Electric arc furnace two-section type feeding method suitable for multi-variety steel production

Abstract

The invention discloses an electric arc furnace two-section feeding method suitable for multi-variety steel production. The method comprises the following steps that A, first hopper materials are fed when an electric arc furnace is started; b, electrode ignition is started, the first hopper material is rapidly heated, and basic molten steel is formed; c, feeding and preheating other raw materials through a continuous feeding device; d, the feeding rate is controlled, and it is ensured that the molten steel heat energy absorption rate and the melting rate are kept balanced; and E, when the current feeding operation needs to be stopped, a discharging opening of the conveyor is separated from a feeding opening of the electric arc furnace, and the raw materials fall into a storage bin. The method has the advantages that under the condition that different steel types are frequently switched within one day, temperature control and component proportioning are both considered, raw materials are prevented from being fed by mistake, the production efficiency of the electric arc furnace is improved, energy consumption is reduced, and the product quality is improved.

Description

Technical Field

[0001] The invention relates to an electric arc furnace charging method, in particular to an electric arc furnace two-stage charging method suitable for producing multiple types of steel. Background Art

[0002] Electric arc furnace steelmaking is widely used in the steelmaking industry. Compared to traditional blast furnace steelmaking, electric arc furnaces use scrap steel as their primary raw material, reducing reliance on primary ore while effectively reducing emissions of greenhouse gases such as carbon dioxide. This makes them a key technology in line with the concept of green manufacturing. Consequently, due to its significant energy-saving, high-efficiency, and environmentally friendly advantages, electric arc furnace steelmaking has become a mainstream technology in global steel production, particularly in mini-process steelmaking.

[0003] The production of multiple or specialty steels presents complex challenges, especially when frequent changes between different steel grades occur within a single production line. Because each heat of molten steel requires unique compositional requirements, the dosing system must precisely calculate the proportions based on the specific steel grades being produced. This requires not only rapid switching between steel grades but also precise adjustment of scrap preheating, temperature control, and alloying ratios after each change.

[0004] Traditional electric arc furnace steelmaking charging systems, such as the Consteel horizontal charging system, require high material consistency and continuity during the charging process. They are more suitable for the production of a single steel grade and require some molten steel to be retained in the furnace to preheat the next charge. This system is not flexible enough to handle frequent steel grade changes during production, which requires the complete removal of excess steel from the furnace. Furthermore, its ability to handle scrap preheating and charging is clearly insufficient when facing the demands of producing multiple steel grades.

[0005] Furthermore, each time steel grades are switched, the temperature and heat distribution within the furnace cannot be adjusted quickly because the high-temperature flue gas has not yet fully accumulated. This results in poor scrap preheating, which in turn affects the melting rate of the molten steel and can lead to problems such as material accumulation and slow melting. These problems are particularly pronounced when steel grades need to be switched multiple times per day, seriously impacting production efficiency and product quality.

[0006] Therefore, with the steel industry's increasing demand for the production of multiple steel grades, especially when switching between different steel grades frequently within a day, how to improve the flexibility, precision and energy efficiency of the feeding system has become an important challenge to improve production efficiency, reduce energy consumption and improve product quality. Summary of the Invention

[0007] The present invention aims to provide a two-stage charging method for an electric arc furnace suitable for producing multiple steel grades. This method balances temperature control and ingredient ratios when frequently switching between different steel grades within a day, prevents the misfeeding of raw materials, improves charging flexibility, precision, and efficiency, and enhances electric arc furnace production efficiency, reducing energy consumption and improving product quality.

