JPS63162824A - Purifying method for metal - Google Patents

Abstract

PURPOSE:To prevent rippling and splashing on a liquid surface and to reduce the amount of the sludge generated, by changing the temp. of the outer peripheral surface of a purified metal crystallizing part of a revolving cooling body so as to be lower and lower from the upper end to the downward part. CONSTITUTION:A specified amount of molten Al 4 containing eutectic impurities is sent into a crucible 1, and the revolving cooling body 2 is submerged in the molten Al 4 so as to locate the liquid surface in the middle part of the height of a cylindrical part of the revolving cooling body 2, which consists of the cylindrical metal noncrystallizing part 7 with a insulating material 6 on its inner peripheral surface and a purified metal crystallizing part 8 tapering down. And the revolving cooling body 2 is revolved while a cooling liquid is supplied to the inner part of the revolving body 2 to firstly allow smooth initial crystals Al of high purity to crystallize on the crystallizing part 8, then, the atmosphere above the molten metal surface is heated so that the temp. of the outer peripheral part of the crystallizing part 8 is higher at the upper end and is lower and lower toward the lower part. As a result, an Al nodule I is formed in a tapered shape expanding downward so that it generates the downward stream in the direction A, and the furious rippling on the molten metal surface is prevented, and the sludge consisting of Al2O3 produced by the reaction between Al and O2 in the air is reduced.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is used in an apparatus for producing metals of higher purity by refining various metals containing eutectic impurities such as aluminum, silicon, magnesium, lead, and zinc. The present invention relates to a rotary cooling body.

Prior Art and its Problems For example, a method is known in which aluminum to be purified, which contains impurities that form eutectic with aluminum, is purified to a higher purity by utilizing the principle of segregation solidification. and,
As shown in FIG. 5, the apparatus used to carry out such a method includes a crucible (1) for holding molten aluminum (4), and a crucible (1) for holding molten aluminum (4). ), and the rotary cooling body (20) has a tapered shape that gradually becomes thinner downward from the upper end. After melting the aluminum, the molten aluminum (4) is placed in the crucible (1) and kept heated to a temperature that exceeds its solidification temperature, and then cooled into the heated molten aluminum (4). By immersing the cooling body (20), maintaining the surface temperature of the cooling body (20) below the solidification temperature, and rotating the cooling body (20) to disperse and mix the impurities discharged near the solidification interface. , the thickness of the impurity-concentrated layer near the solidification interface in the liquid phase is reduced, and as a result, while increasing the temperature gradient in the liquid phase at the impurity-concentrated layer, purity is increased by the circumferential surface of the cooling body (20). Aluminum is refined by crystallizing aluminum with high aluminum content.

In the above, in order to reduce the thickness of the impurity concentrated layer near the solidification interface in the liquid phase and increase the temperature gradient as a result to improve purification efficiency, the cooling body (20) and the molten aluminum (4 ) is one of the conditions.

However, as the cooling body (20) rotates, the molten aluminum (4) also flows in the same direction as the rotational direction of the cooling body, creating a vortex, so there is a limit to the increase in the relative speed, and the improvement in refining efficiency is limited. There are also limits. Moreover, the cooling body (20
), the centrifugal force increases and the cooling body (2
There is a problem in that the crystallized high-purity aluminum becomes difficult to adhere to the peripheral surface of 0), resulting in a decrease in productivity.

Therefore, in order to solve this problem, a device was devised in which a plurality of baffles (3) for reducing the flow rate of molten aluminum are provided on the inner peripheral surface of the crucible (1) at predetermined intervals in the circumferential direction. (Refer to Utility Model Publication No. 61-38912). Although this apparatus can further improve purification efficiency, the following problems arise. That is, when the baffle plate (3) is present, the flow velocity is partially different, and as a result, the flow rate of the molten aluminum (4) along the circumferential surface of the cooling body (20) as shown by the arrow (C) in FIG. An upward flow is generated, the liquid surface is violently rippled, air is drawn into the molten aluminum (4), and this air and aluminum react to produce a large amount of slag consisting of Al2O3. Therefore, a slag removal operation is required, and the ring scatters and adheres to the inner surface of the crucible (1), causing a hindrance to the operation. Furthermore, a large amount of slag is generated, which may reduce purification efficiency.

