JPH07197141A - Apparatus for refining aluminum scrap - Google Patents

Abstract

PURPOSE:To provide an apparatus capable of efficiently refining aluminum alloy scrap. CONSTITUTION:In this refining apparatus of the aluminum alloy scrap applying a fractional crystallizing method, a molten metal holding vessel 1 is constituted of a cylindrical fixed side wall part 2 and a bottom plate part 3, and a passage 4 for discharging the remained molten metal after producing the primary crystal grains is provided at the upper part of the vessel 1. The bottom plate part 3 is formed to be movable in the fixed side wall part 2 and at the lower part thereof, and a removing device 9 for removing the discended primary crystal grain pressed body on the bottom plate part 3 is provided at a prescribe position below the fixed side wall part 2. The remained molten metal can be discharged from the passage 4 by ascending the bottom plate part 3, and the primary crystal grain pressed body can be removed by the removing device 9 by descending the bottom plate part 3, thus the discharge of the remained molten metal and the recovery of the primary crystal grain pressed body are efficiently executed.

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 refining aluminum alloy scrap.

[0002]

2. Description of the Related Art The development of efficient refining technology for aluminum scrap containing elements such as Fe and Si is the most important issue for effective use of resources and reduction of raw material costs. For example, for a tube through which the refrigerant of an aluminum radiator for automobiles passes,
The core material of l-1wt% Mn alloy is Al-3wt% Si alloy (JIS-40
43 etc.) is used as a clad composite material, and a large amount of slitter scraps, etc., of rolled material are generated during the manufacturing process. Most of such aluminum scrap is reused as low grade metal for casting. If this composite material can be turned into a raw material for wrought material, the raw material cost can be significantly reduced, which leads to effective use of resources.

As a method for refining aluminum scrap, there is a crystal fractionation method. This method was previously proposed by the inventors of the present invention (Japanese Patent Application No. 5-202361), and its gist is to hold a molten aluminum scrap in a container and to keep the solidus line below the liquidus line of this molten metal. Within the above temperature range, almost all of this melt is 20 ℃ /
Cooling at a rate of min. or less, to produce purified primary crystal particles, press the primary crystal particles to the lower part of the container by lowering the pressure stamp from above the container, and press this primary crystal particle pressing body. This is a method of separating and recovering from the remaining molten metal. The primary crystal particles have a dendritic shape, and in order to squeeze the high-concentration liquid phase metal trapped between the primary branches from the primary crystal particle pressing body, the primary crystal particles are pressed under a high pressure of 2 to 15 MPa.

[0004]

By the way, in order to separate the primary crystal particle pressing body from the remaining molten metal, the remaining molten metal is solidified on the primary crystal particle pressing body, and the boundary portion is cut with a saw. . However, in this method, the remaining molten metal solidifies, and it takes a long time for the temperature to drop before the saw can be cut, and therefore the equipment availability and productivity were low. Therefore, a method has been proposed in which the container is tilted to discharge the remaining molten metal (JP-A-
62-158830), tilting was troublesome and there was a problem in safety.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been earnestly studied in such a situation, and an object thereof is to provide an apparatus for efficiently refining aluminum alloy scrap. That is, the present invention is to produce primary crystal particles by gradually cooling an aluminum scrap molten metal held in a molten metal holding container within a temperature range below the liquidus line and above the solidus line of the molten metal to produce primary crystal particles. Equipment, primary crystal particle pressing equipment that presses the primary crystal particles generated in the molten metal against the bottom of the container with high pressure, the remaining molten metal above the primary crystal particle pressing body is discharged from the container, and the primary crystal particle pressing body is the container In the apparatus for purifying aluminum scrap, which comprises a primary crystal particle recovery device for recovering from primary particles, the container is composed of a cylindrical fixed side wall part and a bottom plate part, and the residual molten metal after the primary crystal particle generation is discharged to the upper part of the fixed side wall part. A passage is provided, the bottom plate portion is movably arranged in and below the fixed side wall portion, and the primary crystal particle pressing body on the lowered bottom plate portion is removed to a predetermined position below the fixed side wall portion. It is characterized by having a removal machine Is shall.

