Preparation method of 3104 secondary aluminum alloy and zip-top can

Abstract

The invention relates to the field of secondary aluminum, in particular to a preparation method of 3104 secondary aluminum alloy and a zip-top can. According to the preparation method provided by the invention, by reasonably controlling the grade, the proportion, the raw material components and the acceptance process of the regenerated aluminum, the excellent comprehensive performance of the regenerated 3104 alloy is obtained, and engineering and cyclic utilization of the metal packaging aluminum alloy material are met; furthermore, by reasonably controlling raw material selection, the smelting process, melt purification, grain refinement and matching of a proper casting process, a high-purity melt, excellent casting performance and a uniform and fine cast ingot structure are obtained, and then the 3104 regenerated aluminum alloy capable of meeting the comprehensive performance of the zip-top can material is obtained. According to the preparation method provided by the invention, the 3104 regenerated aluminum alloy can be prepared according to the 100% recycled aluminum material proportion, and the obtained 3104 regenerated aluminum alloy has the ultra-low can breakage rate when being used for preparing ring-pull cans. Experiments show that the can breakage rate of the zip-top cans prepared from the 3104 regenerated aluminum alloy is as low as 25 ppm.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of secondary aluminum, in particular to a preparation method of 3104 secondary aluminum alloy and a pop can. BACKGROUND

[0002] The pop can is an aluminum alloy metal packaging aluminum material, which is the largest variety of aluminum alloy plate and strip material at present, and is mainly used for beer beverage production. At present, 100% recovery has been realized abroad, and the recovery rate of pop cans in China has also reached more than 90%. However, due to the lack of standardized recycling channels and the dispersion of the recycling link, the raw materials have many impurities and unstable quality, which cannot meet the food grade requirements, resulting in very low utilization rate of social recycled pop cans, and almost all of them are downgraded for use in non-food fields such as doors and windows, castings, etc., which is extremely inconsistent with the current green recycling and low-carbon development requirements. The pop can is a food-grade material, and with the continuous development of the modern aluminum alloy metal packaging field, more stringent requirements are put forward for the comprehensive performance of material safety and quality. In order to improve the recycling and utilization of pop cans, the 3104 aluminum alloy material with higher purity and higher proportion of secondary aluminum is undoubtedly the preferred solution.

[0003] The pop can aluminum alloy is a material with extremely high requirements for material stability and consistency, and the requirements for pinhole and can breakage rate are close to zero defects. Pinholes are not allowed to appear, and the can breakage rate is within 40 ppm (i.e. no more than 40 cans break out of 1 million cans). Not only is the quality of the melt very high, but also there are very strict requirements for toxic and harmful elements due to the use of the product for food. The secondary aluminum used not only includes enterprise recycling materials, but also a lot of materials from social recycling. There are problems such as mixed composition, high requirements for sorting technology, low purity of secondary aluminum due to paint layer residues, etc. At the same time, most of the secondary and tertiary materials with small size and mixed materials (can body 3104, can cover 5052 and 5182, and ring material 5182) cannot be separated. If they are directly used for remelting, not only will it cause large burning loss, but also it will easily cause the chemical composition of main elements to exceed the standard or toxic and harmful elements to be scrapped, resulting in very low utilization rate of recycled pop cans, almost all of which are downgraded for use in non-food fields, causing a lot of cost waste. The proportion of secondary aluminum is controlled at a low level, generally not more than 60%, and basically all of them are enterprise internal first-class recycling materials with good quality. With the rapid development of aluminum alloy processing technology, low-cost and low-carbon recycling technology has become the trend of current aluminum alloy development. However, in order to meet the comprehensive performance of the material and at the same time meet the food grade requirements, the existing material has to sacrifice the demand for high proportion of secondary aluminum, and cannot digest the secondary and tertiary waste and social recycling cans in a high proportion.

[0004] In order to meet the demand of high-purity recycled material, it is necessary to reasonably design and optimize the recycled aluminum raw material selection, recycled aluminum proportion, recycled aluminum melt purification and evaluation technology, and recycled aluminum grain refinement control technology, while maintaining the casting and processing performance. However, with the increase of recycled aluminum proportion, it brings the problems of difficulty in acceptance of recycled raw materials, great difficulty in chemical composition control, great difficulty in matching and control of melt purification and grain refinement process, and great increase in processing performance and product control difficulty. There is no related production control technology for the recycled 3104 aluminum alloy. SUMMARY

[0005] Therefore, the technical problem to be solved by the present application is to provide a preparation method of 3104 recycled aluminum alloy and a pop can. The preparation method provided by the present application can prepare 3104 recycled aluminum alloy with 100% recycled aluminum material proportion, and the obtained 3104 recycled aluminum alloy has an ultra-low can breaking rate when used for preparing pop cans.

