A method for preparing container aluminum foil with high recycled aluminum content

Abstract

The invention discloses a method for preparing a container aluminum foil with a high recycled aluminum content. The components of the aluminum foil are: Si: 0.2-0.60%, Fe: 1.20-1.60%, Cu: 0.01-0.05%, Mn: 0.4-0.8%, Mg: 0.01-0.05%, Zn: 0.01-0.05%, Ti: 0.015-0.035%, and the balance is Al; the process flow is: smelting-continuous casting and rolling-cold rolling-finished product annealing; the invention makes continuous casting and rolling The proportion of recycled aluminum waste used in the rolling process has increased from 10%-20% to 60%-80%. The energy consumption of the industrial chain has been reduced, pollutant emissions have been reduced, the amount of alloying agents added has been reduced, production costs have been reduced, and the green production effect has been more obvious. The process flow has been greatly shortened, energy consumption has been reduced, pollutant emissions have been reduced, and green production has been implemented. The thickness of the container foil produced is 0.125-0.16mm, the O-state tensile strength is 110-140Mpa, the elongation is ≥30%, and the cupping value is ≥9mm.

Description

Technical Field

[0001] The invention relates to the field of nonferrous metal smelting and processing, and in particular to a method for preparing container aluminum foil with high recycled aluminum content. Background Art

[0002] Aluminum foil is widely used in various fields of the national economy, such as packaging, electrical appliances, radiators and construction, because of its light weight, good airtightness, good wrapping, and environmental protection. Due to the wide application of aluminum foil and the good properties of aluminum metal that are not easily replaced by other metals, the market demand is relatively stable. Aluminum alloy container foil has excellent thermal conductivity, good resistance to thermal denaturation, good corrosion resistance, microwaveability, and advantages such as lightness, durability, hygiene, and recyclability, so it is becoming more and more popular in the food packaging market. With the rapid development of my country's national economy and the improvement of residents' consumption level, the demand for aluminum alloy container foil has increased rapidly year by year, and the high growth potential is obvious.

[0003] At present, the container foil aluminum alloys on the market are mainly 3003, 3004, 8011, 1100 and 8006, which can be produced by casting and rolling process, continuous casting and rolling process and hot rolling process. Among them, the continuous casting and rolling process is characterized by short process and energy saving, and gradually expands its market share. All three production processes use a certain amount of original aluminum and recycled aluminum waste; at present, due to the high speed of continuous casting and rolling, at 6-8m / min, the production rhythm is fast, and it is impossible to increase the proportion of recycled solid waste to achieve continuous production and reduce production costs. Because the alloy elements of recycled waste are more complex, the tolerance of alloy components is generally poor during the casting and rolling production process, and it is impossible to control the main components to ensure the mechanical properties of the product, reasonable tensile strength and high elongation. In the continuous casting and rolling production process, enterprises generally use 80% electrolytic aluminum liquid + 20% recycled aluminum solid waste. The proportion of recycled aluminum waste is low, the energy consumption of the industrial chain is large, the pollutant emissions are large, the amount of alloying agents added is large, and the production cost is high.

[0004] In view of the above reasons, a method for preparing container aluminum foil with high recycled aluminum content is now developed. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing container aluminum foil with a high recycled aluminum content in order to solve the above-mentioned problems, so that the proportion of recycled aluminum waste used in the continuous casting and rolling process is increased from 10%-20% to 60%-80%, the energy consumption of the industrial chain is reduced, the pollutant emissions are reduced, the amount of alloying agents added is reduced, the production cost is reduced, the green production effect is more obvious, the process flow is greatly shortened, the energy consumption is reduced, the pollutant emissions are reduced, and green production is implemented. The container foil produced has a thickness of 0.125-0.16mm, the O-state tensile strength is 110-140Mpa, the elongation is ≥30%, and the cupping value is ≥9mm.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme: the present invention provides a method for preparing a container aluminum foil with a high recycled aluminum content, wherein the components of the container aluminum foil are: Si: 0.2-0.60%, Fe: 1.20-1.60%, Cu: 0.01-0.05%, Mn: 0.4-0.8%, Mg: 0.01-0.05%, Zn: 0.01-0.05%, Ti: 0.035%, and the balance is Al, and the sum of the above components is 100%;

