9 parts antioxidant, 5-7 parts silicon carbide, 1-3 parts alumina, 5-9 parts graphite, 2-4 parts fly ash, 8-10 parts quartz powder, and 9-12 parts clay; S2. Material Mixing: Pour the proportioned materials into a grinding mixer for grinding and mixing. S3, Pressing and Molding: The mixed materials after grinding and mixing are divided into pressing molds and placed into friction brick presses for pressing at a pressure between 80-120MPa; S4, Drying: After the pressed brick blanks are demolded, they are placed in a dryer for drying at a temperature of 150-200℃. S5. Sintering treatment: The dried brick blanks are placed in a high-temperature furnace and sintered at a temperature of 1600-1800℃. S6. Cooling treatment: Move the sintered brick blanks to the cooling zone of the high-temperature furnace and cool them slowly at a rate of 50-80°C per hour.

[0007] The drying time in step S4 is 10-15 hours.

[0008] The grinding and mixing time in step S2 is 20-45 minutes.

[0009] Using the above methods, magnesia particles can be used as the main matrix material to provide high-temperature stability; flake graphite can be used to improve thermal shock resistance and slag erosion resistance; phenolic resin can be used as a binder to provide molding strength; antioxidants can be used to prevent graphite oxidation; silicon carbide can be used to improve strength and hardness; alumina can be used to improve corrosion resistance; graphite can be used to assist the carbon phase; fly ash can be used to adjust performance; quartz powder can be used to adjust sintering performance; and clay can be used to improve molding performance. All raw materials are ground to the same particle size to improve the mixing effect between the raw materials. Then, slow cooling at a rate of 50-80°C per hour can prevent the brick from cracking due to thermal stress.

[0010] The high-temperature furnace equipment used in steps S5-S6 is a gradient sintering equipment for lightweight high-strength magnesia-carbon bricks, including a base, a heating frame fixed on the base, and a furnace body fixed on the heating frame. The furnace body is three-dimensionally wheel-shaped, and a furnace cavity is opened inside the furnace cavity. Sintering rollers are rotatably connected inside the furnace cavity, and multiple sintering chambers are opened on the sintering rollers. A placement frame is rotatably connected to each sintering chamber, and a counterweight is fixed at the bottom center of each placement frame. A heating component is installed inside each heating frame, and the interior of the heating frame is connected to the bottom of the furnace cavity. Heating pipes are fixed on both sides of the heating frame, and one end of each heating pipe is connected to the furnace cavity. Multiple heating pipes are opened on each heating pipe to connect the heating frame and the furnace cavity. The high-temperature outlet inside the furnace cavity has a sintering roller in the shape of a ring. A heat insulation frame is fixed inside the furnace cavity at the center of the sintering roller. A receiving component for receiving magnesia-carbon bricks is installed inside the heat insulation frame. One end of the heat insulation frame extends out of the furnace body, and a cooling frame is fixed on the base. The cooling frame connects to the interior of the heat insulation frame and has a cooling component inside. A blower component is installed in the base. The furnace body has a feed opening that connects to the furnace cavity. A sealed furnace door is hinged inside the feed opening. A pair of pressure relief ports one connecting to the furnace cavity is fixed on the furnace body. A second pressure relief port connecting to the interior of the heat insulation frame is fixed on the heat insulation frame. A drive motor is installed outside the furnace body, and the shaft of the drive motor is coaxially fixed to the sintering roller.

[0011] Using the above structure, the brick blanks in each placement frame can be moved to the heating area by rotating sintering rollers for sintering. Since the heating structure is located at the bottom of the furnace, the temperature range inside the furnace cavity is different. The rotation of the sintering rollers can drive each brick blank to move in different temperature zones, so that the material forms a gradient structure in different areas and the heating surface of each brick blank is uniform, improving the sintering effect. Then, the receiving component receives the sintered brick blanks and brings them to the connection between the heat insulation rack and the cooling rack. The cooling component performs controlled temperature cooling on the brick blanks to prevent cracks in the bricks due to thermal stress.