[0006] The present application provides a preparation method of 3104 recycled aluminum alloy, comprising the following steps:

[0007] 0 wt%~60 wt% of aluminum primary recycled material, 0 wt%~25 wt% of aluminum secondary recycled material, 30 wt%~75 wt% of 3104 alloy aluminum liquid obtained from aluminum recycled material, and 0 wt%~70 wt% of other primary metal material are sequentially subjected to melting, melt purification, grain refinement and casting to obtain 3104 recycled aluminum alloy; the amounts of the aluminum primary recycled material, the aluminum secondary recycled material and the other primary metal material are 0 at different times;

[0008] The aluminum recycled material includes aluminum secondary recycled material and aluminum tertiary recycled material;

[0009] The aluminum primary recycled material, the aluminum secondary recycled material and the tertiary recycled material are respectively first-class waste, second-class waste and third-class waste in accordance with the national standard of classification, recycling and utilization of deformed aluminum and aluminum alloy waste;

[0010] The chemical composition of the 3104 recycled aluminum alloy includes: Si: 0.20 wt%~0.35 wt%, Fe: 0.35 wt%~0.53 wt%, Cu: 0.10 wt%~0.25 wt%, Mn: 0.70 wt%~0.95 wt%, Mg: 1.1 wt%~1.3 wt%, Zn≤0.10 wt%, Cr≤0.05 wt%, Ti≤0.03 wt%, Ca≤0.0010 wt%, Na≤0.0003 wt%, As≤0.01 wt%, Be≤0.0001 wt%, (Cd+Hg+Pb+Cr 6+The chemical composition of the 3104 recycled aluminum alloy is also monitored to be Li≤0.0010 wt%, Bi≤0.0010 wt%, Sn≤0.0010 wt%; for other impurities, the individual impurity should be controlled to be ≤0.03%.

[0011] The method for preparing 3104 recycled aluminum alloy provided by this invention employs three specific forms of recycled aluminum waste in a certain proportion for smelting, melt purification, grain refinement, and casting. This significantly increases the recycling rate of 3104 alloy material, reaching up to 100%, upgrading the utilization of low-grade materials. The resulting 3104 recycled aluminum alloy not only has a lower production cost but also meets the quality requirements for recycled aluminum alloy materials used in beverage cans. Preferably, 20 wt%~40 wt% of primary recycled aluminum, 5 wt%~20 wt% of secondary recycled aluminum, and 50 wt%~70 wt% of 3104 alloy molten aluminum obtained from recycled aluminum are sequentially smelted, purified, and refined to obtain the 3104 recycled aluminum alloy.

[0012] The recycled aluminum waste described in this invention is permitted to exist in only three forms: primary recycled aluminum, secondary recycled aluminum, and molten 3104 alloy aluminum obtained from recycled aluminum. Specifically, the primary recycled aluminum is waste classified as Grade I according to GB / T34640.1 Classification, Recycling and Utilization of Wrought Aluminum and Aluminum Alloy Waste. The secondary recycled aluminum is waste classified as Grade II according to GB / T34640.1 Classification, Recycling and Utilization of Wrought Aluminum and Aluminum Alloy Waste. Due to its smaller size, Grade II waste is easily burned, absorbs gas, and forms slag; therefore, its usage ratio and timing should be carefully controlled. The molten 3104 alloy aluminum obtained from recycled aluminum includes secondary and tertiary recycled aluminum. The secondary recycled aluminum is the same as described above and will not be repeated. The tertiary recycled aluminum is waste classified as Grade III according to GB / T34640.1 Classification, Recycling and Utilization of Wrought Aluminum and Aluminum Alloy Waste. The primary, secondary, and tertiary aluminum recycled materials described in this invention are mainly derived from socially recycled materials, such as materials from blinds and aluminum cans, and are recycled deformed aluminum alloy raw materials obtained from these socially recycled materials. The 3104 alloy aluminum liquid obtained from the aluminum recycled materials in this invention is obtained by remelting, adjusting the composition, and purifying the aluminum recycled materials, including secondary and tertiary aluminum recycled materials. Its hydrogen content should be ≤0.20 mL / 100 g Al or pinholes ≤0.3%, and its temperature is 730℃~760℃, realizing the upgrading and utilization of low-grade metal packaging materials.

[0013] This invention aims to achieve full-chain recycling of aluminum alloy materials for beverage cans. It uses 0 wt%~60 wt% of primary recycled aluminum, 0 wt%~25 wt% of secondary recycled aluminum, 30 wt%~75 wt% of molten 3104 alloy aluminum obtained from the recycled aluminum, and 0 wt%~70 wt% of other primary metal materials as raw materials to prepare 3104 recycled aluminum alloy. The total proportion of recycled aluminum can reach up to 100%. To reduce burn-off and improve production efficiency, the primary recycled aluminum, being a solid material, should be used in combination with the molten alloy aluminum. The proportion of primary recycled aluminum should be controlled at 0~60 wt%, preferably 20 wt%~40 wt%. If the proportion of 3104 alloy aluminum liquid obtained from aluminum recycling is low, the effect on improving production efficiency is minimal. Furthermore, if the aluminum recycling material from which the 3104 alloy aluminum liquid is obtained contains 5xxx alloys, the resulting alloy aluminum liquid will likely have a higher Mg content than conventional 3104 alloy. Therefore, an excessively high proportion is detrimental to the recycling of aluminum in society. Thus, the proportion of 3104 alloy aluminum liquid obtained from aluminum recycling should be 30 wt% to 75 wt%, preferably 50 wt% to 70 wt%. Secondary aluminum recycling material is also a solid material. To reduce the burning loss of secondary aluminum recycling material, its proportion is 0 to 25 wt%, preferably 5 wt% to 20 wt%.

