Method for low-carbon environment-friendly production of 3104 alloy blank with high secondary aluminum ratio

Abstract

The invention belongs to the technical field of aluminum alloy production, and particularly discloses a low-carbon environment-friendly method for producing a 3104 alloy blank with a high secondary aluminum proportion, which comprises the procedures of smelting, melt purification, online degassing filtration, continuous casting and triple continuous rolling, and is characterized in that alloy components are optimized, secondary aluminum waste is used in a large proportion, the Fe content is increased, and the production cost is reduced. Iron and elements such as manganese in the aluminum alloy form intermetallic compounds, the intermetallic compounds can serve as heterogeneous nucleation, obviously refine alloy grains during casting and increase Fe content, the performance of the 3104 alloy blank is improved, meanwhile, aluminum is replaced with iron, the main material cost can be reduced, in addition, due to the fact that the rolling temperature of an inlet of each rack is high, and meanwhile the finish rolling temperature is also high, the service life of the 3104 alloy blank is prolonged. The self-tempering effect is achieved, internal dislocation of materials is eliminated, the blank edge cracking condition is improved, strip breakage caused by the edge cracking problem in the subsequent rolling process is avoided, safe production is guaranteed, the main material cost is reduced, meanwhile, the blank performance is improved, the 3104 alloy blank is efficiently produced in a high-quality mode, and the purposes of low carbon and environment protection are achieved.

Description

Technical Field

[0001] This invention belongs to the field of aluminum alloy production technology, and specifically discloses a method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon emissions in an environmentally friendly manner. Background Technology

[0002] 3104 aluminum alloy possesses moderate strength and good plasticity and elongation, meeting the demands of complex processing such as stamping, bending, and stretching, while ensuring that finished products are not easily deformed or broken during use. As an Al-Mn alloy, it is not prone to rusting in atmospheric, fresh water, and some weakly corrosive environments, eliminating the need for additional complex anti-corrosion treatments. Furthermore, 3104 aluminum alloy exhibits excellent cold and hot working properties, allowing it to be cold-rolled and hot-rolled into various forms such as sheets, foils, and profiles. It also boasts stable welding performance, making it suitable for efficient processing on automated production lines. Thanks to these characteristics, it is widely used in food packaging, building decoration, transportation, and daily hardware industries.

[0003] Currently, domestic 3104 alloy billets are generally produced using hot-rolled billets. For example, the manufacturing methods for 3104 aluminum alloy strips disclosed in existing patents CN104294194 B and CN119351803 A include multiple processes such as melting and casting, milling, homogenization heating, hot rolling, and cold rolling. This results in a long production cycle and high production costs. In addition, since milling must be performed before the hot rolling process, the yield is low and the loss is high, further increasing the production cost. Some companies have also experimented with producing cast-rolled 3104 alloy products, such as Chinese patent CN101912877B. However, the relevant production process parameters for casting and rolling are not detailed. Based on the production experience of most companies, the casting and rolling method for producing 3104 alloy billets has the characteristics of slow production speed, easy sticking to the rolls, excessive rolling force, and difficulty in controlling the shape, which seriously hinders the stable production of cast-rolled billets. Summary of the Invention

