Method for producing high-purity high-conductivity aluminum strip with high efficiency and low carbon

Abstract

The present application relates to the technical field of aluminum alloy production, and specifically discloses a method for efficiently and low-carbon producing high-purity high-conductivity aluminum strip, which uses continuous casting and rolling to produce 1085 alloy high-purity aluminum strip, while ensuring efficient, low-carbon and low-cost production in a short process, adopting a three-time complete recrystallization annealing production process of medium-tempering + cold rolling + medium-tempering + cold rolling + finished product annealing in a cold rolling process to produce 0-state aluminum strip, which is soft in texture and free of large grains, through three-time recrystallization, work hardening is eliminated, impurities are precipitated, the number of lattice distortions is small and the degree is light, the density of dislocation defects is low, the scattering of free electrons is greatly reduced, the conductivity is improved, the tensile strength is only about 53mpa, and the finished product is extremely easy to process and use, the conductivity of the finished product is greater than or equal to 37.5mS / m, which is about 3% higher than that of a traditional process, and is suitable for high-conductivity use scenarios such as power equipment.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy production technology, specifically disclosing a method for producing high-purity, high-conductivity aluminum strips with high efficiency and low carbon emissions. Background Technology

[0002] Copper alloys offer excellent electrical conductivity, but their high density, high price, and scarcity make using only copper conductors extremely costly. Ordinary aluminum alloy strips have low conductivity, generating significant heat during use, wasting energy, accelerating equipment aging, and increasing heat dissipation costs. High-purity aluminum alloys reduce conductor resistance, decrease heat loss, and improve energy efficiency, while also offering advantages such as low density, low cost, ease of processing, and corrosion resistance, aligning with industrial energy conservation and grid loss reduction policies.

[0003] Currently, 1060 and 1070 aluminum alloys are commonly used to produce conductive aluminum strips. However, their aluminum content only meets the requirement of ≥99.60% or ≥99.70%, resulting in high impurity content and a conductivity of around 35.5 mS / m. 1085 alloy, an industrial high-purity aluminum with an Al content of ≥99.85%, has a conductivity of around 36.4 mS / m and is a mainstream material in the power industry. However, the casting and rolling process for producing 1085 alloy aluminum strip is prone to producing coarse grains (level 5) due to the limited number of nucleation points, making stable production impossible. Hot rolling requires multiple processes such as sawing, milling, homogenization, and rolling, resulting in high production costs due to numerous steps and low yield, hindering large-scale industrial production and failing to meet market demand. Summary of the Invention

