JP2001107150A - Method and device for recovering aluminum from aluminum formed product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recover aluminum freed from a coating film from an aluminum formed product coated with the coating film. SOLUTION: For an aluminum formed product such as a beverage container, e.g. wasted after use as the object for treatment, a crushing stage in which the aluminum formed product is crushed to prescribed sizes to form into small pieces 82 to be treated, and the small pieces 82 to be treated obtained by the crushing stage are applied with impact grinding force to peel or separate coating films 262 and 265 deposited on the surfaces of the base materials 260 of the small pieces 82 to be treated, by which the base materials freed from the coating films 262 and 265 are recovered. It is possible that the recovered aluminum is moreover subjected to press molding, or the like, to form into the shape of a lump, by which the surface area is reduced to prevent the oxidation of the surface, or the like. Furthermore, it is also possible that, before the separating and recovering stage, the aluminum formed product before the crushing, the small pieces of the aluminum formed product in the process of the crushing or the small pieces 82 to be treated obtained by the crushing are roasted at the temperature equal to or below the melting temperature of the base materials 260, and the coating films are burnt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a product formed from aluminum or an aluminum alloy as a base material (hereinafter referred to as "aluminum product"). More specifically, the present invention relates to a method and an apparatus for recovering “aluminum” or “aluminum”), and more specifically, aluminum containers such as packaging containers for beverages, building materials such as window frames, vehicle parts, laminated films and sheets, etc. The present invention relates to a method and an apparatus for recovering aluminum by subjecting an aluminum product whose surface is coated with a film made of a resin, a pigment, or the like to a treatment object, and peeling or removing the film from the aluminum product.

[0002] In the present specification, the term "aluminum product" means not only a final product but also an end product generated in the process of manufacturing these as long as the product is based on aluminum or an aluminum alloy as described above. Widely includes materials and chips.

[0003]

2. Description of the Related Art Aluminum is lightweight, corrosion-resistant,
Laminate film used for beverage containers such as so-called "aluminum cans", building materials such as window frames, vehicle bodies, panel materials, vehicle parts such as wheels, packaging materials, etc. because of their excellent thermal conductivity. It is used as a base material for various aluminum products such as sheets and sheets.

[0004] Aluminum products used in these applications and then discarded are actively collected and reused in consideration of effective use of resources and environmental pollution. At present, the recovery rate reaches 70% or more. ing.

[0005] Most of the aluminum products thus recovered are coated with a resin or coated with a paint composed of a resin or a pigment for the purpose of preventing oxidation or corrosion, decoration, etc., and the surface is coated. Coated with

Therefore, if an aluminum product is regenerated while being covered with this film, not only the recovery yield is poor, but also impurities are mixed into the recovered aluminum.

For example, taking the case of an aluminum can used as a beverage container as an example, the outer surface of the aluminum can is generally made of a paint composed of polyester resin and various pigments, and has a trade name, a trademark, a manufacturing company name, A coating is formed by printing various other items, and a coating made of an epoxy resin material is formed on the inner surface in contact with the beverage. When the aluminum can is melted while the coating is still formed, the resin forming the coating is burned to promote oxidation of the molten metal, thereby lowering the melting yield. Titanium (TiO ₂ ) or the like is mixed in the aluminum melt, and there is a problem that the amount of the impurity element in the recovered aluminum increases.

In the case where an aluminum product is manufactured again using only the aluminum recovered in a state in which impurities are mixed as described above as a raw material, it is difficult to recycle, for example, it is difficult to draw in the forming process, and it is necessary to extend the product thinly and uniformly. Can not be regenerated into a beverage container or the like that requires it.

In order to solve such a problem, various methods for removing a film formed on the surface of an aluminum can have been proposed. For example, (1) after crushing the aluminum can with a shredder, A thermal removal method for burning and removing a film formed on the surface of an aluminum can by heating below the melting temperature of aluminum (a so-called “roasting method”). (2) After crushing the aluminum can with a shredder, Mechanical removal method for removing the film adhering to the surface by projecting particles (Japanese Patent Publication No. 7-61611), (3) After crushing an aluminum can with a shredder, mechanically removing the aluminum can while immersing it in a remover Various methods have been proposed, such as a chemical removal method (Japanese Patent Application Laid-Open No. H10-68924) in which a film is removed by imparting a coating.

[0010]

According to the method described above,
Since the film is removed by burning of the film by roasting and mechanical and chemical peeling of the film, when the recovered aluminum is melted and regenerated, combustion of the film in the molten metal does not occur and molten oxidation occurs. The dissolution yield can be suppressed and the dissolution yield can be improved.

However, according to the above-mentioned roasting method, the coating formed on the aluminum can is burned prior to the melting step, so that the coating burns to generate harmful substances. Problems such as adverse effects on the work environment and deterioration of the working environment. In addition, the resin content in the coating and titanium oxide (TiO 2)
₂ ) The flammable pigments adhere to the surface of the aluminum substrate, and these flammables are mixed with the recovered aluminum as an impurity element to deteriorate the workability of the recovered aluminum as described above. The problem has arisen.

In addition, according to the mechanical removal method of removing the coating by projecting the metal particles, the coating can be removed without burning the coating, thereby preventing the generation of harmful substances due to the burning of the coating. . However, according to this method, a part of the projected metal particles also adhere to the surface of the aluminum base material due to an impact at the time of collision with the object to be treated. A problem arises as a result of mixing as impurities.

