JPH07207362A - Device for refining molten al or al alloy - Google Patents

Abstract

PURPOSE:To improve a separating efficiency with suppressing the turbulent component in the vertical direction of horizontal rotating flow by making a container accommodating Al or Al alloy truncated cone shape. CONSTITUTION:A truncated cone-shaped part 2 is protruded in the bottom center of a container 1 accommodating Al or Al alloy. A cooling body 7 is immersed in the container 1. A revolving magnetic field generating device 11 is placed near the outer circumferential wall of the container 1. By impressing an induction current to molten Al in the container 1, the molten Al is horizontally revolved by the electromagnetic force due to the interaction with the revolving magnetic field. When the molten Al is horizontally revolved, at the bottom face of the container 1 and on the surface of the cooling body 7, the liquid phase Al, which contains much of the concentrated impurities existing in the dentrite grown along with progress of solidification, is diffused in remote part from solidification progressing face. A concentration of the impurities of a remaining liquid phase is uniformized and high purity Al is crystallized to the cooling body 7. The remaining liquid phase Al containing much impurities is discharged from a flow out route 4 placed on the top part of the truncated core-shaped part 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for refining molten Al or Al alloy containing impurities to recover high-purity Al or Al alloy with reduced inclusions using the principle of the segregation method. It relates to the device.

[0002]

2. Description of the Related Art Conventionally, a high-purity Al is separated and purified from molten Al containing impurities by using the principle of the segregation method, that is, in the solidification of molten metal, a high-purity portion is solidified first. Various methods have been proposed (see Japanese Patent Publication No. 49-5806). However, this type of segregation method generally has a problem that productivity cannot be increased because the solidification rate cannot be increased, and that the separation efficiency of the high-purity solidified body and the residual liquid phase Al containing a large amount of impurities is poor. There were two problems that it was difficult to obtain pure Al.

As a method for increasing the above-mentioned solidification rate,
It is considered effective to sufficiently stir Al in the residual liquid phase having a high impurity concentration by some means to make the impurity concentration inside the liquid phase uniform quickly. As the stirring means, for example, as shown in Japanese Patent Publication No. 62-11049, there is a method of applying a rotating magnetic field from the outside, and such a method facilitates maintenance and management of equipment as compared with a method using a rotating stirrer. The advantage is that However, although the distribution of the stirring flow velocity due to the rotating magnetic field becomes faster toward the outer periphery of the container, it becomes slower at the center of the container, and the effect of stirring is reduced, and the solidification speed cannot be increased to improve the productivity. There was a problem. In addition, this horizontal rotary stirring flow causes vertical turbulence, and this turbulence is
Although it is useful for making the impurity concentration in the residual liquid phase Al uniform, on the other hand, it not only makes the solidification progress non-uniform, but also makes the stirring flow velocity on the solidification progress surface non-uniform. As a result, it is difficult to purify a solidified body having a uniform impurity concentration.

Further, as a method for efficiently separating a high-purity coagulum and a residual liquid phase containing a large amount of impurities, JP-A-5-148559
As shown in No. 9, the rotating magnetic field generator is
A method is known in which the container is tiltable by setting an angle of 0 ° to 180 °. However, in this separation method, since the rotating efficiency of the molten Al due to the rotating magnetic field is poor, not only a higher output rotating magnetic field generator is required, but also the moving mechanism of the rotating magnetic field generator and the container are tilted. Therefore, there is a problem that a hydraulic mechanism or the like is required, resulting in an increase in equipment cost.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and it is a high-purity Al with low cost, high productivity, excellent separation efficiency, and reduced inclusions.
Another object of the present invention is to provide a refining apparatus for molten Al or molten Al alloy that can obtain an Al alloy.

[0006]

According to the present invention of claim 1,
1 or a container containing the molten Al alloy is placed in a rotating magnetic field, and the segregation method is applied to the molten metal in the container under temperature control by a temperature control mechanism while applying a horizontal rotating flow to the molten Al or Al alloy in the container. In the apparatus for solidifying and refining Al or Al alloy by utilizing it, the apparatus is a refining apparatus for molten Al or Al alloy in which the shape of the container is a truncated cone shape capable of suppressing the vertical turbulent component of the horizontal rotary flow.