[0012] The heating assembly includes a heat-drawing cylinder fixed inside a heating frame and a heating tube coiled on the heat-drawing cylinder. A protective plate is fixed on the heat-drawing cylinder, and multiple heat dissipation holes are provided on both the heat-drawing cylinder and the protective plate.

[0013] With the above structure, the heating tube can be used to heat the heat-conducting cylinder. The heat-conducting cylinder acts as a medium for heat conduction, improving the heat diffusion efficiency inside the furnace and enhancing the heating effect. Furthermore, the protective plate prevents foreign objects from falling and damaging the heating tube, thus improving the overall operational stability.

[0014] The receiving assembly includes a receiving frame slidably connected within a heat insulation frame, a receiving port on the heat insulation frame, a guide groove on the receiving frame, a guide block slidably connected within the guide groove, a receiving groove on the guide block, an adjusting screw rotatably connected within the receiving frame, the adjusting screw being threadedly connected to the guide block, an adjusting worm gear rotatably connected within the receiving frame, the adjusting worm gear being coaxially fixedly connected to the adjusting screw, an adjusting worm gear rotatably connected within the receiving frame, the adjusting worm gear meshing with the adjusting worm gear, and an operating handle and a servo motor fixedly attached to the outside of the receiving frame, the output shaft of the servo motor being coaxially fixedly connected to the adjusting worm gear.

[0015] Using the above structure, a servo motor drives the control worm gear to rotate, which in turn drives the control worm wheel to rotate. The rotation of the control worm wheel then drives the control screw to rotate, which in turn lifts the guide block. This allows the receiving slot to enter the corresponding sintering chamber. Then, through the automatic rotation of the placement frame, the brick blanks inside are poured into the receiving slot. The servo motor then drives the guide block in reverse to retract into the guide groove. At this point, the operator uses the handle to move the receiving frame to the connection between the heat insulation frame and the cooling frame, where the cooling components provide controlled temperature cooling for the brick blanks.

[0016] The furnace cavity has a toothed segment fixed on the top inner wall, and each placement frame is coaxially fixedly connected to a control gear, with each control gear meshing with the toothed segment.

[0017] By adopting the above structure, the meshing action of the gears and tooth segments can be controlled to make each placement frame that moves to the top of the furnace cavity flip, ensuring that the brick blanks in the placement frame can be received by the receiving component, thereby improving the overall operational stability.

[0018] The cooling assembly includes a cooling channel opened inside the cooling rack, the cooling channel connecting to the interior of the heat insulation rack, and a condenser fixed inside the cooling channel.

[0019] Using the above structure, the gas can be cooled by a condenser, thereby achieving the cooling of the brick blank by the cold air.

[0020] The blower assembly includes a pair of blower chambers opened in the base, and a blower impeller rotatably connected in each blower chamber. A pair of transmission gears are provided outside the base, and a transmission belt connects the two transmission gears. Each transmission gear is coaxially fixedly connected to the corresponding blower impeller. The cooling channel and heating frame are connected to the corresponding blower chambers. A pair of airflow inlets are fixed on the base, and each airflow inlet is connected to the corresponding blower chamber. A control motor is fixed outside the base, and the output shaft of the control motor is coaxially fixedly connected to one of the blower impellers.

[0021] With the above structure, a blower impeller can be started by controlling the motor to rotate. The blower impeller drives the transmission gear fixedly connected to it on the same axis to rotate. Through the cooperation of the transmission gear and the transmission belt, the other transmission gear is rotated, and the two blower impellers are rotated at the same time. This allows the gas received in the airflow interface to be injected into the corresponding chamber structure, thereby improving the cooling and sintering effect.

[0022] Compared with existing technologies, the gradient sintering method and equipment for lightweight high-strength magnesia-carbon bricks have the following advantages: 1. Magnesia granules are used as the main matrix material to provide high-temperature stability. Flake graphite is used to improve thermal shock resistance and slag erosion resistance. Phenolic resin is used as a binder to provide molding strength. Antioxidants prevent graphite oxidation. Silicon carbide is used to improve strength and hardness. Alumina is used to improve corrosion resistance. Graphite assists the carbon phase. Fly ash is used to adjust performance. Quartz powder is used to adjust sintering performance. Clay is used to improve molding performance. The raw materials are ground into particles of the same size to improve the mixing effect between the raw materials. Then, the bricks are slowly cooled at a rate of 50-80°C per hour to prevent cracks caused by thermal stress.