[0008] The technical solution of the present invention is a two-stage charging method for an electric arc furnace suitable for producing multiple types of steel, comprising a first charging stage and a second charging stage, wherein the first charging stage comprises the following steps: A. First bucket charge: The first bucket charge is added when the electric arc furnace is started to form the initial composition basis of the molten steel; B. Establishing a molten steel pool: Start electrode ignition to quickly heat the first bucket material, melt the first bucket material, form basic molten steel, and obtain a molten steel pool; The second feeding stage comprises the following steps: C. The remaining raw materials are fed through a continuous feeding device according to the ratio requirements of the target steel grade, and are preheated by the radiation heat of the basic molten steel and the high-temperature flue gas generated in the first charging stage of the electric arc furnace; D. During the feeding process, control the feeding rate to ensure that the heat energy absorption and melting rate of the molten steel are balanced; E. During the feeding process, when the current feeding operation needs to be stopped, the outlet of the conveyor is separated from the feeding port of the electric arc furnace through the retraction conveying device of the continuous feeding device, so that the raw materials on the continuous feeding device fall into the storage bin.

[0009] In the aforementioned two-stage charging method for an electric arc furnace applicable to the production of multiple types of steel, in step A, the first bucket material includes high-grade scrap steel, molten iron, and any one or two of alloying elements.

[0010] In the aforementioned two-stage charging method for an electric arc furnace applicable to the production of multiple types of steel, in step B, the electric arc furnace is operated and heated at 80%-100% of the rated power of the furnace body.

[0011] In the aforementioned two-stage charging method for an electric arc furnace applicable to the production of multiple steel varieties, in step B, after the furnace temperature is stably raised to 1550-1600°C, the first bucket charge is melted to form a basic steel liquid of 25%-30% of the total smelting weight.

[0012] In the aforementioned two-stage charging method for an electric arc furnace suitable for the production of multiple types of steel, in step C, the continuous charging device includes a feeding section, a sealing section and a preheating section, the sealing section is located between the end of the feeding section and the head end of the preheating section, and the end of the preheating section corresponds to the feed port of the electric arc furnace; a hot flue gas duct is provided on the preheating section, and the hot flue gas duct is also connected to the smoke outlet of the electric arc furnace.

[0013] In the aforementioned two-stage charging method for an electric arc furnace suitable for the production of multiple types of steel, in step E, the retracting conveying device includes a slide rail located at the bottom of the preheating section, and a conveyor is slidably connected to the top of the slide rail through a slide, and a mobile drive assembly is provided on the slide, which drives the conveyor close to or away from the electric arc furnace. A storage bin is provided below the slide rail, and a drop-out port corresponding to the storage bin is provided on the slide rail.

[0014] In the aforementioned two-stage charging method for an electric arc furnace suitable for producing multiple types of steel, the mobile drive assembly includes a motor frame, a drive motor is provided on the motor frame, a drive gear is provided on the drive motor, a drive rack is fixedly connected to the slide, and the drive rack is meshed with the drive gear.

[0015] In the aforementioned two-stage charging method for an electric arc furnace suitable for producing multiple types of steel, a high-temperature camera is provided on one side of the storage bin, and a weighing sensor and a forced cooling air duct are provided inside the storage bin.

[0016] In the aforementioned two-stage charging method for an electric arc furnace applicable to the production of multiple steel varieties, in step C, when the raw material preheating temperature exceeds 400°C, the raw material enters the molten steel pool, is fully mixed with the base molten steel, and is finally melted to the target amount.

[0017] In the aforementioned two-stage charging method for an electric arc furnace applicable to the production of multiple steel varieties, the second charging stage further includes the following steps: F. When the feeding is nearly completed, the composition of the molten steel is precisely controlled according to the composition requirements of the target steel grade through real-time temperature monitoring and chemical analysis to ensure that the composition of the molten steel meets the composition requirements of the target steel grade; G. When the molten steel reaches the predetermined temperature and composition, it is tapped.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention introduces a two-stage charging method. By charging in stages, the high-grade scrap steel or molten iron in the first bucket is quickly heated in the first charging stage, so that the first bucket forms basic molten steel, providing a stable molten steel foundation for the second charging stage; in the second charging stage, the radiant heat of the basic molten steel in the electric arc furnace and the high-temperature flue gas introduced by the continuous charging device are used to preheat the raw materials, ensuring that the scrap steel has reached an appropriate temperature before being put into the furnace, thereby significantly improving the efficiency and stability of the charging process, and is particularly suitable for the production needs of multiple types of steel.