According to the second aspect of the present invention, a container containing Al or molten Al alloy is placed in a rotating magnetic field, and Al in the container is placed.
Alternatively, in a device for solidifying and refining Al or Al alloy by utilizing the segregation method under the temperature control by a temperature control mechanism for the molten metal in the container while applying a horizontal rotating flow to the molten aluminum alloy, The apparatus for refining molten Al or molten Al alloy is provided with a protrusion for discharging the molten metal.

A third aspect of the present invention is an apparatus for refining an Al or Al alloy molten metal, which uses the configuration of the first aspect and the configuration of the second aspect together. According to a fourth aspect of the present invention, in the purifying apparatus of the third aspect, an outflow passage having an on-off valve is connected to the outer peripheral side portion of the container bottom and the top of the protrusion.

According to a fifth aspect of the present invention, in the refining apparatus of the third aspect, the temperature control mechanism is arranged at least on the outer side of the bottom of the container and on the inner side of the top of the protrusion. According to a sixth aspect of the present invention, the refining apparatus according to any one of the first to fifth aspects is immersed in the molten metal to form A on the surface thereof.
It is characterized by further comprising a cooling body device constituted by a cooling body for solidifying 1 and a surface temperature control mechanism for arbitrarily peeling the solidified body from the surface of the cooling body.

[0010]

According to the first aspect of the present invention, the frustoconical container suppresses the vertical turbulence component of the horizontal rotary flow to rectify the rotary flow and increase the peripheral velocity of the rotary flow, thereby increasing the dendritic shape. The stirring effect of impurities concentrated between the crystals is enhanced. According to the second aspect, the progress of solidification in the low-speed region of the horizontal rotational flow is rejected by the projecting portion projecting from the center inside the container bottom.

According to claim 3, the rotating flow is rectified, and the progress of solidification in the vicinity of the center of rotation, which is a low speed region of the horizontal rotating flow, is rejected. According to claim 4, high-purity molten Al or Al alloy with reduced inclusions is taken out from the outflow passage provided on the outer peripheral side of the container bottom, and impurities are extracted from the outflow passage provided at the top of the protrusion. Residual liquid phase containing Al
Is taken out.

According to claim 5, the Al solidification rate from the bottom of the container and the advancing surface are made uniform. According to claim 6, the high-purity Al solidified body crystallized on the surface of the cooling body can be arbitrarily peeled off.

[0013]

The present invention will be described in detail below with reference to the drawings. FIG. 1 is a schematic vertical cross-sectional view showing an embodiment of an apparatus for separating and refining molten aluminum or aluminum alloy. In the figure, 1 is a holding container for storing the raw material molten Al (hereinafter simply referred to as container 1
2) is a truncated cone-shaped portion as a projecting portion protruding from the center of the bottom surface of the container 1, 3 is a discharge passage for high-purity molten Al for taking out remelted high-purity molten Al, 4 Is a discharge passage for residual liquid phase Al containing a large amount of impurities, 5a is a temperature control mechanism provided outside the bottom of the container 1, and 5b is provided inside the top of the truncated cone 2. Temperature control mechanism, 6 is a temperature control mechanism provided on the outer peripheral wall of the container 1, 7 is immersed in molten Al, and high purity A
Cooling body for crystallizing l, 8 is a cooling body surface temperature control mechanism for controlling the cooling body surface temperature, 9 and 10 are opening / closing valves provided in the discharge passage of molten Al, 11 is continuous or discontinuous A rotating magnetic field generator provided annularly around the container 1 for applying a rotating force to the molten Al in the container 1, 12 is a high-purity Al solidified body solidified in the container 1 in the initial stage of refining, and 13 and 14 are cooling bodies. 7 solidified body crystallized on the surface and its separated solidified body, 15 is a high-purity solidified body at the end of purification in the container 1, 1
6 is a residual liquid phase Al containing a large amount of impurities. The temperature control mechanism includes a heater, a circuit for energizing the heater, a control circuit for controlling energization, and the like. In addition, the cooling body 7
And the cooling body surface temperature control mechanism can be regarded as a cooling body device.