In the present invention, the molten metal holding container is composed of the fixed side wall portion and the bottom plate portion, the discharge passage is provided at the upper portion of the fixed side wall portion, and the bottom plate portion is formed so as to be movable up and down. And the remaining molten metal is discharged from the upper side wall portion, and after the remaining molten metal is discharged, the bottom plate portion is lowered to a predetermined position below the side wall portion and the primary crystal particle pressing body is placed on the bottom plate portion.
This is because it can be easily removed without being disturbed by the side wall. The discharge passage may be provided by forming a hole in the fixed side wall or by cutting a groove on the upper surface of the fixed side wall. Workability is improved by disposing a gutter at the tip of the discharge passage to guide the remaining molten metal to the storage tank. A plurality of discharge passages may be provided.

The position for removing the primary crystal grain pressing body on the bottom plate portion is arbitrary as long as the fixed side wall portion does not interfere with the removal. A hydraulic cylinder or an air cylinder is suitable for the remover for removing the primary crystal grain pressing body from the bottom plate portion. It is advantageous for automation to use hydraulic pressure or pneumatic pressure to drive the bottom plate and the remover as described above. The primary crystal particle pressing body on the bottom plate is placed in a receiving box below the bottom plate and dropped there. Further, if a conveyor is arranged beside the removing machine and the primary crystal grain pressing body is collected at a position away from the container, a working space in the vicinity of the removing machine will have room. It is convenient to place the roller type conveyor with a downward slope.

In the present invention, the primary crystal grain producing device is a cooling jacket used by being closely placed on the outer periphery of the molten metal holding container, an internal water flow type cooling element immersed in the molten metal, and the like. When allowing the melt to cool slowly, install a heater in the container.
In the heater, an electromagnetic induction heater has a stirring action of the molten metal,
It is preferable because the temperature and concentration distribution of the molten metal can be made uniform. For stirring, a propeller-type stirrer used by immersing in a molten metal is also applied. As the molten metal holding container, a container that can withstand a high pressing force such as a castable refractory lining in a heat-resistant steel shell is used. Among them, those having excellent releasability such as graphite are preferable. The cross-sectional shape of the molten metal holding container is arbitrary, such as circular or rectangular.

In the present invention, the cooling rate of the molten metal is 20 ° C.
/ min. or less is preferable because the obtained primary crystal particles have high purity.
If the pressing force of the primary crystal particles is less than 2 MPa, the high-concentration liquid phase metal trapped in the primary crystal particles cannot be sufficiently squeezed out.
Even if it exceeds Pa, the squeezing out of the high-concentration liquid phase metal is saturated.
Therefore, 2 to 15 MPa is suitable.

[0010]

In the present invention, the molten metal holding container is composed of a cylindrical fixed side wall part and a bottom plate part, the bottom plate part is movably arranged in the fixed side wall part and below the fixed side wall part, and the primary crystal grains are provided above the container. Since a passage for discharging the remaining molten metal after generation is provided, the remaining molten metal after pressing the primary crystal particles can be safely discharged from the discharging passage by raising the bottom plate portion. it can. Further, at a predetermined position below the fixed side wall portion, a removing machine for removing the lowered primary crystal particle pressing body on the bottom plate is provided, so that the collection of the primary crystal particles lowers the bottom plate portion and drives the removing machine. This can be done easily.

[0011]

EXAMPLES The present invention will be described in detail below with reference to examples. Embodiment 1 FIG. 1 is a side view showing an embodiment of the device of the present invention. A molten metal holding container 1 is composed of a fixed side wall portion 2 and a bottom plate portion 3. A passage 4 is provided on the upper surface of the fixed side wall portion 2 for discharging the remaining molten metal after the primary crystal grains are generated. A tubular gutter 5 is arranged at the tip of the discharge passage 4, and a remaining molten metal storage tank 6 is arranged at the tip thereof. Further, an electromagnetic induction heater 7 is provided on the outer periphery of the fixed side wall portion 2. A pressure stamp 8 is arranged above the molten metal holding container 1. A primary crystal grain pressing body removing machine 9 is installed at a predetermined position below the fixed side wall portion 2. A roller type conveyor is provided at the height of the removing machine 9.
10 is arranged in a descending gradient, and the primary crystal grain recovery box 11 is arranged ahead of it. The pressure stamp 8 and the bottom plate portion 3 are driven by a hydraulic stamp 16, respectively.