[0004] To address the problems in the background art, this invention discloses a method for producing 3104 alloy billets with a high proportion of recycled aluminum, resulting in low-carbon and environmentally friendly production. By using a large proportion of recycled aluminum waste, optimizing the alloy composition, reducing the cost of the main material, and improving the billet performance, this method enables efficient and high-quality production of 3104 alloy billets, achieving the goals of low carbon and environmental protection.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon emissions, comprising the following steps: S1. Smelting and Batching: Electrolytic aluminum liquid (5-10% by mass) and recycled aluminum waste (80-95% by mass) are placed in a smelting furnace to prepare aluminum melt. Samples are taken for testing. Based on the test results, quick-dissolving silicon, iron, copper, manganese, magnesium ingots, and titanium are added to the smelting furnace and stirred evenly to adjust the alloy composition to meet the requirements. The mass percentages of each component are as follows: Si: 0.3-0.5%, Fe: 0.55-0.75%, Cu: 0.1-0.25%, Mn: 0.85-1.15%, Mg: 0.85-1.25%, Ti: 0.025-0.045%, other individual impurities ≤0.03%, total ≤0.15%, and the balance is Al. S2. Melt purification treatment: After the aluminum melt composition is adjusted to meet the requirements, refining begins. Refining is carried out simultaneously using a refining machine and manual refining. Argon is used as the refining gas. Electromagnetic stirring is turned on throughout the refining process. After refining, the aluminum melt is allowed to stand and then slag is removed. After slag removal, it is allowed to stand for 30-40 minutes before the furnace is started. S3. Online degassing and filtration: After the furnace is started, the aluminum melt flows into the degassing box and plate filter box in sequence through the guide channel for online degassing and filtration. The aluminum melt after degassing and filtration flows into the front box. At the inlet of the degassing box and the plate filter box, aluminum titanium boron wire crystal refiner is added to the aluminum melt at a uniform speed. S4. Continuous casting: The temperature of the aluminum melt in the front box is 700-710℃. The aluminum melt flows into the casting chamber of the casting machine through the casting nozzle. The melt solidifies in the casting chamber to form a billet. The billet is discharged from the plate as the upper and lower steel strips rotate in the same direction. The casting speed is 8.5-9.2m / min and the billet thickness is 19mm. S5. Three-stand rolling: After passing through the mill pinch rolls, the billet enters the three-stand rolling mill for rolling. The billet exit thickness of the first stand of the three-stand rolling mill is 11.0-12.0 mm, the billet exit thickness of the second stand of the three-stand rolling mill is 7.0-8.0 mm, and the billet exit thickness of the third stand of the three-stand rolling mill is 4.0-5.0 mm. The material exiting the third stand of the three-stand rolling mill is coiled into a coil on the coiler to obtain the finished 3104 alloy billet. S6. Inspection and Packaging: When aluminum strip passes through three rolling mills, the edge cracks of the exit strip must be inspected. The cracks must be ≤2mm. After the material leaves the mill, samples are taken for testing. The tensile strength must be ≥295MPa, the elongation must be ≥9.0%, and the grain size must meet the national standard grade one. After passing the inspection, the strip is packaged as required.

[0006] Furthermore, in the method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon and environmental protection, in step S1, before sampling and testing, a slag remover is used to mechanically stir the aluminum melt in the smelting furnace to make it uniform.

[0007] Furthermore, in the method for producing 3104 alloy billet with a high proportion of recycled aluminum and low carbon and environmental protection, in step S1, when adding magnesium ingots into the melting furnace, the magnesium ingots are placed in an iron frame welded from stainless steel. The iron frame containing the magnesium ingots is preheated on the surface of the melt for 10 to 20 minutes using a feeding cart. Then, the iron frame is quickly lowered and immersed below the surface of the melt, and the iron frame is shaken to melt the magnesium ingots.

[0008] Furthermore, in the method for producing 3104 alloy billet with a high proportion of recycled aluminum and low carbon and environmental protection, in step S2, the argon pressure during refining is 0.5±0.1MPa, the rotor speed is 500±50 rpm, and the refining time is 50-60 min, to ensure the refining effect of the melt and at the same time play a role in local stirring and uniformity, avoiding component segregation.

[0009] Furthermore, in the method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon and environmental protection, in step S3, argon gas is introduced into the degassing box for online refining, with an argon gas pressure of 0.4±0.05MPa and a rotor speed of 300±10 rpm for the three sets of rotors.

[0010] Furthermore, in the method for producing 3104 alloy billet with a high proportion of recycled aluminum and low carbon and environmental protection, in step S3, aluminum-titanium-boron wire is added uniformly to the aluminum melt at a speed of 3.5±0.5m / min at the inlet of the degassing box, and aluminum-titanium-boron wire is added uniformly to the aluminum melt at a speed of 1.5±0.5m / min at the inlet of the plate filter box.