The structure of each part of the refining apparatus of this embodiment will be described more concretely by taking the case of separating and refining Al as an example. First, the separately dissolved raw material Al is supplied and held in the container 1 in a molten state. The container 1 includes temperature control mechanisms 5a and 6 on the outside of the bottom of the container and the outer peripheral wall of the container, respectively.
And is controlled so that the solidification rate from the bottom surface of the container 1 and the advancing surface become uniform. The temperature control mechanism 6 arranged on the outer peripheral wall of the container 1 may have a temperature distribution in the height direction of the container 1 if necessary. That is,
The heater may be energized so as to be gradually turned off from the bottom side to the top side of the container 1. In addition, the temperature control mechanism 5b arranged inside the top of the truncated cone 2 is
In order to prevent solidification from the top of the truncated cone portion 2, the purpose is to keep heat and heat.

The cooling body 7 is rotatably immersed in the container 1 as required, and the surface temperature control mechanism 8 thereof causes Al crystallization and solidification on the surface of the cooling body 7. It is configured so that the body can be peeled off in a predetermined time. The separated high-purity solidified body settles due to the difference in specific gravity from the liquid phase, and adheres to the solidification progressing surface at the bottom of the container 1. That is, in the present embodiment, the temperature control mechanisms 5a and 6 arranged on the bottom and the outer peripheral wall of the container as the solidification means and the cooling body 7 are used in combination, whereby the total solidification from the bottom of the container 1 is performed. It has become possible to increase speed and improve productivity.

The rotating magnetic field generator 11 is arranged near the outer peripheral wall of the container 1 as described above, and the molten Al in the container 1 is melted.
An inductive current is applied to and the molten Al is horizontally rotated by the electromagnetic force due to the interaction with the rotating magnetic field. By horizontally rotating the molten Al in this manner, the liquid Al containing a large amount of concentrated impurities existing between the dendrites that grow with the progress of solidification on the bottom surface of the container 1 and the surface of the cooling body 7 can be obtained. As a result, it becomes possible to sufficiently diffuse away from the surface where solidification proceeds, to make the impurity concentration of the residual liquid phase uniform, and to crystallize high-purity Al. In this case, if the container 1 has a columnar shape as conventionally used, vertical turbulence components are generated in the horizontal rotating flow of molten Al, so that the solidification progress from the bottom surface of the container 1 is made uniform. Cannot be obtained, and as a result, a flat coagulation progressing surface cannot be obtained, and as a result, the flow velocity distribution on the coagulation progressing surface becomes non-uniform. Therefore, if the container 1 is shaped like a truncated cone as in the present embodiment, the turbulent flow components in the vertical direction are suppressed, the progress of solidification is made uniform, and the smoothness of the solidification progress surface can be maintained, thereby improving the solidification rate. Further, it becomes possible to realize high purification of the solidified body.

Suppressing the above-mentioned turbulent components also accelerates the sedimentation speed of the solidified and separated solidified body on the surface of the cooling body 7 as described above, prevents remelting during floating, and makes sticking to the bottom uniform. Act as you do. As a result, it is possible to increase the overall solidification rate from the bottom of the container 1, and as a result, it is possible to improve productivity.

Further, in the conventional cylindrical container, since the horizontal rotating flow due to the rotating magnetic field has a low flow velocity near the center of rotation, the diffusion speed of the concentrated impure liquid phase Al near the center of rotation is slow, and the solidification rate is Could not be speeded up. Therefore, if the truncated cone-shaped portion 2 is provided on the inner bottom portion of the container 1 as in the present embodiment, the solidification at the rotation center can be rejected and the outer peripheral side of the truncated cone-shaped portion 2 where a relatively uniform stirring flow velocity can be obtained. Since the coagulation is performed only from the bottom surface of the container 1, the coagulation rate can be increased.