Further, in the case of a chemical removal method in which a film is removed by applying a mechanical peeling force while immersing the aluminum can in a stripping solution after crushing the aluminum can, if an organic solvent or the like is used as the stripping solution, the organic solvent is removed. The solvent is volatilized to cause air pollution and deterioration of the working environment, and the cost for using the stripping solution and safely treating the stripping solution after use increases.

Accordingly, the present invention has been made to solve the above-mentioned drawbacks in the prior art, and prevents oxidation during dissolution by preventing not only the film but also impurities from being mixed when the film is removed. Decrease in melting yield due to
Disclosed is a method and an apparatus for recovering aluminum from an aluminum product, which can reduce the contamination of the recovered aluminum with foreign metals such as titanium oxide and impurities composed of foreign substances such as a flammable film. With the goal.

[0015]

In order to achieve the above object, the present invention provides a method for recovering aluminum from an aluminum product, comprising the steps of:
A crushing step of crushing the aluminum product 80 into a plurality of small pieces 82 to be processed, and subjecting the crushed individual small pieces 82 to impact grinding It is characterized in that it comprises a separation / recovery step of peeling or separating the coatings 262 and 265 on the surface of the substrate 260 of the small piece 82 to be processed and recovering the aluminum forming the substrate 260.

In another method of recovering aluminum according to the present invention, the aluminum product 80 before the crushing process and the small pieces 8 of aluminum product during the crushing process are provided before the separation / recovery process.
1, or a roasting step of burning the coatings 262 and 265 by roasting at a temperature equal to or lower than the melting temperature of the substrate 260 when at least one of the small pieces to be processed 82 obtained through the crushing step is provided; A configuration may be adopted in which the cinders of the coating film adhering to the surface of the substrate 260 are separated or separated by the application of the impact grinding force in the separation / recovery step, and the aluminum forming the substrate 260 is recovered.

In each of the above methods, the crushing step may be composed of a plurality of steps.
It is also possible to adopt a configuration comprising a crushing step of crushing 0 to form a plurality of small pieces 81 and a fine crushing step of further crushing the small pieces 81 obtained in the crushing step to obtain small pieces 82 to be treated. . Further, the crushing step may be a step having a plurality of stages.

When the crushing step is constituted by a plurality of steps, the roasting step can be performed on the small pieces 81 of the aluminum product formed by the crushing step.

Further, the method of recovering aluminum of each of the above structures may include a pressing step of pressing the aluminum recovered in the separation / recovery step into a block.

Further, the aluminum recovery apparatus for carrying out the above-mentioned method includes a crushing means (crusher 1) for crushing the aluminum product 80 having the coatings 262 and 265 formed on the surface of the aluminum base 260 into a plurality of small pieces 82 to be processed.
10) and a cutter mill 120), and a fixed side separation on which a plurality of fixing pins 134 are sequentially implanted on a plurality of rotation trajectories on a fixed disk 131 having a central portion communicated with a supply input portion 132 of the small piece 82 to be processed. .Recovery means and the fixed-side disk 13
A movable-side separating / collecting means in which movable pins 144 are sequentially implanted on a plurality of rotation trajectories different from the fixed pins 134 on a movable disk 141 rotatably provided opposite to the first movable pin 141; A take-out means is provided for taking out the substrate 260 of the small piece 82 to be treated, from which the coating has been peeled or removed from the coating, into the outlet 153, and between the fixed pin 134 and the movable pin 144, the material is subjected to impact grinding force. Separation / recovery in which the treated pieces 82 are ground to separate or separate the coatings 262 and 265 from the substrate 260 and collect the substrate 260 from which the coating has been separated.
It is characterized by comprising recovery means (cleaning separator 130).

The aluminum recovering apparatus further includes, before the separation / recovery step, the aluminum product 80 before the crushing step, the small piece 81 of the aluminum product during the crushing step, or the small piece 82 to be processed obtained through the crushing step. In at least one of the states, a roasting means such as an electric furnace for roasting at a temperature equal to or lower than the melting temperature of the substrate 260 to burn the coatings 262 and 265 may be provided. The collection means (cleaning separator 130)
The small pieces 82 to be treated are crushed to peel or separate the cinders of the film adhered to the substrate 260 generated during roasting, and the substrate 260 from which the film has been peeled is recovered.

Further, the crushing means includes a crusher 11 for roughly crushing the aluminum product 80 to be treated.
0 or the like, and a combination of a plurality of devices such as a fine crushing means such as a cutter mill 120 formed by further crushing the aluminum product 80 crushed by the crushing means into a small piece to be processed. In this case, the roasting means such as an electric furnace can roast small pieces 81 of aluminum product formed by crushing by crushing means such as a crusher 110.

Further, a pressing means for pressing the aluminum 83 as the base material 260 collected by the cleaning separator 130 as the separating / collecting means to form a block may be included.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described below with reference to the accompanying drawings.

[Object to be treated] The aluminum product 80 to be treated in the present invention is an aluminum product 80 having a coating made of a resin or a pigment formed on the surface thereof. An aluminum product 80 having a film formed by applying a resin, a resin made of an acrylic resin, or a paint made of such a resin and a pigment.

Examples of such an aluminum product 80 include aluminum cans used as beverage containers,
Aluminum frame parts such as window frames, other aluminum building materials, vehicle bodies, panel materials, wheels,
There are laminated films, sheets and the like including a layer made of aluminum.

As an example, the structure of an aluminum can is shown in Table 1 below.