[0011] Furthermore, in the method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon and environmental protection, in step S4, during continuous casting, the casting nozzle used is an SL-type nozzle with a mixing zone, and the upper and lower steel strips are Y-type ceramic steel strips.

[0012] Furthermore, in the method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon emissions in an environmentally friendly manner, in step S5, before the cast plate enters the continuous rolling mill stand, it must be rinsed and cooled with emulsion. The emulsion mass percentage concentration of the first stand of the three-stand rolling mill is 4.5±0.1%, the emulsion mass percentage concentration of the second stand of the three-stand rolling mill is 3.5±0.1%, and the emulsion mass percentage concentration of the third stand of the three-stand rolling mill is 3.5±0.1%.

[0013] Furthermore, in the method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon emissions, in step S5, the slab inlet temperature of the first stand of the three-stand rolling mill is 480-550℃, and the slab outlet temperature of the first stand of the three-stand rolling mill is 400-470℃; the slab inlet temperature of the second stand of the three-stand rolling mill is 380-450℃, and the slab outlet temperature of the second stand of the three-stand rolling mill is 270-340℃; the slab inlet temperature of the third stand of the three-stand rolling mill is 250-320℃, and the slab outlet temperature of the third stand of the three-stand rolling mill is 150-220℃.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention discloses a method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon emissions, which optimizes the alloy composition, increases the Fe content, and forms intermetallic compounds with elements such as manganese in the aluminum alloy. These compounds can act as heterogeneous nuclei, significantly refining the grains of the alloy during casting. Increasing the Fe content improves the performance of the 3104 alloy billet while achieving the substitution of aluminum with iron, which can reduce the cost of main materials. In addition, due to the high inlet rolling temperature of each stand and the high final rolling temperature, a self-tempering effect is achieved to eliminate internal dislocations in the material, improve the edge cracking condition of the billet, avoid strip breakage due to edge cracking problems during subsequent rolling processes, and ensure safe production. 2. The method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon emissions disclosed in this invention can make a large proportion of recycled aluminum waste, and at the same time, combined with appropriate refining processes, ensure the quality of the melt, so that the billet can be of stable quality and meet the standards during subsequent rolling. Relying on the good cooling effect of the Hazlet casting machine, a production efficiency of more than 35 tons per hour can be achieved, thus realizing high-efficiency production. Detailed Implementation

[0015] The present invention will be further explained and illustrated below with reference to embodiments. However, this should not be construed as limiting the scope of protection of the present invention. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. Example 1

