JP2662178B2 - Aluminum scrap refining equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for efficiently purifying aluminum scrap, particularly aluminum brazing sheet.

[0002]

2. Description of the Related Art Development of an efficient technology for refining aluminum scrap containing elements such as Fe and Si is the most important issue for effective utilization of resources and reduction of raw material costs. For example, a tube through which the refrigerant of an aluminum radiator for automobiles passes
Al-3 wt% Mn alloy (JIS-3003 etc.) core material is Al-3
A composite material clad with a skin material of a wt% Si alloy (such as JIS-4043) is used, and in the manufacturing process, a large amount of slitter dust and the like of rolled material is generated. Most of such aluminum scrap is reused as a low-grade ingot for casting. If this composite material can be turned into a raw material for wrought material, the cost of the raw material can be significantly reduced, which in turn leads to effective utilization of resources.

[0003] As a method of purifying aluminum scrap, there is a crystal fractionation method. This method has been previously proposed by the present inventors (Japanese Patent Application No. 5-202361), and the gist of the method is to hold a molten aluminum scrap in a container and to use a solidus line below the liquidus line of the molten metal. Within the above temperature range, almost the entire area of this molten
cooling at a speed of min. or less, to generate purified primary crystal particles, press down the pressure stamp from above the container to press the primary crystal particles to the lower portion of the container, and press the primary crystal particle pressing body. This is a method of separating and collecting the remaining molten metal. The primary crystal particles have a dendritic shape, and the primary crystal particles are pressed by applying a high pressure of 2 to 15 MPa in order to squeeze the high-concentration liquid phase metal trapped between the tree branches from the primary crystal particle pressing body.

[0004]

When a large amount of aluminum scrap is treated by the above-mentioned refining method, it takes a lot of time to generate primary crystal particles, discharge the remaining molten metal, and collect primary crystal particles. In addition, in this method, a series of operations such as generation and pressing of primary crystal particles, subsequent discharge of the remaining molten metal, and recovery of primary crystal particles are performed by operating each of the instruments so that the molten metal holding container is placed in one place. The rate and productivity were low.

[0005]

SUMMARY OF THE INVENTION The present invention has been intensively studied in such a situation, and an object of the present invention is to provide an apparatus for efficiently purifying aluminum scrap. In other words, the invention of claim 1 is to reduce the aluminum scrap molten metal held in the molten metal holding container to a temperature below the liquidus line of the molten metal.
A primary crystal pressing device that presses the primary crystal particles in the molten metal held and generated within a temperature range equal to or higher than the solidus line to the bottom of the molten metal holding container with a high pressure, and the remaining molten metal above the primary crystal particle pressing body. In the aluminum scrap refining apparatus, comprising: a molten metal discharging device for discharging the molten metal from the container; and a primary crystal particle collecting device for recovering the primary crystal particle pressing body from the container. A crystal particle collecting device is sequentially installed at a predetermined interval, and a gap between the primary crystal particle collecting device and the primary crystal particle pressing device for preheating the molten metal holding vessel at a stage before the molten metal is supplied. A furnace is arranged, and the appliances are sequentially arranged at predetermined positions on a conveyor for transferring the containers.

In the present invention, in order to generate primary crystal particles in the aluminum scrap molten metal held in the molten metal holding container, the molten metal is naturally cooled, and the cooling rate is reduced by using a primary crystal particle generating device. It can also be controlled artificially. A second aspect of the present invention is an apparatus for the latter case, which is configured to cool the aluminum scrap molten metal held in the molten metal holding vessel at a predetermined speed within a temperature range below the liquidus line and above the solidus line of the molten metal. A primary crystal particle generating device for generating primary crystal particles, a primary crystal particle pressing device for pressing the primary crystal particles generated in the molten metal to the bottom of the molten metal holding container at a high pressure, and the remaining molten metal above the primary crystal particle pressing body. Remaining molten metal discharge device to be discharged from the container,
In an aluminum scrap refining apparatus comprising a primary crystal particle recovery device for recovering a primary crystal particle pressing body from a container, the primary crystal particle generation device, the primary crystal particle pressing device, the remaining molten metal discharge device, and the primary crystal particle recovery device are sequentially arranged. It is installed at a predetermined interval, and between the primary crystal particle collection device and the primary crystal particle generation device, at a stage before the molten metal is supplied, a running furnace for preheating the molten metal holding vessel is arranged. , Each of the devices is sequentially arranged at a predetermined position on a conveyor for transferring the containers.

