Method for manufacturing aluminum recycled ingot and method for manufacturing recycled aluminum cans

Abstract

To make a reproduction rate of aluminum cans approach 100%, or make it 100%, by making an input amount of a new block for constituent adjustment minimum, or zero, when reproducing cans from used aluminum cans.SOLUTION: When melting a recovered block including used cylindrical cans having lids with lids attached to the openings of aluminum cylindrical cans, and used bottle cans having caps with caps attached to the threads of aluminum cylindrical cans, a JIS 3000 series aluminum reproduction block is produced by a melting process of adding and melting the recovered block comprising a used cup made of an aluminum cup, which is a bottomed cylindrical integrally molded product, and a casting process for casting a reproduction block from the melted aluminum melt.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an aluminum recycled ingot for recycling used aluminum cans, and a method for manufacturing a recycled aluminum can using the recycled ingot. In the law It relates to.

Background Art

[0002] As containers for various carbonated beverages, alcoholic beverages, etc., aluminum cans (hereinafter referred to as aluminum cans), which are lightweight and excellent in workability and corrosion resistance, are widely used. Such aluminum cans include a cylindrical can composed of a cylindrical body and a lid for closing its opening, and a bottle-shaped can composed of a bottle-shaped body and a cap coupled to its mouth.

[0003] And used aluminum cans (Used aluminum beverage cans; abbreviated as UBC) are collected and melted, and recycled as aluminum recycled ingots, which are the materials for aluminum cans. It is said that the electric energy required to produce such aluminum recycled ingots is about 3% of the electric energy required to newly produce recycled ingots (slabs) by electrolytic refining from bauxite. Therefore, due to the increasing demand for energy conservation, environmental protection of the global environment, and effective utilization of resources in recent years, used aluminum cans are collected and recycled to be made into aluminum cans again.

[0004] As shown in Patent Document 1, a conventional method for recovering and recycling aluminum cans is known which continuously performs the following steps: a fumigation step in which pressed block-like recovered material consisting mainly of used aluminum cans is fumigated; a crushing step in which the recovered material is crushed; a sorting step in which non-aluminum materials are separated from the recovered material; a roasting step in which the sorted aluminum cans are roasted and the roasted aluminum cans are supplied to a vibrating screen while being maintained at a temperature in the range of 200°C to 550°C to remove deposits; a melting step in which the aluminum cans that have been subjected to the roasting step are melted; and a casting step in which slabs or recycled blocks are obtained from the molten aluminum obtained in the melting step.

[0005] Incidentally, with regard to the collected aluminum cylindrical cans and aluminum bottle-shaped cans, 80% or more of the can weight is made up of body material (the material of the cylindrical can or bottle-shaped can body) made of Al-Mn alloy A3004 or A3104 (both of which are JIS standard names). However, the lid material of the cylindrical can or the cap material of the bottle-shaped can that make up these aluminum cans is made of Al-Mg alloys such as A5052A, 5082 or A5182, and the tabs attached to the lids of the cylindrical cans are made of A5182 or the like.

[0006] If the molten metal obtained by melting used aluminum cans (cylindrical cans and bottle-shaped cans) containing a mixture of these various materials is used as a slab as is, it will contain too much Mg (magnesium) and will not be able to be made into a recycled ingot of 3000-series alloy suitable for use as a body material. Therefore, in order to recycle used aluminum cans and produce recycled ingots for new aluminum can body materials, it is necessary to feed new ingots into a holding furnace and adjust the alloy composition so that the Mg content is 1.3% or less. The challenge is to reduce the amount of new aluminum cans added for adjusting the composition as much as possible and increase the weight percentage of aluminum cans recycled from UBC to as close to 100% as possible.

[0007] On the one hand, in recent years, there has been environmental destruction such as plastic marine pollution, and plastic reduction has become a social issue. Therefore, instead of plastic cups, aluminum cups as disclosed in Patent Document 2 have emerged overseas.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0009] When recycling aluminum cans from used aluminum cans, the present invention aims to minimize or eliminate the amount of new ingots (pure aluminum, for example, aluminum ingots with a purity of 99.0 to 99.9% by mass) for component adjustment, and produce recycled ingots, and then manufacture aluminum cans from 100% or nearly 100% recycled aluminum materials produced from the recycled ingots.