[0007] The process flow is: smelting - continuous casting and rolling - cold rolling - finished product annealing;

[0008] Melting: 20% to 40% of electrolytic aluminum liquid, 40% to 70% of recycled aluminum waste remelted aluminum liquid and 10% to 20% of recycled aluminum solid waste are put into a melting furnace for melting to prepare aluminum melt. The melting furnace temperature is controlled at 745 ± 5 °C;

[0009] Continuous casting and rolling: During continuous casting, the aluminum melt is injected into two steel belts rotating in opposite directions at an equal amount and at a uniform speed through a casting nozzle made of high-temperature resistant inorganic non-metallic materials. The outer sides of the two steel belts are connected to circulating cooling water. The heat in the aluminum melt is taken away through the steel belts and cooling water. During continuous casting, the temperature of the aluminum melt is maintained at 685±10℃, the casting speed is controlled at 6-8m / min, the thickness of the cast slab is controlled at 19±1mm, and the temperature of the cast slab is controlled at 520-580℃ by adjusting the pressure and flow of the cooling water;

[0010] The continuously cast slab directly enters the three-pass rolling mill and is lubricated and cooled by emulsion. The first pass rolling processing rate is controlled at 50-60%, the rolling inlet temperature is controlled at 450-520℃, and the outlet temperature is controlled at 380-440℃. The second pass rolling processing rate is controlled at 30-45%, the rolling inlet temperature is controlled at 330-390℃, and the outlet temperature is controlled at 290-360℃. The third pass processing rate is controlled at 20-33%, the inlet temperature is controlled at 250-320℃, and the outlet temperature is controlled at 200-230℃. After the third pass processing, a 2-3mm thick aluminum coil is prepared;

[0011] Cold rolling: After continuous casting and rolling to produce 2-3mm thick aluminum coils, they are directly put into the cold rolling unit for rolling into 0.4-0.5mm cold rolled coils in each pass. The processing rate of each cold rolling pass is controlled at 40-50%. When the thickness of the cold rolled coil reaches 1.0-2.0mm, intermediate annealing is carried out. During intermediate annealing, the 1.0-2.0mm thick cold rolled coil is first placed in the annealing furnace, and then the furnace temperature is raised to 220℃ in 2h, kept warm for 4h, and then the furnace temperature is raised to 580℃ in 3h, kept warm for 10-20h, and then the furnace temperature is lowered to 530℃ in 2h, kept warm for 4h, and finally taken out of the furnace when the furnace temperature is lowered to 170℃. The cold rolled coil after intermediate annealing needs to be air-cooled to below 60℃ before being transferred to subsequent rolling passes;

[0012] The 0.4-0.5mm thick cold rolled coil is cold rolled twice at a processing rate of 35%-45% to produce 0.125-0.16mm aluminum foil. The roughness of the working roll in the first rolling pass is 0.28-0.33μm, and the roughness of the working roll in the second rolling pass is 0.16-0.22μm. In the finished product pass, the rolling oil temperature is controlled at 35-50℃, and the fan-shaped duckbill compressed air is added to blow the upper plate surface to control the amount of oil on the surface.

[0013] Finished product annealing: Put the 0.125-0.16mm thick aluminum foil coil into the annealing furnace for finished product annealing. First, raise the furnace temperature to 310℃ in 4 hours, keep it warm for 20-30 hours, then lower the furnace temperature to 170℃, take it out of the furnace and cool it naturally to room temperature.