[0028]

[Table 1]

[Crushing Process] As described above, the aluminum product 80 having the coating formed on its surface is separated as necessary, and then is sized to pass a predetermined size, for example, a screen mesh of φ10 mm as an example. And crushed into small pieces to form a small piece to be treated 82. The small piece 82 to be treated is subjected to an impact grinding force described below to remove the coating.

As an example, the structure of a small piece 82 to be processed formed by crushing a general aluminum can is shown in FIG.
And FIG. 1 (B).

FIG. 1A shows a small piece 82 to be processed formed by crushing the body of an aluminum can. The outer surface of a base 260 made of an Al-Mn-Mg alloy is coated with a polyester resin. A coating 262 made of a resin 263 and a pigment 264 such as titanium oxide is formed, and a coating 265 made of an epoxy resin is formed on the inner surface that comes into contact with the beverage.

FIG. 1B shows a small piece 82 to be processed formed by crushing the lid of an aluminum can.
Epoxy-based resin films 262 and 265 are formed on the front and back surfaces of a substrate 260 made of an Al-Mg-based alloy.

In this crushing step, the processing object can be crushed to a predetermined size in one step to form the small piece to be processed 82. In the present embodiment, the aluminum product 80 to be processed is roughly crushed. The crushing is performed by a two-stage process of a crushing step of performing a fine crushing step in which a small piece 81 of an aluminum product formed by crushing is further finely crushed to form a small piece 82 to be processed.

In the present embodiment, the object to be treated in the crushing step is, for example, a square having a side of about 20 × 50 mm,
Rectangles such as rectangles, trapezoids, triangles, and other polygons are crushed into irregularly shaped small pieces 81, and the small pieces 81 obtained in this step are further finely crushed so that they can pass through a screen mesh of φ10 mm in a fine crushing step. The pieces to be processed 82 are obtained by crushing the pieces into pieces.

As described above, by performing the crushing step in two or more steps, for example, when the object to be processed is provided in the form of a press can in which a plurality of aluminum cans are compressed into briquettes. If so, the crushing can be performed efficiently.

This crushing step can be carried out using any equipment capable of crushing the aluminum product 80 to be treated to the above-mentioned size, and is formed by combining crushers of the same or different types. The crushing can be performed using a crushing means. In the present embodiment, as an example, the crushing is performed by a crushing step using a twin-screw crusher (crusher 110: see FIG. 2) as a crushing means, This is performed by a fine crushing step using a single-shaft crusher (cutter mill 120: see FIGS. 2 and 3) shown in FIG. Therefore,
In the present embodiment, the crushing step includes two steps of a coarse crushing step and a fine crushing step, and the crushing means is constituted by combining the twin-screw crusher and the single-screw crusher.

(1) Twin-screw crusher The twin-screw crusher used in the crushing step includes:
For example, Gainax Crusher manufactured by Horai Co., Ltd.
Alternatively, various known mono-cutters, shredders, crushers, and the like (hereinafter, these are collectively referred to as “crushers”) such as a roll crusher manufactured by Nara Machinery Co., Ltd. can be used.

The crusher 110 is, for example, shown in FIG.
As shown in the figure, two axes that rotate inward each other are provided in parallel in the crusher body, a plurality of rotating blades are provided on each axis at a predetermined interval, and the rotating blades of each axis mesh with each other and rotate each other. 3 protruding from the outer peripheral surface of the blade so as to form an equal angle
The object to be crushed is provided so as to be cut into crushed pieces each composed of a large piece as appropriate by the individual claw blades.

The material to be crushed introduced from the inlet at the top of the crusher is drawn into the interior by the claw blades of the two-axis rotating blades rotating inward each other, and between the outer peripheral edges of the rotating blades rotating in a meshed state. Then, the crushed pieces are crushed and cut by the compressing force acting at the time of retraction while being slit by the continuously acting decay force to form crushed pieces. In this embodiment, the aluminum product 80 to be treated is 2
The size of the claw teeth and edges is selected so as to be roughly crushed to about 0 × 50 mm, and a crushed piece formed by crushing the object to be processed into the size described above is a screen provided below the biaxial rotary blade. It passes and is discharged from the discharge port. The small pieces 81 formed by crushing in this manner are rectangular,
It is crushed into small pieces 81 of irregular shape such as square, rectangular, triangular, trapezoidal, rhombic, etc., and discharged from the outlet.

(2) Single-screw crusher The small pieces 81 crushed as described above are, for example, a known crushing means which is a single-screw crusher (referred to as a “cutter mill” for convenience in the present specification) in the present embodiment. As an example, a small piece sized to pass through a screen mesh having a small hole having a diameter of 10 mm is crushed and used as a small piece to be processed 82.

FIG. 3 shows a cutter mill as an example of the crushing means. Reference numeral 121 denotes a cutter mill body, and an input port 123 is provided on the upper surface.
In the cutter mill main body 121, a cutter support 124 is provided in the cutter mill main body 121, which is supported by the cutter mill main body 121 and is rotated in a vertical direction by rotation driving means (not shown). Four rotating blades 125 that are long in the horizontal direction are provided so as to form an equal angle of 90 degrees in the rotating direction of the cutter support 124, and the cutting edges of these four rotating blades 125 are located on the same rotation locus.

Further, the two fixed blades 126 are separated from the rotation locus of the cutting edge of the four rotary blades 125 by a small gap.
Is fixed to the cutter mill main body 121 at a position substantially symmetrical with the rotation locus of the cutting edge of the rotary blade 125, the inside of the cutter mill main body 121 is divided by the two fixed blades 126, the cutter support 124 and the rotary blade 125, and the input chamber 127 and the crushing chamber are crushed. A chamber 128 is formed. The charging port 123 communicates with the charging chamber 127. In addition,
The clearance between the second fixed blade 126 and the rotary blade 125 can be freely adjusted so that the object to be crushed can be cut into a desired size or, in a broad sense, crushed.