An object of the present invention is to provide a metal refining method that solves the above problems.

Means for Solving the Problems The metal refining method according to the present invention involves placing molten metal in a crucible, immersing a rotary cooling body in the molten metal, and rotating the rotary cooling body to improve the purity of the surrounding surface. When crystallizing refined metal, as a rotating cooling body, the upper part of the part below the surface of the molten metal serves as a metal amorphous part, and the lower part serves as a refined metal crystallization part. Use a device whose outlet part is in the shape of a downwardly expanding or cylindrical shape with the same diameter from the upper end to the lower end, and the temperature of at least the upper outer circumferential surface of the refined metal crystallizing part is the highest at the upper end and directed downward. By making the metal crystallization rate lower, the rate of metal crystallization into the refined metal crystallization area is slowest at the upper end and becomes faster toward the bottom. It is characterized in that it has a downwardly expanding shape that is larger than the metal amorphous portion.

In the above, the downwardly expanding shape of the metal amorphous part has a tapered shape that gradually becomes thicker downward from the upper end, and two or more cylindrical parts with different thicknesses are arranged from the top in order from the smallest to the next. This includes a shape in which the cylindrical part gradually becomes thicker downwards, connected through a connecting part, and a shape in which the connected part becomes a curved part that spreads outward toward the bottom.Also, metal In the amorphous part, the upper inner or outer peripheral surface of the part below the molten metal surface of the rotary cooling body is covered with a heat-resistant heat insulating material, or the entire upper part of the part below the molten metal surface is covered with a heat-resistant insulating material. The heat insulating material may be made of a heat insulating material that has a heat insulating property, or by increasing the thickness of the upper portion of the peripheral wall of the cooling body that is below the surface of the molten metal so that this portion has heat insulating properties.

In addition, in the above, as a method for making the temperature of at least the upper outer circumferential surface of the refined metal crystallization part of the rotary cooling body highest at the upper end and decreasing downward, the upper end opening of the crucible can be opened and closed. A method of heating the atmosphere above the liquid level of molten metal in a crucible by closing it with a lid, a method of heating a portion of the molten metal above the liquid level of a rotating cooling body, and a method of supplying the metal into a rotating cooling body. A method of decreasing the amount of cooling fluid at the upper end and increasing it toward the bottom;
There are also methods that combine these methods.

Example Examples of the present invention will be described below.

The following example applies the method of this invention to the production of high-purity aluminum. Note that the same parts and parts are denoted by the same reference numerals throughout the drawings.

FIG. 1 shows a first specific example of the apparatus used to carry out the invention.

In Fig. 1, the high-purity aluminum manufacturing apparatus includes a graphite melt holding crucible (1), a rotary cooling body (2) that can move up and down, and crucibles (1) spaced apart at predetermined intervals in the circumferential direction.
It consists of a plurality of baffle plates (3) for reducing the flow rate of molten aluminum that are detachably fixed to the inner peripheral surface of the molten aluminum flow rate. The upper end opening of the crucible (1) is closed with a lid (path shown) that can be opened and closed. Further, the amount of molten aluminum (4) put into the crucible (1) is set to be approximately constant. The rotary cooling body (2) is a hollow body made of graphite, ceramics, etc., and has a cylindrical shape with the same diameter as a whole up to a predetermined length, and gradually tapers downward from the lower end. ing. Then, the inner peripheral surface of the cylindrical part is covered with a heat insulating material (
8). The rotary cooling body (2) is attached to the lower end of the hollow rotating shaft (5), and cooling fluid is supplied to the inside thereof from a cooling fluid supply pipe (path shown) disposed within the hollow rotating shaft (5). It has become so. The rotary cooling body (2) also includes a predetermined amount of molten aluminum (
4) The liquid level of molten aluminum (4) is immersed in the middle part of the height of the cylindrical part, and the part of the cylindrical part below the liquid level is a high-purity aluminum amorphous part. (7), and the tapered part below it is a high-purity aluminum crystallization part (8) (refined metal crystallization part).