[0014] The beneficial effects are: using a double-chamber furnace to melt recycled aluminum waste into aluminum liquid to replace part of the electrolytic aluminum liquid, the proportion of recycled aluminum waste used in the continuous casting and rolling process can be increased from 10%-20% to 60%-80%. Compared with electrolytic aluminum liquid, the high-content recycled aluminum waste is remelted and used, the energy consumption of the industrial chain is reduced, the pollutant emissions are reduced, the amount of alloying agents added is reduced, the production cost is reduced, and the green production effect is more obvious; the new way of applying high-content recycled aluminum is different from the traditional recycled aluminum recycling, but is applied in a combination of electrolytic aluminum liquid and waste; the natural gas energy consumption of solid materials in the melting process is 50-60m³ / t, and after using recycled aluminum with aluminum liquid, the natural gas consumption is roughly 25-30m³ / t, with significant energy-saving effects;

[0015] Mn plays a role in solid solution strengthening in the alloy, Fe and Si can reduce the supersaturation of Mn in aluminum, thereby reducing the intracrystalline segregation of Mn. Si and Fe can also accelerate the decomposition process of Mn from the supersaturated solid solution during thermal deformation, and can also improve some mechanical properties. Trace amounts of copper and zinc can improve the mechanical properties of the alloy, greatly shorten the process flow, reduce energy consumption, reduce pollutant emissions, and implement green production. The produced container foil has a thickness of 0.125-0.16mm, an O-state tensile strength of 110-140Mpa, an elongation of ≥30%, and a cupping value of ≥9mm. DETAILED DESCRIPTION

[0016] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0017] 20% to 40% of electrolytic aluminum liquid, 40% to 70% of recycled aluminum waste remelted aluminum liquid and 10% to 20% of recycled aluminum solid waste are put into a smelting furnace for smelting to prepare aluminum melt. The smelting furnace temperature is controlled at 745±5℃. During smelting, the chemical composition of the aluminum melt should meet the requirements of aluminum foil composition after testing, and it is required to be cleanly degassed and deslaged and fully stirred to ensure the quality of the aluminum melt;

[0018] Continuous casting and rolling: During continuous casting, the aluminum melt is injected into two steel belts rotating in opposite directions at an equal amount and at a uniform speed through a casting nozzle made of high-temperature resistant inorganic non-metallic materials. The outer sides of the two steel belts are connected to circulating cooling water. The heat in the aluminum melt is taken away through the steel belts and cooling water. During continuous casting, the temperature of the aluminum melt is maintained at 685±10℃, the casting speed is controlled at 6-8m / min, the thickness of the cast slab is controlled at 19±1mm, and the temperature of the cast slab is controlled at 520-580℃ by adjusting the pressure and flow of the cooling water;

[0019] The continuously cast slab directly enters the three-pass rolling mill and is lubricated and cooled by emulsion. The first pass rolling processing rate is controlled at 50-60%, the rolling inlet temperature is controlled at 450-520℃, and the outlet temperature is controlled at 380-440℃. The second pass rolling processing rate is controlled at 30-45%, the rolling inlet temperature is controlled at 330-390℃, and the outlet temperature is controlled at 290-360℃. The third pass processing rate is controlled at 20-33%, the inlet temperature is controlled at 250-320℃, and the outlet temperature is controlled at 200-230℃. After the third pass processing, a 2-3mm thick aluminum coil is prepared;

[0020] Cold rolling: After continuous casting and rolling to produce 2-3mm thick aluminum coils, they are directly put into the cold rolling unit for rolling into 0.4-0.5mm cold rolled coils in each pass. The processing rate of each cold rolling pass is controlled at 40-50%. When the thickness of the cold rolled coil reaches 1.0-2.0mm, intermediate annealing is carried out. During intermediate annealing, the 1.0-2.0mm thick cold rolled coil is first placed in the annealing furnace, and then the furnace temperature is raised to 220℃ in 2h, kept warm for 4h, and then the furnace temperature is raised to 580℃ in 3h, kept warm for 10-20h, and then the furnace temperature is lowered to 530℃ in 2h, kept warm for 4h, and finally taken out of the furnace when the furnace temperature is lowered to 170℃. The cold rolled coil after intermediate annealing needs to be air-cooled to below 60℃ before being transferred to subsequent rolling passes;

[0021] The 0.4-0.5mm thick cold rolled coil is cold rolled twice at a processing rate of 35%-45% to produce 0.125-0.16mm aluminum foil. The roughness of the working roll in the first rolling pass is 0.28-0.33μm, and the roughness of the working roll in the second rolling pass is 0.16-0.22μm. In the finished product pass, the rolling oil temperature is controlled at 35-50℃, and the fan-shaped duckbill compressed air is added to blow the upper plate surface to control the amount of oil on the surface.