[0014] To ensure the overall performance of the prepared recycled 3104 aluminum alloy, the recycled aluminum raw materials used should have low impurity content and minimal fluctuations, while strictly limiting toxic and harmful elements. Impurities such as Zn, Ca, and Na not only negatively impact material plasticity but also casting performance, deformation processing, and deep drawing performance; their content should be strictly controlled. Impurities such as Pb, Cd, Hg, and Cr... 6+As and Be are toxic and harmful elements. These elements can easily contaminate the recycled raw materials during the recycling process, affecting the food safety of the final product. Therefore, they should be strictly controlled. Ti content is mainly used to refine the grains. Since recycled aluminum is used in large proportions, the amount of Ti added should be reasonably controlled. In order to make reasonable use of recycled aluminum from aluminum cans, it is not necessary to distinguish between the can body, can lid and pull ring. 1xxx, 3xxx and 5xxx alloy recycled aluminum can also be used. However, in order to facilitate precise control of the composition, the fluctuation of the main element content in each batch should be minimized. The chemical composition of the 3104 alloy aluminum liquid obtained from aluminum recycling material according to the present invention includes: Si: 0.15 wt%~0.35 wt%, Fe: 0.35 wt%~0.65 wt%, Cu: 0.10 wt%~0.25 wt%, Mn: 0.70 wt%~0.95%, Mg: 1.00 wt%~1.60 wt%, Zn≤0.15 wt%, Cr≤0.05 wt%, Ti≤0.03 wt%, Ca≤0.0005 wt%, Na≤0.0005 wt%, As≤0.01 wt%, Be≤0.0001 wt%, (Cd+Hg+Pb+Cr) 6+ ) ≤0.01 wt%, balance is Al; for other impurities, control the individual impurity to ≤0.03%.

[0015] The primary and secondary recycled aluminum materials described in this invention are solid materials. The recycled aluminum materials used in this invention to prepare 3104 alloy aluminum liquid are also all solid materials. These solid materials are free from foreign matter such as sludge, water, films, coatings, silicone felt, and refractory materials on their inner and outer surfaces. The surface area of ​​each of these solid materials is allowed to be no greater than 100 mm². 2 Individual corrosions should not exceed 20% of the total corrosion area. Furthermore, the surface of the 3104 alloy aluminum melt obtained from recycled aluminum as described in this invention must be clean and free of scum.

[0016] The chemical composition of the 3104 recycled aluminum alloy finally prepared by this invention includes: Si: 0.20 wt%~0.35 wt%, Fe: 0.35 wt%~0.53 wt%, Cu: 0.10 wt%~0.25 wt%, Mn: 0.70 wt%~0.95 wt%, Mg: 1.1 wt%~1.3 wt%, Zn≤0.10 wt%, Cr≤0.05 wt%, Ti≤0.03 wt%, Ca≤0.0010 wt%, Na≤0.0003 wt%, As≤0.01 wt%, Be≤0.0001 wt%, (Cd+Hg+Pb+Cr) 6+The chemical composition of the 3104 recycled aluminum alloy needs to be monitored, with Li ≤ 0.0010 wt%, Bi ≤ 0.0010 wt%, and Sn ≤ 0.0010 wt%. For other impurities, the individual impurity should be controlled to ≤ 0.03%. To ensure the alloy's deep-drawing performance, zero pinholes, and low breakage rate, and to avoid the mixing of other alloys or elements into the recycled aluminum raw materials, this invention increases the analytical and monitoring elements for the recycled 3104 alloy. Because the source of recycled aluminum raw materials is complex and irregular in shape, it is more prone to oxidation and slagging during melting, resulting in poor oxide film density. 3104 alloy is a food-grade aluminum material, and the addition of toxic elements such as Pb, Cd, Hg, and Cr during the process should be strictly controlled. 6+ As, Be.

[0017] In the preparation method provided by this invention, in addition to primary aluminum recycled material, secondary aluminum recycled material, and 3104 alloy aluminum liquid obtained from aluminum recycled material, other primary metal materials ranging from 0 wt% to 70 wt% can also be used to meet the requirements of good casting performance and comprehensive product performance of the alloy. However, other primary metal materials are not mandatory. This invention uses other primary metal materials with high purity and good uniformity to ensure that impurities, trace amounts, and toxic and harmful elements are controlled at extremely low levels. The other primary metal materials mentioned in this invention include one or more of primary aluminum ingots, primary magnesium ingots, aluminum-containing master alloys, and metal additives. The primary aluminum ingots are primary aluminum ingots with an Al grade of 99.70 or higher, the primary magnesium ingots are primary magnesium ingots with an Al grade of 99.9 or higher, the aluminum-containing master alloys include one or more of high-quality AlSi, AlFe, AlCu, AlMn, and AlTi master alloys, and the metal additives include one or more of aluminum-based Fe agents and Mn agents.