[0007] Examples of the primary crystal particle generating device include a cooling jacket that is used in close contact with the outer periphery of a molten metal holding container, and an internal water-cooling type cooler that is immersed in the molten metal. When cooling the molten metal sufficiently, a heater is provided in the container. As the heater, an electromagnetic induction heater is preferable because it has a function of stirring the molten metal and can make the temperature and concentration distribution of the molten metal uniform. For the stirring, a propeller type stirrer immersed in a molten metal is also used. As the molten metal holding container, a material capable of withstanding a high pressing force, such as a material in which a castable refractory is lined with a heat-resistant steel shell is applied. Among them, those excellent in releasability such as graphite are particularly preferable. The cross-sectional shape of the molten metal holding container is arbitrary, such as circular or square. A transfer body for transferring the molten metal holding container is a roller type conveyor, a cart, or the like.

In the first and second aspects of the present invention, the cooling rate of the molten metal is preferably 20 ° C./min. Or less. The pressing force of the primary crystal particles is 2M.
If it is less than Pa, the high-concentration liquid metal trapped in the primary crystal particles cannot be sufficiently squeezed out, and if it exceeds 15 MPa, the squeezing of the high-concentration liquid metal will be saturated. Therefore, 2 to 15 MPa is appropriate.

[0009]

According to the first aspect of the present invention, the primary crystal particle pressing device, the remaining molten metal discharging device, and the primary crystal particle collecting device are sequentially installed at predetermined intervals, and the primary crystal particle collecting device and the primary crystal particle pressing device are disposed between the primary crystal pressing device and the primary crystal pressing device. In a stage before the molten metal is supplied, a running furnace for preheating the molten metal holding container is arranged, and the respective appliances are sequentially arranged at predetermined positions on a conveyor for transferring the container. Therefore, by preparing a plurality of molten metal holding containers, placing them on a transfer body and transferring between the respective devices, it is possible to perform a plurality of processes at the same time, so that the device operation rate and productivity are improved. improves. According to the second aspect of the present invention, a primary crystal particle generating device is added to the apparatus according to the first aspect of the present invention so that the cooling rate of the aluminum scrap melt can be artificially controlled, so that the primary crystal particles can be highly purified. Becomes

[0010]

The present invention will be described below in detail with reference to examples. Embodiment 1 FIGS. 1 to 5 are side views or plan views, respectively, showing an embodiment of each device and a moving body constituting the apparatus of the present invention. 1A and 1B are a side view and a plan view, respectively, of a primary crystal particle generation device. The primary crystal particle producing device 1 is a cooling jacket of an internal water flow type, and is provided in close contact with the outer periphery of the molten metal holding container 2. The molten metal holding container 2 has a shell 3 made of heat-resistant steel having a circular cross section and a release material (graphite) 4 lined. FIG. 2 is a side view of the primary crystal particle pressing device. The primary crystal particle pressing device 5
It comprises a pressure stamp 6 immersed in the molten metal and a hydraulic cylinder 7 for transmitting a pressing force to the stamp. The replacement pressure stamp 23 is transported in parallel on the rail 24. FIG.
(A) and (b) are side views of the remaining molten metal discharging device. The remaining molten metal discharge device 8 includes a hydraulic crane 9 for tilting the molten metal holding container 2 and a residual molten metal storage tank (not shown) (FIG. 3A). The hook 10 of the hydraulic crane 9 is hung on the handle 11 at the lower part of the outer periphery of the molten metal holding container 2 and pulled up (FIG. 3B). FIG.
(A) and (b) are side views of the primary crystal particle collection device. The primary crystal particle collecting device 12 is composed of a pair of axially rotatable supports 13 sandwiching the molten metal holding container 2 from both sides (FIG. 4A). The support 13 is rotated about its axis to drop the primary crystal pressing body 5 (FIG. 4B). FIG. 5 is a plan view of the transfer body. The transfer body 14 is an annular roller type conveyor.