[0004] To address the technical problems in the background art, this invention discloses a method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions. The method utilizes continuous casting and rolling to produce 1085 alloy high-purity aluminum strip. While ensuring efficient, low-carbon, and low-cost production through a short process, the method employs three annealing processes in the cold rolling stage to produce 0-state aluminum strip. The finished product is soft, with a tensile strength of only about 53 MPa, making it extremely easy to process and use. The finished product has a conductivity ≥37.5 mS / m, which is about 3% higher than traditional processes, making it suitable for high-conductivity applications such as power equipment.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: The specific steps of the method for producing high-purity, high-conductivity aluminum strip in a high-efficiency, low-carbon manner are as follows: S1. Material preparation: Samples of 85 aluminum ingots and 85 electrolytic aluminum molten metal were taken and tested for alloy composition. 85 aluminum ingots and 85 electrolytic aluminum molten metal with iron content ≤0.08%, silicon content ≤0.05%, and aluminum content ≥99.86% were selected for use. S2. Smelting: First, add aluminum ingots to the smelting furnace, then pour molten aluminum into the smelting furnace through the aluminum inlet, heat the smelting furnace to prepare aluminum melt, take samples to test the alloy composition, and after confirming that the Al content in the aluminum melt is ≥99.85%, turn on the automatic refining machine to refine, each refining time is at least 30 minutes, after each refining is completed, let it stand and remove slag, each batch of melt is refined and removed slag at least four times according to the above steps, and then let it stand for at least 60 minutes before taking it out of the furnace; S3. Online melt treatment: The aluminum melt flows smoothly into the guide channel that is uniformly coated with boron nitride paint, and then flows into the degassing box and the filter box for degassing and filtration in sequence. The treated melt flows directly into the front box. S4, Continuous casting: The temperature of the melt in the front box is 675±5℃. The melt flows into the casting chamber of the casting machine through the casting nozzle and is cooled by the upper and lower steel strips to form a billet. The billet thickness is 19mm, and the casting speed is 6.8~7.5m / min. S5. Continuous rolling: The billet passes through a looper and enters a three-roll mill for continuous rolling. The rolling passes are 19mm→11mm→6.5mm→4.0mm. After three-roll mills, the strip is coiled into coils on a coiler. S6, One-time annealing: The coil obtained in S5 is directly transferred to the annealing furnace after being wrapped with steel strip. After 3 hours, the furnace temperature is raised to 500-530℃ at a uniform rate and held for 20-25 hours. Then, the furnace temperature is lowered to 170℃ and the coil is taken out of the furnace. S7, One-time cold rolling: The material annealed in S6 is cooled to below 40°C and then rolled on a cold rolling mill, with rolling passes ranging from 4.0mm to 2.0mm. S8, Secondary Annealing: The cold-rolled coil obtained in