[0018] The preparation method of this invention involves sequentially smelting, purifying the melt, refining the grains, and casting 0 wt%~60 wt% of primary recycled aluminum, 0 wt%~25 wt% of secondary recycled aluminum, 30 wt%~75 wt% of molten 3104 alloy aluminum obtained from the recycled aluminum, and 0 wt%~70 wt% of other primary metal materials. The invention first performs smelting. During this smelting process, due to the high proportion of recycled aluminum and the presence of a certain proportion of small-sized raw materials in the solid material, the furnace bottom needs to be protected to avoid generating more oxide slag during melting. Specifically, the smelting process involves: smelting in a furnace, first adding one or more of the secondary recycled aluminum and other primary metal materials to the furnace for layering, then adding the remaining primary recycled aluminum and other primary metal materials, and finally adding molten 3104 alloy aluminum obtained from the recycled aluminum. More specifically, smaller-sized raw materials should be prioritized for layering. According to relevant national standards, the size of secondary recycled aluminum is always smaller than that of primary recycled aluminum. Therefore, when both primary and secondary recycled aluminum are present in the raw materials, secondary recycled aluminum should be used for layering first. If other primary metal materials are also present in the raw materials, it is not necessary to distinguish between the types of secondary recycled aluminum and other primary metal materials; the smaller-sized material should be selected for layering. The 3104 alloy aluminum liquid obtained from the aluminum recycling material described in this invention is added in the form of 2-5 ton aluminum ladles, using a forklift to add it through a guide channel. To improve smelting efficiency and reduce energy loss, the alloy aluminum liquid addition rate should be controlled to ≥0.5 tons / min.

[0019] This invention involves melt purification after smelting. To obtain a high-purity melt, granular refining agent is sprayed into the smelting furnace in an argon-chlorine mixed gas atmosphere. This refining is also known as melt purification. The melt purification time is ≥30 min, and the settling time after purification should be no less than 45 min to allow the removed slag to fully float or settle. The dosage of the granular refining agent used in melt purification is 0.4 kg / t~0.6 kg / t. The hydrogen content in the furnace after melt purification should be controlled below 0.30 mL / 100 g Al. An online high-efficiency rotary degassing device is used to reduce the hydrogen content of the melt after purification to below 0.12 mL / 100 g Al. To achieve excellent filtration, deep bed filtration or deep bed + tubular filtration is used for online filtration, and the slag content after filtration is controlled below 0.010 mm. 2 Within / kg.

[0020] This invention refines grains after melt purification. In aluminum alloys, intermediate alloys containing Ti and B or Ti and C are generally added to refine the as-cast grains. B wire has the best refining ability, but excessive B-containing refining agents easily form TiB2 particle aggregates, becoming ingot crack sources. To ensure refining ability and avoid TiB2 aggregation, AlTi5B1 wire and AlTi5B0.2 wire are used in combination for refining. C wire has a slightly weaker refining ability and is generally not used. Recycled aluminum raw materials already contain refining agents. As the proportion increases, the Ti content also increases. However, the refining ability of Ti in recycled aluminum is significantly lower than that added during production. Excessive Ti also has certain failure characteristics and causes more aggregates, and is also detrimental to the reuse of recycled aluminum. This invention, while increasing the proportion of recycled aluminum, must meet the grain refinement requirements, avoid the failure and hazards caused by excessive refining agents, and also achieve recycling by rationally matching the amount of refining agent according to the proportion. The grain refinement described in this invention specifically involves online refinement using a combination of AlTi5B1 and AlTi5B0.2 wires. When the total proportion of the primary aluminum recycled material, the secondary aluminum recycled material, and the 3104 alloy aluminum liquid obtained from the aluminum recycled material is ≤70%, the respective amount of AlTi5B1 and AlTi5B0.2 wires is 0.8±0.2 kg / t. When the total proportion of the primary aluminum recycled material, the secondary aluminum recycled material, and the 3104 alloy aluminum liquid obtained from the aluminum recycled material is >70%, the respective amount of AlTi5B1 and AlTi5B0.2 wires is 0.5±0.1 kg / t.

[0021] This invention involves grain refinement followed by casting. In order to obtain high-performance ingots, the casting process of this invention generally employs a relatively fast casting speed, which results in finer ingot grains and microstructure, and increased ingot density. However, excessively high speeds increase the tendency to crack. Increasing cooling intensity refines the size of primary crystal compounds and reduces regional segregation. A lower effective crystallization height (i.e., the direct distance from the contact point between the melt and the crystallizer wall to the ingot and the secondary direct water cooling) leads to a faster cooling rate, insufficient diffusion of solute elements, a finer intragranular structure, and a smoother ingot surface. However, excessively low heights increase the tendency to crack. To obtain good ingot quality and overall product performance, the casting speed of this invention is 50 mm / min to 60 mm / min, the aluminum melt temperature at the end of the casting plate is 685℃ to 705℃, and the cooling water flow rate is 40 m³ / min. 3 / h.block~80m 3 The casting cooling water temperature is 20℃~30℃, and the crystallizer liquid level height (i.e., the direct distance from the contact point between the melt and the crystallizer wall to the lower edge of the crystallizer) is 40 mm~60 mm. After casting, the product undergoes one or more processes such as machining, rolling, deep drawing, and forming to obtain a 3104 recycled aluminum alloy product that meets the requirements of high-quality metal packaging materials.

[0022] This invention also provides a beverage can made from 3104 recycled aluminum alloy obtained by any of the above-described preparation methods. Specifically, the 3104 recycled aluminum alloy obtained by any of the above-described preparation methods is then subjected to one or more processes such as machining, rolling, deep drawing, and forming to obtain the beverage can. The beverage can of this invention is specifically a recycled 3104 beverage can. Because it is made from 3104 recycled aluminum alloy obtained by any of the above-described preparation methods, its thickness can reach 0.24 mm or less, and it also has an ultra-low breakage rate, meeting the requirements for high-quality metal packaging materials.