[0019] The present invention provides a retraction conveying device on the continuous feeding device. When the feeding needs to be interrupted, the retraction function of the retraction conveying device can disconnect the retraction conveying device from the furnace mouth of the electric arc furnace, preventing the raw materials from continuing to be transported to the electric arc furnace, thereby avoiding the raw materials from mistakenly entering the furnace, and ensuring the stability of the production process and the quality of the molten steel. Subsequent raw materials are received through the storage bin and the raw materials are safely recovered or exported, thereby effectively avoiding component deviation and waste waste. The retraction conveying device not only enhances the emergency response capability of the present invention, but also improves the flexibility and safety of the overall production process, solves the problem of waste mistakenly entering the electric arc furnace when the feeding is interrupted, and adapts to the switching needs between different steel grades.

[0020] The present invention also ensures that the composition and temperature of the molten steel are maintained within the target range during each feeding process by controlling the feeding speed, raw material preheating temperature and alloy ratio during the second feeding stage, thereby improving the melting efficiency of the molten steel and avoiding the process instability caused by too fast or too slow feeding; while meeting the switching of steel grades, it also reduces excessive dependence on high-temperature flue gas in the furnace, improves energy utilization efficiency, ensures the quality of the molten steel, reduces energy consumption and optimizes the production cycle.

[0021] Therefore, in a production environment where steel grades are frequently switched, the present invention can accurately control the feeding process at each stage, ensure that the temperature and composition of the raw materials always meet the requirements, and respond to emergencies through a retracting conveyor device, thereby effectively improving the flexibility of the process and production efficiency, saving energy consumption and reducing material waste, and effectively solving the adaptability problem of traditional continuous feeding systems when steel grades are frequently switched, overcoming the challenges of difficulty in preheating the first section of materials and limited decision-making in mid-process furnace changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a top view of the continuous feeding device of the present invention.

[0023] Figure 2 It is a schematic diagram of the feeding state of the continuous feeding device of the present invention.

[0024] Figure 3 It is a schematic diagram of the retracted state of the continuous feeding device of the present invention.

[0025] Figure 4 It is a structural schematic diagram of the retraction conveying device of the present invention.

[0026] The marks in the accompanying drawings are: 1. Feeding section; 2. Sealing section; 3. Preheating section; 4. Storage bin; 5. High-temperature camera; 6. Retraction conveyor; 61. Slide rail; 611. Slide; 62. Conveyor; 63. Motor frame; 64. Drive motor; 65. Drive gear; 66. Drive rack; 7. Hot flue gas duct; 8. Electric arc furnace. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the examples, but they are not intended to limit the present invention.

[0028] Example 1: Before adding materials, confirm the target steel grade and its chemical composition requirements, and calculate and generate a reasonable batching plan based on actual production needs, covering the types and proportions of raw materials such as scrap steel, alloys, recycled materials, coolants, etc., to ensure the accuracy of the batching plan and the composition of the molten steel, avoid smelting deviations caused by mismatched raw material compositions, and lay the foundation for subsequent stable production.

[0029] If the type of steel being smelted in the current electric arc furnace 8 is the same as the type of steel to be smelted in the next furnace, and it is planned to retain some molten steel in the furnace after the smelting of this furnace is completed to preheat the raw materials for the next furnace, a continuous feeding method is adopted, and the raw materials are continuously transported to the electric arc furnace 8 along the conveying path at a constant speed via a chain or belt conveyor 62. The conveying path is closed and is suitable for continuous smelting scenarios where the type of steel remains unchanged, thereby achieving stability and efficiency of the feeding process.

[0030] When the smelting steel type is switched or under the same steel type, the molten steel in the furnace needs to be completely emptied after the current heat is completed and the residual molten steel cannot be used for preheating, a two-stage charging method is adopted.

