JP2807740B2 - How to treat used aluminum cans - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for treating a used aluminum can for directly reusing the used aluminum can as a raw material for dissolving a plate for the aluminum can.

[0002]

2. Description of the Related Art In recent years, a large number of aluminum cans using aluminum and aluminum alloys (hereinafter, simply referred to as aluminum) have been used as containers for alcohols, soft drinks, and the like. Utilization is taking place. In order to use the used aluminum can as a raw material for dissolving the aluminum can plate material, impurities are mixed, so the used aluminum can is dissolved and subjected to appropriate purification to make an ingot close to the original material of the aluminum can .

[0003]

However, in this method, in order to remove impurities or to dilute the impurities, a melting step must be performed as a pretreatment. At this time, the metal aluminum is oxidized and the yield is reduced. In addition, a large amount of energy is consumed for melting, thereby increasing the total cost of recycling. Another problem is that the aluminum nitride in the aluminum dross generated during the dissolution reacts with the moisture in the air to generate ammonia, which makes disposal difficult. The present invention has been made in view of such circumstances, and a method for treating a used aluminum can that can efficiently remove impurities when reusing a used aluminum can and directly reuse the raw material as a melting raw material for an aluminum can plate. The purpose is to provide.

[0004]

According to the present invention, there is provided a semiconductor device comprising:
The method for treating used aluminum cans described in the above is a first step in which used aluminum cans compressed by a press are crushed and separated into pieces, and aluminum obtained by cutting the crushed aluminum cans into chips. A second step of forming a piece, and a third step of subjecting the chipped aluminum piece to a magnetic separator to separate a magnetic substance.
And separating the magnetically separated aluminum pieces into pieces from 550 to 60
A fourth step of firing at 0 ° C. to burn off the paint and resin adhering to the aluminum pieces, and putting the fired aluminum pieces into a repulsion-type pulverizer so that the adhering carbon and titanium oxide A fifth step of separating the aluminum small spherical ingot into pieces, and pressing the aluminum small spherical ingot to form an apparent density of 1.5 to
A sixth step of forming an aluminum lump in the range of 2.5,
The used aluminum can is directly used as a raw material for dissolving the aluminum can plate. In addition, the repulsion type crusher referred to herein refers to a crusher, a impact crusher, a cage mill, a rolling crusher, an impact mill, or the like, which applies a shock to a processed material to perform processing. If the apparent density of the aluminum lump is less than 1.5, the surface area of the aluminum is large and the aluminum is liable to be oxidized.

[0005]

In the method for treating a used aluminum can according to the first aspect, since the used aluminum can is cut, foreign substances contained in the can can be taken out. In addition, the resin, paint, and the like in the can are easily removed in a later step. And 550
Since it is fired at 600 ° C., the paint and the like adhering to the surface of the aluminum piece are burned and removed. Further, the residual stress during the forming of the aluminum can is removed by annealing, and the aluminum hardened by work hardening is softened. When put into a repulsion pulverizer in this state, the aluminum piece is hit by impact and becomes spherical. In addition, classification is performed to remove small particles that are difficult to use as raw materials and burned powders such as paints. Thereafter, since the aluminum mass is formed by pressure molding, the surface of the aluminum in contact with the air is reduced, and the aluminum is hardly oxidized.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will now be described with reference to the accompanying drawings to provide an understanding of the present invention. Here, FIG. 1 is a flowchart of a method for treating a used aluminum can according to one embodiment of the present invention, FIG. 2 is a side sectional view of an impact mill, and FIG. 3 is a sectional view taken along line AA in FIG. .
First, an impact mill 10 which is an example of a repulsion type pulverizer used in the method for treating a used aluminum can according to one embodiment of the present invention will be described with reference to FIGS. The impact mill 10 includes a cylindrical drum main body 11 that rotates at a low speed, and a drum main body 11 inside the drum main body 11.
A rotor 12 which is arranged concentrically with a gap and rotates at a high speed; a raw material supply unit 14 having a screw feeder 13 for supplying a raw material to the drum main body 11;