[0023] This invention provides a method for preparing 3104 recycled aluminum alloy and an aluminum can. The preparation method provided by this invention, through reasonable control of the grade, proportion, raw material composition, and acceptance process of recycled aluminum, obtains excellent comprehensive performance of the recycled 3104 alloy, meeting the requirements for the engineering and recycling of aluminum alloy materials in metal packaging. Furthermore, by reasonably controlling the selection of raw materials, the smelting process, melt purification, grain refinement, and matching with appropriate casting processes, a high-purity melt, excellent casting performance, and a uniform and fine ingot structure are obtained, thus yielding a 3104 recycled aluminum alloy that meets the comprehensive performance requirements of aluminum can materials. The preparation method provided by this invention can prepare 3104 recycled aluminum alloy with a 100% recycled aluminum ratio. The resulting 3104 recycled aluminum alloy used to manufacture aluminum cans exhibits an ultra-low can breakage rate. Experiments show that the can breakage rate of aluminum cans made from the 3104 recycled aluminum alloy prepared by this invention is as low as 25 ppm. The preparation method provided by this invention realizes the engineering application of high-proportion recycling technology in aluminum alloys for metal packaging materials, promotes the development of aluminum recycling technology for metal packaging materials, reduces production costs, and is simple, clear, and highly feasible for on-site implementation. Detailed Implementation

[0024] This invention discloses a method for preparing 3104 recycled aluminum alloy and a beverage can. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The method and application of this invention have been described through preferred embodiments, and those skilled in the art can obviously make modifications or appropriate alterations and combinations to the method and application described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0025] The present invention will be further described below with reference to the embodiments:

[0026] Example 1

[0027] Aluminum alloys are prepared according to the following method: the following steps are performed in sequence: selection and testing of recycled aluminum (recycled aluminum ratio, recycled aluminum raw material composition), acceptance of recycled aluminum raw materials, raw material selection, smelting process, melt purification, grain refinement, and casting process.

[0028] Aluminum recycling options: Primary recycled material, Secondary recycled material, and 3104 alloy molten aluminum;

[0029] The aluminum recycling ratio is as follows: 30% primary recycled material, 10% secondary recycled material, and 60% molten 3104 alloy aluminum.

[0030] Composition of recycled aluminum raw materials: The composition of both primary and secondary recycled materials is as follows: Si: 0.23 wt%, Fe: 0.41 wt%, Cu: 0.19 wt%, Mn: 0.85 wt%, Mg: 1.08 wt%, Zn: 0.04 wt%, Cr: 0.01 wt%, Ti: 0.01 wt%, Ca: 0.0002 wt%, Na: 0.0002 wt%, As: 0.0005 wt%, Be: not detected, (Cd+Hg+Pb+Cr) 6+ ): 0.0031wt%, balance Al;

[0031] The composition of 3104 alloy aluminum liquid is as follows: Si: 0.26 wt%, Fe: 0.48 wt%, Cu: 0.21 wt%, Mn: 0.81 wt%, Mg: 1.35 wt%, Zn: 0.048 wt%, Cr: 0.02 wt%, Ti: 0.025 wt%, Ca: 0.0004 wt%, Na: 0.0001 wt%, As: 0.0004 wt%, Be: not detected, (Cd+Hg+Pb+Cr) 6+ ): 0.0024 wt%, balance Al.

[0032] Acceptance of recycled aluminum raw materials: Grade I and Grade II recycled materials are free of foreign matter such as sludge, water, film, coating, silicone felt, refractory materials, and corrosion; the pinhole degree of liquid recycled aluminum is 0.08%, the temperature of alloy aluminum liquid is 756℃, and there is no scum on the surface of aluminum liquid.

[0033] Smelting process: Since it is 100% recycled aluminum, a layer of smaller secondary recycled material is first laid to protect the furnace bottom, then primary recycled material is added, and finally 60% alloy aluminum liquid is added. In order to avoid temperature loss caused by opening and closing the furnace door due to intermittent addition, and to improve smelting efficiency and reduce energy consumption, the 60% alloy aluminum liquid is continuously added by forklift in the form of 3-ton alloy aluminum liquid ladles at a rate of 1.5 tons / min.

[0034] Melt purification: To obtain a high-purity melt, granular refining agent is injected into the furnace for refining at a rate of 0.5 kg / t. The holding furnace uses an argon-chlorine mixed gas for refining for 30 minutes, followed by a 50-minute settling time. After furnace treatment, the hydrogen content is 0.254 mL / 100gAl. An online high-efficiency rotary degassing device is used, resulting in a melt hydrogen content of 0.103 mL / 100gAl. Deep-bed filtration is employed, achieving a slag content of 0.008 mm after filtration. 2 / kg.

[0035] Grain refinement: AlTi5B1 + AlTi5B0.2 wires were added online for joint refinement at a dosage of 0.5 kg / t;

[0036] Casting process: Casting speed 54 mm / min, water flow rate 65 m³ / min 3 / h. block, aluminum liquid temperature in the flow plate 701℃, liquid level in the crystallizer 50 mm, water temperature 27℃; ingot forming effect is good;

[0037] After the above processes, the ingot is machined and rolled into 0.24mm plates, and then deep-drawn and formed to obtain 3104 recycled aluminum alloy that meets the requirements of high-quality metal packaging materials.