[0031] The invention discloses a two-stage charging method for an electric arc furnace suitable for producing multiple types of steel, comprising a first charging stage and a second charging stage.

[0032] Wherein, the first feeding stage comprises the following steps: A. Adding the First Charge: When the electric arc furnace 8 is started, the first charge is added through the hopper. High-grade scrap steel, such as heavy scrap, mill waste, and briquettes, is used as the first charge. 3-5 tons of molten iron may also be added to accelerate initial melting and stabilize the furnace temperature. In addition, alloying elements such as silicon, manganese, chromium, and nickel, accounting for 0.5%-1.5% of the first charge's mass, are added to form the initial compositional foundation of the molten steel and enhance its deoxidation capacity.

[0033] B. Establishing the Molten Steel Pool: After the first charge is added, the electrodes are ignited, establishing an arc. The furnace is then operated at 80%-100% of its rated power, rapidly heating the first charge and promoting efficient melting, forming an initial pool of molten steel with sufficient heat capacity. As heating progresses, the furnace temperature steadily rises to 1550-1600°C, the arc stabilizes, and a base steel pool comprising 25%-30% of the total melt weight is formed, ensuring the safe start of the subsequent second charging phase. This step effectively ensures the continuous melting efficiency of the scrap steel, avoids charging anomalies due to insufficient temperature or an unstable melt pool, and ensures an efficient and stable smelting process.

[0034] The second feeding stage includes the following steps: C. After the molten steel pool is established, the subsequent raw materials are added through the continuous feeding device according to the ratio requirements of the target steel grade. During this period, the raw materials are preheated by the radiation heat of the basic molten steel and the high-temperature flue gas generated in the first charging stage of the electric arc furnace 8. When the preheated temperature of the raw materials exceeds 400°C, they enter the electric arc furnace 8, are fully mixed with the basic molten steel, and finally melted to the target amount.

[0035] like Figure 1-Figure 4 As shown, the continuous feeding device includes a feeding section 1, a sealing section 2 and a preheating section 3. The sealing section 2 is located between the end of the feeding section 1 and the head end of the preheating section 3. The end of the preheating section 3 corresponds to the feed port of the electric arc furnace 8. A hot flue gas duct 7 is provided on the preheating section 3, and the hot flue gas duct 7 is also connected to the smoke outlet of the electric arc furnace 8.

[0036] Raw materials enter the electric arc furnace 8 for smelting through the feed section 1, sealing section 2, and preheating section 3. The high-temperature flue gas generated by the molten steel in the first heating stage of the electric arc furnace 8 is discharged through the hot flue gas duct 7 to the preheating section 3, where it is used to preheat the raw materials in the second charging stage. The raw materials in the preheating section 3 are also preheated by the radiation heat from the basic molten steel generated in the first charging stage of the electric arc furnace 8. A temperature sensor is installed in the preheating section 3. During this preheating process, the raw material temperature is kept between 300°C and 600°C, effectively reducing the heating time of the electric arc furnace 8 and improving overall energy efficiency.

[0037] The preheating section 3 is provided with a retracting conveyor 6. The retracting conveyor 6 implements emergency response and reverse recovery of the charging system, ensuring that when charging is interrupted, the raw materials are promptly blocked from entering the electric arc furnace 8, and the raw materials that have not entered the electric arc furnace 8 are safely withdrawn or guided out of the continuous charging device, thereby effectively responding to emergencies and preventing raw materials from accidentally entering the electric arc furnace 8.

[0038] The retracting conveyor 6 comprises a slide rail 61 at the bottom of the preheating section 3. A conveyor 62 is slidably connected to the upper portion of the slide rail 61 via a slide 611. The slide 611 is equipped with a mobile drive assembly that drives the conveyor 62 toward or away from the electric arc furnace 8. A storage bin 4 is located below the slide rail 61, and a material discharge port corresponding to the storage bin 4 is provided on the slide rail 61. The conveyor 62 can be a chain conveyor 62 or a belt conveyor 62. The storage bin 4 not only provides temporary storage space for raw materials to prevent spillage, but also provides a buffer for subsequent processing.