Means for Solving the Problems

[0010] The method for manufacturing an aluminum recycled ingot of the present invention includes a melting step of melting a recovered ingot composed of used aluminum cups, which are bottomed cylindrical integrally molded products made of JIS 3000 series aluminum materials, and a casting step of casting a recycled ingot from the molten aluminum obtained by melting, thereby manufacturing a JIS 3000 series aluminum recycled ingot.

[0011] This aluminum cup is different from a cylindrical can with a lid or a bottle-shaped can with a cap, and does not include members made of different materials such as lids or caps. Since it is made of a 3000 series aluminum alloy, by collecting and melting the used cups, it is possible to manufacture a 3000 series aluminum recycled ingot without using new ingots.

[0012] In the method for manufacturing the recycled aluminum ingot, in the melting step, in addition to the recovered ingot made of the used cups, can-making scraps or rolling scraps of JIS 3000 series aluminum can be melted.

[0013] Since the bottle-shaped body of the aluminum bottle-shaped can is also formed of a 3000 series aluminum alloy, by adding can-making scraps or rolling scraps of the bottle-shaped body without a cap or the can body of the cylindrical can and melting them, similar to the case of only the recovered ingot made of used aluminum cups, a 3000 series recycled aluminum ingot can be efficiently manufactured.

[0014] Further, in the method for manufacturing the recycled aluminum ingot, in the melting step, a used capped cylindrical can in a state where a lid is attached to the opening of the aluminum cylindrical can of the bottomed cylindrical integral molded product, and a used capped bottle-shaped can in a state where a cap is attached to the threaded portion of the aluminum bottle-shaped can having a threaded portion at the mouth portion with a reduced diameter compared to the body portion, which is a bottomed cylindrical integral molded product, can also be melted.

[0015] Since the lid and the cap of the used capped cylindrical can and the used capped bottle-shaped can are made of JIS 5000 series materials, as described above, in order to obtain a recycled ingot of 3000 series aluminum, it was necessary to add a new ingot. However, by appropriately controlling the blending with the used cups of the aluminum cups, a 3000 series recycled aluminum ingot can be manufactured without using a new ingot or minimizing the use of a new ingot.

[0016] In the method for manufacturing the recycled aluminum ingot, the recovered ingot made of the used cups is prepared separately from the recovered ingot made of the used capped cylindrical can and the used capped bottle-shaped can. In the melting step, when melting the recovered ingot made of the used capped cylindrical can and the used capped bottle-shaped can, it is preferable to add the recovered ingot made of the used cups.

[0017] By adopting this method, since the used cups can be handled individually, it is possible to facilitate the adjustment of components by the collected mass composed of used cups.

[0018] The aluminum recycled mass obtained as described above can be used as a recycled mass for manufacturing at least any one of an aluminum cup, the cylindrical body of an aluminum bottle can, and the cylindrical body of an aluminum cylindrical can, and these cans can be manufactured as follows.

[0019] That is, from the aluminum alloy plate obtained by rolling the recycled mass manufactured by the method for manufacturing the aluminum recycled mass, a cylindrical body forming step of forming a bottomed cylindrical body by drawing and ironing, a diameter expanding step of forming the diameter of the opening larger than that of the bottom of the bottomed cylindrical body, and a curl forming step of rounding the opening end portion after the diameter expanding step to form a curl portion are passed through to manufacture a recycled aluminum cup.

[0020] Also, from the aluminum alloy plate obtained by rolling the recycled mass manufactured by the method for manufacturing the aluminum recycled mass, a cylindrical body forming step of forming a bottomed cylindrical body by drawing and ironing, and an opening forming step of processing the opening end portion of the bottomed cylindrical body to form a flange are passed through to manufacture a recycled cylindrical body for an aluminum cylindrical can to which a lid can be wound and tightened on the flange.

[0021] Furthermore, from the aluminum alloy plate obtained by rolling the recycled mass manufactured by the method for manufacturing the aluminum recycled mass, a cylindrical body forming step of forming a bottomed cylindrical body by drawing and ironing, a diameter reducing step of reducing the diameter of the opening end portion of the bottomed cylindrical body to form a bottle-shaped cylindrical body having a small diameter portion on the body portion, and a mouth forming step of forming a screw portion around the small diameter portion and rounding the end portion of the small diameter portion to form a curl portion are passed through to manufacture a recycled bottle-shaped body for an aluminum bottle-shaped can to which a cap can be attached to the screw portion.