The crushing chamber 128 is provided with the second fixed blade 12.
The six screens are separated by a mesh screen 129 so as to surround the rotation locus of the rotary blade 125. In this embodiment, the screen 129 uses a punching metal in which holes having a diameter of 10 mm are formed innumerably. A discharge port 1 for discharging the small pieces to be processed 82 is provided below the crushing chamber 128.
31 are provided.

In the above-mentioned cutter mill 120, small pieces 81 formed by being coarsely crushed by the crusher 110 are introduced from the introduction port 123, and the cutter support 124 is used as an example by a rotation driving means (power 5.5 KW) not shown. 800
When rotated at min- ¹ , small pieces 81 formed by crushing are obtained.
Is formed through a screen 129 between the rotary blade 125 and the fixed blade 126 of the cutter support 124, and the shape and area thereof are not fixed.
When used as a long side or long diameter is 9.5x
It is roughly crushed into rectangular pieces such as rectangles or squares having a size of about 9.5 mm or less, or irregularly shaped pieces such as triangles, trapezoids, and rhombuses, and is discharged from the outlet 131. The small piece obtained through the fine crushing step by the cutter mill 120 in this manner becomes the small piece to be processed 82.

In the embodiment shown in FIG. 2, the cutter mill 120 is shown as having a vertical rotation axis, but the cutter mill 1 used in the present invention is used.
Any type 20 can be used, and any other device other than the cutter mill 120 can be used as long as the small pieces 81 can be processed small pieces of a predetermined size. May be used.

[Roasting Step] Although the present roasting step is not an essential step in the present invention, the processing time in the later-described separation / recovery step can be reduced by passing through this step.

In this roasting step, the aluminum product 80 before passing through the crushing step, the small piece 82 to be treated obtained through the crushing step, or the crushing step as described above is a coarse crushing step, a fine crushing step, etc. In the case of including a plurality of steps, a step of firing the small piece 81 of the aluminum product obtained through any one of the steps at a temperature equal to or lower than the melting temperature of aluminum to burn the resin or pigment covering the surface thereof It is.

In the present embodiment, the roasting step is performed during the above-described crushing step, that is, on the small pieces 81 of the aluminum product obtained by the coarse crushing step.

As described above, the roasting is performed on the small pieces 81 of the aluminum product obtained in the crushing step, because the roasting is performed on the aluminum product 80 before the crushing step. This is because the amount of one treatment is reduced because the object to be treated is bulky. The reason why the treatment is performed before the fine crushing step is that the small piece 81 after the roasting is subjected to an impact by the fine crushing step. This is because pigments such as titanium oxide and resin agglomerates adhere to the surface of the small piece 81, which can be expected to shorten the processing time in the separation / recovery step described later.

In this embodiment, the roasting is performed in an electric furnace at a temperature of 300 to 400 ° C. for about 5 to 10 minutes.

Further, in the embodiment shown in FIG. 2, this electric furnace is shown as a conveyor furnace, but various types of furnaces other than the conveyor furnace, such as a box furnace, a bell furnace, a trolley furnace, a tunnel furnace and the like. A known type of furnace, such as a furnace having a heating element that generates heat by fuel other than electricity, such as gas, can be used.

[Separation / Recovery Step] As described above, a small piece to be processed formed by crushing the aluminum product 80 to be treated in the crushing step into an irregular shape having a side of about 9.5 × 9.5 mm. 82, an impact milling force is applied thereto, and coatings 262, 265 covering the surface of the base material 260 of the small piece 82 to be processed when the roasting step has not been performed.
However, after the roasting step, the base material 26 of the small piece 82 to be treated is
Alumina used as a raw material is recovered by removing or removing the cinders such as resin and pigment adhered to the surface.

FIGS. 4 to 7 show examples of the constitution of the separation / recovery means (in the present embodiment, referred to as "cleaning separator" for convenience) used in the present invention.

First, the general outline of the cleaning separator 130 will be described.
30 is provided with a supply inlet 132 into which each of the small pieces 82 to be processed is charged, and the coatings 262 and 265 covering the surface of the base 260 of the small piece 82 to be processed by processing the small pieces 82 in the cleaning separator 130. Or, the cinders of the pigment or resin adhering to the surface of the small piece 82 to be processed are peeled off, and the outlet 153 from which the aluminum as the base material 260 is taken out, and the coating peeled off from the base material 83, or the cinder of the coating, And the base material 26
And a discharge port 152 for discharging aluminum powder or the like generated by shaving.

The small pieces 82 processed in the crushing step or the small pieces 82 subjected to the crushing step and the roasting step are supplied to the supply inlet 132 through a supply pipe 231 (see FIG. 7). ). The outlet 153 is the supply inlet 13
2 through a communication pipe 235, and a pipe 236 from a compressed air supply source (not shown) is connected to an outlet side of the communication pipe 235.
To communicate. A flow straightening plate is provided at a communicating portion of the pipe 236 so that compressed air mainly flows to the supply inlet 132. Further, the communication pipe 235 is branched to form a base material 260.
A branch pipe 237 that reaches the recovery tank 240 is provided, and a three-way solenoid valve 238 that is switched at appropriate intervals by, for example, a timer circuit is provided at a branch point of the branch pipe 237.