The outflow passage 4 provided at the top of the truncated cone portion 2 is for the residual liquid phase Al containing a large amount of impurities. That is, in the final stage of purification, the solidification progressing surface of the solidified body 15 becomes concave as a result of temperature control by the temperature control mechanisms 5b and 6 provided on the top of the truncated cone 2 and the outer peripheral wall of the container 1, respectively. It is formed. Here, by opening the on-off valve 10, the residual liquid phase Al is discharged to the outside of the container 1 and treated as impure scrap.

Similarly, the outflow passage 3 is for discharging high-purity Al, and after the residual liquid phase Al containing a large amount of impurities is discharged, the solidified body 1 is discharged.
5 is reheated in the container 1 to be in a molten state, the valve 9 is opened, the material is discharged from the outflow passage 3 and cast to obtain high purity metal. According to this method, there is no need for a hydraulic mechanism for tilting the container, a moving mechanism for a rotating magnetic field generator, etc., unlike the conventional device, and the residual liquid phase containing a large amount of impurities and high purity can be easily and inexpensively obtained. It is possible to separate and obtain the solidified body of.

Example 1 An experiment was carried out to verify the effect of the above truncated cone-shaped container in the apparatus shown in FIG. 99.
A 99% pure Al ingot is separately melted and held at 700 ° C. in a melting furnace and adjusted so that Fe and Si are 0.1 wt% in total. 11 AC current of 5Hz, 200A is applied to the container 1
The molten Al in a was rotated. The solidification is uniformly performed from the bottom of the container 1a by using the temperature control mechanisms 5c and 6 arranged on the outer bottom surface and the outer peripheral wall of the container 1a, and the supplied raw material A is added.
l The molten Al was kept rotating until all solidified. Then, after completion of solidification and precipitation, the solidified body is taken out of the container 1a, and 2
The bottom side solidified body, which is a solidified body of high-purity Al, was remelted by cutting in the horizontal direction at equal positions, and separated and obtained as purified Al for analysis. The processing time until the solidification and precipitation is completed is 2 to 12 hours, the shape of the container 1a is such that the bottom surface has a constant diameter, and the angle a between the container side surface and the container bottom surface is 90 °, 80.
Purification tests were conducted by changing the angle from 60 ° to 60 °. The analysis results of the obtained purified Al are collectively shown in FIG. In FIG. 3, the horizontal axis represents the processing time until the solidification is completed,
The vertical axis represents the total concentration of Fe and Si as the impurity concentration.

As is clear from FIG. 3, as compared with the case where the container 1a has a cylindrical shape and a = 90 °, a
It can be seen that, in the truncated cone-shaped container inclined at 80 ° and 60 °, higher purity purified Al can be obtained in a shorter solidification time. Further, as compared with a = 60 °, a = 80 ° provides purified Al of higher purity, and an optimum value exists for the angle a formed between the side surface and the bottom surface in the truncated cone container. I understand. The preferable range of the angle a is 70 ° ≦ a ≦ 85 °, and when the angle a is smaller than 70 °, the distance between the rotating magnetic field generator 11 and the container 1a becomes too large, and the electromagnetic force does not sufficiently act. Instead, the flow velocity will decrease. Further, when the angle a becomes larger than 85 °, the influence of the turbulent flow in the vertical direction becomes remarkable.

If the rotating magnetic field generator 11 is tilted so as to correspond to the gradient of the container 1a, the distance between the rotating magnetic field generator 11 and the container 1a will not be separated, and it can be set to 70 ° or less. is there. However, molten Al
Considering that workability such as maintenance is not impaired as a container for storing the above, the preferable range of the angle a in such a configuration is 55 ° ≦ a ≦ 85 °.