A method for purifying a raw material molten metal using the apparatus of the present invention will be specifically described below with reference to FIGS. 2A to 2D and FIGS. 3A and 3B. The molten metal 12 of aluminum scrap heated to a predetermined temperature above the liquidus temperature is held in the molten metal holding container 1 (FIG. 2A). The molten metal 12 is gradually cooled by weakening the output of the electromagnetic induction heater 7 on the outer periphery, and primary crystal grains 13 are generated. The electromagnetic induction heater 7 also serves to stir, so that the solute distribution and the melt temperature are made uniform (FIG. 2B). Next, the primary crystal particles 13 in the molten metal are pressed against the bottom plate portion 3 of the container 1 by the pressure stamp 8 (FIG. 2C). Next, the bottom plate 3 is raised to discharge the residual molten metal 14 from the discharge passage 4 above the fixed side wall 2 through the tubular trough 5 to the residual molten metal storage tank 6 (FIG. 2D). Next, the bottom plate 3 on which the primary crystal grain pressing body 15 is placed is held down by the pressure stamp 8 and lowered to the position of the remover 9 (FIG. 3A). The primary crystal particle pressing body 15 is extruded from the bottom plate portion 3 onto the conveyor 10, and the primary crystal particle pressing body 15 is placed on the conveyor 10 and collected in the primary crystal particle recovery box 11 (FIG. 3B).

Using the above apparatus, Al-3 wt% Si-1 wt% M
After refining 10 tons of aluminum scrap of n alloy,
4 tons of a purified product having a composition of 1-0.9 wt% Si-0.9 wt% Mn was obtained. The processing time was halved compared to the saw cutting method. The workability was good and there was no problem in terms of safety. This refined product was used by blending it with the raw material of the wrought material, and a product of the same quality as when using only the virgin raw material was obtained.

Although the case of refining aluminum scrap containing Si and Mn has been described above, the same effect can be obtained even if the apparatus of the present invention is applied to the refining of aluminum scrap containing other alloy elements.

[0015]

As described above, according to the apparatus of the present invention, the aluminum scrap can be efficiently refined, and the industrially remarkable effect is exhibited.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the device of the present invention.

FIG. 2 is a process explanatory view of a method for purifying aluminum scrap using the device of the present invention.

FIG. 3 is a process explanatory diagram of a method for purifying aluminum scrap using the device of the present invention.

[Explanation of symbols]

 1 Molten Metal Container 2 Fixed Side Wall 3 Bottom Plate 4 Discharge Path 5 Cylindrical Gutter 6 Remaining Molten Metal Storage Tank 7 Electromagnetic Induction Heater 8 Pressurized Stamp 9 Remover for Pressing Primary Crystal Particles 10 Roller Conveyor 11 Recovery of Primary Crystal Particles Box 12 Molten metal 13 Primary crystal particles 14 Remaining molten metal 15 Primary crystal particle pressing body 16 Hydraulic cylinder

(72) Inventor Toshihito Komata 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Koichi Ohara 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Industry Co., Ltd.

Claims (1)

[Claims] 1. A primary crystal grain producing device for producing primary crystal grains by gradually cooling an aluminum scrap molten metal held in a molten metal holding container within a temperature range below the liquidus line and above the solidus line of the molten metal. The primary crystal particle pressing device that presses the primary crystal particles generated in the molten metal to the container bottom with high pressure, the residual molten metal above the primary crystal particle pressing body is discharged from the container, and the primary crystal particle pressing body is discharged from the container. In an aluminum scrap refining device comprising a primary crystal particle recovery device for recovery, the container is composed of a cylindrical fixed side wall portion and a bottom plate portion, and the residual molten metal after the primary crystal particle generation is discharged to the upper portion of the fixed side wall portion. A passage is provided, the bottom plate portion is movably arranged in and below the fixed side wall portion, and the primary crystal grain pressing body on the lowered bottom plate portion is removed at a predetermined position below the fixed side wall portion. Machine is provided Aluminum scrap refining equipment.