JPH09176755A - Device for recovering aluminum for paint coated aluminum product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove nonmetallic inclusion in a pigment contained in a paint on a coated aluminum product. SOLUTION: A recovery device is provided with a heating chamber 1 for heating molten aluminum, a melting chamber 3 for melting the paint coated aluminum product with the heat having the molten metal fed from the heating chamber 1 after charging the paint coated aluminum product to be treated and a treating gas blowing and floated slag removing chamber 4 for removing the floated slag on the molten metal surface after floating up the non-metallic inclusion in the pigment contained in the paint on the molten metal surface together with treating gas by blowing the treating gas into the molten metal fed out from the melting chamber 3. A pump 5 feeding the molten aluminum in the heating chamber 1 to the melting chamber 3 and the treating gas blowing and floated slag removing chamber 4 in order, and further, returning the molten metal after removing the floated slag back to the heating chamber 1, is provided. In the melting chamber 3, a stirring device for 9 developing eddy of the molten aluminum is arranged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention removes non-metallic inclusions in a pigment contained in a paint from a paint-coated aluminum product such as a commercially available aluminum can (hereinafter referred to as UBC) to remove aluminum. It relates to a device for collecting.

[0002] In this specification, the term "aluminum" shall include aluminum alloys in addition to pure aluminum.

[0003]

2. Description of the Related Art Conventionally, the recovery treatment of aluminum from UBC has been carried out by steam-baking UBC using a rotary kiln or the like, burning the organic matter in the paint, and then melting it.

[0004]

However, in the conventional recovery method, non-metallic inclusions as pigments contained in the paint of UBC, for example, oxides of Ti, Fe, Si, Cr and the like are removed. However, there is a problem in that the recovered aluminum obtained is contaminated with Ti, Fe, Si, Cr, etc., and cannot be made to have a required concentration. Therefore, the recovered aluminum can be used only as a raw material for die-casting and casting aluminum alloys, and as a deoxidizing agent for steelmaking. For example, aluminum alloys for wrought materials such as blanks for forming aluminum cans. It could not be used as a raw material.

Further, in order to remove the non-metallic inclusions as pigments contained in the UBC paint, a large-scale facility is required, and there is a problem that the facility cost becomes high.

An object of the present invention is to provide an apparatus for recovering aluminum from a paint-coated aluminum product which solves the above problems.

[0007]

According to the present invention, there is provided an apparatus for recovering aluminum from a paint-coated aluminum product, wherein a paint-covered aluminum product which has been previously steamed to burn organic substances in the paint is used to remove the pigment contained in the paint. Is a device for removing non-metallic inclusions and recovering aluminum, the heating chamber for heating the molten aluminum and the heat of the molten aluminum sent from the heating chamber into which the paint-coated aluminum product to be treated is charged. A melting chamber for melting paint-coated aluminum products, a means for generating a swirl of the molten aluminum in the melting chamber, and a pigment contained in the molten aluminum that has been blown with a processing gas into the molten aluminum sent from the melting chamber. The non-metallic inclusions in the process gas are floated on the surface of the molten metal together with the process gas to form a slag. The melting chamber, the debris removal chamber that removes the debris floating on the surface of the molten metal, and the aluminum melt in the heating chamber are sequentially sent to the melting chamber, the process gas blowing chamber, and the debris removal chamber to further remove the debris. And means for returning the molten metal to the heating chamber.

According to the aluminum recovery apparatus from the paint-coated aluminum product of the present invention, the aluminum product introduced into the melting chamber is prevented from floating on the surface of the molten metal due to the vortex generated by the vortex generating means. As a result, it is quickly melted by the molten metal sent from the heating chamber. Moreover, since the aluminum product is melted by the heat of the molten aluminum, the entire aluminum product is prevented from being oxidized. In addition, if aluminum products are directly melted by flames etc., they all become oxides and become ash. Further, non-metallic inclusions as pigments, such as oxides of Ti, Fe, Si, Cr, etc., contained in the molten aluminum fed from the melting chamber are blown into the molten aluminum in the processing gas blowing chamber. The bubbles of the treated gas are carried to the surface of the molten metal and float on the surface of the molten metal. Then, it is removed in the debris removal chamber.