S7 is directly transferred to the annealing furnace for annealing. After 2 hours, the furnace temperature is raised to 320-350℃ at a uniform rate and then held at that temperature. The coil metal temperature is measured to reach 260℃ and then immediately removed from the furnace. S9, Secondary Cold Rolling: The material from the S8 annealing furnace is cooled to below 40°C and then rolled on a cold rolling mill, with rolling passes ranging from 2.0mm to 1.0mm. S10, Finished product annealing: The cold-rolled coil obtained in S9 is directly transferred to the annealing furnace for finished product annealing. After the furnace temperature is uniformly raised to 250-280℃ for 2 hours, it is held at that temperature. The coil metal temperature is measured to reach 210℃ and then it is taken out of the furnace immediately. S11. Inspection and Packaging: Take samples of the finished annealed material for mechanical property testing and electrical conductivity testing. The tensile strength in both the transverse and longitudinal directions should be ≤55MPa, and the electrical conductivity should be ≥37.5mS / m. Finally, pack the finished product.

[0006] Furthermore, in the method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions, in step S2, the rotational speed of the silicon nitride rotor of the automatic refining machine is set to 450±50 rpm, and high-purity argon gas is introduced into the rotor at a pressure of 1.0±0.2 MPa.

[0007] Furthermore, in the method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions, in step S2, the tilt angle of the smelting furnace during start-up does not exceed 28°, and the melt remaining in the smelting furnace after return to the furnace is not used to produce 1085 alloy billets.

[0008] Furthermore, in the method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions, in step S3, during the online processing of the melt, 1070 aluminum alloy wire rods with an aluminum content ≥99.70% and a titanium content ≤0.01% are added to the melt, with 1.0 to 1.3 kg of 1070 aluminum alloy wire rods added per ton of melt.

[0009] Furthermore, in the method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions, in step S4, during continuous casting, four ultrasonic casting tool heads are placed in the front box, and the frequency of the ultrasonic casting tool heads is 40-60KHZ.

[0010] Furthermore, in the method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions, in step S4, during continuous casting, circulating cooling water is introduced into the upper and lower steel strips, with a cooling water temperature ≤24℃ and a cooling water flow rate ≥3000L / min.

[0011] Furthermore, in the method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions, in step S5, during continuous rolling, natural gas torches are used to heat the strip between the first and second stands and between the second and third stands of the three-stand rolling mill to ensure that the temperature of the strip is not lower than 380°C before entering the roll gap of the second stand and not lower than 310°C before entering the roll gap of the third stand.

[0012] Furthermore, in the method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions, in step S5, steel sleeves are respectively provided inside the coiled material.