[0022] The aluminum cup of the present invention is composed of a recycled aluminum alloy having a JIS 3000 series composition, has a bottomed cylindrical shape with an opening larger than the bottom, and has a tapered cylindrical portion whose diameter gradually increases from the bottom toward the opening. A curled portion formed by rounding the end thereof is formed along the circumferential direction at the opening.

Effect of the Invention

[0023] According to the present invention, by utilizing used aluminum cups, it is possible to recycle with the minimum or zero input of new ingots. Further, when only the recovered mass of JIS 3000 series aluminum cups and 3000 series aluminum scraps are melted, the aluminum cups can be recycled from 100% recycled ingots.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0025] Hereinafter, embodiments of a method for manufacturing an aluminum recycled ingot (which may be simply referred to as a recycled ingot) according to the present invention and a method for manufacturing a recycled aluminum can (which may be simply referred to as a recycled can) using the recycled ingot will be described with reference to the drawings. First, the aluminum cans to be targeted will be described. There are three types of aluminum cans: the aluminum cylindrical can 10 shown in FIG. 4, the aluminum bottle-shaped can 20 shown in FIG. 5, and the aluminum cup 40 shown in FIG. 6.

[0026] The aluminum cylindrical can (hereinafter, may be simply referred to as a cylindrical can) 10 has, as shown in FIG. 4, a bottomed cylindrical body (cylindrical body) 11 and a lid 12 wound and tightened around the opening of the cylindrical body 11. The cylindrical body 11 is a bottomed cylindrical integral molded product, and the bottom 13 and the body portion 14 are integrally molded. The bottom 13 has a dome portion 15 curved in a concave shape on the central axis C, and a rim portion 16 that is continuous with the outer peripheral edge thereof and serves as a grounding portion when placed on a table or the like is formed, and the outer peripheral end of the rim portion 16 is continuous with the lowermost end of the body portion 14. The body portion 14 is formed in a substantially straight cylindrical shape, and the lid 12 is wound and tightened around the opening end portion at the upper end thereof. The lid 12 has a tab 18 for opening attached to the central portion of the lid body 17. This lid 12 is fixed to the cylindrical body 11 by being wound and tightened around a flange 19 formed at the opening of the cylindrical body 11.

[0027] The cylindrical body 11 of this cylindrical can 10 is formed of an Al-Mn-based aluminum alloy of alloy number 3004 or 3104 as defined in JIS (JIS H4000:2006) for plates and strips of aluminum and aluminum alloys, and the lid 12 has a lid body 17 made of an Al-Mg-based aluminum alloy of 5052, 5082, or 5182, and the tab 18 is made of an Al-Mg-based aluminum alloy of 5182.

[0028] An aluminum bottle-shaped can (hereinafter sometimes simply referred to as a bottle-shaped can) 20 has a bottle-shaped body (bottle-shaped body) 21 and a cap 23 attached to a mouth portion 22 having a reduced diameter at the upper part of the bottle-shaped body 21. The bottle-shaped body 21 is an integrally formed product having a bottomed cylindrical shape, and its bottom portion 13 has substantially the same shape as the bottom portion 13 of the cylindrical body 11 in the aluminum cylindrical can 10 described above, so the same reference numerals are given and the description is omitted. This bottle-shaped body 21 is formed in a bottle shape having a bottomed cylindrical body portion 25 having a bottom portion 13, a tapered shoulder portion 26 that gradually reduces in diameter upward from the upper end of the body portion 25, and a small-diameter (for example, 38 mm diameter) mouth portion 22 that extends upward from the upper end of this shoulder portion 26. A screw portion 27 is formed on the outer peripheral portion of the mouth portion 22, and a curl portion 28 is formed at the open end portion above the screw portion 27 by rounding the end portion including its edge outward. The cap 23 is composed of a cap body 29 and a sealing material 30, and is attached to the mouth portion 22 by being formed along the screw portion 27 etc. of the mouth portion 22 after being placed over the mouth portion 22 of the bottle-shaped body 21.