The drum main body 11 has a plurality of repulsion plate mounting members 17 each having a F-shaped cross section mounted on the inner periphery thereof at an obtuse angle with an interval therebetween. A plate 19 is provided detachably. And the repulsion plate 1
9 a partition plate 20 protruding inward from the repulsion plate 19
Are spirally mounted so as to gradually transport the raw material to the loading side, and a portion surrounded by the repulsion plate mounting member 17 and the partition plate 20 forms a raw material transport unit 21. Therefore, when the raw material lifted and crushed by the raw material transport unit 21 falls and falls, the raw material enters the raw material transport unit 21 near the unloading side. Further, on the loading side of the drum main body 11, a raw material loading section 22 is provided, and the closed end plate 2 of the raw material loading section 22 is provided.
Inside the 3, twelve first guide blades 24 are attached in an inclined manner, and a hole 25 is formed between each adjacent first guide blade 24. Further, the drum body 11
A raw material discharge portion 26 is provided on the discharge side of the container. Eight second guide vanes 28 are attached to the inside of the closed end plate 27 of the raw material discharge portion 26 in an inclined manner, and the respective second guide blades 28 are adjacent to each other. A hole 29 is formed between the second guide vanes 28. Rings 30 are provided on both sides of the outer periphery of the drum main body 11, and the rings 30 are mounted on a pair of drum receiving rollers 31. A large-diameter sprocket 33 is attached to the center of the outer periphery of the drum main body 11 via a support member 32. A sprocket 34 connected to the sprocket 33 by a chain is provided below the drum main body 11 with a rotating shaft 35. And a sprocket 36 is attached to the rotating shaft 35. Then, a sprocket is driven by a drive motor (not shown),
The sprocket 36 is rotated via a chain to rotate the drum body 11 at a low speed (about 10 to 30 rpm, preferably about 20 rpm).

The rotor 12 is mounted on a rotating shaft 42 held on both sides by bearings 41 mounted on a gantry 40. The fixed surface 44 of the striking plate attaching member 43 has an angle β (115 ° to 1 °) on the outer periphery of the rotor 12.
The striking plate 45 is attached to the surface 44 to be fixed at an angle of 55 ° and is detachably provided on the surface 44 to be fixed. A V pulley 46 is provided on the discharge side of the rotary shaft 42.
The rotor 12 is rotated at a high speed (about 500 to 4000 rpm, preferably 1000 to 1000 rpm) in the same direction as the drum main body 11 by rotating a V pulley 46 via a V pulley and a V belt by a drive motor (not shown).
(About 2500 rpm).

The raw material supply section 14 has a screw feeder 13 for supplying raw material to a hole 25 of the drum main body 11 provided on the charging side, and a hopper 50 is provided above the screw feeder 13. The raw material supplied from the hopper 50 is supplied to the screw feeder 13.
To be sent to the pool 51. The dust collecting hood 16 is provided on the discharge side of the drum main body 11 so that powder and small particles generated during processing are sent from the dust collecting hood 16 to a dust collector (not shown) and collected. It has become.

A method of treating a used aluminum can using the impact mill 10 will be described. First, as shown in FIG. 1, scrap aluminum compressed by a press is pulverized by a hammer crusher type pulverizer and separated into pieces (first step). Then, the aluminum can is cut into chips by a biaxial shearing crusher (second step). Next, the chipped aluminum piece is passed through a magnetic force separator to separate a magnetic substance such as iron (third step).

The aluminum piece from which the magnetic material has been removed is placed in a rotary kiln-type firing furnace and fired at 550 to 600 ° C. to remove paint and resin adhering to the aluminum piece by burning (fourth step). By sintering in this manner, the residual stress at the time of forming the aluminum can is removed, and the aluminum piece that has been hardened by work hardening becomes soft. The white paint used for the base contains titanium (Ti) and burns to form titanium oxide (TiO ₂ ). When the aluminum containing the titanium oxide is dissolved, a huge inclusion of the titanium oxide is generated. When the aluminum can is manufactured as it is, the titanium oxide causes defects such as scratches. Therefore, it is desired that the content of titanium is as low as possible for forming an aluminum can. However, there is no problem if the content of titanium is 0.05% or less. Thus, Table 1 shows the analysis values of carbon and titanium and the firing yield of aluminum, which are guidelines for depainting after firing at 550 to 600 ° C., with 0.24% carbon and 0.15% titanium.
include. As a comparative example, the calcination yield and the analysis values of carbon and titanium when calcination is performed at 600 to 650 ° C. are shown. The carbon content is 0.20% and the titanium is 0.12%. Also, 100% scrap aluminum excluding moisture
In this case, the firing yield after firing is 550 to 600 ° C.
When calcined at 93.91%, 600 to 65%
When calcined at 0 ° C., it is 93.09%,
When fired at 0 to 650 ° C., aluminum is easily oxidized, so that the yield after firing is poor.