[0013] Furthermore, in the method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions, the rolling force during the first cold rolling in step S7 is not less than 400KN, and the rolling force during the second cold rolling in step S9 is not less than 300KN.

[0014] Furthermore, in the method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions, during steps S8 and S10, holes are punched in the coil during the secondary annealing and finished product annealing, and thermocouples are placed in the holes to measure the temperature of the coil metal.

[0015] Due to the adoption of the technical solution described above, the present invention has the following advantages: 1. The present invention provides a method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions. It uses carefully selected electrolytic aluminum water and aluminum ingots with an aluminum content of 99.85% or higher to reduce the entry of impurities such as iron and silicon into the melt. After multiple refining processes, the melt is left to stand for a long time to promote the settling of impurities such as iron and silicon to the bottom of the furnace under their own gravity. When starting the furnace, the tilt angle of the smelting furnace is controlled to ensure that the iron-rich and silicon-rich melt at the bottom of the furnace is left at the bottom and does not participate in the production, thereby achieving the purification of the melt alloy and ensuring the stable production of high-purity 1085 alloy. 2. The present invention provides a method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions. It adopts a continuous casting and rolling process to produce 1085 alloy billets. During the online melt treatment, no aluminum-titanium alloy is added. Instead of aluminum-titanium-boron wire, 1070 aluminum alloy wire rods with an aluminum content of more than 99.70% are used. The front box is equipped with an ultrasonic casting tool head for vibration, and the casting machine uses a large flow rate of low-temperature cooling water for casting cooling. This achieves first-level casting grain size without adding titanium and boron grain refining elements, providing a source grain foundation for subsequent finished product grain size control. 3. The present invention provides a method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon content. The method involves continuous casting and rolling to produce 1085 alloy billets, which are low in iron and silicon, resulting in less lattice distortion within the material. Simultaneously, the production of coarse second phases such as Al3Fe and AlFeSi is reduced. The combined effect of these two factors weakens electron scattering and significantly improves the electrical conductivity of the strip. Furthermore, the strip does not contain elements such as Ti and B, further reducing the solid solution strengthening effect and lattice distortion, while avoiding the formation of TiB2 agglomerates. The matrix is ​​close to the pure aluminum lattice, resulting in minimal electron scattering and high electrical conductivity. 4. The present invention provides a method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions. It involves producing 1085 alloy billets via continuous casting and rolling, employing a three-stage fully recrystallized annealing process consisting of intermediate annealing, cold rolling, intermediate annealing, cold rolling, and finished product annealing. By rationally setting the rolling power and annealing process, large grains are prevented. Through three stages of recrystallization, work hardening is eliminated, solid solution impurities precipitate, the number and severity of lattice distortion are reduced, dislocation defect density is low, and free electron scattering is significantly weakened, thereby improving electrical conductivity. 5. The present invention provides a method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions. The method involves continuous casting and rolling to produce 1085 alloy billets, which can integrate the casting and hot rolling processes in the existing technology. This method saves at least 30% energy, shortens the process by 70%, increases the yield to 95%, and reduces the production cost by about 35% compared to the hot rolling method, thus achieving green, low-carbon, large-scale, and efficient production. Detailed Implementation