[0023] 2. The rotating sintering rollers move the brick blanks in each placement frame to the heating area for sintering. The heating structure is located at the bottom of the furnace, resulting in different temperature zones throughout the furnace cavity. The rotation of the sintering rollers can move each brick blank in different temperature zones, creating a gradient structure in different areas of the material and ensuring uniform heating of each brick blank, thus improving the sintering effect.

[0024] 3. The receiving component receives the sintered brick blanks and brings them to the connection between the heat insulation rack and the cooling rack. The cooling component cools the brick blanks at a controlled temperature to prevent cracks in the bricks due to thermal stress. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the sintering method steps of the present invention.

[0026] Figure 2 This is a schematic diagram of the overall structure of the present invention.

[0027] Figure 3 This is a schematic diagram of the furnace body in this invention.

[0028] Figure 4 This is a schematic diagram of the internal structure of the heat extraction cylinder in this invention.

[0029] Figure 5 This is a schematic diagram of the internal structure of the heat insulation frame in this invention.

[0030] Figure 6This is a schematic diagram of the structure for controlling the meshing of the gear and tooth segment in this invention.

[0031] Figure 7 This is a schematic diagram of the internal structure of the base in this invention.

[0032] Figure 8 These are schematic diagrams of the experimental data from Examples 1-4 of this invention.

[0033] In the diagram: 1. Base; 2. Heating rack; 3. Furnace body; 4. Furnace cavity; 5. Sintering roller; 6. Sintering chamber; 7. Placement frame; 8. Counterweight; 9. Heating pipe; 10. High-temperature outlet; 11. Heat insulation rack; 12. Cooling rack; 13. Feed opening; 14. Sealed furnace door; 15. Pressure relief port one; 16. Pressure relief port two; 17. Drive motor; 18. Heat extraction cylinder; 19. Heating tube; 20. Protective plate; 21. Receiving device. 21. Frame; 22. Receiver port; 23. Guide slide; 24. Guide block; 25. Receiver slot; 26. Adjusting screw; 27. Adjusting worm gear; 28. Adjusting worm; 29. ​​Operating handle; 30. Servo motor; 31. Gear segment; 32. Control gear; 33. Cooling channel; 34. Condenser; 35. Blower chamber; 36. Blower impeller; 37. Transmission gear; 38. Transmission toothed belt; 39. Airflow interface; 40. Adjusting motor. Detailed Implementation

[0034] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0035] like Figures 1-8 As shown, a gradient sintering method for lightweight, high-strength magnesia-carbon bricks includes the following steps: S1. Raw material ratio: The raw materials for this lightweight high-strength magnesia-carbon brick are prepared from the following parts by weight: 50-70 parts of high-purity fused magnesia, 10-15 parts of flake graphite, 3-5 parts of phenolic resin, 5-9 parts of antioxidant, 5-7 parts of silicon carbide, 1-3 parts of alumina, 5-9 parts of graphite, 2-4 parts of fly ash, 8-10 parts of quartz powder, and 9-12 parts of clay. S2. Material Mixing: Pour the proportioned materials into a grinding mixer for grinding and mixing. During the mixing process, the grinding mixer rotates at 150-300 rpm to grind the raw materials into particles of the same size. S3. Pressing and molding: The mixed materials, after grinding and mixing, are packaged into pressing molds, and the filled pressing molds are placed into friction brick presses. The friction brick presses are used for pressing, with a pressure between 80-120MPa. S4. Drying treatment: After the pressed brick blanks are demolded, they are placed in a dryer for drying treatment. The drying temperature is set at 150-200℃. S5. Sintering treatment: The dried brick blanks are placed in a high-temperature furnace and sintered at a temperature of 1600-1800℃. S6. Cooling treatment: Move the sintered brick blanks to the cooling zone of the high-temperature furnace and cool them slowly at a rate of 50-80°C per hour.

[0036] The drying time in step S4 is 10-15 hours.

[0037] The grinding and mixing time in step S2 is 20-45 minutes.