In the above apparatus, a processing gas supply port is formed in the bottom wall of the processing gas blowing chamber, a porous body is fitted in the processing gas supply port, and the processing gas passes through the porous body to form fine particles. In some cases, bubbles are blown into the molten metal, and the process gas blowing chamber also serves as a debris removing chamber. In this case, since the processing gas blowing chamber also serves as the debris removal chamber,
The entire device can be downsized.

Further, in the above apparatus, a vertical rotation shaft having a processing gas passage extending in the lengthwise direction therein is provided in the processing gas blowing chamber, and the lower end of the vertical rotation shaft is fixedly provided and connected to the processing gas passage. A bubble discharger having a processing gas blowout port, a bubble discharger composed of a rotating body for dispersion, and a dispersing device are arranged, and a debris removal chamber is provided separately from the processing gas blow-in chamber through a partition wall to blow the process gas. In some cases, the processing gas is blown into the chamber and the molten metal having non-metallic inclusions on its surface flows into the debris removal chamber over the partition wall. In this case, the processing gas is
As compared with the case of blowing through a porous body, it is possible to promote the miniaturization and dispersion of the processing gas bubbles in the aluminum melt, so that the removal efficiency of non-metallic inclusions is improved.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
This will be described with reference to the drawings. The following embodiment is an application of the device of the present invention to the recovery of aluminum from UBC.

Embodiment 1 This embodiment is shown in FIGS. 1 and 2.

In FIGS. 1 and 2, an apparatus for recovering aluminum from UBC comprises a heating chamber (1) for heating molten aluminum, a pump chamber (2) having a pump (5), and a pre-steamed composition for coating the paint. UBC is charged by the heat of the aluminum melt that has been fed with UBC in which organic matter has been burned and to be treated and sent from the heating chamber (1) through the pump chamber (5).
The melting chamber (3) for melting BC and the non-metallic inclusions in the pigment contained in the aluminum melt together with the processing gas by blowing the processing gas into the aluminum melt sent from the melting chamber (3) The chamber is provided with a processing gas blowing and debris removal chamber (4) that floats on the surface and removes the debris that floats on the surface of the molten metal. Pump (5) is heating chamber (1)
The molten aluminum from which the non-metallic inclusions have been removed is sent to the pump chamber (2), the melting chamber (3) and the process gas blowing and debris removal chamber (4) in sequence, and the heating chamber (1) To return to. The heating chamber (1), the pump chamber (2), the melting chamber (3), and the process gas blowing / debris removal chamber (4) are provided by partitioning one chamber with partition walls.

The heating chamber (1) is provided with a plurality of, for example, two burners (6) for heating the molten aluminum. After the aluminum melt is melted in another melting furnace (not shown),
It is fed into the heating chamber (1). As this aluminum molten metal, a molten aluminum of 99.70 wt% purity,
The recovered molten aluminum is used.

A partition between the heating chamber (1) and the pump chamber (2)
A communication port (8) is formed at the lower end of (7),
(1) The molten aluminum heated to the specified temperature in
It flows into the pump chamber (2) through this communication port (8). The molten aluminum that has flowed into the pump chamber (2) is fed into the melting chamber (3) by the pump (5) over the partition (12) between the pump chamber (2) and the melting chamber (3).

A stirring device (9) for generating a vortex in the melting chamber (3)
Is arranged. The stirrer (9) has a vertical rotary shaft (10)
And a stirring blade (11) fixedly provided at the lower end of the vertical rotation shaft (10). In the dissolution chamber (3), a vortex flow generation pump may be arranged instead of the stirring device (9).