[0016] 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

[0017] A method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions specifically includes the following steps: S1. Material preparation: For each bundle of 85 aluminum ingots, sample samples are cut and tested for alloy composition. Select aluminum ingots with iron content of 0.07%, silicon content of 0.04%, and aluminum content of 99.88% for later use. Samples of 85 electrolytic aluminum liquid are taken and tested for alloy composition. Select aluminum liquid with iron content of 0.06%, silicon content of 0.03%, and aluminum content of 99.86% for later use. S2. Smelting: First, aluminum ingots are added to the smelting furnace, then molten aluminum is poured into the smelting furnace through the aluminum inlet. The smelting furnace is heated to prepare aluminum melt. No iron, quick-dissolving silicon, manganese, titanium, copper or other alloying agents are added. The alloy composition is sampled and tested. The Al content in the aluminum melt is 99.86%. The HD2000 automatic refining machine is turned on for refining. The silicon nitride rotor of the automatic refining machine is set to a speed of 475 rpm. High-purity argon gas is introduced into the rotor at a pressure of 0.95 MPa. Each refining process takes 35 minutes. After each refining process, the melt is allowed to stand for 17 minutes before slag removal. After slag removal, the surface of the melt is mirror-like and there is no slag with an area greater than 20 mm × 20 mm. Each batch of melt is refined and slag removed four times according to the above steps. After standing for 64 minutes, the furnace is taken out. When taking out the furnace, the tilt angle of the smelting furnace reaches 27.9° and the melt is returned to the furnace. The melt left in the furnace after returning to the furnace is not used to produce 1085 alloy billets. S3. Online melt treatment: The melt flows smoothly into the guide channel, and the inner wall of the guide channel is uniformly coated with boron nitride coating. During online melt treatment, aluminum-titanium-boron wire is not added. Instead, 1070 aluminum alloy wire rods with an aluminum content of 99.73% and a titanium content of 0.002% are added to the melt. 1.2 kg of 1070 aluminum alloy wire rods are added per ton of melt. After passing through the guide channel, the melt flows into the degassing box and the filter box for degassing and filtration in sequence. The treated melt flows directly into the front box. S4. Continuous casting: Four ultrasonic casting tool heads are placed in the front box. The frequency of the ultrasonic casting tool heads is 55KHZ. The melt temperature in the front box is 672℃. The melt flows into the upper and lower steel strips of the casting machine through the casting nozzle. There are synchronously rotating side chain blocks on both sides of the steel strips. The upper and lower steel strips and the two side chain blocks work together to form the casting cavity. Circulating water is introduced into the upper and lower steel strips for cooling. The cooling water temperature is 22℃ and the cooling water flow rate is 3200L / min. The cooling water inside the steel strip cools the melt in the casting cavity to form a billet. The billet thickness is 19mm and the billet width is 1505mm. The casting speed is 6.9m / min. S5. Continuous rolling: The billet passes through the looper and enters the three-stand continuous rolling mill for continuous rolling. Natural gas torches are used to heat the strip between the first and second stands and between the second and third stands. The temperature of the strip before entering the roll gap of the second stand is 395℃ and the temperature before entering the roll gap of the third stand is 320℃. The rolling passes are 19mm→11mm→6.5mm→4.0mm. After three consecutive rolling, the strip is coiled into coils on the coiler. Steel sleeves are installed in the coils. S6, One-time annealing: The coil obtained in S5 is directly transferred to the annealing furnace after being wrapped with steel strip. After 3 hours, the furnace temperature is raised to 530℃ at a uniform rate and held for 22 hours. Then the furnace temperature is lowered to 170℃ and the coil is taken out of the furnace. S7, One-time cold rolling: The material annealed in S6 is cooled to 33°C and then rolled on a cold rolling mill. The rolling passes are 4.0mm→2.0mm, and the rolling force is 480KN. S8, Secondary Annealing: The cold-rolled coil obtained in S7 is directly transferred to the annealing furnace for annealing. After 2 hours, the furnace temperature is raised to 350℃ at a uniform rate and held for 18h35min. Holes are punched in the coil, and thermocouples are placed in the holes to measure the metal temperature in the middle of the coil. The metal temperature in the middle of the coil is 265℃. The coil is then immediately removed from the furnace. S9, Secondary Cold Rolling: The material from the S8 annealing furnace is cooled to 38°C and then rolled on a cold rolling mill. The rolling passes are 2.0mm→1.0mm, and the rolling force is 360KN. S10, Finished product annealing: The cold-rolled coil obtained in S9 is directly transferred to the annealing furnace for finished product annealing. After 2 hours, the furnace temperature is raised to 260℃ at a uniform rate and then held for 15h20min. Holes are punched in the coil, and thermocouples are placed in the holes to measure the metal temperature in the middle of the coil. The metal temperature in the middle of the coil is 215℃. The coil is then immediately removed from the furnace. S11. Inspection and Packaging: Samples of the finished annealed material are taken for mechanical property testing and electrical conductivity testing. The transverse tensile strength is 53MPa, the longitudinal tensile strength is 51MPa, and the electrical conductivity is 37.7mS / m. After passing the test, the material is packaged. Example 2