[0038] Using the above methods, magnesia particles can be used as the main matrix material to provide high-temperature stability; flake graphite can be used to improve thermal shock resistance and slag erosion resistance; phenolic resin can be used as a binder to provide molding strength; antioxidants can be used to prevent graphite oxidation; silicon carbide can be used to improve strength and hardness; alumina can be used to improve corrosion resistance; graphite can be used to assist the carbon phase; fly ash can be used to adjust performance; quartz powder can be used to adjust sintering performance; and clay can be used to improve molding performance. All raw materials are ground to the same particle size to improve the mixing effect between the raw materials. Then, slow cooling at a rate of 50-80°C per hour can prevent the brick from cracking due to thermal stress.

[0039] The high-temperature furnace equipment used in steps S5-S6 is a gradient sintering equipment for lightweight high-strength magnesia-carbon bricks, including a base 1, a heating frame 2 fixed on the base 1, and a furnace body 3 fixed on the heating frame 2. The furnace body 3 is three-dimensionally wheel-shaped, and a furnace cavity 4 is opened inside the furnace body 3. Sintering rollers 5 are rotatably connected inside the furnace cavity 4, and multiple sintering chambers 6 are opened on the sintering rollers 5. A placement frame 7 is rotatably connected inside each sintering chamber 6, and a counterweight 8 is fixed at the bottom center of each placement frame 7. A heating component is installed inside each heating frame 2, and the interior of the heating frame 2 is connected to the bottom of the furnace cavity 4. Heating pipes 9 are fixed on both sides of the heating frame 2, and one end of each heating pipe 9 is connected to the furnace cavity 4. Multiple high-temperature outlets 10 are opened on each heating pipe 9, connecting the heating frame 2 and the interior of the furnace cavity 4. The sintering roller 5 is in the shape of a circular wheel, and a heat insulation frame 11 located at the center of the sintering roller 5 is fixed inside the furnace cavity 4. A receiving component for receiving magnesia-carbon bricks is provided inside the heat insulation frame 11. One end of the heat insulation frame 11 extends out of the furnace body 3, and a cooling frame 12 is fixed on the base 1. The cooling frame 12 connects to the interior of the heat insulation frame 11, and a cooling component is provided inside the cooling frame 12. A blower component is provided inside the base 1, and a feeding opening 13 connecting to the furnace cavity 4 is opened on the furnace body 3. A sealed furnace door 14 is hinged inside the feeding opening 13, and a pair of pressure relief ports 15 connecting to the furnace cavity 4 are fixed on the furnace body 3. A second pressure relief port 16 connecting to the interior of the heat insulation frame 11 is fixed on the heat insulation frame 11. A drive motor 17 is provided outside the furnace body 3, and the shaft of the drive motor 17 is coaxially fixedly connected to the sintering roller 5.

[0040] Using the above structure, the brick blanks in each placement frame 7 can be moved to the heating area by the rotating sintering roller 5 for sintering. Since the heating structure is located at the bottom of the furnace body 3, the temperature range inside the entire furnace cavity 4 is different. The rotation of the sintering roller 5 can drive each brick blank to move in different temperature zones, so that the material forms a gradient structure in different areas and the heating surface of each brick blank is uniform, improving the sintering effect. Then, the receiving component receives the sintered brick blanks and brings them to the connection between the heat insulation frame 11 and the cooling frame 12. The cooling component cools the brick blanks at a controllable temperature to prevent the bricks from cracking due to thermal stress.

[0041] The heating assembly includes a heat-drawing cylinder 18 fixed inside the heating frame 2, a heating tube 19 coiled on the heat-drawing cylinder 18, a protective plate 20 fixed on the heat-drawing cylinder 18, and multiple heat dissipation holes on both the heat-drawing cylinder 18 and the protective plate 20.

[0042] With the above structure, the heating tube 19 can heat the heat-conducting cylinder 18. The heat-conducting cylinder 18 serves as a medium for heat conduction, improving the heat diffusion efficiency inside the furnace body 3 and enhancing the heating effect. Furthermore, the protective plate 20 prevents foreign objects from falling and damaging the heating tube 19, thus improving the overall operational stability.