[0012]

[Table 1]

When the baked and softened aluminum pieces are fed from the hopper 50 of the impact mill 10, the aluminum pieces are sent to the pool 51 by the screw feeder 13, and the aluminum pieces in the pool 51 are sent later. The drum enters the drum main body 11 through the hole 25 of the closed end plate 23 of the drum main body 11 which is being pressed and rotated by the coming aluminum piece. Then, the aluminum pieces scooped up by the first guide blades 24 are put into the raw material transport section 21 of the drum main body 11.
The aluminum piece of the raw material transport section 21 is lifted in accordance with the rotation of the drum main body 11, and falls at a certain height. Most of the fallen aluminum pieces are from the rotor 12 rotating at high speed.
Hits the hitting plate 45. The blown aluminum piece hits the striking plate 45 again or the drum body 1
The repelling plate 19 of the first material transporting unit 19 is repeatedly dropped, a part of which falls into the lower raw material transporting unit 21 on the loading side from the first raw material transporting unit 21, and most of the raw material transporting unit 2 close to the lower discharging side.
Enter 1. In addition, the aluminum pieces that have not hit the striking plate 45 fall along the spiral partition plate 20 and are returned to the raw material transport unit 21 on the raw material loading side. By repeating such a process many times, the aluminum pieces become small aluminum spherical lumps and are gradually sent to the discharge side. Then, the aluminum small spherical mass reaching the discharge side of the drum main body 11 is scooped up by the second guide blade 28, discharged from the hole 29 of the closed end plate 27, and sent to a discharge device (not shown). The powder generated at this time is discharged to the discharge side along the spiral partition plate 20 together with the wind generated by the rotation of the rotor 12, and is sent from the dust collecting hood 16 to a dust collector (not shown). Collected. In this way, aluminum pieces are continuously formed into small aluminum spherical blocks (fifth step). Table 2 shows the yield and the analysis values of carbon and titanium after molding when the scrap aluminum from which water was removed was taken as 100%, as in the case of Table 1. The carbon and titanium adhering to the aluminum pieces are separated by the impact of the impact mill 10, and when the firing temperature is 550 to 600 ° C, carbon is reduced to 0.2.
4% to 0.08%, titanium is reduced from 0.15% to 0.04%, and when the firing temperature is 600 to 650 ° C, carbon is reduced from 0.20% to 0.08% and titanium is reduced. It has dropped from 0.12% to 0.05%. As described above, in the calcination stage at 550 to 600 ° C., although the titanium which adversely affects the forming of the aluminum can is 0.15% and more than the target value of 0.05%, it is separated by the impact in the impact mill 10. , Released below target value (0.04%)
It has become. Also, the sintering temperature of the molding yield is 550-6.
In the case of 00 ° C., it is 91.57%, and the firing temperature is 600 to
This shows a higher value than 88.52% at 650 ° C. Therefore, it is shown that firing at 550 to 600 ° C. is advantageous.

[0014]

[Table 2]