[0018] A method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions specifically includes the following steps: S1. Material preparation: For each bundle of 85 aluminum ingots, sample samples are cut and tested for alloy composition. Select aluminum ingots with iron content of 0.06%, silicon content of 0.05%, and aluminum content of 99.88% for later use. Samples of 85 electrolytic aluminum liquid are taken and tested for alloy composition. Select aluminum liquid with iron content of 0.05%, silicon content of 0.05%, and aluminum content of 99.88% for later use. S2. Smelting: First, aluminum ingots are added to the smelting furnace, then molten aluminum is poured into the smelting furnace through the aluminum inlet. The smelting furnace is heated to prepare aluminum melt. No iron, quick-dissolving silicon, manganese, titanium, copper or other alloying agents are added. The alloy composition is sampled and tested. The Al content in the aluminum melt is 99.86%. The HD2000 automatic refining machine is turned on for refining. The silicon nitride rotor of the automatic refining machine is set to a speed of 490 rpm. High-purity argon gas is introduced into the rotor at a pressure of 1.05 MPa. Each refining process takes 38 minutes. After each refining process, the melt is allowed to stand for 20 minutes before slag removal. After slag removal, the surface of the melt is mirror-like and there is no slag with an area greater than 20 mm × 20 mm. Each batch of melt is refined and slag removed four times according to the above steps. After standing for 61 minutes, the furnace is taken out. When taking out the furnace, the tilt angle of the smelting furnace reaches 27.8° and the melt is returned to the furnace. The melt left in the furnace after returning to the furnace is not used to produce 1085 alloy billets. S3. Online melt treatment: The melt flows smoothly into the guide channel, and the inner wall of the guide channel is uniformly coated with boron nitride coating. During online melt treatment, aluminum-titanium-boron wire is not added. Instead, 1070 aluminum alloy wire rods with an aluminum content of 99.75% and a titanium content of 0.006% are added to the melt. 1.1 kg of 1070 aluminum alloy wire rods are added per ton of melt. After passing through the guide channel, the melt flows into the degassing box and the filter box for degassing and filtration in sequence. The treated melt flows directly into the front box. S4. Continuous casting: Four ultrasonic casting tool heads are placed in the front box. The frequency of the ultrasonic casting tool heads is 50KHZ. The melt temperature in the front box is 678℃. The melt flows into the upper and lower steel strips of the casting machine through the casting nozzle. There are synchronously rotating side chain blocks on both sides of the steel strips. The upper and lower steel strips and the two side chain blocks work together to form the casting cavity. Circulating water is introduced into the upper and lower steel strips for cooling. The cooling water temperature is 20℃ and the cooling water flow rate is 3400L / min. The cooling water inside the steel strip cools the melt in the casting cavity to form a billet. The billet thickness is 19mm and the billet width is 1305mm. The casting speed is 7.5m / min. S5. Continuous rolling: The billet passes through the looper and enters the three-stand continuous rolling mill for continuous rolling. Natural gas torches are used to heat the strip between the first and second stands and between the second and third stands. The temperature of the strip before entering the roll gap of the second stand is 385℃ and the temperature before entering the roll gap of the third stand is 315℃. The rolling passes are 19mm→11mm→6.5mm→4.0mm. After three consecutive rolling, the strip is coiled into coils on the coiler. Steel sleeves are installed in the coils. S6, One-time annealing: The coil obtained in S5 is directly transferred to the annealing furnace after being wrapped with steel strip. After 3 hours, the furnace temperature is raised to 525℃ at a uniform rate and held for 25 hours. Then, the furnace temperature is lowered to 170℃ and the coil is taken out of the furnace. S7, One-time cold rolling: The material annealed in S6 is cooled to 33°C and then rolled on a cold rolling mill. The rolling passes are 4.0mm→2.0mm, and the rolling force is 430KN. S8, Secondary Annealing: The cold-rolled coil obtained in S7 is directly transferred to the annealing furnace for annealing. After 2 hours, the furnace temperature is raised to 340℃ at a uniform rate and held for 19h25min. Holes are punched in the coil, and thermocouples are placed in the holes to measure the metal temperature in the middle of the coil. The metal temperature in the middle of the coil is 270℃. The coil is then immediately removed from the furnace. S9, Secondary Cold Rolling: The material from the S8 annealing furnace is cooled to 38°C and then transferred to a cold rolling mill for rolling. The rolling passes are 2.0mm→1.0mm, and the rolling force is 320KN. S10, Finished product annealing: The cold-rolled coil obtained in S9 is directly transferred to the annealing furnace for finished product annealing. After 2 hours, the furnace temperature is raised to 270℃ at a uniform rate and then held for 16h40min. Holes are punched in the coil, and thermocouples are placed in the holes to measure the metal temperature in the middle of the coil. The metal temperature in the middle of the coil is 225℃. The coil is then immediately removed from the furnace. S11. Inspection and Packaging: Samples of the finished annealed material are taken for mechanical property testing and electrical conductivity testing. The transverse tensile strength is 52MPa, the longitudinal tensile strength is 54MPa, and the electrical conductivity is 37.9mS / m. After passing the test, the material is packaged. Example 3