[0043] The receiving assembly includes a receiving frame 21 slidably connected within a heat insulation frame 11, a receiving port 22 on the heat insulation frame 11, a guide groove 23 on the receiving frame 21, a guide block 24 slidably connected within the guide groove 23, a receiving groove 25 on the guide block 24, an adjusting screw 26 rotatably connected within the receiving frame 21, the adjusting screw 26 being threadedly connected to the guide block 24, an adjusting worm gear 27 rotatably connected within the receiving frame 21, the adjusting worm gear 27 being coaxially fixedly connected to the adjusting screw 26, an adjusting worm 28 rotatably connected within the receiving frame 21, the adjusting worm 28 meshing with the adjusting worm gear 27, and an operating handle 29 and a servo motor 30 fixedly attached to the outside of the receiving frame 21, the output shaft of the servo motor 30 being coaxially fixedly connected to the adjusting worm 28.

[0044] Using the above structure, the servo motor 30 drives the regulating worm gear 28 to rotate, which in turn drives the regulating worm wheel 27 to rotate. The rotating worm wheel 27 then drives the regulating screw 26 to rotate, which in turn lifts the guide block 24. This allows the receiving slot 25 to enter the corresponding sintering chamber 6. Then, through the automatic rotation of the placement frame 7, the brick blanks inside are poured into the receiving slot 25. The servo motor 30 then drives the guide block 24 back into the guide slide 23. At this point, the operator uses the operating handle 29 to move the receiving rack 21 to the connection between the heat insulation rack 11 and the cooling rack 12, where the cooling components provide controllable temperature cooling for the brick blanks.

[0045] A toothed segment 31 is fixed on the inner wall of the top of the furnace cavity 4, and a control gear 32 is coaxially fixedly connected to each placement frame 7. Each control gear 32 meshes with the toothed segment 31.

[0046] With the above structure, the meshing action of gear 32 and tooth segment 31 can be controlled to make each placement frame 7 that moves to the top of the furnace cavity 4 flip, ensuring that the brick blank in the placement frame 7 can be received by the receiving component, thereby improving the overall operational stability.

[0047] The cooling assembly includes a cooling channel 33 opened in the cooling rack 12, the cooling channel 33 is connected to the interior of the heat insulation rack 11, and a condenser 34 is fixed in the cooling channel 33.

[0048] With the above structure, the gas can be cooled by the condenser 34, thereby achieving the cooling of the brick blank by the cold air.

[0049] The blower assembly includes a pair of blower chambers 35 opened in the base 1, and a blower impeller 36 rotatably connected in each blower chamber 35. A pair of transmission gears 37 are provided outside the base 1, and a transmission toothed belt 38 is connected between the two transmission gears 37. Each transmission gear 37 is coaxially fixedly connected to the corresponding blower impeller 36. The cooling channel 33 and the heating frame 2 are connected to the corresponding blower chambers 35. A pair of airflow inlets 39 are fixed on the base 1, and each airflow inlet 39 is connected to the corresponding blower chamber 35. A regulating motor 40 is fixed outside the base 1, and the output shaft of the regulating motor 40 is coaxially fixedly connected to one of the blower impellers 36.

[0050] With the above structure, the motor 40 can be adjusted to drive one blower impeller 36 to rotate, thereby driving the transmission gear 37, which is fixedly connected to it on the same axis, to rotate. Through the cooperation of the transmission gear 37 and the transmission belt 38, the other transmission gear 37 is rotated, and the two blower impellers 36 are rotated simultaneously. This allows the gas received in the airflow interface 39 to be injected into the corresponding chamber structure, thereby improving the cooling and sintering effect.