On the other hand, the discharge port 152 communicates with the collection tank 250 through a discharge pipe 239, and the coating film discharged from the discharge port 152 or the cinders of pigments and resins generated by roasting, and the substrate 260 The dust 84 made of aluminum powder or the like generated by scraping is sucked into the discharge pipe 239 provided with the blower 157 and collected in the collection tank 250.

In order to prevent a dust explosion from being ignited by igniting the coating 84 collected by the collecting tank 250 or the dust 84 made of pigment or resin, etc., water is collected in the collecting tank 250. Is stored.

The internal structure of the cleaning separator 130 will be described with reference to FIGS. 4 to 6. The cleaning separator 130 used in this embodiment is a small one for an experimental device.
Reference numeral 2 denotes an opening communicating with the center of a fixed disk 131 having a diameter of 400 mm, and a fixed end plate 133 is attached to the fixed disk 131 in the processing space 1.
The outer peripheral edges of the fixed end plate 133 are fixed to the fixed disk 131 with the peripheral side plate 135. A movable disk 141 having substantially the same diameter as the fixed end plate 133 is provided in the processing space 155 and is driven to rotate by the rotating horizontal shaft 142. The rotating horizontal shaft 142 has bearings 143 and 143.
Is pivoted by The rotation horizontal shaft 142 is rotationally driven by a rotation driving unit such as a motor 161.

On the fixed disk 131, identification pins 134 are sequentially implanted on a plurality of concentric circles (relative to the movable disk 141) on rotation trajectories a1 to a6 (FIG. 6). On the other hand, on the movable disk 141, movable pins 144 that are alternately inserted between rotation trajectories of the fixed pins 134 on a plurality of rotation trajectories b1 to b6 different from the fixed pins 134 are sequentially planted. The fixed and movable pins 134 and 144 are arranged so that the fibrous layer 262 on the surface of the small piece 82 to be separated is separated or separated by the impact attrition force.

More specifically, the number of the fixing pins 134 is 16 on the rotation trajectory a1 near the center of the fixed disk 131.
The rotation locus a located on the outer peripheral side of the rotation locus a1
On 2 above, 24 are planted.

On the other hand, the number of movable pins 144 is
41 on the rotation trajectory b1 near the center of 41, and 4 on the rotation trajectory b2 located on the outer peripheral side of the rotation trajectory b1.
This is planted.

In practice, the fixed and movable pins 134, 1
The grinding force applied to the small piece to be processed 82 is reduced by increasing the clearance between the pieces 44, and the grinding force is increased by decreasing the clearance.

Further, in FIG. 4, a discharge space 15 is provided on the outer peripheral side of the movable disk 141 and on the inner peripheral side of the peripheral side plate 135.
A screen 151 having a predetermined mesh in which pores are formed by hunting is provided around the screen 6, and a discharge port 152 is provided below the discharge space 156. In the present embodiment, the screen 151 is preferably a mesh having a diameter of 1 mm.

The screen 151 of the processing space 155
An outlet 153 is provided in the lower part of the
Reference numeral 3 denotes a collection tank for communicating with the supply inlet 132 through the communication pipe 235 as described above, and for collecting the base material 260 collected via the branch pipe 237 that branches off the supply inlet side of the communication pipe 235. 240. As another example, a plug valve for opening and closing control is provided in the outlet 153, and the outlet 153 is supplied through a blower 158 that sucks air in the cleaning separator 130 as shown in FIG. It can communicate with the input port 132.

Therefore, the cleaning separator 1
In 30, the rotating disk 142 is rotated by the rotation driving means of the motor 161 to rotate the movable disk 141, and each of the small pieces 82 is supplied to the supply slot 132. At the center, each of the small pieces 82 to be processed is hit by the impact of the fixed and movable pins 134 and 144 between the fixed and movable pins 134 and 144 by the impact attrition force. The surface of the small piece 82 to be treated or the surface of the small piece 82 to be treated is rubbed against each other, so that the surface of the small piece 82 to be treated is crushed to coat the surface, or the pigment adhering to the substrate 260 The burnt residue of the resin and the resin is finely pulverized to be in the form of dust, and is separated from the surface of the small piece 82 to be processed. The base of the small piece to be processed 82 is partly shaved by the application of the impact attrition force into a powder form, and is peeled off together with the coating 262. In this manner, the coating peeled off from the small piece to be processed 82, or the cinders of the pigment and the coating are removed by the movable pins 14
After passing through the screen 151 by the centrifugal action of No. 4 and being classified into the discharge space 156, it is sucked and discharged from the discharge port 152 to the outside via the blower 157 (FIG. 7).

In this embodiment, the blower 157 is 15 kw, pressure 460 mmAg, suction speed 65 m ³ / min in a large machine, 3.7 kw, pressure 4 in a medium machine.
60 mmAg, suction speed 51 m ³ / min., For small machines, 1.5 kw, pressure 400 mmAg, suction speed 3.4 m ³ / min. And powdered aluminum scraped off from the substrate 260 and the cleaning separator 1
It sucks in with the air in 30.