[0019] A method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions specifically includes the following steps: S1. Material preparation: For each bundle of 85 aluminum ingots, sample samples are cut and tested for alloy composition. Select aluminum ingots with iron content of 0.06%, silicon content of 0.05%, and aluminum content of 99.88% for later use. Samples of 85 electrolytic aluminum liquid are taken and tested for alloy composition. Select aluminum liquid with iron content of 0.05%, silicon content of 0.04%, and aluminum content of 99.88% for later use. S2. Smelting: First, aluminum ingots are added to the smelting furnace, then molten aluminum is poured into the smelting furnace through the aluminum inlet. The smelting furnace is heated to prepare aluminum melt. No iron, quick-dissolving silicon, manganese, titanium, copper or other alloying agents are added. The alloy composition is sampled and tested. The Al content in the aluminum melt is 99.86%. The HD2000 automatic refining machine is turned on for refining. The silicon nitride rotor of the automatic refining machine is set to a speed of 425 rpm. High-purity argon gas is introduced into the rotor at a pressure of 1.15 MPa. Each refining process takes 43 minutes. After each refining process, the melt is allowed to stand for 25 minutes before slag removal. After slag removal, the surface of the melt is mirror-like and there is no slag with an area greater than 20 mm × 20 mm. Each batch of melt is refined and slag removed four times according to the above steps. After standing for 65 minutes, the furnace is taken out. When taking out the furnace, the tilt angle of the smelting furnace reaches 27.9° and the melt is returned to the furnace. The melt left in the furnace after returning to the furnace is not used to produce 1085 alloy billets. S3. Online melt treatment: The melt flows smoothly into the guide channel, and the inner wall of the guide channel is uniformly coated with boron nitride coating. During online melt treatment, aluminum-titanium-boron wire is not added. Instead, 1070 aluminum alloy wire rods with an aluminum content of 99.75% and a titanium content of 0.006% are added to the melt. 1.25 kg of 1070 aluminum alloy wire rods are added per ton of melt. After passing through the guide channel, the melt flows into the degassing box and the filter box for degassing and filtration in sequence. The treated melt flows directly into the front box. S4. Continuous casting: Four ultrasonic casting tool heads are placed in the front box. The frequency of the ultrasonic casting tool heads is 45KHZ. The melt temperature in the front box is 670℃. The melt flows into the upper and lower steel strips of the casting machine through the casting nozzle. There are synchronously rotating side chain blocks on both sides of the steel strips. The upper and lower steel strips and the two side chain blocks work together to form the casting cavity. Circulating water is introduced into the upper and lower steel strips for cooling. The cooling water temperature is 20℃ and the cooling water flow rate is 3400L / min. The cooling water inside the steel strip cools the melt in the casting cavity to form a billet. The billet thickness is 19mm and the billet width is 1305mm. The casting speed is 7.3m / min. S5. Continuous rolling: The billet passes through the looper and enters the three-stand continuous rolling mill for continuous rolling. Natural gas torches are used to heat the strip between the first and second stands and between the second and third stands. The temperature of the strip before entering the roll gap of the second stand is 382℃ and the temperature before entering the roll gap of the third stand is 315℃. The rolling passes are 19mm→11mm→6.5mm→4.0mm. After three consecutive rolling, the strip is coiled into coils on the coiler. Steel sleeves are installed in the coils. S6, One-time annealing: The coil obtained in S5 is directly transferred to the annealing furnace after being wrapped with steel strip. After 3 hours, the furnace temperature is raised to 515℃ at a uniform rate and held for 25 hours. Then, the furnace temperature is lowered to 170℃ and the coil is taken out of the furnace. S7, One-time cold rolling: The material annealed in S6 is cooled to 33°C and then rolled on a cold rolling mill. The rolling passes are 4.0mm→2.0mm, and the rolling force is 450KN. S8, Secondary Annealing: The cold-rolled coil obtained in S7 is directly transferred to the annealing furnace for annealing. After 2 hours, the furnace temperature is raised to 320℃ at a uniform rate and held for 22 hours. Holes are punched in the coil, and thermocouples are placed in the holes to measure the metal temperature in the middle of the coil. The metal temperature in the middle of the coil is 265℃. The coil is then immediately removed from the furnace. S9, Secondary Cold Rolling: The material from the S8 annealing furnace is cooled to 38°C and then transferred to a cold rolling mill for rolling. The rolling passes are 2.0mm→1.0mm, and the rolling force is 350KN. S10, Finished product annealing: The cold-rolled coil obtained from S9 is directly transferred to the annealing furnace for finished product annealing. After 2 hours, the furnace temperature is raised to 280℃ at a uniform rate and then held for 15h40min. Holes are punched in the coil, and thermocouples are placed in the holes to measure the metal temperature in the middle of the coil. The metal temperature in the middle of the coil is 215℃. The coil is then immediately removed from the furnace. S11. Inspection and Packaging: Samples of the finished annealed material are taken for mechanical property testing and electrical conductivity testing. The transverse tensile strength is 52MPa, the longitudinal tensile strength is 54MPa, and the electrical conductivity is 37.9mS / m. After passing the test, the material is packaged.