In such a configuration, molten aluminum (4) to be purified containing eutectic impurities such as Fes Sis Cu and Mg melted in a melting furnace (path shown) is fed into the crucible (1). At this time, the rotary cooling body (2) is in the raised position and outside the crucible (1). After putting a predetermined amount of molten aluminum (4) into the crucible (1), the rotary cooling body (2
) is immersed in molten aluminum (4) so that the liquid level is at the middle of the height of the cylindrical part, and the upper opening of the crucible (1) is closed with a lid. Then, when the rotary cooling body (2) is rotated while supplying cooling fluid into the inside of the rotary cooling body (2), the high-purity aluminum crystallization portion (6) of the rotary cooling body (2) is first smoothed. High purity primary aluminum with a solidification surface is crystallized.

The eutectic impurities are discharged into the liquid phase, forming an impurity-concentrated layer of eutectic impurities in the liquid phase near the solidification interface.

Molten aluminum (4) is heated by the rotation of the rotary cooling body (2).
) also flows in the same direction as the rotating direction of the rotary cooling body (2),
Since the flow velocity of the molten aluminum (4) is reduced by the baffle plate (3), the relative velocity between the rotary cooling body (2) and the liquid phase, that is, the peripheral speed of the rotary cooling body (2) and the molten aluminum (4) The difference in flow velocity is quite large. Therefore, the impurity concentration layer formed near the interface is effectively stirred and mixed with most of the other liquid phase, and the impurities in the impurity concentration layer are dispersed throughout the liquid phase, resulting in impurity concentration. The thickness of the layer becomes thinner and the temperature gradient in this region also becomes larger. Furthermore, the baffle plate (3) also generates a turbulent flow of the molten aluminum (4), which also causes the impurity concentrated layer to become thinner.

If solidification is allowed to proceed in this state, an aluminum lump with much higher purity than the original aluminum will be obtained on the circumferential surface of the cooling body (2).

At this time, the atmosphere above the liquid level in the crucible (1) is heated with a burner, etc., and the temperature of the outer peripheral surface of the high-purity aluminum crystallization part (6) of the rotary cooling body (2) is set to the highest temperature at the upper end. And make it lower towards the bottom. Then, the amount of crystallization in the high-purity aluminum crystallization part (6) is small at the upper end, increases toward the bottom, becomes equal below, and crystallizes on the outer peripheral surface of the high-purity aluminum crystallization part (6). The shape of the high-purity aluminum ingot is thinnest at the upper end and gradually widens toward the bottom. Therefore, in the vicinity of the cooling body (2), the high-purity aluminum ingot (
1), a downward flow as shown by the arrow (A) in FIG. 1 occurs. As a result, severe ripples on the liquid surface are prevented, and the amount of slag made of Al2O3 produced as a result of the reaction between oxygen in the air and aluminum is reduced.

Next, more specific examples will be described.

Six baffle plates (3) were provided on the inner peripheral surface of the crucible (1). Also, the outer diameter of the cylindrical part of the cooling body (2) is set to 1
It was set as 5011I11. Then, molten aluminum (4) containing 07 vt% of FeO and 04 vt% of SiO was placed in the crucible (L) and kept heated at 670°C. Further, the atmosphere above the liquid level of the molten aluminum (4) was heated and maintained at 700°C.

Next, the rotary cooling body (2) is immersed in molten aluminum (4), and the rotation speed is 4 while supplying cooling fluid into the inside of the rotary cooling body (2).
It was rotated at 0 rpm. After performing this operation for 30 minutes, the rotation of the cooling body (2) was stopped and the cooling body (2) was raised. A 10 kg aluminum lump was crystallized on the circumferential surface of the cooling body (2). Thereafter, the aluminum lump (1) crystallized on the circumferential surface of the cooling body (2) was removed, and the average impurity concentration of Fe and St in the aluminum lump (1) was measured. As a result, Fed, 0046vt%, SiO,
0067wt%, and the effective distribution coefficient obtained by dividing this value by the original impurity concentration is K (Fe) - 0,06, K (Si)
-0.16. Further, although some ripples were observed on the liquid surface immediately after the start of this operation, the ripples disappeared midway through, and the liquid surface of the molten aluminum (4) was calm and no slag was observed.