In the above, the changes in the analytical values of carbon and titanium and the melting yield were examined. This time, the rotational speed of the drum body 11 of the impact mill 10 was kept constant at 20 rpm, and the rotational speed of the rotor 12 was changed. The relationship between the number, the particle size distribution of the aluminum small spherical ingot, the apparent density of the aluminum ingot after briquetting, and the melting yield when the dissolved raw material is 100% is examined. 550 pieces of aluminum treated as before before firing
Bake at ~ 600 ° C. Then, the fired and softened aluminum pieces are put in from the hopper 50 of the impact mill 10, and the rotation speed of the rotor 12 is rotated at 2080 rpm (fifth step). As a result, the particle size distribution becomes as shown in Sample 1 of Table 3. An aluminum small spherical mass of 20 mm or less is obtained. This aluminum small spherical lump is 57mm x 31 with a briquette machine.
It is pressed into a size of mm × 22 mm (sixth step) to form an aluminum lump. The apparent density of this aluminum lump is 2.25. Next, after the aluminum piece treated in the same manner as described above before firing was fired at 550 to 600 ° C., the rotor 12 was put into an impact mill 10 having a rotation speed of 1400 rpm (fifth step). An aluminum small spherical mass having a particle size distribution as shown in Sample 3 is obtained. As shown in Sample 2, an aluminum small spherical mass under 20 mm is pressed to a size of 57 mm × 31 mm × 22 mm using a briquette machine to form an aluminum mass (sixth step). The apparent density of this aluminum lump is 2.20. And sample 3
The aluminum small spherical lump having a length of over 20 mm shown in (1) was not formed into an aluminum lump by a briquette machine for comparison. The apparent density of this aluminum small spherical mass is 1.40. As a result, as apparent from Table 3, the sample 3 having the small apparent density of the aluminum small spherical ingot of 1.40 had the lowest dissolution yield of 92.8%, and the apparent density of the sample 2 was 2.28%. The melting yield of the aluminum lump in the case of 20 was 94.5%, and the melting yield of the aluminum lump in the case where the apparent density of Sample 1 was 2.25 was 95.0%. Good dissolution yield results. Sample 1
Table 4 shows the results of analysis of the components after dissolution of the aluminum lump and aluminum small spherical lump in Table 3. As shown in Table 4, all of them satisfy the JIS3004 standard. Is about half of 0.05% that is not given. However, both samples have high dissolution yields. Therefore, a large-sized aluminum small spherical ingot is directly reused as a raw material for dissolving aluminum can plates, and only a small size is made into an aluminum lump by a briquette machine and reused as a molten raw material. It is possible to select a method in which a lump is made into an aluminum lump by a briquette machine and reused as a raw material for melting. As described above, the used aluminum can can be directly reused as a raw material for dissolving the plate material for the aluminum can.

[0016]

[Table 3]

[0017]

[Table 4]

In the present embodiment, the impact mill 10 is used to convert the aluminum pieces into aluminum small spherical blocks, but a hammer crusher or the like may be used.

[0019]

According to the method for treating a used aluminum can according to the first aspect, the used aluminum can is cut, fired at 550 to 600 ° C., put into a repulsion pulverizer to form a spherical mass, and further classified. After removing the powder content, it was pressed and formed into a large lump,
An aluminum lump having high purity and being hardly oxidized can be obtained. Therefore, it can be directly reused as a raw material for dissolving the plate material of an aluminum can with good yield.

[Brief description of the drawings]

FIG. 1 is a flowchart of a method for treating a used aluminum can according to one embodiment of the present invention.

FIG. 2 is a side sectional view of the impact mill.

FIG. 3 is a sectional view taken along the line AA in FIG. 2;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Impact mill 11 Drum main body 12 Rotor 13 Screw feeder 14 Raw material supply part 16 Dust collecting hood 17 Repulsion plate attaching member 18 Fixed surface 19 Repulsion plate 20 Partition plate 21 Raw material transport part 22 Raw material loading part 23 Closed end plate 24 First Guide blade 25 hole 26 Raw material discharge section 27 Closed end plate 28 Second guide blade 29 hole 30 Ring 31 Drum receiving roller 32 Support member 33 Sprocket 34 Sprocket 35 Rotary shaft 36 Sprocket 40 Mounting frame 41 Bearing 42 Rotating shaft 43 Striking plate mounting member 44 Fixed surface 45 Striking plate 46 V pulley 50 Hopper 51 Reservoir

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-287231 (JP, A) JP-A-1-188637 (JP, A) JP-B-45-12211 (JP, B1) (58) Field (Int.Cl. ⁶ , DB name) C22B 1/00-61/00

Claims (1)

(57) [Claims] 1. A first step in which used aluminum cans compressed by a press are crushed and separated into pieces, and a second step in which the crushed aluminum cans are cut into chipped aluminum pieces. And a third step of separating the magnetically separated product by passing the chipped aluminum piece through a magnetic separator, and baking the separated aluminum piece at 550 to 600 ° C. A fourth step of burning and removing the resin, and a fifth step of putting the fired aluminum pieces into a repulsion-type pulverizer to separate the attached carbon and titanium oxide into small aluminum spherical lumps. The aluminum small spherical mass is pressure molded, and the apparent density is 1.
A sixth step of forming an aluminum lump in the range of 5 to 2.5, wherein the used aluminum can is directly used as a raw material for dissolving a plate material for an aluminum can. Method.