[0020] The parts of this invention not described in detail are prior art.

[0021] 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 high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions, characterized in that: Specifically, the following steps are included: S1. Material preparation: Samples of 85 aluminum ingots and 85 electrolytic aluminum molten metal were taken and tested for alloy composition. 85 aluminum ingots and 85 electrolytic aluminum molten metal with iron content ≤0.08%, silicon content ≤0.05%, and aluminum content ≥99.86% were selected for use. S2. Smelting: First, add aluminum ingots to the smelting furnace, then pour molten aluminum into the smelting furnace through the aluminum inlet. Heat the smelting furnace to prepare aluminum melt. Take samples to test the alloy composition. After confirming that the Al content in the aluminum melt is ≥99.85%, turn on the automatic refining machine for refining. Each refining should last at least 30 minutes. After each refining, let it stand and remove slag. Each batch of melt should be refined and slag removed at least four times according to the above steps. Then let it stand for at least 60 minutes before taking it out of the furnace. When taking it out of the furnace, the tilt angle of the smelting furnace should not exceed 28°. The melt left in the smelting furnace after returning it to the furnace is not used to produce 1085 alloy billets. S3. Online melt treatment: The aluminum melt flows smoothly into the guide channel uniformly coated with boron nitride paint, and then flows into the degassing box and the filter box for degassing and filtration in sequence. The treated melt flows directly into the front box. During online melt treatment, 1070 aluminum alloy wire rods with an aluminum content ≥99.70% and a titanium content ≤0.01% are added to the melt. 1.0 to 1.3 kg of 1070 aluminum alloy wire rods are added per ton of melt. S4, Continuous casting: The temperature of the melt in the front box is 675±5℃. The melt flows into the casting chamber of the casting machine through the casting nozzle and is cooled by the upper and lower steel strips to form a billet. The billet thickness is 19mm, and the casting speed is 6.8~7.5m / min. S5. Continuous rolling: The billet passes through a looper and enters a three-roll mill for continuous rolling. The rolling passes are 19mm→11mm→6.5mm→4.0mm. After three-roll mills, the strip is coiled into coils on a coiler. S6, One-time annealing: The coil obtained in S5 is directly transferred to the annealing furnace after being wrapped with steel strip. After 3 hours, the furnace temperature is raised to 500-530℃ at a uniform rate and held for 20-25 hours. Then, the furnace temperature is lowered to 170℃ and the coil is taken out of the furnace. S7, One-time cold rolling: The material annealed in S6 is cooled to below 40°C and then rolled on a cold rolling mill, with rolling passes ranging from 4.0mm to 2.0mm. S8, Secondary Annealing: The cold-rolled coil obtained in S7 is directly transferred to the annealing furnace for annealing. After 2 hours, the furnace temperature is raised to 320-350℃ at a uniform rate and then held at that temperature. The coil metal temperature is measured to reach 260℃ and then immediately removed from the furnace. S9, Secondary Cold Rolling: The material from the S8 annealing furnace is cooled to below 40°C and then transferred to a cold rolling mill for rolling, with rolling passes ranging from 2.0mm to 1.0mm. S10, Finished product annealing: The cold-rolled coil obtained from S9 is directly transferred to the annealing furnace for finished product annealing. After 2 hours, the furnace temperature is raised to 250-280℃ at a uniform rate and then held at that temperature. The coil is taken out of the furnace immediately after the metal temperature reaches 210℃. S11. Inspection and Packaging: Take samples of the finished annealed material for mechanical property testing and electrical conductivity testing. The tensile strength in both the transverse and longitudinal directions should be ≤55MPa, and the electrical conductivity should be ≥37.5mS / m. Finally, pack the finished product.

2. The method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions according to claim 1, characterized in that, In step S2, the rotational speed of the silicon nitride rotor of the automatic refining machine is set to 450±50 rpm, and high-purity argon gas is introduced into the rotor at a pressure of 1.0±0.2 MPa.

3. The method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions according to claim 1, characterized in that, In step S4, during continuous casting, four ultrasonic casting tool heads are placed in the front box, and the frequency of the ultrasonic casting tool heads is 40-60KHZ.

4. The method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions according to claim 1, characterized in that, In step S4, during continuous casting, circulating cooling water is introduced into the upper and lower steel strips. The cooling water temperature is ≤24℃ and the cooling water flow rate is ≥3000L / min.

5. The method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions according to claim 1, characterized in that, In step S5, during continuous rolling, natural gas torches are used to heat the strip between the first and second stands and between the second and third stands of the three-stand rolling mill to ensure that the temperature of the strip is not lower than 380°C before entering the roll gap of the second stand and not lower than 310°C before entering the roll gap of the third stand.

6. The method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions according to claim 1, characterized in that, In step S5, steel sleeves are installed inside the coiled material.

7. The method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions according to claim 1, characterized in that, In step S7, the rolling force during the first cold rolling is not less than 400KN, and in step S9, the rolling force during the second cold rolling is not less than 300KN.

8. The method for producing high-purity, high-conductivity aluminum strip with high efficiency and low carbon emissions according to claim 1, characterized in that, In steps S8 and S10, during the secondary annealing and finished product annealing, holes are punched in the coil, and thermocouples are placed in the holes to measure the temperature of the coil metal.