[0016] The specific steps for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon emissions in an environmentally friendly manner are as follows: S1. Smelting and Batching: 5.85% by mass of molten aluminum and 94.15% by mass of recycled aluminum scrap are added to the smelting furnace to prepare molten aluminum. A slag remover is used for mechanical stirring to ensure the molten aluminum is homogeneous. Samples are taken for testing. Based on the test results, quick-dissolving silicon, iron, copper, manganese, magnesium ingots, and titanium are added to the smelting furnace. The furnace is then electromagnetically stirred for 30 minutes to adjust the alloy composition to the required level. When adding magnesium ingots to the smelting furnace, the ingots are placed in a stainless steel welded iron frame. Using a feeding cart, the iron frame containing the magnesium ingot is preheated on the surface of the melt for 12 minutes. Then, the iron frame is quickly lowered and immersed below the surface of the melt, and the iron frame is shaken back and forth and left and right to melt the magnesium ingot. The mass percentage of each component is as follows: Si: 0.35%, Fe: 0.58%, Cu: 0.15%, Mn: 0.89%, Mg: 0.87%, Ti: 0.026%, other individual impurities ≤0.03%, total ≤0.15%, and the balance is Al. S2. Melt Purification Treatment: The qualified aluminum melt begins refining. During refining, electromagnetic stirring must be kept on throughout the process. HD2000 refining and manual refining are used in parallel for 50 minutes to ensure the refining effect of the melt and to achieve localized uniform stirring to avoid component segregation. Argon is used as the refining gas in HD2000 refining, and the argon pressure is maintained at 0.48MPa, with the rotor speed maintained at 460 rpm. Argon is also used as the refining gas in manual refining. After refining, the melt is allowed to stand for 20 minutes, and then slag is removed using a slag removal vehicle. The surface of the aluminum melt after slag removal should be mirror-like, and there should be no slag with an area exceeding 50mm×50mm. After slag removal, the melt is allowed to stand for 32 minutes before the furnace is started. S3. Online Degassing and Filtration: After furnace start-up, the molten aluminum flows sequentially into the degassing box and plate filter box via the guide channel for online degassing and filtration. The online degassing box requires slag removal once per hour. The molten aluminum flows into the degassing box, where argon gas is introduced for online refining at a pressure of 0.38 MPa. The three rotor speeds are set to 298 min. After exiting the degassing box, the molten aluminum enters the plate filter box. Two ceramic filter plates of 30+40 ppi are placed in series in the plate filter box. The gaps between the filter plates and the inner lining of the plate filter box need to be sealed with asbestos. The filter plates are pressed tightly using pressure blocks. The molten aluminum after degassing and filtration flows into the front box through a vertical flow stabilizer. Aluminum-titanium-boron wire is added to the molten aluminum at a uniform speed of 3.0 m / min at the inlet of the degassing box and at a uniform speed of 2.0 m / min at the inlet of the plate filter box. The temperature at the point where the aluminum-titanium-boron wire is added is 720℃. S4, Continuous Casting: The temperature of the molten aluminum in the front box is maintained at 702℃, and the fluctuation of the liquid level in the front box must be less than 2mm. The molten aluminum flows into the casting cavity of the casting machine through the casting nozzle. The casting nozzle used is the SL-type mixing zone nozzle. The heat of the molten aluminum is carried away by the circulating cooling water inside the steel strip through the steel strip. The molten aluminum solidifies in the casting cavity to form a billet. The billet is ejected from the plate as the upper and lower steel strips rotate in the same direction. The upper and lower steel strips are Y-type ceramic steel strips. The casting speed is 8.8m / min, and the billet thickness is 19mm. S5, Three-Stage Rolling: After passing through the mill pinch rolls, the slab enters the three-stage rolling mill for rolling. Before entering the mill stand, the slab must be rinsed and cooled with emulsion at a flow rate of 2000 L / min. The emulsion concentration on the first stand of the three-stage rolling mill is 4.45% by mass, the slab exit thickness is 11.0 mm, the slab inlet temperature on the first stand is 520℃, and the slab outlet temperature on the first stand is 440℃. The emulsion concentration on the second stand of the three-stage rolling mill is 3.4% by mass. The slab thickness at the exit of the three-stand rolling mill is 7.0 mm, the slab inlet temperature of the second stand of the three-stand rolling mill is 420℃, and the slab outlet temperature of the second stand of the three-stand rolling mill is 280℃; the emulsion mass percentage concentration of the third stand of the three-stand rolling mill is 3.48%, the slab thickness at the exit of the three-stand rolling mill is 4.0 mm, the slab inlet temperature of the third stand of the three-stand rolling mill is 260℃, and the slab outlet temperature of the third stand of the three-stand rolling mill is 190℃. The material exiting the three stands is coiled into coils on the coiler to obtain the finished 3104 alloy billet. S6. Inspection and Packaging: When the aluminum strip passes through the three-roll mill, the edge cracks of the exit strip are inspected, and the cracks of the entire roll are ≤1mm. After the material exits the mill, the thickness, width, end face quality, surface quality and other quality indicators of the material are inspected. Samples are taken to test the mechanical properties of the finished product, with a tensile strength of 299MPa and an elongation of ≥9.5%. Samples are also taken for pickling to test the grain size, and the grain size meets the national standard grade one. After the inspection and testing are qualified, the material is packaged according to the packaging requirements using cardboard, plastic film, desiccant and wooden pallets. After packaging, a material label is affixed to the outside of the cardboard. The label must include information such as alloy, condition, specifications, net weight, gross weight and packaging date. Example 2