For comparison, a comparative example using a conventional device will be described. The outer diameter of the portion of the rotary cooling body (20) in contact with the liquid surface of the molten aluminum (4) is 150 mIn.
I kept it as. Then, in the crucible (1), FeO,0
Molten aluminum (4) containing 7 wt% and 04 wt% of SiO was added and kept heated at 670°C. Next, the rotary cooling body 20) is immersed in the molten aluminum (4), and the rotation speed is increased to 4 while supplying cooling fluid into the interior of the rotary cooling body 20).
Rotated at 00 rpa+. After performing this operation for 30 minutes, the rotation of the cooling body (20) is stopped, and the rotation of the cooling body (20) is stopped.
) rose. A 10 kg aluminum lump was crystallized on the circumferential surface of the cooling body (20). After that, the cooling body (20
) is removed, and the average impurity concentration of Fe and Si in this aluminum lump is 01.
Established. As a result, FeO,0070wt%, Si
O,0088vt%, and this effective distribution coefficient is K (
Fe)-0,1, K(S1)=0. It was '21. Furthermore, during the operation, intense molten metal splashing occurred on the surface of the molten aluminum (4), and a large amount of slag was generated.

This slag adhered to the inner peripheral surface of the crucible (1) above the liquid level and became an obstacle to the continuation of the refining operation.

FIG. 2 shows a second specific example of the apparatus used to practice the invention.

In Fig. 2, the rotary cooling body (10) has a tapered shape with a lower floor extending from the upper end to a predetermined length, and the lower part thereof has a cylindrical shape with the same thickness as the lower end of the tapered part. The inner peripheral surface of the tapered portion is covered with a heat insulating material (11). Then, it is immersed in molten aluminum (4) so that the liquid level is at the tapered part, and the part of the tapered part below the liquid level becomes an amorphous part (12), and the cylindrical part becomes high. The crystallized portion (13) is made of pure aluminum.

In such a configuration, when manufacturing high-purity aluminum, a crucible (1
) by heating the atmosphere above the liquid level with a burner, etc.
High-purity aluminum crystallization part (13
) so that the temperature of the outer peripheral surface is highest at the top and decreases toward the bottom. Then, the shape of the high-purity aluminum lump (1) crystallized in the high-purity aluminum crystallization part (13) is such that the upper end is the thinnest and gradually widens downward.
The portion below the predetermined height position has a cylindrical shape with the same diameter. Therefore, in the vicinity of the cooling body (10), the amorphous part (
12) and the upper part of the high-purity aluminum lump (+), a downward flow as shown by the arrow (B) in FIG. 2 occurs. As a result, violent ripples on the liquid surface are prevented, and the A/2
The liability of slag consisting of 03 is reduced.

FIG. 3 shows a third specific example of the apparatus used to carry out the invention.

In FIG. 3, the high-purity aluminum manufacturing apparatus includes a melting furnace (15) for melting aluminum to be purified, followed by four crucibles (1i) to (ID), and four crucibles (IA) to (ID). ID), a baffle plate (3) is provided in the same way as in the device of the above embodiment. Further, a rotary cooling body (2) for crystallizing high purity aluminum, which is movable up and down, is provided corresponding to each crucible (LA) to (10). Adjacent crucibles (IA) to (10) are connected to each other by a connecting gutter (1B) at the upper end, and a melting furnace (15) is connected to the leftmost crucible (IA).
) A gutter (17) is attached to the receiver to receive the molten aluminum supplied from the crucible (LD) on the right end.
A molten metal discharge gutter (18) is attached to the upper end.

In the apparatus for manufacturing high-purity aluminum having such a configuration, aluminum to be purified is melted in the melting furnace (15) and sent to each crucible (IA) to (ID). When the amount of molten metal in each crucible (IA) to (ID) reaches a predetermined amount, the cooling body (2) is lowered and immersed in the molten metal, and the upper openings of the crucibles (IA) to (ID) are closed. . Then, the atmosphere above the liquid level of the molten aluminum (4) is heated and maintained at a temperature higher than its liquidus temperature.