[0039] The transverse drive assembly includes a motor frame 63, mounted with a drive motor 64, which is equipped with a drive gear 65. A drive rack 66 is fixedly connected to the slide 611 and meshes with the drive gear 65. The rotation of the drive gear 65 drives the drive rack 66, thereby moving the conveyor 62. Alternatively, the transverse drive assembly employs a hydraulic drive connected to the slide 611.

[0040] A high-temperature camera 5 is installed on one side of the storage bin 4. Inside the storage bin 4, a weighing sensor and a forced cooling air duct are installed. The high-temperature camera 5 monitors the height of the raw materials in the storage bin 4. When the height of the raw materials in the storage bin 4 exceeds a set threshold, the conveyor 62 stops conveying and removes the currently full storage bin 4 to prevent excessive accumulation of scrap steel in the storage bin 4. The weighing sensor is used to detect the weight of the raw materials in the storage bin 4. The forced cooling air duct cools the preheated high-temperature raw materials.

[0041] D. During the feeding process, the feeding speed can be dynamically adjusted according to the real-time furnace temperature and melting state to ensure that the heat energy absorption of the molten steel and the melting rate are balanced, and the melting process in the furnace is stable, avoiding the problem of excessively high or low furnace temperature and unstable process due to feeding too fast or too slow, which affects the quality of the molten steel and production efficiency.

[0042] E. During the feeding process, when it is necessary to switch raw materials or adjust the scheduling and terminate the current feeding operation, the transverse drive assembly drives the slide 611 and the conveyor 62 on the slide 611 to retract along the incoming material direction. The retraction distance and speed can be flexibly adjusted according to the size, stacking state and process requirements of the raw materials, so that they are separated from the furnace mouth of the electric arc furnace 8, so that the raw materials fall into the storage bin 4 through the drop port under the action of gravity, preventing the raw materials from continuing to be transported to the electric arc furnace 8, and reducing production accidents caused by the problem of raw materials entering by mistake.

[0043] F. When charging is nearly complete, the composition adjustment phase begins. Real-time temperature monitoring and laboratory analysis are used to precisely control the composition of the molten steel by adding necessary alloying elements, deoxidizers, and desulfurizers based on the target steel grade's composition requirements. Fine-tuning can be performed after each adjustment based on laboratory feedback, such as adjusting the charge ratio and heating time. This ensures precise control of the molten steel's composition, improving steel quality and reducing material waste.

[0044] G. When the molten steel reaches the desired temperature and composition, it enters the tapping phase. The furnace inclination is adjusted according to actual conditions, and tapping is initiated. The molten steel is poured into a ladle and sent to subsequent processing stages such as LF and VD. After tapping, the slag is promptly cleaned, and the furnace is inspected and cleaned to ensure optimal equipment operation for the next batch of production. During the interval between tapping from the current batch, preparations for the next batch are initiated. During this time, the furnace can be loaded with the first hopper of the next batch, fully preparing for production and starting when process conditions permit.

[0045] Example 2: Taking the production of a batch of Cr12 mold steel as an example, the target steel grade is first determined based on the production schedule. Typical composition is C = 2.0%, Cr = 11.5%, Si ≤ 0.5%, Mn ≤ 0.6%, with moderately controlled Mo and V content. This steel grade is a high-carbon alloy steel. This steel grade requires high composition control and alloy fusion uniformity. If the previous batch was low-carbon steel with C ≤ 0.15%, the steel grade needs to be switched to high-carbon chromium steel. After the previous batch is tapped, the slag is cleaned, ensuring the furnace bottom and walls are clean to prepare for the next batch.