[0017] The specific steps for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon emissions in an environmentally friendly manner are as follows: S1. Smelting Batching: Electrolytic aluminum liquid (9.21% by mass) and recycled aluminum scrap (90.79% by mass) are added to the smelting furnace to prepare molten aluminum. A slag remover is used for mechanical stirring to ensure the molten aluminum is homogeneous. Samples are taken for testing. Based on the test results, quick-dissolving silicon, iron, copper, manganese, magnesium ingots, and titanium are added to the smelting furnace. Electromagnetic stirring is turned on for 40 minutes to ensure the alloy composition is adjusted to the required standard. When adding magnesium ingots to the smelting furnace, the magnesium ingots are placed inside a stainless steel welded iron... In the process of preparing the magnesium ingot, the iron frame containing the magnesium ingot is preheated on the surface of the melt for 20 minutes using a feeding cart. Then, the iron frame is quickly lowered and immersed below the surface of the melt, and the frame is shaken back and forth and left and right to melt the magnesium ingot. The mass percentage of each component is as follows: Si: 0.48%, Fe: 0.72%, Cu: 0.23%, Mn: 1.12%, Mg: 1.21%, Ti: 0.044%, other individual impurities ≤0.03%, total ≤0.15%, and the balance is Al. S2. Melt Purification Treatment: The qualified aluminum melt begins refining. During refining, electromagnetic stirring must be kept on throughout the process. HD2000 refining and manual refining are used in parallel for 60 minutes to ensure the refining effect of the melt and to achieve localized uniform stirring to avoid component segregation. Argon is used as the refining gas in HD2000 refining, and the argon pressure is maintained at 0.58MPa, with the rotor speed maintained at 535 rpm. Argon is also used as the refining gas in manual refining. After refining, the melt is allowed to stand for 15 minutes, and then slag is removed using a slag removal vehicle. The surface of the aluminum melt after slag removal should be mirror-like, and there should be no slag with an area exceeding 50mm×50mm. After slag removal, the melt is allowed to stand for 39 minutes before the furnace is started. S3. Online Degassing and Filtration: After furnace start-up, the molten aluminum flows sequentially into the degassing box and plate filter box via the guide channel for online degassing and filtration. The online degassing box requires slag removal once per hour. The molten aluminum flows into the degassing box, where argon gas is introduced for online refining at a pressure of 0.43 MPa. The three rotor speeds are set to 308 rpm. After exiting the degassing box, the molten aluminum enters the plate filter box. Two ceramic filter plates of 30+40 ppi are placed in series in the plate filter box. The gaps between the filter plates and the inner lining of the plate filter box need to be sealed with asbestos. The filter plates are pressed tightly using pressure blocks. The molten aluminum after degassing and filtration flows into the front box through a vertical flow stabilizer. Aluminum-titanium-boron wire is added to the molten aluminum at a uniform speed of 4.0 m / min at the inlet of the degassing box and at a uniform speed of 1.0 m / min at the inlet of the plate filter box. The temperature at the point where the aluminum-titanium-boron wire is added is 730℃. S4, Continuous Casting: The temperature of the molten aluminum in the front box is maintained at 709℃, and the fluctuation of the liquid level in the front box must be less than 2mm. The molten aluminum flows into the casting cavity of the casting machine through the casting nozzle. The casting nozzle used is the SL-type nozzle with a mixing zone. The heat of the molten aluminum is carried away by the circulating cooling water inside the steel strip through the steel strip. The molten aluminum solidifies in the casting cavity to form a billet. The billet is ejected from the plate as the upper and lower steel strips rotate in the same direction. The upper and lower steel strips are Y-type ceramic steel strips. The casting speed is controlled at 9.1m / min, and the billet thickness is 19mm. S5, Three-Stage Rolling: After passing through the mill pinch rolls, the slab enters the three-stage rolling mill for rolling. Before entering the mill stand, the slab must be rinsed and cooled with emulsion at a flow rate of 2200 L / min. The emulsion concentration on the first stand of the three-stage rolling mill is 4.58% by mass, the slab exit thickness is 11.9 mm, the slab inlet temperature on the first stand is 540°C, and the slab outlet temperature on the first stand is 460°C. The emulsion concentration on the second stand of the three-stage rolling mill is 3.5% by mass. The slab thickness at the exit is 7.8 mm. The slab inlet temperature of the second stand of the three-stand rolling mill is 440℃, and the slab outlet temperature of the second stand of the three-stand rolling mill is 300℃. The emulsion mass percentage concentration of the third stand of the three-stand rolling mill is 3.52%, the slab thickness at the exit is 4.8 mm, the slab inlet temperature of the third stand of the three-stand rolling mill is 280℃, and the slab outlet temperature of the third stand of the three-stand rolling mill is 210℃. The material exiting the three stands is coiled into coils on the coiler to obtain the finished 3104 alloy billet. S6. Inspection and Packaging: When the aluminum strip passes through the three-roll mill, the edges of the exit strip are inspected for cracks, and no cracks are found on the entire roll. After the material exits the mill, the thickness, width, end face quality, surface quality, and other quality indicators are inspected. Samples are taken to test the mechanical properties, with a tensile strength of 302MPa and an elongation of ≥9.9%. Samples are also taken for pickling to test the grain size, which meets the national standard grade one. After the inspection is qualified, the material is packaged according to the packaging requirements using cardboard, plastic film, desiccant, and wooden pallets. After packaging, a material label is affixed to the outside of the cardboard. The label must include information such as alloy, condition, specifications, net weight, gross weight, and packaging date.