[Embodiment 2] An experiment demonstrating the effect of providing the truncated cone-shaped portion 2 on the bottom surface of the container 1b in the apparatus shown in FIG. 4 and the effect of combining the truncated cone-shaped portion 2 and the truncated cone-shaped container 1b. Was similarly performed. Here, the case where there is a truncated cone part 2 at the bottom inside the container 1b and the case where it is not provided are carried out. As the container shape, the angle a between the side surface and the bottom surface is a = 80 °, and the other conditions are those of the first embodiment. And exactly the same. As the dimensions of the truncated cone portion 2, the diameter of the bottom portion of the truncated cone portion 2 is set to 1/2 of the bottom diameter of the container 1b, and the height is set to 1/2 the height of the container. The angle b between the side surface and the bottom surface was the same as the angle a between the side surface and the bottom surface of the container 1b. The analysis result is also shown in FIG. As described above, in the case of having the truncated cone-shaped portion 2 and the case of not having the truncated cone-shaped portion 2, the purified Al having a higher purity can be obtained in a shorter solidification time in the case of having the truncated cone-shaped portion 2, and thus the present invention is effective. The sex was confirmed. In addition, in the present embodiment, the shape of the protruding portion is configured to be a truncated cone shape that opens downward, but the present invention is not limited to this, and it may be configured to be a truncated cone shape that opens upward, and is also cylindrical. Any structure may be used, and any structure can be used as long as it can reject the low speed region of the horizontal rotary flow. Further, the protruding portion may be integrated with the container or may be a separate body.

[Embodiment 3] An experiment was carried out to verify the effect of providing the molten Al outflow passage, the temperature control mechanism, and the cooling body in the apparatus shown in FIG. Here, the shape of the container 1 and the shape of the truncated cone portion 2 are the same as those in the above-described Embodiment 2, and the molten Al outflow passages 3 and 4 equipped with valves that can be opened and closed at any time are located near the outer peripheral side of the bottom portion of the container 1. And the truncated cone-shaped portion 2 projecting from the bottom surface to the top. The progress of solidification proceeds uniformly from the bottom surface of the container 1 by the temperature control by the temperature control mechanisms 5a and 6 provided on the outer side of the bottom of the container 1 and the outer peripheral wall thereof, and the surface temperature control of the cooling body 7 immersed in the container 1 is performed. The mechanism 8 solidifies the molten Al and separates the solidified body, and deposits the separated solidified body on the bottom of the container 1.

As in the first and second embodiments, Fe,
About 1 t of raw material Al containing 0.1% by weight of Si in total was charged into the container 1, and the rotating magnetic field generator 11 was set to 5 Hz, 200
The alternating current of A was applied and the molten Al was rotated to solidify and precipitate. The solidification precipitation amount is up to 50% by weight, and at this time, the temperature control mechanism 5b at the top of the truncated cone portion 2 works to prevent the progress of solidification at the top, so that the solidified body 15 has a concave shape. Maintained. After the solidification precipitation amount reached 50% by weight, the on-off valve 10 was opened, and the residual liquid phase Al containing a large amount of impurities was discharged from the outflow passage 4. On the other hand, the solidified material that solidified and precipitated was re-melted in the container 1, the on-off valve 9 was opened, and the solidified material was discharged from the outflow passage 3, thereby separated and obtained as purified Al, and analyzed.

FIG. 6 shows the ratio of the solidification by the cooling body 7 and the solidification by the temperature control mechanisms 5a and 6 in the obtained solidified body as a contribution rate. For example, a contribution ratio of 10: 0 is solidification only by the cooling body 7 (the temperature of the bottom surface and the side wall of the container 1 is maintained at the primary crystal precipitation temperature or higher, solidification does not proceed from the bottom surface, and the solidification from the surface of the cooling body 7 is performed. (When only the body is deposited), the contribution ratio 6: 4 represents the case where the solidification by the cooling body 7 is 6 and the solidification by the temperature control mechanisms 5a and 6 is 4, and the contribution ratio 0:10 is the temperature control. Solidification by only the mechanisms 5a and 6 (only the progress of solidification from the bottom surface of the container 1 is performed) is shown.