Melting chamber (3) and processing gas injection and debris removal chamber
A communication port (18) is formed at the lower end of the partition wall (17) between (4) and the molten aluminum containing the melted UBC, and the processing gas is blown through this communication port (18). It also flows into the debris removal chamber (4) chamber. Processing gas injection and debris removal chamber (4)
A processing gas supply port (14) is formed on the bottom wall of the porous body made of a material having heat resistance such as ceramics and not contaminating the molten aluminum at the processing gas supply port (14). (15) is stopped. Then, the processing gas is blown from the processing gas supply port (14) through the porous body (15) into the molten metal in the processing gas blowing / removing chamber (4) in the form of fine bubbles. As the processing gas, an inert gas of the periodic table such as Ar, a gas inert to aluminum such as N ₂ ,
Alternatively, these gases mixed with Cl ₂ are used. It is preferable to use a mixture of Cl ₂ and Ar ₂ or N ₂ gas, rather than using Ar gas or N ₂ gas alone. The proportion of Cl ₂ in this mixed gas is preferably about 10 to 30 vol%. The non-metallic inclusions in the pigment contained in the molten aluminum are floated together with the processing gas bubbles to form a float (16), and this float (16) uses a Dereck-type float remover (not shown). It is scraped out mechanically or manually.

Treatment gas blowing and debris removal chamber (4) and heating chamber
A communication port (13) is formed in the lower end of the partition wall (19) between (1) and (1), and the slag (16) is introduced in the process gas injection and slag removal chamber (4).
The removed aluminum melt flows into the heating chamber (1) through the communication port (13).

In such a structure, UBC is a melting chamber.
It is injected from above into the center of the vortex in (3). The vortex flow prevents the UBC from floating above the surface of the molten metal,
It is rapidly dissolved by the molten metal sent from (1) through the pump chamber (2). At this time, since the molten aluminum is applied from above the UBC, the UBC is also efficiently melted by this. The molten aluminum containing the dissolved UBC flows into the processing gas blowing / debris removal chamber (4) through the communication port (18). The processing gas is blown from the processing gas supply port (14) through the porous body (15) into the molten aluminum in the chamber (4) in the form of bubbles, and non-metallic inclusions in the pigment contained in the molten aluminum. Is floated on the surface of the molten metal together with the processing gas and becomes a slag (16). Then, the slag removing device removes the slag (16), thereby removing the non-metallic inclusions. The aluminum melt from which non-metallic inclusions have been removed passes through the communication port (13) and is heated in the heating chamber.
Returned to (1). Then, when the recovery process of the predetermined amount of UBC is completed, all the molten aluminum in the tank is taken out to form a regenerated mass.

Embodiment 2 This embodiment is shown in FIGS. 3 and 4.

3 and 4, an apparatus for recovering aluminum from UBC has a heating chamber (20) for heating molten aluminum, a pump chamber (21) having a pump (22), and a coating chamber for preliminarily steam-baking paint. UBC is added by the heat of the molten aluminum which is charged with UBC in which organic matter has been burned and which is sent from the heating chamber (20) through the pump chamber (21).
The melting chamber (23) for melting BC and the molten aluminum in the melting chamber (23) are fed and a processing gas is blown into the molten aluminum to remove non-metallic inclusions in the pigment contained in the molten aluminum. A processing gas blowing chamber (24) for floating the molten metal on the surface of the molten metal and a debris removing chamber (25) for removing the floating debris floating on the surface of the molten metal are provided. pump
(22) is the molten aluminum of the heating chamber (20) pump chamber (2
1), the melting chamber (23), the processing gas blowing chamber (24), and the slag removing chamber (25) in order, and the molten metal from which non-metallic inclusions have been removed is returned to the heating chamber (20). Is. The heating chamber (20), the pump chamber (21), the melting chamber (23), the processing gas blowing chamber (24) and the debris removal chamber (25) are provided by partitioning one tank with a partition wall. .

The heating chamber (20) is provided with a plurality of, for example, two burners (26) for heating the molten aluminum. After the aluminum melt is melted in another melting furnace (not shown),
It is fed into the heating chamber (20). As this aluminum molten metal, a molten aluminum of 99.70 wt% purity,
The recovered molten aluminum is used.

A partition (2) between the heating chamber (20) and the pump chamber (21)
A communication port (28) is formed at the lower end of 7), and the heating chamber (20)
The molten aluminum which is heated to a predetermined temperature therein flows into the pump chamber (21) through the communication port (28). pump room
The molten aluminum which has flowed into the (21) is sent to the melting chamber (23) by the pump (22) over the partition (29) between the pump chamber (21) and the melting chamber (23).