[0029] The bottle-shaped body 21 of this bottle-shaped can 20 is formed of an aluminum alloy of alloy number 3004 or 3104 according to the aforementioned JIS, and the cap 23 is formed of an aluminum alloy such as 5052, 5082, 5182, etc.

[0030] The aluminum cup 40 is generally bottomed cylindrical in shape, but its diameter is formed such that the opening portion 42 is larger than the bottom portion 13, and a curl portion 43 with its end rounded is formed along the circumferential direction at the opening portion 42. The bottom portion 13 has substantially the same shape as the bottom portions of the respective body portions 11, 21 of the aluminum cylindrical can 10 and the aluminum bottle-shaped can 20 described above, and the same reference numerals are given.

[0031] In addition, in the illustrated example, straight cylindrical portions 44 and 45 along the central axis C are formed on the side surfaces near the bottom 13 and near the opening 42. Between the upper end of the lower cylindrical portion 44 continuous from the bottom 41 and the lower end of the upper cylindrical portion 45 continuous from the curled portion 43, a tapered cylindrical portion 46 is formed whose diameter gradually increases from bottom to top.

[0032] The curled portion 43 is formed by rounding an end portion having an edge from the upper end of the upper cylindrical portion 44 so as to fold it outward in the radial direction. It is formed in a shape slightly larger than the curled portion 28 of the aluminum bottle-shaped can 20 described above. This aluminum cup 40 is made of a material with a JIS alloy number of 3004 or 3104.

[0033] Figure 2 is a flowchart for manufacturing these three types of aluminum cans 10, 20, and 40. In Figure 2, since the processes up to the cylindrical body forming process are the same for all cans, they are commonly shown. To manufacture the aluminum cylindrical can 10, an aluminum alloy plate is drawn and formed into a relatively shallow cup, and the cup is further drawn and ironed to form a bottomed cylindrical body 50 shown in Figure 3 (cylindrical body forming process). This bottomed cylindrical body 50 has a bottom 13 and a straight cylindrical body portion 51 integrally formed. Since the bottom 13 is formed in substantially the same shape as the product of the aluminum can described above, the same reference numerals are used as in Figures 4 to 6. Next, after printing and painting are applied to the outer surface of this bottomed cylindrical body 50, a flange 19 is formed at the opening (opening forming process). After coating and the like are applied to the inner surface, the cylindrical body 11 is manufactured. The lid 12 is manufactured separately from the cylindrical body 11, and after the cylindrical body 11 is filled with beverage, the lid 12 is wound and tightened on the flange 19.

[0034] To manufacture the aluminum bottle-shaped can 20, after forming the bottomed cylindrical body 50 by the same cylindrical body forming process as in the case of the aluminum cylindrical can 10, printing, painting, etc. are applied, and the opening end of the bottomed cylindrical body 50 is subjected to diameter reduction processing to form a bottle-shaped cylindrical body 53 having a shoulder 26 on the body portion 25 and a small-diameter portion 52 on the shoulder 26 (both shown by a two-dot chain line in FIG. 3) (diameter reduction processing step). A screw portion 27 is formed around the small-diameter portion 52, and the end of the small-diameter portion 52 is rounded to form a curl portion 28 to form the mouth portion 22 (mouth portion forming step), and the bottle-shaped body 21 is manufactured. The cap 23 is manufactured separately from the bottle-shaped body 21, and after the bottle-shaped body 21 is filled with a beverage, the cap 23 is put on and fixed to the mouth portion 22.

[0035] To manufacture the aluminum cup 40, after forming the bottomed cylindrical body 50 by the same cylindrical body forming process as in the case of the aluminum cylindrical can 10, printing, painting, etc. are applied as necessary, and a diameter expansion process of forming the diameter of the opening larger than that of the bottom 13 of the bottomed cylindrical body 50, and a curl portion forming process of rounding the opening end after the diameter expansion process to form a curl portion 43 are carried out.

[0036] Next, a method for recycling these aluminum cans 10, 20, 40 to manufacture recycled cans, and a method for manufacturing an aluminum recycled ingot produced therein will be described.