On the other hand, the substrate 260 having a size that does not pass through the screen 151 accumulates in the screen 151. In the coating pieces 262 and 265 or the small pieces 82 to be treated from which the pigment or resin cinders are removed, the coating 26 still remains on the surface.
Small pieces 8 to be treated with 2,265 or film cinders
2 is mixed. However, the outlet 53 and the supply inlet 1
Since the small piece 82 is communicated with the second through the communication pipe 235, the small piece 82 taken out from the outlet 153 is returned to the supply inlet 132, and is again subjected to the impact grinding force in the cleaning separator 130 and repeatedly beat. Small pieces 8 to be treated
The coatings 262, 265 or the cinders of the coating adhering to the surface of No. 2 are peeled off from the small pieces 82 to be treated, leaving only the substrate 260.

As described above, the coating 262, 264, or the small piece to be processed 82, from which the cinders of the coating have been removed to become only the substrate 260, are refluxed, but are not finely ground so as to pass through the screen 151. Most remains in the screen 151. The above-described separation / recovery process can be repeated a plurality of times as necessary until the coatings 262, 265 of the small pieces to be processed 82 in one batch or the cinders of the coating are almost separated from the substrate 260.

The above-mentioned cleaning separator 130 is driven by the rotary driving means 161 to open the downstream side of the communication pipe 235 with a three-way solenoid valve 238 and to open the branch pipe 237.
By closing the side and supplying compressed air from the pipe 236 to the communication pipe 235, the supply inlet 132, the processing space 155, and the outlet 15
3, and an airflow circulating to the communication pipe 235 is generated. When each batch 82 to be processed is supplied to the supply inlet 132 through the supply pipe 231, the cleaning separator 13
The resin or pigment powder formed by finely pulverizing the coating 262 that has been treated within 0 and peeled off from the surface of the small piece 82 to be treated, or the base material of the small piece 82 to be treated is burned off by burning the resin or pigment. Dust 8 composed of formed aluminum powder, etc.
4 passes through the screen 151 and is discharged to the collection tank 250 by the blower 157, while the screen 15
The base material remaining in 1 is sucked into the communication pipe 235 by the circulating airflow, is again supplied to the processing space 155, and is processed in the cleaning separator 130. This series of processes is performed by coating the surface of the small piece 82 to be processed in one batch. Is repeated a plurality of times as needed until is peeled off. Next, after the above processing is completed, the downstream side of the communication pipe 235 is closed with a three-way solenoid valve 238 and the branch pipe side is opened, so that the base material 260 of the small piece 82 to be processed left in the screen 151 is removed. A certain aluminum 83 passes from the communication pipe 235 through the branch pipe 237, and a chip-shaped or flake-shaped aluminum 83 having one side or a long side of 2 to 5 mm is collected into the collection tank 2.
Collected at 40.

Note that, instead of the three-way solenoid valve 238, a solenoid valve for opening and closing the branch pipe 237 and the communication pipe 2
It is also possible to provide an electromagnetic valve that opens and closes the downstream side of 35, and to open and close these two electromagnetic valves alternately.

[Compression Step] The chip or flake-like aluminum 83 collected as described above can be compressed into a mass having a specific gravity equivalent to that of an aluminum ingot.

In this compression step, in this embodiment, the chip-like or flake-like aluminum, which is the base material 260 of the small piece to be processed 82 recovered through the above-mentioned separation / recovery step, is compressed by a press machine. In the present embodiment, the aluminum charged in a cylindrical mold having a diameter of 42 mm is pressed by a hydraulic pressure at a pressure of 245 Mpa and compressed to a volume reduction ratio of about 50%. 42m in diameter
m, a 28 mm long cylindrical aluminum block. The specific gravity of this aluminum lump is 2.4.

By reducing the specific surface area by compressing the collected chip-shaped aluminum in this way, surface oxidation can be prevented and the efficiency of recycling can be improved, and the specific gravity can be reduced to about an ingot. Thus, the work for forming the ingot can be facilitated, and the loss in the melting step can be reduced.

Test Example Next, in the case where aluminum cans were to be treated, the following comparative tests 1 to 5 were performed to confirm the optimal treatment conditions in each step.

Test Example 1 Table 2 shows the results of performing the treatment according to the method of the present invention by changing the size of the small pieces 82 to be treated and setting other conditions to be the same.

In this test example, the diameter was 3 mm and the diameter was 6 mm.
A small experiment in which small pieces to be processed formed by a cutter mill having screen meshes with holes of 10 mm, 10 mm, 12 mm, and 15 mm were fixed, and the diameter of the movable disk was 400 mm and the maximum number of revolutions was 4460 min ^-1. The cleaning separator was used for 15 minutes at a rotation speed of 1270 min ^-1 .

The reason why the hole of the screen mesh of the cutter mill is 15 mm or less and the size of the small piece to be subjected to the impact grinding force is 15 mm or less is that when the small piece of 15 mm or more is put into the cleaning separator, This is because there is a concern that the load on the cleaning separator is too large.

The diameter of the pores formed in the screen mesh of the cleaning separator is 1 mm, and the amount of the small pieces to be treated is 550 g.

Further, in this test example, the roasting was not performed on any of the aluminum product, the small piece 81 of the aluminum product in the crushing step, and the small piece 82 to be treated.

[0080]

[Table 2]

In Table 2 above, the “residual rate of coating” refers to the small pieces to be processed in which the coating still remains from the small pieces to be processed after the treatment with the cleaning separator, and the small pieces of the small pieces to be processed which are put into the cleaning separator. The weight of the remaining small particles to be treated of the selected coating with respect to the weight is expressed as a percentage (wt%).

The "yield" in Table 2 is a comparison of the weight of the small pieces to be processed before and after the separation / recovery step. Yield = (weight of small pieces to be processed after processing / small pieces to be processed before processing) Weight) × 100.