[0018] The parts of this invention not described in detail are prior art.

[0019] The embodiments selected herein for the purpose of disclosing the inventive objectives are currently considered suitable; however, it should be understood that the invention is intended to include all variations and modifications of the embodiments that fall within the scope of this concept and invention.

Claims

1. A method for producing 3104 alloy billets with a high proportion of recycled aluminum, characterized by low carbon emissions and environmental friendliness. Includes the following steps: S1. Smelting and Batching: Electrolytic aluminum liquid (5-10% by mass) and recycled aluminum waste (80-95% by mass) are placed in a smelting furnace to prepare aluminum melt. Samples are taken for testing. Based on the test results, quick-dissolving silicon, iron, copper, manganese, magnesium ingots, and titanium are added to the smelting furnace and stirred evenly to adjust the alloy composition to meet the requirements. The mass percentages of each component are as follows: Si: 0.3-0.5%, Fe: 0.55-0.75%, Cu: 0.1-0.25%, Mn: 0.85-1.15%, Mg: 0.85-1.25%, Ti: 0.025-0.045%, other individual impurities ≤0.03%, total ≤0.15%, and the balance is Al. S2. Melt purification treatment: After the aluminum melt composition is adjusted to meet the requirements, refining begins. Refining is carried out simultaneously using a refining machine and manual refining. Argon is used as the refining gas. Electromagnetic stirring is turned on throughout the refining process. After refining, the aluminum melt is allowed to stand and then slag is removed. After slag removal, it is allowed to stand for 30-40 minutes before the furnace is started. S3. Online degassing and filtration: After the furnace is started, the aluminum melt flows into the degassing box and plate filter box in sequence through the guide channel for online degassing and filtration. The aluminum melt after degassing and filtration flows into the front box. At the inlet of the degassing box and the plate filter box, aluminum titanium boron wire crystal refiner is added to the aluminum melt at a uniform speed. S4. Continuous casting: The temperature of the aluminum melt in the front box is 700-710℃. The aluminum melt flows into the casting chamber of the casting machine through the casting nozzle. The melt solidifies in the casting chamber to form a billet. The billet is discharged from the plate as the upper and lower steel strips rotate in the same direction. The casting speed is 8.5-9.2m / min and the billet thickness is 19mm. S5. Three-stand rolling: After passing through the mill pinch rolls, the billet enters the three-stand rolling mill for rolling. The billet exit thickness of the first stand of the three-stand rolling mill is 11.0-12.0 mm, the billet exit thickness of the second stand of the three-stand rolling mill is 7.0-8.0 mm, and the billet exit thickness of the third stand of the three-stand rolling mill is 4.0-5.0 mm. The material exiting the third stand of the three-stand rolling mill is coiled into a coil on the coiler to obtain the finished 3104 alloy billet. S6. Inspection and Packaging: When aluminum strip passes through three rolling mills, the edge cracks of the exit strip must be inspected. The cracks must be ≤2mm. After the material leaves the mill, samples are taken for testing. The tensile strength must be ≥295MPa, the elongation must be ≥9.0%, and the grain size must meet the national standard grade one. After passing the inspection, the strip is packaged as required.