A stirring device (30) for generating a vortex in the melting chamber (23)
Is arranged. The agitator (30) has a vertical rotation shaft (31).
And a stirring blade (32) fixedly provided at the lower end of the vertical rotation shaft (31). A vortex flow generation pump may be arranged in the dissolution chamber (23) instead of the stirring device (30).

A communication port (34) is formed at the lower end of the partition wall (33) between the melting chamber (23) and the processing gas blowing chamber (24), and the molten aluminum containing the melted UBC is The gas flows into the processing gas blowing chamber (24) through the communication port (34). In the processing gas blowing chamber (24), a vertical rotation shaft (36) having a processing gas passage (not shown) extending in the lengthwise direction is fixedly provided at the lower end of the vertical rotation shaft (36). In addition, a bubble discharger having a process gas outlet (not shown) connected to the process gas passage, a bubble discharge consisting of a dispersion rotor (37), and a dispersion device (3
5) is arranged. Then, the processing gas becomes
It is discharged in the form of fine bubbles into the molten metal from the processing gas outlet of the rotating body (37) through the processing gas passage of (6), and the processing gas bubbles are rotated by the rotation of the rotating body (37) ( 24) Dispersed throughout. As the processing gas, the same gas as in the first embodiment is used. However, C is used as an inert gas of the periodic table such as Ar and a gas inert to aluminum such as N ₂
If those mixed with l ₂ is used, it is preferable that the ratio of the Cl ₂ in the mixed gas is about 3~10vol%. The non-metallic inclusions in the pigment contained in the molten aluminum are floated together with the processing gas bubbles to form a slag (38).

A notch (40) is formed at the upper end of the partition wall (39) between the processing gas blowing chamber (24) and the debris removal chamber (25) down to the surface of the molten aluminum. The process gas is blown into the process gas injection chamber (24) and the molten metal in which the slag (38) containing non-metallic inclusions is present on the surface is the notch (40).
It flows through the slag removal chamber (25).
In the debris removal chamber (25), the debris (38) is mechanically or manually scraped by using a Derek type debris remover (not shown). A communication port (42) is formed at the lower end of the partition wall (41) between the debris removal chamber (25) and the heating chamber (20).
The molten aluminum from which the slag (38) has been removed flows into the heating chamber (20) through 2).

In such a structure, UBC is a melting chamber.
It is injected from above into the center of the vortex in (23). The vortex flow prevents the UBC from floating above the surface of the molten metal,
It is rapidly melted by the molten aluminum sent from (20) through the pump chamber (21). At this time, since the molten aluminum is applied from above the UBC,
This also effectively dissolves UBC. The molten aluminum containing the dissolved UBC flows into the processing gas blowing chamber (24) through the communication port (34). The processing gas is bubbled into the molten aluminum in the chamber (24) through the processing gas outlet of the rotating body (37) of the dispersion device (35) into the molten aluminum in the chamber (24), and the pigment contained in the molten aluminum is discharged. The non-metallic inclusions of (3) are floated on the surface of the molten metal together with the processing gas to form a slag (38). Then, the molten metal having the slag (38) on the surface flows into the slag removing chamber (25) through the notch (40) of the partition wall (39), and the slag removing device is placed in this chamber (25). Removes the debris (38), which removes non-metallic inclusions. The molten aluminum having the non-metallic inclusions removed is returned to the heating chamber (20) through the communication port (42). And a certain amount of UBC
When the recovery process of is completed, the molten aluminum in the tank
All are taken out and a regenerated mass is formed.

In the above two embodiments, the device of the present invention is shown applied to the recovery of aluminum from UBC, but the device of the present invention is used to recover aluminum from other paint-coated aluminum products. It can also be applied to collection.

[0029]

EXAMPLES Specific examples will be described below together with comparative examples.

Example 1 This example was performed using the apparatus of the first embodiment.

450 kg of molten aluminum having a purity of 99.70 wt% was placed in the heating chamber (1), and JI was placed in the melting chamber (3).
680 kg of UBC, which consists of a can body made of S A3004 alloy and a lid made of JIS A5183 alloy, and which has been steam-baked to burn off the organic matter in the paint, is introduced and a processing gas blowing and debris removal chamber (4) 25 l / min of Cl _{2 (} 20 vol%) and the balance Ar were blown into the flask at a rate of 25 liters / minute and the slag (16) was removed. The impurity concentration in the reclaimed aluminum melt obtained in this way was measured.
0.02 wt%, Fe 0.52 wt%, Si 0.25 wt%,
Cr was 0.02 wt%.