From the above results, when both the yield and the film removal rate were comprehensively determined, it was found that φ10
A small piece (about 9.5 mm on a side) formed by a cutter mill provided with a screen mesh of mm can provide the best results, and the size of the piece 82 to be processed is 5.
It is preferable to set it to about 5 to 2 × 11.5 mm.

Test Example 2 Next, Table 3 shows the results of carrying out the method of the present invention under the same conditions except that the rotation speed of the cleaning separator was different. In this test example, the roasting step was not included in the processing step. The conditions other than the rotation speed of the cleaning separator are as follows.

First, the aluminum can to be treated is roughly crushed into a size of about 20 × 50 mm by the crusher 110, and the roughly crushed small piece 81 is further cut into a cutter mill 120.
Then, an impact crushing force by a cleaning separator is applied to the small piece 82 to be processed, which is finely crushed into a size of about 9.5 mm on a side, and the processing is performed for 15 minutes at each rotation speed shown in Table 3. went. The amount of the small pieces to be processed is 550 g.
And the screen mesh of the cleaning separator is 1 mm. In this test example, the roasting was not performed on any of the aluminum product, the small piece 81 of the aluminum product in the crushing step, and the small piece to be processed.

[0086]

[Table 3]

As a result, it was confirmed that the impact grinding force applied by the cleaning separator most effectively removed the film when the cleaning separator was set at 1270 min ^-1 .

Test Example 3 For the purpose of examining the film removal efficiency depending on the presence or absence of roasting, other conditions were made common, one was to apply an impact grinding force to the roasted small pieces, and the other was to roasting. Table 4 shows the results obtained by applying an impact milling force to the small pieces 82 that have not been baked.

In this test example, in the roasting step, the aluminum can to be treated was crushed by the crusher 110 by 20 ×.
After roughly crushing to a size of about 50 mm, 300
The roasted small pieces were further crushed by a cutter mill 120 to a size of about 9.5 mm on a side to form small pieces 82 to be treated. The impact grinding force of the cleaning separator 130 was applied to the small pieces 82. Incidentally, the comparative example is a coarse crushing step,
Except for the point that roasting is not performed during the fine crushing step, the processing target piece formed by the same processing as described above is targeted.

The number of rotations of the cleaning separator was 1270 min ^-1 , and
2 was put into the cleaning separator and then treated for 8 minutes. The screen mesh of the cleaning separator is 1 mm.

[0091]

[Table 4]

As a result, by roasting the small pieces to be treated before the separation / recovery step, the processing time in the separation / recovery step could be eliminated.

Incidentally, the film remaining ratio was 1.
In order to recover about 1 wt% of aluminum chips, the processing time by the cleaning separator needs to be about twice as long as when performing roasting. Processing time could be shortened.

Test Example 4 The processing target piece (1.3 wt%) having the lowest coating residual ratio obtained in Test Example 1 was treated, and the processing target piece 82 was subjected to a pressure of 245 MPa in a cylinder having a diameter of 42 mm. Table 5 shows the results obtained by performing a hydraulic press to form a cylinder having a diameter of 42 mm and a length of 28 mm.

[0095]

[Table 5]

As described above, since the ingot-shaped aluminum lump formed after pressing has a surface area reduced by 96.4%, the contact surface with the outside air is reduced, and surface oxidation can be prevented. In addition, since a predetermined amount of aluminum can be handled as one lump during subsequent melting or the like, loss during work can be reduced.

Test Example 5 The compressed aluminum product obtained in Test Example 4 above and a compressed aluminum product obtained by crushing an aluminum can and obtained by compressing a small piece without a coating (comparative example) were both 720.
Table 6 shows the results of measuring the content of titanium in the molten metal dissolved at 0 ° C.

[0098]

[Table 6]

When the recovered aluminum is recycled as a body material of an aluminum can, the content of titanium is 0.03%.
The following is required (JIS 3004), but the aluminum in the molten metal that has been melted without removing the coating is
It contains twice as much 0.09% titanium and cannot be recycled as aluminum cans.

On the other hand, titanium detected from the molten aluminum recovered by the method of the present invention was 0.1%.
It can be recycled again as a body material of an aluminum can.

Therefore, conventionally, it has been practiced to mix the recovered aluminum into the virgin raw material to reduce the titanium content. However, the aluminum recovered by the method and apparatus of the present invention is used alone. Can be used as a raw material for recycling aluminum cans.

[0102]

According to the structure of the present invention described above, the film formed on the surface of the aluminum product can be suitably removed without generating harmful substances by roasting and without using an organic solvent or the like. As a result, a method and an apparatus for recovering aluminum from an aluminum product with a low content of impurities were obtained.

Further, in the method and apparatus of the present invention including the step and apparatus for roasting aluminum products or small pieces obtained by coarsely crushing or crushing aluminum products, the processing in the separation / recovery step by the cleaning separator is performed. Time was saved.

[Brief description of the drawings]

FIG. 1 shows a configuration example of an aluminum can as an example of an aluminum product to be treated according to the present invention;
(A) is a sectional view of a trunk, and (B) is a sectional view of a lid.

FIG. 2 is a schematic explanatory view schematically showing each step in the present invention.

FIG. 3 is a sectional view of an essential part showing an example of a fine crushing means (cutter mill) used in the embodiment of the present invention.

FIG. 4 is an overall perspective view showing a main part of a separation / collection unit (cleaning separator) used in the embodiment of the present invention.