[0038] Quality Inspection:

[0039] (1) Low magnification of ingots: grain size grade 1; the test method is GB / T3246.2 "Methods for testing the microstructure of wrought aluminum and aluminum alloy products - Part 2: Methods for testing the microstructure of low magnification";

[0040] (2) Chemical composition: Si: 0.24 wt%, Fe: 0.44 wt%, Cu: 0.22 wt%, Mg: 1.21 wt%, Mn: 0.91 wt%, Cr: 0.02 wt%, Zn: 0.05 wt%, Ti: 0.02 wt%, Be: not detected, Ca: 0.0003 wt%, Na: 0.0002 wt%, As: 0.004 wt%, (Cd+Hg+Pb+Cr 6+ ): 0.0035 wt%, balance Al; the detection methods are GB / T 20975 "Analytical Methods for Aluminum Alloys" and GB / T 7999 "Direct Reading Photoelectric Emission Spectroscopy Analysis Method for Aluminum and Aluminum Alloys";

[0041] (3) Hydrogen content: H content before degassing is 0.254 mL / 100 g Al, and H content after degassing is 0.103 mL / 100 g Al; the detection method is YS / T600 "Closed-loop circulation method for hydrogen determination in liquid aluminum and aluminum alloys";

[0042] (4) Slag content: The slag content after filtration is 0.008 mm. 2 / kg; Test method: YS / T1681-2023 "Offline Slag Content Determination Method for Wrought Aluminum and Aluminum Alloy Melts"

[0043] (5) Can breakage rate: 25 ppm (currently the industry accepts less than 40 ppm).

[0044] Comparative Example 1

[0045] Aluminum alloys are prepared according to the following method: the following steps are performed in sequence: selection and testing of recycled aluminum (recycled aluminum ratio, recycled aluminum raw material composition), acceptance of recycled aluminum raw materials, raw material selection, smelting process, melt purification, grain refinement, and casting process.

[0046] Aluminum recycling options: Primary recycling, Secondary recycling, and Tertiary recycling;

[0047] The aluminum recycling ratio is as follows: 60% primary recycled material, 30% secondary recycled material, and 10% tertiary recycled material.

[0048] Composition of recycled aluminum raw materials: The compositions of primary, secondary, and tertiary recycled materials are as follows: Si: 0.22 wt%, Fe: 0.42 wt%, Cu: 0.20 wt%, Mn: 0.84 wt%, Mg: 1.25 wt%, Zn: 0.04 wt%, Cr: 0.02 wt%, Ti: 0.02 wt%, Ca: 0.0004 wt%, Na: 0.0001 wt%, As: 0.0005 wt%, Be: not detected, (Cd+Hg+Pb+Cr) 6 + ): 0.0034 wt%, balance Al.

[0049] Acceptance of recycled aluminum raw materials: Grade I, II, and III recycled materials are free of foreign matter such as oil sludge, water, film, coating, silicone felt, refractory materials, and corrosion.

[0050] Smelting process: Since it is 100% recycled aluminum, smaller tertiary recycled material is used to replace the primary aluminum ingots. A layer is first laid to protect the furnace bottom and prevent excessive burning from direct contact with the flame. Then secondary recycled material is added, and finally large pieces of primary waste are added.

[0051] Melt purification: To obtain a high-purity melt, granular refining agent is injected into the furnace for refining at a dosage of 0.5 kg / t. Argon-chlorine mixed gas refining is used in the holding furnace for 30 min, followed by a 50 min settling time. The hydrogen content after furnace treatment is 0.296 mL / 100gAl. An online high-efficiency rotary degassing device is used, resulting in a melt hydrogen content of 0.149 mL / 100gAl. Deep-bed filtration is employed, achieving a slag content of 0.035 mm after filtration. 2 / kg.

[0052] Grain refinement: AlTi5B1 + AlTi5B0.2 wires were added online for joint refinement at a dosage of 0.5 kg / t;

[0053] Casting process: Casting speed 54 mm / min, water flow rate 65 m³ / min 3 / h. block, aluminum liquid temperature in the flow plate 703℃, liquid level in the crystallizer 50 mm, water temperature 27℃; ingot forming effect is good;

[0054] Because the raw materials used are directly grade 3 scrap and a high proportion of grade 2 recycled materials, the melt has a high H content and slag content after the above processes. The ingot is machined and rolled into 0.24 mm plates, and then deep-drawn and formed to obtain 3104 recycled aluminum alloy.

[0055] Quality Inspection:

[0056] (1) Low magnification of ingots: grain size grade 1; the test method is GB / T3246.2 "Methods for testing the microstructure of wrought aluminum and aluminum alloy products - Part 2: Methods for testing the microstructure of low magnification";

[0057] (2) Chemical composition: Si: 0.23 wt%, Fe: 0.46 wt%, Cu: 0.21 wt%, Mg: 1.25 wt%, Mn: 0.92 wt%, Cr: 0.01 wt%, Zn: 0.04 wt%, Ti: 0.02 wt%, Be: not detected, Ca: 0.0004 wt%, Na: 0.0002 wt%, As: 0.005 wt%, (Cd+Hg+Pb+Cr 6+ ): 0.0032 wt%, balance Al; detection methods are GB / T 20975 "Analytical Methods for Aluminum Alloys" and GB / T 7999 "Direct Reading Photoelectric Emission Spectroscopy Analysis Method for Aluminum and Aluminum Alloys";

[0058] (3) Hydrogen content: H content before degassing is 0.296 mL / 100 g Al, and H content after degassing is 0.149 mL / 100 g Al; the detection method is YS / T600 "Closed-loop circulation method for hydrogen determination in liquid aluminum and aluminum alloys";

[0059] (4) Slag content: The slag content after filtration is 0.035 mm. 2 / kg; Test method: YS / T1681-2023 "Offline Slag Content Determination Method for Wrought Aluminum and Aluminum Alloy Melts"

[0060] (5) Can breakage rate: 137 ppm (Feedback from users indicates that the can breakage rate is relatively high; the industry currently accepts less than 40 ppm).