[0046] Then a two-stage feeding method is adopted, including the first feeding stage and the second feeding stage, specifically: A. Adding the First Batch of Charge: The electric arc furnace 8 is turned on and the first batch of charge is added through the hopper. The first batch of charge includes high-grade medium-carbon scrap steel, recycled materials, and preliminary alloying materials such as high-carbon ferrochrome, a small amount of aluminum, and ferrosilicon. The total amount of the first batch of charge accounts for approximately 30% of the planned smelting volume.

[0047] B. Establishing a molten steel pool: Start electrode ignition and operate the electrode arc at 80%-100% of the rated power of the furnace body to ensure that heat quickly penetrates the thick scrap steel layer in the first bucket, causing the first bucket to enter the rapid melting stage. When the furnace temperature is ≥1550℃ and the basic molten steel weight is 25%-30% of the total smelting weight, a molten steel pool is obtained.

[0048] C. The remaining raw materials are preheated and added according to the remaining proportions through a continuous feeding device. The continuous feeding device comprises a feeding section 1, a sealing section 2, and a preheating section 3. The preheating section 3 is equipped with a flue gas duct connected to the electric arc furnace 8 and a retracting conveyor 6. The raw materials are preheated using the base steel and high-temperature flue gas generated in the first feeding stage within the electric arc furnace 8. The raw material temperature is monitored in real time during the preheating process. When the preheated raw material temperature exceeds 400°C, the raw material enters the molten steel pool, where it is thoroughly mixed with the base steel and ultimately melted to the target volume.

[0049] D. During the raw material feeding process, control the feeding rate to ensure that the heat energy absorption of the molten steel and the melting rate are balanced.

[0050] E. During the raw material feeding process, if scheduling adjustments or steel grade changes necessitate interrupting the current feeding process, the retracting conveyor 6 of the continuous feeding device is retracted to prevent further raw material from entering the furnace opening of the electric arc furnace 8. After retraction, the raw material falls by gravity into the storage silo 4 below the conveyor 62. This silo is equipped with forced cooling air ducts, weighing sensors, and a material barcode reader to monitor the raw material quantity and composition in real time and reduce its temperature. The raw material in the storage silo 4 is classified based on the monitoring results to determine whether it can be used in the production of the current steel grade. If unusable, it is returned to the main stockyard or other suitable area via a return conveyor.

[0051] A high-temperature camera 5 is provided on one side of the storage bin 4 to monitor the accumulation of raw materials in the storage bin 4 in real time. Once the accumulation of raw materials exceeds the set threshold, the retraction conveyor 6 will be stopped immediately. The operator can remove the fully loaded storage bin 4 and replace it with an empty storage bin 4 to ensure that the raw materials will not cause problems in the production process due to excessive accumulation.

[0052] F. After adding materials to the fourth section, the composition of the liquid steel is monitored in real time to ensure that the Cr and C contents initially meet the standards, and the composition adjustment stage is entered. At this time, through real-time temperature monitoring and chemical analysis, a trace amount of ferromolybdenum, ferrovanadium and a small amount of desulfurizer are added for refining. The electrode temperature is raised to the range of 1650-1680℃, and the stirring device is started at the same time to homogenize the molten steel. It is confirmed that the Cr content of the molten steel is 11.8%, the C content is 1.95%, and the impurity control is qualified. Then the steel-making instruction is generated to prepare for the LF treatment.

[0053] G. After tapping, the forehearth is deslagging and the next furnace is ready, ensuring a seamless transition throughout the production process. The first batch of material from the new furnace is pre-loaded into the hopper or continuous charging device, ensuring a highly efficient and continuous process.