[0051] The working principle of this invention is as follows: Brick blanks are placed into placement frames 7 through the feed opening 13, and then the sealed furnace door 14 is closed. Heating tubes 19 heat the heat-conducting cylinder 18, which acts as a heat transfer medium, improving the heat diffusion efficiency within the furnace body 3 and enhancing the heating effect. A drive motor 17 rotates the sintering rollers 5, moving the brick blanks in each placement frame 7 to the heating area for sintering. Since the heating structure is located at the bottom of the furnace body 3, the temperature zones within the entire furnace cavity 4 are different. The rotation of the sintering rollers 5 moves each brick blank within its respective temperature zone, creating a gradient structure in different areas and ensuring uniform heating of each brick blank, thus improving the sintering effect. By controlling the meshing action of gears 32 and tooth segments 31, each placement frame 7 that moves to the top of the furnace cavity 4 will flip. Simultaneously, a servo motor 30 drives the regulating worm gear 28 to rotate, which in turn drives the regulating worm wheel 27 to rotate, thus regulating the temperature. After the worm gear 27 rotates, it drives the regulating screw 26 to rotate. The rotating regulating screw 26 drives the guide block 24 to rise, so that the receiving slot 25 enters the corresponding sintering chamber 6. Then, through the automatic rotation of the placement frame 7, the brick blanks inside are poured into the receiving slot 25. Then, through the reverse drive of the servo motor 30, the guide block 24 is retracted into the guide slide 23. At this time, the operator holds the operating handle 29 to move the receiving rack 21 to the connection between the heat insulation rack 11 and the cooling rack 12. The regulating motor 40 drives one blower impeller 36 to rotate, so that the blower impeller 36 drives the transmission gear 37 fixedly connected to it to rotate. Through the cooperation of the transmission gear 37 and the transmission belt 38, the other transmission gear 37 is rotated, so that the two blower impellers 36 rotate simultaneously. This injects the gas received in the airflow interface 39 into the corresponding chamber structure. The condenser 34 cools the gas, so that the cold air cools the brick blanks and improves the cooling and sintering effect.

[0052] In summary, the rotating sintering rollers 5 move the brick blanks in each placement frame 7 to the heating area for sintering. Since the heating structure is located at the bottom of the furnace body 3, the temperature range inside the entire furnace cavity 4 is different. The rotation of the sintering rollers 5 can drive each brick blank to move in different temperature zones, so that the material forms a gradient structure in different areas and the heating surface of each brick blank is uniform, improving the sintering effect. The receiving component then receives the sintered brick blanks and brings them to the connection between the heat insulation frame 11 and the cooling frame 12. The cooling component controls the temperature of the brick blanks to prevent cracks in the bricks due to thermal stress.

[0053] To evaluate the performance of the gradient sintering method and equipment for lightweight high-strength magnesia-carbon bricks, product performance tests were conducted on lightweight high-strength magnesia-carbon bricks prepared using this method and equipment, as well as those prepared using traditional equipment and methods. Raw materials: All experimental examples and comparative examples used the same batch of high-purity fused magnesia.

[0054] Experimental Example 1 Mixing: The grinding mixer operates at 350 rpm during the mixing process; Molding: Pressure at 130MPa; Drying: The drying temperature is set at 230℃; Sintering: Sintering temperature reaches 2000℃; Cooling: Slowly cool at a rate of 100°C per hour.

[0055] Experimental Example 2 The difference between this experimental example and Experimental Example 1 is that the sintering temperature is 1600℃.

[0056] Experimental Example 3 Mixing: The grinding mixer operates at 300 rpm during the mixing process; Molding: Pressure at 120MPa; Drying: The drying temperature is set at 210℃, and the drying time is 20 hours; Sintering: The sintering temperature reaches 1500℃; Cooling: Cool slowly at a rate of 30°C per hour.

[0057] Experiment Example 4 Mixing: The grinding mixer operates at 240 rpm during the mixing process; Molding: Pressure at 150MPa; Drying: The drying temperature is set at 180℃, and the drying time is 6 hours; Sintering: The sintering temperature reaches 1700℃; Cooling: Cool slowly at a rate of 50°C per hour.

[0058] To test product performance, performance tests were conducted on key parameters. The test results are as follows: Figure 8 ; The performance test data in Examples 1-4 show that drying temperature and drying time have a significant impact on the performance after sintering. When the drying temperature and drying time are within the range given by this invention, the overall performance of the obtained product is excellent, which can significantly improve the performance of lightweight high-strength magnesia-carbon bricks. Compared with Example 2, Example 1 uses the same equipment, only the sintering temperature is different. This shows that while maintaining the high dryness of the material, by stabilizing the sintering temperature in a suitable range, a higher performance product was successfully obtained. This proves that the method and equipment have excellent product adjustability. Compared with Example 4, Example 1, Example 2, Example 3 and Example 4 all use different equipment and methods. Existing methods lack a stable sintering temperature range, cannot effectively improve the fusion effect between various materials, and have low sintering efficiency, resulting in product structural performance and structural strength that are far lower than those of this invention. This proves that the sintering method and equipment of this invention are significantly better than existing traditional methods in terms of product sintering effect and sintering efficiency.