[0061] Comparative Example 2

[0062] Aluminum alloys are prepared according to the following method: the following steps are performed in sequence: selection and testing of recycled aluminum (recycled aluminum ratio, recycled aluminum raw material composition), acceptance of recycled aluminum raw materials, raw material selection, smelting process, melt purification, grain refinement, and casting process.

[0063] Aluminum recycling options: Primary recycled material, Secondary recycled material, and 3104 alloy molten aluminum;

[0064] The aluminum recycling ratio is as follows: 5% primary recycled material, 5% secondary recycled material, and 90% molten 3104 alloy aluminum.

[0065] Composition of recycled aluminum raw materials: The composition of both primary and secondary recycled materials is as follows: Si: 0.25 wt%, Fe: 0.46 wt%, Cu: 0.21 wt%, Mn: 0.89 wt%, Mg: 1.05 wt%, Zn: 0.04 wt%, Cr: 0.01 wt%, Ti: 0.01 wt%, Ca: 0.0002 wt%, Na: 0.0002 wt%, As: 0.0004 wt%, Be: not detected, (Cd+Hg+Pb+Cr) 6+ ): 0.0036wt%, balance Al;

[0066] The composition of 3104 alloy aluminum liquid is as follows: Si: 0.32 wt%, Fe: 0.64 wt%, Cu: 0.22 wt%, Mn: 0.78 wt%, Mg: 1.30 wt%, Zn: 0.08 wt%, Cr: 0.02 wt%, Ti: 0.025 wt%, Ca: 0.0005 wt%, Na: 0.0001 wt%, As: 0.0004%, Be: not detected; (Cd+Hg+Pb+Cr) 6+ ): 0.0033 wt%, balance Al.

[0067] Acceptance of recycled aluminum raw materials: Grade I and Grade II recycled materials are free of foreign matter such as sludge, water, film, coating, silicone felt, refractory materials, and corrosion; liquid recycled aluminum has a pinhole degree of 0.10%, the temperature of the alloy aluminum liquid is 754℃, and there is no scum on the surface of the aluminum liquid.

[0068] Smelting process: Since it is 100% recycled aluminum, a layer of smaller secondary recycled material is used to replace the primary aluminum ingots to protect the furnace bottom. Then, primary recycled material is added, and finally, 90% alloy aluminum liquid is added. In order to avoid temperature loss caused by opening and closing the furnace door due to intermittent addition, and to improve smelting efficiency and reduce energy consumption, a forklift is used to continuously add 3 tons of aluminum liquid, and the alloy aluminum liquid is added at a rate of 1.5 tons / min.

[0069] Melt purification: To obtain a high-purity melt, granular refining agent is injected into the furnace for refining at a rate of 0.5 kg / t. The holding furnace uses an argon-chlorine mixed gas for refining for 30 minutes, followed by a 50-minute settling time. The hydrogen content after furnace treatment is 0.267 mL / 100gAl. An online high-efficiency rotary degassing device is used, resulting in a melt hydrogen content of 0.135 mL / 100gAl. Deep-bed filtration is employed, achieving a slag content of 0.028 mm after filtration. 2 / kg.

[0070] Grain refinement: AlTi5B1 + AlTi5B0.2 wires were added online for joint refinement at a dosage of 0.5 kg / t;

[0071] Casting process: Casting speed 54 mm / min, water flow rate 65 m³ / min 3 / h. block, aluminum liquid temperature in the flow plate 701℃, liquid level in the crystallizer 50 mm, water temperature 27℃; ingot forming effect is good;

[0072] Because the raw material uses a high proportion of alloy aluminum liquid (up to 90%), after the above processes, the melt has a high H content and slag content, and the Fe content is also as high as 0.63%. The ingot is machined and rolled into 0.24 mm plates, and then deep-drawn and formed to obtain 3104 recycled aluminum alloy.

[0073] Quality Inspection:

[0074] (1) Low magnification of ingots: grain size grade 1; the test method is GB / T3246.2 "Methods for testing the microstructure of wrought aluminum and aluminum alloy products - Part 2: Methods for testing the microstructure of low magnification";

[0075] (2) Chemical composition: Si: 0.27 wt%, Fe: 0.62 wt%, Cu: 0.22 wt%, Mg: 1.27 wt%, Mn: 0.90 wt%, Cr: 0.01 wt%, Zn: 0.07 wt%, Ti: 0.03 wt%, Be: not detected, Na: 0.0002 wt%, As: 0.005 wt%, (Cd+Hg+Pb+Cr 6+): 0.0036wt%, balance Al; the detection methods are GB / T 20975 "Analytical Methods for Aluminum Alloys" and GB / T 7999 "Direct Reading Photoelectric Emission Spectroscopy Analysis Method for Aluminum and Aluminum Alloys";

[0076] (3) Hydrogen content: H content before degassing is 0.267 mL / 100 g Al, and H content after degassing is 0.135 mL / 100 g Al; the detection method is YS / T600 "Closed-loop circulation method for hydrogen determination in liquid aluminum and aluminum alloys";

[0077] (4) Slag content: The slag content after filtration is 0.028 mm. 2 / kg; Test method: YS / T1681-2023 "Offline Slag Content Determination Method for Wrought Aluminum and Aluminum Alloy Melts"

[0078] (5) Can breakage rate: 86 ppm (Feedback from users indicates a high can breakage rate; the industry currently accepts less than 40 ppm).