[0037] First, a method for manufacturing an aluminum recycled ingot will be described. As shown in the flow chart of Fig. 1, the method for producing this recycled aluminum ingot includes a fumigation process in which a lump-shaped recovered material made of used aluminum cans is fumigated with steam, a crushing process in which the recovered material is crushed, a sorting process in which non-aluminum materials are separated from the crushed recovered material to obtain aluminum material, a roasting process in which the sorted aluminum material is roasted and the roasted aluminum material is supplied to a vibrating screen while being kept at a temperature range of 200°C to 550°C to remove deposits, a melting process in which the aluminum material that has been subjected to the roasting process is melted, and a casting process in which slabs or recycled ingots are obtained from the molten aluminum obtained in the melting process. As recovery and regeneration facilities required for carrying out this recycling method, equipment such as a fumigation device and a crusher are installed in sequence on a specific site.

[0038] At the recovery facility, bulk recovered materials consisting mostly of used aluminum cans that have been pressed into blocks of a certain size by recovery companies are brought in by transport means such as trucks. Some used aluminum cans are collected as is and not pressed into blocks, and waste materials such as surplus materials generated during cutting and pressing in the manufacturing process of aluminum cans are also brought in.

[0039] (fumigation process) After being brought in, at least the lump-shaped collected materials are first fumigated with steam, thereby killing microorganisms that cause unpleasant odors contained in the collected materials and killing insects and their eggs that may be contained inside.

[0040] (Crushing process and sorting process) Next, the fumigated lumps of recovered material are successively crushed and then sorted while being transported on a belt conveyor or the like. As sorting means, a magnetic separator that uses magnetism to attract and remove iron, and a wind-powered separator that injects air onto the recovered material to separate and remove impurities such as plastics and scraps that are lighter than aluminum materials, non-magnetic metals such as copper and stainless steel that are heavier than aluminum materials, and concrete fragments.

[0041] (roasting process) In this way, since the crushed and separated recovered materials have organic substances such as paint and resin layers adhering to them, they are put into a rotary kiln (not shown) at regular intervals and roasted at a temperature lower than the melting point of aluminum to directly vaporize and burn the organic substances adhering to the surface. After the remainder is made into carbides and oxides, the further roasted recovered materials are supplied to a vibrating screen (not shown) while being maintained in the temperature range of 200°C to 550°C to separate the carbides, oxides, and adhering substances such as sand that were not removed in the sorting process.

[0042] (Melting process) Next, the roasted recovered materials are put into a melting furnace (not shown) and melted. Regarding waste materials such as surplus materials generated in the cutting and pressing processes in the manufacturing process of aluminum cans, they may be put into the melting furnace and melted. The molten aluminum alloy obtained by melting is sent to a holding furnace (not shown), and the components of the alloy are adjusted as necessary. While removing gas components such as hydrogen contained in the molten metal passing through the holding furnace and filtering the molten metal to remove non-metallic inclusions and the like, it is sent to a casting machine and cast into a slab (recycled ingot).

[0043] The obtained slab is carried out to a rolling factory and rolled into an aluminum alloy plate. The recycled aluminum alloy plate rolled in this way can be made into a component corresponding to the 3000 series alloy of JIS without adding new ingots (pure aluminum, for example, aluminum ingots with a purity of 99.0 to 99.9 mass%) in the melting process by appropriately controlling the mixing ratio of the used aluminum cylindrical cans 10, aluminum bottle cans 20, and aluminum cups 40 in the melting process.

[0044] Therefore, this slab can be rolled and used as a material for aluminum cans (the cylindrical body 11 of the cylindrical aluminum can 10, the bottle-shaped body 21 of the bottle-shaped aluminum can 20, and the aluminum cup 40). To manufacture aluminum cans (recycled aluminum cans) using aluminum alloy sheets obtained from this slab of recycled aluminum alloy (recycled aluminum alloy), the cylindrical body (recycled cylindrical body) 11 of the cylindrical aluminum can 10, the bottle-shaped body (recycled bottle-shaped body) 21 of the bottle-shaped aluminum can 20, and the aluminum cup (recycled aluminum cup) 40 can be manufactured respectively by the method shown in Fig. 2 described above.