FIGS. 6A to 6C are explanatory views of the state from the formation of primary crystal grains to the discharge of the remaining molten metal. The primary crystal particles 15 are generated by the primary crystal particle generation device 1 (FIG. 6A), and the primary crystal particles 15 are pressed by the press stamp 6 of the primary crystal particle pressing device (FIG. 6B), and the remaining molten metal discharge device. Then, the remaining molten metal 16 is discharged (FIG. 6C).

Hereinafter, the apparatus of the present invention will be specifically described with reference to the drawings. FIG. 7 is a plan view showing an embodiment of the apparatus of the present invention constituted by the respective instruments and transfer bodies shown in FIGS. A primary crystal particle generating device 1, a primary crystal pressing device 5, a residual molten metal discharging device 8, and a primary crystal particle collecting device 12 are sequentially installed at predetermined positions of a transfer body 14 of an annular roller type conveyor, and primary crystal particles are respectively provided. A formation zone, a primary crystal particle pressing zone, a residual molten metal discharge zone, and a primary crystal particle recovery zone are formed.

Next, an embodiment of continuously refining a molten aluminum alloy using the above-mentioned apparatus will be described with reference to FIG. Seven molten metal holding containers (hereinafter abbreviated as containers) 31 to 37 are arranged on a transfer body 14 of an annular roller type conveyor.
The containers 31 and 32 are preheated in the running furnace 17.
The molten metal 18 is supplied from the melting furnace 19 through the gutter 20 to the container 33 that has been preheated in the running furnace 17. The molten metal 18 is heated to a temperature higher than the liquidus line. Next, there is a primary crystal particle generation zone. In this case, the container 34 holding the molten metal, the primary crystal particle generation device 1 of the cooling jacket is closely mounted on the outer periphery thereof,
Slow cooling is performed within the temperature range below the liquidus line and above the solidus line, and primary crystal particles are generated in the molten metal. In the next primary crystal particle pressing zone, the primary crystal particles of the molten metal in the container 35 in which the primary crystal particles have been generated are pressed against the bottom of the container 35 by the pressure stamp. A plurality of heating stamps 6 are used, and are preheated in the running furnace 27. In the next remaining molten metal discharge zone, the container where the primary crystal particles were pressed
As shown in FIG. 3, the hook 36 of the hydraulic crane 9 is hung on the handle 11 and tilted, and the remaining molten metal inside is discharged to the remaining molten metal storage tank 21. In the last primary crystal recovery zone, a container 37 from which the remaining molten metal has been discharged is sandwiched between a pair of supports 13 as shown in FIG. Collected at 22. The container 37 in which the primary crystal particles have been recovered enters the traveling furnace 17 and is preheated.
The processing time is the same for the five processes except for preheating, and when the process is completed, the conveyor rollers are automatically rotated, and each of the containers 31 to 37 undergoes the next process.

According to this apparatus, all the processing tools can be operated at all times. Productivity also increases with the number of containers used. Both processes are easy to operate, and can be easily automated, including the transfer of containers.

Using the above apparatus, Al-3wt% Si-1wt%
10 tons of Mn alloy brazing sheet scrap was purified. A series of operations was automated, and the same two-person operation as before was performed. The purified product with the composition of Al-0.9wt% Si-0.9wt% Mn is 5
T got. The processing time has been reduced to almost 1/4 of the conventional one. This refined product was blended with the raw material of the wrought material and used, but a product of the same quality as when only the virgin raw material was used was obtained.