The contribution rate of the cooling body 7 to the progress of solidification is 0 to
FIG. 6 shows the results obtained by changing the time to 10 and changing the time until the completion of 50% by weight solidification precipitation to 1 to 6 hours. As shown in the figure, by setting the contribution ratio to 2: 8, higher-purity purified Al was obtained in a shorter solidification treatment time, confirming the effectiveness of the present invention. Although the present invention has been described with reference to the case of refining high-purity Al in the above-mentioned embodiment, the present invention can be applied to the case of reducing inclusions from an Al alloy.

[0029]

As described above, according to the refining apparatus for molten Al or Al alloy of the present invention, the productivity is low, the productivity is high, and the inclusion efficiency is high. It is possible to industrially separate and obtain pure Al or Al alloy.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional view of a refining device for molten Al or Al alloy according to an embodiment of the present invention.

FIG. 2 is a schematic vertical sectional view of a molten Al separating and refining apparatus according to a first embodiment.

FIG. 3 is a characteristic diagram showing the effect of separating and refining molten Al using the apparatus of FIG.

FIG. 4 is a schematic vertical sectional view of a molten Al separating and refining device according to a second embodiment.

5 is a characteristic diagram showing the effect of separating and refining molten Al using the apparatus of FIG.

FIG. 6 is a characteristic diagram showing the effect of separating and refining molten Al using the apparatus of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Raw material molten Al holding container 2 Cone trapezoidal part 3 High-purity molten Al discharge path 4 Residual liquid phase Al discharge path 5a Temperature control mechanism at the bottom of the container 5b Temperature control mechanism at the top of the truncated cone part 6 Container outer peripheral wall Temperature control mechanism 7 Cooling body 8 Cooling body surface temperature control mechanism 9,10 Opening / closing valve 11 Rotating magnetic field generator 12 High-purity Al solidified body solidified in the initial stage of refining 13 Solidified body 14 deposited on the surface of the cooling body 14 Exfoliated solidified body 15 High-purity solidified body at the end of refining 16 Residual liquid phase Al containing many impurities

Claims (6)

[Claims] 1. A container containing an Al or Al alloy molten metal is placed in a rotating magnetic field, and a temperature control mechanism is applied to the molten metal in the container while applying a horizontal rotating flow to the Al or Al alloy molten metal in the container. In an apparatus for solidifying and refining Al or Al alloy using a segregation method under temperature control, the shape of the container is a truncated cone shape capable of suppressing a vertical turbulent component of the horizontal rotary flow. Equipment for refining molten Al or molten Al alloy. 2. A container containing an Al or Al alloy melt is placed in a rotating magnetic field, and a temperature control mechanism is applied to the molten metal in the container while a horizontal rotating flow is applied to the Al or Al alloy melt in the container. An apparatus for solidifying and refining Al or Al alloy by utilizing a segregation method under temperature control, characterized in that a protrusion for discharging the molten metal is provided at a rotation center portion of the container. Refining equipment. 3. A container containing an Al or Al alloy molten metal is placed in a rotating magnetic field, and a temperature control mechanism is applied to the molten metal in the container while applying a horizontal rotating flow to the Al or Al alloy molten metal in the container. In an apparatus for solidifying and refining Al or Al alloy by utilizing a segregation method under temperature control, the shape of the container is a truncated cone shape capable of suppressing a vertical turbulent component of the horizontal rotating flow, and the container is rotated. A refining apparatus for molten Al or Al alloy, characterized in that a protrusion for discharging the molten metal is provided in a central portion. 4. The refining device according to claim 3, wherein an outflow passage having an on-off valve is connected to a portion of the container bottom portion on the outer peripheral side and a top portion of the protruding portion. 5. The refining device according to claim 3, wherein the temperature control mechanism is arranged at least outside the bottom of the container and inside the top of the protrusion. 6. The surface of the molten metal immersed in the molten metal
The refining device according to any one of claims 1 to 5, further comprising a cooling body device configured by a cooling body for solidifying the cooling body and a surface temperature control mechanism for arbitrarily separating the solidification body from a surface of the cooling body.