2. The method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon emissions according to claim 1, characterized in that, In step S1, before sampling and testing, a slag remover is used to mechanically stir the molten aluminum in the smelting furnace to ensure uniform mixing.

3. The method for producing 3104 alloy billet with a high proportion of recycled aluminum and low carbon emissions according to claim 1, characterized in that the steps are as follows: In S1, when adding magnesium ingots into the melting furnace, the magnesium ingots are placed in a stainless steel welded iron frame. The iron frame containing the magnesium ingots is preheated on the surface of the melt for 10 to 20 minutes using a feeding cart. Then, the iron frame is quickly lowered and immersed below the surface of the melt, and the iron frame is shaken to melt the magnesium ingots.

4. The method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon emissions according to claim 1, characterized in that, In step S2, the argon pressure during refining is 0.5±0.1MPa, the rotor speed is 500±50 rpm, and the refining time is 50-60 min. This ensures the refining effect of the melt and also plays a role in local stirring and uniformity, thus avoiding component segregation.

5. The method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon emissions according to claim 1, characterized in that, In step S3, argon gas is introduced into the degassing box for online refining. The argon gas pressure is 0.4±0.05MPa, and the rotation speed of the three rotors is 300±10 rpm.

6. The method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon emissions according to claim 1, characterized in that, In step S3, aluminum-titanium-boron wires are added uniformly to the aluminum melt at a speed of 3.5±0.5 m / min at the inlet of the degassing box, and aluminum-titanium-boron wires are added uniformly to the aluminum melt at a speed of 1.5±0.5 m / min at the inlet of the plate filter box.

7. The method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon emissions according to claim 1, characterized in that, In step S4, during continuous casting, the casting nozzle used is the SL-type nozzle for the mixing zone, and the upper and lower steel strips are Y-type ceramic steel strips.

8. The method for producing 3104 alloy billet with a high proportion of recycled aluminum and low carbon emissions according to claim 1, characterized in that, In step S5, before the cast plate enters the continuous rolling mill stand, it must be rinsed and cooled with emulsion. The emulsion mass percentage concentration of the first stand of the three-stand rolling mill is 4.5±0.1%, the emulsion mass percentage concentration of the second stand of the three-stand rolling mill is 3.5±0.1%, and the emulsion mass percentage concentration of the third stand of the three-stand rolling mill is 3.5±0.1%.

9. The method for producing 3104 alloy billets with a high proportion of recycled aluminum and low carbon emissions according to claim 1, characterized in that, In step S5, the slab inlet temperature of the first stand of the three-stand rolling mill is 480-550℃, and the slab outlet temperature of the first stand of the three-stand rolling mill is 400-470℃; the slab inlet temperature of the second stand of the three-stand rolling mill is 380-450℃, and the slab outlet temperature of the second stand of the three-stand rolling mill is 270-340℃; the slab inlet temperature of the third stand of the three-stand rolling mill is 250-320℃, and the slab outlet temperature of the third stand of the three-stand rolling mill is 150-220℃.