Although the case where aluminum scrap containing Si and Mn is purified has been described above, the same effect can be obtained by applying the apparatus of the present invention to the purification of aluminum scrap containing another alloy element. In addition, although the slow cooling of the aluminum scrap melt was performed using a primary crystal particle generation device (cooling jacket), it may be performed by natural cooling.

[0017]

As described above, according to the apparatus of the present invention, aluminum scrap, particularly scrap of aluminum brazing sheet, can be efficiently purified, and a large amount of scrap can be processed, which has a remarkable industrial effect.

[Brief description of the drawings]

FIG. 1 is a side view and a plan view showing an embodiment of a primary crystal particle producing device constituting the present invention.

FIG. 2 is a side view showing an embodiment of a primary crystal particle pressing device constituting the present invention.

FIG. 3 is a side view showing an embodiment of a residual molten metal discharging device constituting the present invention.

FIG. 4 is a side view showing an embodiment of a primary crystal particle collecting device constituting the present invention.

FIG. 5 is a plan view showing an embodiment of a transfer body constituting the present invention.

FIG. 6 is an explanatory diagram of the situation from generation of primary crystal particles to discharge of the remaining molten metal in the present invention.

FIG. 7 is a plan view showing an embodiment of the device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Primary crystal particle generator 2 Melt holding container 3 Heat resistant steel shell 4 Mold release material 5 Primary crystal particle pressing body 6 Press stamp 7 Hydraulic cylinder 8 Remaining molten metal discharge device 9 Hydraulic crane 10 Hydraulic crane hook 11 Handle for molten metal holding container 12 Primary crystal particle collection equipment 13 Support rod 14 Transfer body 15 Primary crystal particles 16 Remaining molten metal 17,27 Running furnace 18 Molten metal 19 Melting furnace 20 Gutter 21 Remaining molten metal storage tank 22 Primary crystal particle collection box 23 Press stamp for replacement 24 Rail 31-37 Molten holding container

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Koichi Ohara 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Examiner, Furukawa Electric Co., Ltd. Kenichi Morooka

Claims (2)

(57) [Claims] 1. The primary crystal particles in the aluminum scrap produced by holding the aluminum scrap molten metal held in the molten metal holding vessel in a temperature range below the liquidus line and above the solidus line of the molten metal, A primary crystal pressing device for pressing the bottom of the molten metal container with high pressure, a residual molten metal discharging device for discharging the remaining molten metal above the primary crystal particle pressing body from the container, and a primary crystal for recovering the primary crystal pressing body from the container. In the apparatus for purifying aluminum scrap comprising a particle recovery device, the primary crystal particle pressing device, the remaining molten metal discharge device, and the primary crystal particle recovery device are sequentially installed at predetermined intervals, and the primary crystal particle recovery device and the primary crystal particle pressing device are installed. With instruments
In the meantime, before the molten metal is supplied,
A running furnace for heating is arranged, and each of the above appliances is
Are sequentially disposed at predetermined positions on a conveyor for transferring said containers . 2. Primary crystal particles for producing primary crystal particles by cooling an aluminum scrap molten metal held in a molten metal holding container at a predetermined speed in a temperature range below the liquidus line and above the solidus line of the molten metal. A generating device, a primary crystal particle pressing device for pressing the primary crystal particles generated in the molten metal to the bottom of the molten metal holding container at a high pressure, a residual molten metal discharging device for discharging the remaining molten metal above the primary crystal particle pressing body from the container, In an aluminum scrap refining apparatus comprising a primary crystal particle recovery device for recovering a primary crystal particle pressing body from a container, the primary crystal particle generation device, the primary crystal particle pressing device, the remaining molten metal discharge device, and the primary crystal particle recovery device are sequentially arranged. Installed at predetermined intervals, primary crystal particle collection equipment and primary crystal particle generation
Before the molten metal is supplied to the equipment, the molten metal is held
A running furnace for preheating the vessel is arranged,
Equipment is located at a predetermined position on the conveyor for transferring the containers.
An aluminum scrap refining device, which is sequentially arranged in a unit.