[0022] Finished product annealing: Put the 0.125-0.16mm thick aluminum foil coil into the annealing furnace for finished product annealing. First, raise the furnace temperature to 310℃ in 4 hours, keep it warm for 20-30 hours, then lower the furnace temperature to 170℃, take it out of the furnace and cool it naturally to room temperature.

[0023] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing container aluminum foil with high recycled aluminum content, characterized in that: The components of the container aluminum foil are: Si: 0.2-0.60%, Fe: 1.20-1.60%, Cu: 0.01-0.05%, Mn: 0.4-0.8%, Mg: 0.01-0.05%, Zn: 0.01-0.05%, Ti: 0.035%, and the balance is Al, and the sum of the above components is 100%; The process flow is: smelting - continuous casting and rolling - cold rolling - finished product annealing; Melting: 20% to 40% of electrolytic aluminum liquid, 40% to 70% of recycled aluminum waste remelted aluminum liquid and 10% to 20% of recycled aluminum solid waste are put into a melting furnace for melting to prepare aluminum melt. The melting furnace temperature is controlled at 745 ± 5 °C; Continuous casting and rolling: During continuous casting, the aluminum melt is injected into two steel belts rotating in opposite directions at an equal amount and at a uniform speed through a casting nozzle made of high-temperature resistant inorganic non-metallic materials. The outer sides of the two steel belts are connected to circulating cooling water. The heat in the aluminum melt is taken away through the steel belts and cooling water. During continuous casting, the temperature of the aluminum melt is maintained at 685±10℃, the casting speed is controlled at 6-8m / min, the thickness of the cast slab is controlled at 19±1mm, and the temperature of the cast slab is controlled at 520-580℃ by adjusting the pressure and flow of the cooling water; The continuously cast slab directly enters the three-pass rolling mill and is lubricated and cooled by emulsion. The first pass rolling processing rate is controlled at 50-60%, the rolling inlet temperature is controlled at 450-520℃, and the outlet temperature is controlled at 380-440℃. The second pass rolling processing rate is controlled at 30-45%, the rolling inlet temperature is controlled at 330-390℃, and the outlet temperature is controlled at 290-360℃. The third pass processing rate is controlled at 20-33%, the inlet temperature is controlled at 250-320℃, and the outlet temperature is controlled at 200-230℃. After the third pass processing, a 2-3mm thick aluminum coil is prepared; Cold rolling: After continuous casting and rolling to produce 2-3mm thick aluminum coils, they are directly put into the cold rolling unit for rolling into 0.4-0.5mm cold rolled coils in each pass. The processing rate of each cold rolling pass is controlled at 40-50%. When the thickness of the cold rolled coil reaches 1.0-2.0mm, intermediate annealing is carried out. During intermediate annealing, the 1.0-2.0mm thick cold rolled coil is first placed in the annealing furnace, and then the furnace temperature is raised to 220℃ in 2h, kept warm for 4h, and then the furnace temperature is raised to 580℃ in 3h, kept warm for 10-20h, and then the furnace temperature is lowered to 530℃ in 2h, kept warm for 4h, and finally taken out of the furnace when the furnace temperature is lowered to 170℃. The cold rolled coil after intermediate annealing needs to be air-cooled to below 60℃ before being transferred to subsequent rolling passes; The 0.4-0.5mm thick cold rolled coil is cold rolled twice at a processing rate of 35%-45% to produce 0.125-0.16mm aluminum foil. The roughness of the working roll in the first rolling pass is 0.28-0.33μm, and the roughness of the working roll in the second rolling pass is 0.16-0.22μm. In the finished product pass, the rolling oil temperature is controlled at 35-50℃, and the fan-shaped duckbill compressed air is added to blow the upper plate surface to control the amount of oil on the surface. Finished product annealing: Put the 0.125-0.16mm thick aluminum foil coil into the annealing furnace for finished product annealing. First, raise the furnace temperature to 310℃ in 4 hours, keep it warm for 20-30 hours, then lower the furnace temperature to 170℃, take it out of the furnace and cool it naturally to room temperature.