[0045] In the present invention, used cans are referred to as used cylindrical cans, used bottle-shaped cans, and used cups. Also, among used cylindrical cans, used cylindrical cans with lids, and used bottle-shaped cans, those without caps are referred to as used bottle-shaped bodies, and those with caps attached are sometimes referred to as used bottle-shaped cans with caps. Furthermore, aluminum cans manufactured from recycled ingots are referred to as recycled cans, recycled cylindrical bodies, recycled bottle-shaped bodies, and recycled cups.

[0046] Incidentally, among 3000 series aluminum alloys, the alloy compositions of 3004 and 3104 are as shown in Table 1. The unit of each numerical value described in the table is mass%, and those not specified within a range indicate the upper limit. Also, in the "Others" column, "individual" refers to individual components, and "total" refers to the total of the components included in "Others".

[0047]

Table 1

[0048] In the above recycling process, the aluminum cup 40 is used only in limited spaces such as various event venues, stadiums for baseball, soccer, etc. Therefore, the recycled materials consist only of the aluminum cups 40, and the aluminum cups 40 do not contain aluminum of a different material from the body 11, 21, such as a lid 12 or a cap 23, unlike other aluminum cylindrical cans 10 or aluminum bottle cans 20. Thus, the recycled materials are made of a 3000 - series aluminum alloy.

[0049] Therefore, it is possible to use the recycled materials of this aluminum cup 40 as a substitute for the new ingots added for component adjustment. However, since paint or the like is attached, it is necessary to put it into a rotary kiln in the roasting process instead of the melting process to make the paint or the like disappear. At this time, slight component fluctuations may also occur. Therefore, it is advisable to increase the addition amount of this aluminum cup 40 or add a small amount of new ingots in the melting process.

[0050] The following is the result of simulating the Mg content of the aluminum alloy obtained by recycling aluminum cans. Table 2 shows the case of recycling with two types of used products, an aluminum cylindrical can and an aluminum bottle - shaped can, without including the aluminum cup. Table 3 shows an example of recycling using three types of used products, an aluminum cylindrical can, an aluminum bottle - shaped can, and an aluminum cup.

[0051] In both tables, the columns of "formulation (parts by weight)" and "Mg content" in the recycled products are the total amounts when formulated in each part by weight, and in the bottom row, the Mg content rate (mass%) calculated from these total amounts is described. However, since about 10% of the Mg content floats as dross during melting and is discharged, it was calculated as 90%.

[0052]

Table 2

[0053]

Table 3

[0054] For the aluminum alloys of JIS 3004 and 3104, the Mg content is 0.8 - 1.3 mass% as shown in Table 1. In the recycled products without using the aluminum cups in Table 2, the Mg content is 1.31 mass%, which is higher than the JIS standard. However, for the products with the addition of the aluminum cups in Table 3, an aluminum alloy within the JIS standard with a Mg content of 1.28 mass% was obtained. From these tables, it can be seen that in the conventional recycling method without using aluminum cups, a considerable amount of new ingots made of pure aluminum must be added during melting in order to recycle it as a 3000 - series aluminum alloy. By using used aluminum cups (used cups), it is possible to recycle it as a 3000 - series aluminum alloy without adding new ingots.

[0055] Next, aluminum cups (recycled cups) were manufactured from the recycled products (recycled ingots) shown in Table 3, and a simulation was conducted for the case where these recycled cups were recycled again. Specifically, the case where the total amount of the aluminum cups in the formulation shown in Table 3 was all recycled cups was simulated. The results are shown in Table 4. Table 5 shows the case where aluminum cups (recycled cups) were manufactured from the recycled products (recycled ingots) shown in Table 4 and recycled again. It is the result of a simulation for the case where the total amount of the aluminum cups in the formulation shown in Table 3 was the recycled cups obtained from the recycled ingots shown in Table 4.

[0056]

Table 4

[0057]

Table 5

[0058] From the results of these tables, it can be seen that even without using pure aluminum ingots, 3000 series recycled aluminum ingots can be produced, and it is possible to recycle used cans repeatedly by recycling using aluminum cups.

[0059] Although it is a lot different from the above, Table 6 shows the results of measurements including components other than Mg, and Table 7 shows an example of measuring the mechanical properties of a plate formed by rolling the recycled aluminum alloy. The ear ratio is the ratio obtained by dividing the difference in unevenness generated at the open end when a bottomed cylindrical body is formed by drawing with a punch diameter of 33 mm and a drawing ratio of 1.75 by the height (minimum height) of the cylindrical body. The AB strength is the strength after baking paint on the recycled aluminum alloy sheet.