FIG. 5 is a plan view of FIG. 4;

FIG. 6 is a sectional view of an essential part taken along line VV in FIG. 4;

FIG. 7 is an overall perspective view of a separation / recovery unit (cleaning separator) used in the embodiment of the present invention and devices connected to the cleaning separator.

[Explanation of symbols]

 Reference Signs List 80 aluminum product 81 small piece of aluminum product (after crushing treatment) 82 small piece to be treated 83 collected aluminum 84 dust 100 roasting means (electric furnace) 110 crusher (crushing means) 120 cutter mill (fine crushing means) 121 cutter mill Main body 123 Input port 124 Cutter support 125 Rotary blade 126 Fixed blade 127 Input chamber 128 Crushing chamber 129 Screen 130 Cleaning separator (grinding means) 131 Fixed disk 132 Supply input port 133 Fixed end plate 134 Fixed pin 135 Peripheral plate 141 Movable disk 142 Rotating horizontal shaft 143 Bearing 144 Movable pin 151 Screen 152 Outlet 153 Outlet 155 Processing space 156 Drainage space 157 Blower 158 Blower 161 Motor 231 Supply pipe 235 Communication pipe 236 Pipe 237 Branch pipes 238 three-way solenoid valve 239 discharge pipe 240 recovery tank 250 collection tank 260 substrate 262,265 film 263 resin material 264 pigment

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D004 AA07 AA21 AA27 AA31 BA05 CA03 CA04 CA08 CA12 CA28 CB13 CB15 4K001 AA02 BA22 CA01 CA11

Claims (10)

[Claims] 1. A crushing step of crushing an aluminum product having a coating formed on the surface of an aluminum base material into a plurality of small pieces to be treated; While applying an impact grinding force to peel or separate the coating on the substrate surface of the small piece to be treated, and recovering the aluminum constituting the substrate,
A method for recovering aluminum from an aluminum product, comprising a separation / recovery step. 2. A crushing step of crushing the aluminum product having a coating formed on the surface of an aluminum base material into a plurality of small pieces to be processed; and an aluminum product before the crushing step; A roasting step of roasting at least one of the small pieces of the aluminum product in the process or the small pieces to be treated after the crushing step at a temperature equal to or lower than the melting temperature of the base material and burning the coating; and the individual small pieces to be treated. Separating and recovering the aluminum forming the base material while applying an impact milling force to the flakes to separate or remove the cinders of the film adhered to the base material surface of the small piece to be processed. A method for recovering aluminum from aluminum products. 3. The crushing step is a crushing step of crushing an aluminum product to form a plurality of small pieces, and a fine crushing step of further crushing the small pieces obtained in the crushing step to obtain small pieces to be treated. The method for recovering aluminum from an aluminum product according to claim 1, wherein the method comprises: 4. The method for recovering aluminum from an aluminum product according to claim 3, wherein the roasting is performed on small pieces of the aluminum product formed by the crushing step. 5. The method for recovering aluminum from an aluminum product according to claim 1, further comprising a pressing step of pressing the aluminum recovered in the separation / recovery step into a block. 6. A crushing means for crushing an aluminum product having a coating formed on the surface of an aluminum substrate into a plurality of small pieces to be processed, and a fixed disk having a central portion communicating with a supply / input section for the small pieces to be processed. A fixed-side separating / collecting means in which each fixed pin is sequentially implanted on a plurality of rotation trajectories; and a movable disk provided rotatably to face the fixed-side disk, wherein each fixed pin is Movable side separation / recovery means in which movable pins are sequentially implanted on a plurality of rotation trajectories different from the pins, and take-out means for taking out the base material of the small piece to be processed from which the coating has been peeled or the coating film has been peeled off or removed to the outlet Separating / collecting means for grinding the small piece to be treated by an impact grinding force between the fixed pin and the movable pin to peel or separate the coating from the substrate, and recovering the substrate from which the coating has been peeled; Characterized by being made of aluminum Apparatus for recovering aluminum from beam formed article. 7. A crushing means for crushing an aluminum product having a film formed on the surface of an aluminum substrate into a plurality of small pieces to be treated, an aluminum product before the crushing step, a small piece of the aluminum product during the crushing step, or A roasting means for roasting at least one of the small pieces to be processed after the crushing step at a temperature equal to or lower than the melting temperature of the base material and burning the coating; A fixed-side separating / collecting means on the disk, on which a plurality of fixed pins are sequentially implanted on a plurality of rotation trajectories; and a movable disk provided rotatably opposite to the fixed-side disk. A movable-side separating / recovering means in which movable pins are sequentially implanted on a plurality of rotation trajectories different from the fixed pins, and a take-out means for taking out a small piece to be processed which has been ground and made only a base material to an outlet. , The fixing pin and Separation / recovery in which the small pieces to be treated are crushed by an impact crushing force between the moving pins to separate or remove the cinders of the coating adhering to the substrate and recover the substrate from which the coating has been removed. An apparatus for recovering aluminum from an aluminum product, comprising: 8. The crushing means comprises: a crushing means for crushing an aluminum product to be treated; and a fine crushing means for further crushing the aluminum product crushed by the crushing means into small pieces to be processed. The apparatus for recovering aluminum from an aluminum product according to claim 6 or 7, comprising: 9. The apparatus for recovering aluminum from an aluminum product according to claim 8, wherein the roasting means roasts a small piece of the aluminum product formed by the crushing means. 10. The aluminum product according to claim 6, further comprising pressing means for pressing the base material of the small pieces collected by said separation / collection means into a lump. Equipment for collecting aluminum.