Example 2 This example was performed using the apparatus of the second embodiment.

450 kg of molten aluminum having a purity of 99.70 wt% was placed in the heating chamber (20), and JI was placed in the melting chamber (23).
750 kg of UBC, which consists of a can body made of S A3004 alloy and a lid made of JIS A5183 alloy, and which has been steam-baked to burn the organic substances in the paint, is introduced into the processing gas blowing chamber (24) with Cl ₂ 7 vol. 25 liters / minute of a processing gas containing 10% of the balance Ar was blown, and the slag was removed in the slag removal chamber (25). Impurity concentrations in the reclaimed aluminum melt thus obtained were measured and found to be Ti 0.02 wt%, Fe 0.53 wt%, Si 0.2
It was 4 wt% and Cr was 0.02 wt%.

Comparative Example 700 kg of UBC composed of a can main body made of JIS A3004 alloy and a lid made of JIS A5183 alloy and steam-baked to burn the organic matter in the paint was used.
It was melted with 450 kg of 9.70 wt% aluminum melt. The impurity concentration in the reclaimed aluminum melt thus obtained was measured and found to be 0.05 wt% Ti, 0.5 Fe
The content was 8 wt%, Si 0.32 wt% and Cr 0.04 wt%.

[0035]

According to the apparatus of the first aspect of the present invention, as described above, the non-metal inclusions made of the metal oxide contained as the pigment in the paint are efficiently removed.
Therefore, the recycled aluminum that has been subjected to the recycling process,
For example, it can be used as a raw material of an aluminum alloy for a wrought material such as a blank for forming an aluminum can.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a plan view showing a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

[Explanation of symbols]

 (1) (20) Heating chamber (3) (23) Melting chamber (4) Processing gas blowing and debris removal chamber (5) (22) Pump (9) (30) Stirrer for generating vortex flow (24) Processing Gas injection chamber (25) Debris removal chamber

Claims (3)

[Claims] 1. An apparatus for recovering aluminum by removing non-metallic inclusions in a pigment contained in a paint from a paint-coated aluminum product which has been previously steam-baked to burn organic substances in the paint. A heating chamber for heating the molten metal, a melting chamber for charging the paint-coated aluminum product to be treated and melting the paint-coated aluminum product by the heat of the molten aluminum sent from the heating chamber, and a swirling flow of the molten aluminum in the melting chamber. And a process gas is blown into the molten aluminum sent from the melting chamber to cause non-metallic inclusions in the pigment contained in the molten aluminum to float along with the processing gas on the surface of the molten metal. The process gas blowing chamber, the debris removal chamber that removes the debris floating on the surface of the molten metal, and the aluminum melt in the heating chamber Solution chamber,
An apparatus for recovering aluminum from a paint-coated aluminum product, comprising means for sequentially feeding a treated gas blowing chamber and a slag removing chamber and returning the molten metal from which the slag has been removed to a heating chamber. 2. A processing gas supply port is formed in the bottom wall of the processing gas blowing chamber, and a porous body is fitted into the processing gas supply port, and the processing gas passes through the porous body to form fine bubbles. An apparatus for recovering aluminum from a paint-coated aluminum product according to claim 1, wherein the aluminum is blown into the molten metal in the shape of a pipe, and the processing gas blowing chamber also serves as a float removing chamber. 3. A processing gas blowing chamber has a vertical rotation shaft internally having a processing gas passage extending in the lengthwise direction, and a processing gas blower fixedly provided at the lower end of the vertical rotation shaft and connected to the processing gas passage. A bubble discharger having an outlet, a bubble discharger composed of a dispersion rotor, and a dispersion device are arranged, and a debris removal chamber is provided separately from the processing gas blowing chamber through a partition, and the processing gas is blown in the processing gas blowing chamber. 2. The paint-coated aluminum product according to claim 1, wherein the molten metal in which the slag containing the non-metallic inclusions is blown into the surface and flows into the slag removing chamber over the partition wall. Aluminum recovery equipment.