[0059] As can be seen from the above embodiments and comparative examples, the innovation of the rubber composition of the present invention lies in the following: using magnesia particles as the main matrix material to provide high-temperature stability; using flake graphite to improve thermal shock resistance and slag erosion resistance; using phenolic resin as a binder to provide molding strength; using antioxidants to prevent graphite oxidation; using silicon carbide to improve strength and hardness; using alumina to improve corrosion resistance; using graphite to assist the carbon phase; using fly ash to adjust performance; using quartz powder to adjust sintering performance; using clay to improve molding performance; and grinding the raw materials into particles of the same size to improve the mixing effect between the raw materials. Then, slow cooling at a rate of 50-80°C per hour prevents the brick from cracking due to thermal stress.

[0060] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A gradient sintering method for lightweight high-strength magnesia-carbon bricks, comprising the following steps: S1. Raw material ratio: The raw materials for this lightweight high-strength magnesia-carbon brick are prepared from the following parts by weight: 50-70 parts of high-purity fused magnesia, 10-15 parts of flake graphite, 3-5 parts of phenolic resin, 5-9 parts of antioxidant, 5-7 parts of silicon carbide, 1-3 parts of alumina, 5-9 parts of graphite, 2-4 parts of fly ash, 8-10 parts of quartz powder, and 9-12 parts of clay. S2. Material Mixing: Pour the proportioned materials into a grinding mixer for grinding and mixing. During the mixing process, the grinding mixer rotates at 150-300 rpm to grind the raw materials into particles of the same size. S3. Pressing and molding: The mixed materials, after grinding and mixing, are packaged into pressing molds, and the filled pressing molds are placed into friction brick presses. The friction brick presses are used for pressing, with a pressure between 80-120MPa. S4. Drying treatment: After the pressed brick blanks are demolded, they are placed in a dryer for drying treatment. The drying temperature is set at 150-200℃. S5. Sintering treatment: The dried brick blanks are placed in a high-temperature furnace for sintering at a temperature of 1600-1800℃. S6. Cooling treatment: Move the sintered brick blanks to the cooling zone of the high-temperature furnace and cool them slowly at a rate of 50-80°C per hour.

2. The gradient sintering method for lightweight high-strength magnesia-carbon bricks according to claim 1, characterized in that, The magnesium oxide content of the high-purity fused magnesia in step S1 needs to reach more than 95%, and the scale size of the flake graphite is generally around 0.1-1mm.

3. The gradient sintering method for lightweight high-strength magnesia-carbon bricks according to claim 1, characterized in that, The drying time in step S4 is 10-15 hours.

4. The gradient sintering method for lightweight high-strength magnesia-carbon bricks according to claim 1, characterized in that, The grinding and mixing time in step S2 is 20-45 minutes.