[0054] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Those skilled in the art may modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein; and all these modifications and replacements should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A two-stage charging method for an electric arc furnace suitable for producing multiple types of steel, characterized by: The first feeding stage comprises the following steps: A. Throwing the first bucket of material: Throwing the first bucket of material when the electric arc furnace (8) is turned on to form the initial composition basis of the molten steel; B. Establishing a molten steel pool: Start electrode ignition to quickly heat the first bucket material, melt the first bucket material, form basic molten steel, and obtain a molten steel pool; The second feeding stage comprises the following steps: C. The remaining raw materials are fed through a continuous feeding device according to the ratio requirements of the target steel grade, and are preheated by the radiation heat of the basic molten steel and the high-temperature flue gas generated in the first feeding stage of the electric arc furnace (8); D. During the feeding process, control the feeding rate to ensure that the heat energy absorption and melting rate of the molten steel are balanced; E. During the feeding process, when the current feeding operation needs to be stopped, the outlet of the conveyor (62) is separated from the feeding port of the electric arc furnace (8) by the retracting conveying device (6) of the continuous feeding device, so that the raw materials on the continuous feeding device fall into the storage bin (4).

2. The two-stage charging method for an electric arc furnace suitable for producing multiple types of steel according to claim 1, characterized in that: In step A, the first bucket material includes high-grade scrap steel, molten iron and any one or two of alloying elements.

3. The two-stage charging method for an electric arc furnace suitable for producing multiple types of steel according to claim 1, characterized in that: In step B, the electric arc furnace (8) is operated and heated at 80%-100% of the rated power of the furnace body.

4. The two-stage charging method for an electric arc furnace suitable for producing multiple types of steel according to claim 1, characterized in that: In step B, after the furnace temperature is stably raised to 1550-1600°C, the first batch of materials is melted to form a basic steel liquid with a total weight of 25%-30%.

5. The two-stage charging method for an electric arc furnace suitable for producing multiple types of steel according to claim 1, characterized in that: In step C, the continuous feeding device includes a feeding section (1), a sealing section (2) and a preheating section (3), the sealing section (2) is located between the end of the feeding section (1) and the beginning of the preheating section (3), and the end of the preheating section (3) corresponds to the feed port of the electric arc furnace (8); the preheating section (3) is provided with a hot flue gas duct (7), and the hot flue gas duct (7) is also connected to the smoke outlet of the electric arc furnace (8).

6. The two-stage charging method for an electric arc furnace suitable for producing multiple types of steel according to claim 5, characterized in that: In step E, the retracting conveying device (6) includes a slide rail (61) located at the bottom of the preheating section (3), a conveyor (62) is slidably connected to the top of the slide rail (61) via a slide (611), a movable drive assembly is provided on the slide (611), and the movable drive assembly drives the conveyor (62) to approach the electric arc furnace (8) or move away from the electric arc furnace (8), a storage bin (4) is provided below the slide rail (61), and a drop opening corresponding to the storage bin (4) is provided on the slide rail (61).

7. The two-stage charging method for an electric arc furnace suitable for producing multiple types of steel according to claim 6, characterized in that: The mobile drive assembly includes a motor frame (63), a drive motor (64) is provided on the motor frame (63), a drive gear (65) is provided on the drive motor (64), a drive rack (66) is fixedly connected to the slide (611), and the drive rack (66) is meshed with the drive gear (65).

8. The two-stage charging method for an electric arc furnace suitable for producing multiple types of steel according to claim 6, characterized in that: A high-temperature camera (5) is provided on one side of the storage bin (4), and a weighing sensor and a forced cooling air duct are provided inside the storage bin (4).

9. The two-stage charging method for an electric arc furnace suitable for producing multiple types of steel according to claim 1, characterized in that: In step C, when the raw material preheating temperature exceeds 400°C, the raw material enters the molten steel pool, is fully mixed with the base molten steel, and is finally melted to the target amount.

10. The two-stage charging method for an electric arc furnace suitable for producing multiple types of steel according to claim 1, characterized in that: The second feeding stage also includes the following steps: F. When the feeding is nearly completed, the composition of the molten steel is precisely controlled according to the composition requirements of the target steel grade through real-time temperature monitoring and chemical analysis to ensure that the composition of the molten steel meets the composition requirements of the target steel grade; G. When the molten steel reaches the predetermined temperature and composition, it is tapped.

Images