[0060]

Table 6

[0061]

Table 7

[0062] It is recognized that it is equivalent to the alloy composition of the 3000 series ingots shown in Table 1, except that 0.02 mass% of Cr and 0.03 mass% of Ti are contained. Also, it can be seen that its mechanical properties are suitable for can manufacturing.

Explanation of Signs

[0063] 10 Aluminum cylindrical can 11 Cylindrical body 12 Lid 13 Bottom 14 Body part 15 Dome part 16 Rim part 17 Lid body 18 Tab 19 Flange 20 Aluminum bottle-shaped can 21 Bottle-shaped body 22 Mouth 23 Cap 25 Barrel 26 Shoulder 27 Threaded part 28 Curled part 29 Cap body 30 Sealing material 40 Aluminum cup 42 Opening 43 Curled part 44, 45 Cylindrical part 46 Tapered cylindrical part 50 Bottomed cylinder 51 Barrel 52 Small-diameter part 53 Bottle-shaped cylinder

Claims

A method for manufacturing a recycled aluminum ingot, comprising a melting step of melting a recovered material composed of a used cylindrical can with a lid attached to an opening of an aluminum cylindrical can which is a bottomed cylindrical integrally formed product, and a used bottle-shaped can with a cap attached to a threaded portion of an aluminum bottle-shaped can having a threaded portion at a mouth portion whose diameter is reduced compared to a body portion, which is a bottomed cylindrical integrally formed product, and a casting step of casting a recycled ingot from the molten aluminum obtained by melting, In the melting step, in addition to the recovered material composed of the used cylindrical can with a lid and the used bottle-shaped can with a cap, aluminum can scrap or rolling scrap of JIS 3000 series is melted, and When melting the recovered material composed of the used cylindrical can with a lid and the used bottle-shaped can with a cap, a recovered material composed of used cups made of aluminum of JIS 3000 series, which are bottomed cylindrical integrally formed products, is also melted, and the mixing ratio of the used cups, the used cylindrical cans with lids, and the used bottle-shaped cans with caps is controlled to produce a recycled aluminum ingot of JIS 3000 series. A method for manufacturing a recycled aluminum ingot, characterized by the above.

2. The method for manufacturing a recycled aluminum ingot according to claim 1, wherein the recovered material composed of the used cups is produced separately from the recovered material composed of the used cylindrical cans with lids and the used bottle-shaped cans with caps.

3. A method for manufacturing a recycled aluminum can, characterized by forming a bottomed cylindrical body by ironing and ironing forming from an aluminum alloy plate obtained by rolling the recycled ingot manufactured by the method for manufacturing a recycled aluminum ingot according to claim 1 or 2, a diameter expansion step of forming the diameter of the opening larger than the bottom of the bottomed cylindrical body, and a curl forming step of rounding the open end after the diameter expansion step to form a curl portion.

4. A method for manufacturing a recycled aluminum can, characterized in that a recycled cylindrical body for an aluminum cylindrical can capable of winding and fastening a lid to the flange is manufactured through a cylindrical body forming step of forming a bottomed cylindrical body by ironing and squeezing from an aluminum alloy plate obtained by rolling the recycled block manufactured by the method for manufacturing a recycled aluminum block according to claim 1 or 2, and an opening forming step of processing the opening end of the bottomed cylindrical body to form a flange.

5. A method for manufacturing a recycled aluminum can, characterized in that a recycled bottle-shaped body for an aluminum bottle-shaped can capable of attaching a cap to the threaded portion is manufactured through a cylindrical body forming step of forming a bottomed cylindrical body by ironing and squeezing from an aluminum alloy plate obtained by rolling the recycled block manufactured by the method for manufacturing a recycled aluminum block according to claim 1 or 2, a necking step of forming a bottle-shaped cylinder having a small-diameter portion on the body by reducing the diameter of the opening end of the bottomed cylindrical body, and a mouth forming step of forming a threaded portion around the small-diameter portion and rounding the end of the small-diameter portion to form a curled portion.

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