5. A gradient sintering device for lightweight high-strength magnesia-carbon bricks as described in any one of claims 1-5, characterized in that, The high-temperature furnace equipment used in steps S5-S6 is a gradient sintering equipment for lightweight high-strength magnesia-carbon bricks, including a base (1), a heating rack (2) fixed on the base (1), and a furnace body (3) fixed on the heating rack (2). The furnace body (3) is three-dimensional wheel-shaped, and a furnace cavity (4) is opened inside the furnace body (3). A sintering roller (5) is rotatably connected inside the furnace cavity (4). Multiple sintering chambers (6) are opened on the sintering roller (5), and each sintering chamber (6) is rotatably connected inside. Each heating frame (7) is equipped with a placement frame (7), and a counterweight (8) is fixed at the center of the bottom of each placement frame (7). Each heating frame (2) is equipped with a heating component, and the interior of the heating frame (2) is connected to the bottom of the furnace cavity (4). Heating pipes (9) are fixed on both the left and right sides of the heating frame (2). One end of each heating pipe (9) is connected to the furnace cavity (4), and each heating pipe (9) has multiple high-temperature outlets (10) that connect the heating frame (2) to the interior of the furnace cavity (4). The sintering roller (5) is in the shape of a ring, and a heat insulation frame (11) located at the center of the sintering roller (5) is fixed inside the furnace cavity (4). A receiving component for receiving magnesia-carbon bricks is provided inside the heat insulation frame (11). One end of the heat insulation frame (11) extends out of the furnace body (3), and a cooling frame (12) is fixed on the base (1). The cooling frame (12) is connected to the interior of the heat insulation frame (11), and a cooling component is provided inside the cooling frame (12). A blower component is provided inside the base (1). The furnace body (3) has a feed opening (13) that connects to the furnace cavity (4). A sealed furnace door (14) is hinged inside the feed opening (13). A pair of pressure relief ports (15) that connect to the furnace cavity (4) are fixed on the furnace body (3). A pressure relief port (16) that connects to the inside of the heat insulation frame (11) is fixed on the heat insulation frame (11). A drive motor (17) is installed outside the furnace body (3). The shaft of the drive motor (17) is coaxially fixedly connected to the sintering roller (5).

6. The gradient sintering equipment for lightweight high-strength magnesia-carbon bricks according to claim 5, characterized in that, The heating assembly includes a heat-drawing cylinder (18) fixed inside the heating frame (2) and a heating tube (19) coiled on the heat-drawing cylinder (18). A protective plate (20) is fixed on the heat-drawing cylinder (18). Both the heat-drawing cylinder (18) and the protective plate (20) have multiple heat dissipation holes.

7. The gradient sintering equipment for lightweight high-strength magnesia-carbon bricks according to claim 5, characterized in that, The receiving assembly includes a receiving frame (21) slidably connected within a heat insulation frame (11), a receiving port (22) on the heat insulation frame (11), a guide groove (23) on the receiving frame (21), a guide block (24) slidably connected within the guide groove (23), a receiving groove (25) on the guide block (24), and an adjusting screw (26) rotatably connected within the receiving frame (21), the adjusting screw (26) threadedly engaging with the guide block (24). The receiver (21) is connected to a control worm gear (27) which is rotatably connected inside the receiver (21). The control worm gear (27) is coaxially fixedly connected to the control screw (26). The receiver (21) is also connected to a control worm (28) which meshes with the control worm gear (27). The receiver (21) is also fixedly connected to an operating handle (29) and a servo motor (30). The output shaft of the servo motor (30) is coaxially fixedly connected to the control worm (28).

8. The gradient sintering equipment for lightweight high-strength magnesia-carbon bricks according to claim 5, characterized in that, The furnace cavity (4) has a toothed segment (31) fixed on the top inner wall, and each placement frame (7) is coaxially fixedly connected with a control gear (32), and each control gear (32) meshes with the toothed segment (31).

9. The gradient sintering equipment for lightweight high-strength magnesia-carbon bricks according to claim 1, characterized in that, The cooling assembly includes a cooling channel (33) opened in the cooling rack (12), the cooling channel (33) is connected to the interior of the heat insulation rack (11), and a condenser (34) is fixed in the cooling channel (33).

10. The gradient sintering equipment for lightweight high-strength magnesia-carbon bricks according to claim 9, characterized in that, The blower assembly includes a pair of blower chambers (35) opened in the base (1), and a blower impeller (36) rotatably connected in each blower chamber (35). A pair of transmission gears (37) are provided outside the base (1), and a transmission toothed belt (38) is connected between the two transmission gears (37). Each transmission gear (37) is coaxially fixedly connected to the corresponding blower impeller (36). The cooling channel (33) and the heating frame (2) are connected to the corresponding blower chambers (35). A pair of airflow interfaces (39) are fixed on the base (1), and each airflow interface (39) is connected to the corresponding blower chamber (35). A regulating motor (40) is fixed outside the base (1), and the output shaft of the regulating motor (40) is coaxially fixedly connected to one of the blower impellers (36).

Images