[0079] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing 3104 recycled aluminum alloy, characterized in that, Includes the following steps: 0 wt%~60 wt% of primary recycled aluminum, 0 wt%~25 wt% of secondary recycled aluminum, 30 wt%~75 wt% of molten 3104 alloy aluminum obtained from the recycled aluminum, and 0 wt%~70 wt% of other primary metal materials are sequentially smelted, purified, refined, and cast to obtain 3104 recycled aluminum alloy; the amounts of primary recycled aluminum, secondary recycled aluminum, and other primary metal materials are all 0. The aluminum recycled material includes secondary aluminum recycled material and tertiary aluminum recycled material; The aluminum primary recycled material, aluminum secondary recycled material, and aluminum tertiary recycled material are respectively primary, secondary, and tertiary waste materials that meet the national standards for the classification, recycling, and utilization of wrought aluminum and aluminum alloy waste. The chemical composition of the 3104 recycled aluminum alloy includes: Si: 0.20 wt%~0.35 wt%, Fe: 0.35 wt%~0.53 wt%, Cu: 0.10 wt%~0.25 wt%, Mn: 0.70 wt%~0.95 wt%, Mg: 1.1 wt%~1.3 wt%, Zn≤0.10 wt%, Cr≤0.05 wt%, Ti≤0.03 wt%, Ca≤0.0010 wt%, Na≤0.0003 wt%, As≤0.01 wt%, Be≤0.0001 wt%, (Cd+Hg+Pb+Cr) 6+ ) ≤0.01 wt%, with the balance being Al.

2. The preparation method according to claim 1, characterized in that, 20 wt%~40 wt% of primary recycled aluminum, 5 wt%~20 wt% of secondary recycled aluminum, and 50 wt%~70 wt% of 3104 alloy molten aluminum obtained from recycled aluminum are successively smelted, purified, and refined to obtain 3104 recycled aluminum alloy.

3. The preparation method according to claim 1, characterized in that, The chemical composition of the 3104 alloy aluminum liquid obtained from aluminum recycling includes: Si: 0.15 wt% - 0.35 wt%, Fe: 0.35 wt% - 0.65 wt%, Cu: 0.10 wt% - 0.25 wt%, Mn: 0.70 wt% - 0.95%, Mg: 1.00 wt% - 1.60 wt%, Zn ≤ 0.15 wt%, Cr ≤ 0.05 wt%, Ti ≤ 0.03 wt%, Ca ≤ 0.0005 wt%, Na ≤ 0.0005 wt%, As ≤ 0.01 wt%, Be ≤ 0.0001 wt%, (Cd + Hg + Pb + Cr 6+ ) ≤ 0.01 wt%, and the balance is Al.

4. The preparation method according to claim 1, characterized in that, The 3104 alloy aluminum liquid obtained from aluminum recycling has a hydrogen content ≤0.20 mL / 100 g Al or a pinhole degree ≤0.3%, and its temperature is 730℃~760℃.

5. The preparation method according to claim 1, characterized in that, The other primary metal materials include one or more of primary aluminum ingots, primary magnesium ingots, aluminum-containing master alloys, and metal additives.

6. The preparation method according to claim 1, characterized in that, The smelting process specifically involves: smelting in a furnace, first adding one or more of the secondary aluminum recycled material and other primary metal materials to the furnace for layering, then adding the remaining primary aluminum recycled material and other primary metal materials to the furnace, and finally adding molten 3104 alloy aluminum obtained from the aluminum recycled material to the furnace.

7. The preparation method according to claim 1, characterized in that, The hydrogen content of the melt obtained by the melt purification is ≤0.12 mL / 100 g Al.

8. The preparation method according to claim 1, characterized in that, The grain refinement specifically involves online refinement using a combination of AlTi5B1 and AlTi5B0.2 wires. When the total proportion of the primary aluminum recycled material, the secondary aluminum recycled material, and the 3104 alloy aluminum liquid obtained from the aluminum recycled material is ≤70%, the respective amount of AlTi5B1 and AlTi5B0.2 wire is 0.8±0.2 kg / t; When the total proportion of the primary aluminum recycled material, the secondary aluminum recycled material, and the 3104 alloy aluminum liquid obtained from the aluminum recycled material is greater than 70%, the respective amount of AlTi5B1 and AlTi5B0.2 wire is 0.5±0.1 kg / t.

9. The preparation method according to claim 1, characterized in that, The casting speed is 50 mm / min to 60 mm / min, the temperature of the molten aluminum at the end of the casting plate is 685℃ to 705℃, and the cooling water flow rate is 40 m³ / min. 3 / h.block~80m 3 / h. block, the cooling water temperature of the casting is 20℃~30℃, and the liquid level height of the crystallizer of the casting is 40 mm~60 mm.

10. An aluminum can, characterized in that, It is obtained from 3104 recycled aluminum alloy prepared by any of the preparation methods described in claims 1 to 9.