Next, it is rotated while supplying cooling fluid from the hollow rotating shaft (5) into its interior. Then, due to the principle of segregation solidification, high purity aluminum is crystallized only in the high purity aluminum crystallization portion (8) in the rotary cooling body (2). The eutectic impurities are expelled into the liquid phase and are moved away from the cooling body (2) by the centrifugal force generated by the rotation of the cooling body (2). In this way, aluminum of higher purity and desired purity than the original aluminum supplied from the melting furnace (15) is obtained. The rotary cooling body (
The principle of obtaining high-purity aluminum on the circumferential surface of 2) is the same as in the case of the apparatus of Example 1 above.

In this device, if the aluminum to be refined contains impurities that will form peritectics with aluminum, a boron addition device equipped with a stirrer between the melting furnace (15) and the leftmost crucible (IA) is used. It is a good idea to have a crucible ready for use. Then, the molten metal is first fed into this crucible from the melting furnace (15), and boron is added to the molten metal in this crucible and stirred by the above-mentioned stirrer. Then, boron reacts with peritectic impurities such as Ti, V, and Zr contained in the molten metal to form TiB.
Insoluble borides such as 2, VB2, and Zr82 are produced. Excess boron is removed as a eutectic impurity. The above boride is heated in a cooling body (
The aluminum is moved away from the cooling body (2) by the centrifugal force generated by the rotation of the cooling body (2), and is no longer included in the aluminum crystallized on the circumferential surface of the cooling body (2).

FIG. 4 shows a fourth specific example of the apparatus used to carry out the invention.

The difference in FIG. 4 from the apparatus shown in FIG. 1 is that a baffle plate (3) is not provided on the inner circumferential surface of the crucible (1), and the other configurations are the same.

Furthermore, the baffle plate (3) may not be provided in the apparatus shown in FIGS. 2 and 3 as well.

Effects of the Invention According to the metal refining method of the present invention, as a rotary cooling body, the upper part of the part below the molten metal surface is a metal amorphous part, and the lower part is a purified metal crystallization part. At the same time, the metal amorphous part has a shape that expands upward or a cylindrical shape with the same diameter from the top end to the bottom end,
By setting the temperature of at least the upper outer circumferential surface of the refined metal crystallization section to be highest at the upper end and to decrease toward the bottom, the rate of metal crystallization into the refined metal crystallization section can be increased.
The crystallization is slowest at the top end and becomes faster toward the bottom, and the shape of the crystallized metal lump is such that the outer diameter at the top end is equal to or larger than the metal amorphous part, and the shape is rounded at the bottom. Therefore, after metal lump crystallization, near the rotary cooling body,
Near the liquid level, a downward flow occurs along the upper part of the metal block. Therefore, the occurrence of ripples on the liquid surface, scattering of molten metal, etc. is prevented, and as a result, the amount of slag consisting of Al2O3 produced as a result of the reaction between oxygen in the air and aluminum is reduced, which occurs as a result of generation of a large amount of slag. Problems are prevented before they occur. In addition, since the upper part of the rotary cooling body below the molten metal surface is the metal amorphous part,
Crystallization of metal in this area is prevented, resulting in the following effects. In other words, the purity of the metal that crystallizes in this area is lower than the purity of the metal that crystallizes in other areas, so if it also crystallizes in this area, it will be difficult to remove it from the cooling body after the refining work is completed. There is a risk that it will mix with high-purity crystals that have crystallized in other parts, reducing the overall purity.
The method of this invention can prevent this decrease in purity.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing a first specific example of the device used to carry out the present invention, FIG. 2 is a vertical cross-sectional view showing a second specific example of the device used to carry out the present invention, and FIG. The figure is a vertical sectional view showing a third specific example of the device used to carry out this invention, FIG. 4 is a vertical sectional view showing a fourth specific example of the device used to carry out this invention, and FIG. 1 is a vertical cross-sectional view of the apparatus used to carry out the conventional method; FIG. (1)<LA) ~ (10)... Crucible, (2) (10
)...rotary cooling body, (4)...molten aluminum,
(7)(12)...Amorphous mountain part, (8)(13)...
High-purity aluminum crystallization part, (+)...high-purity aluminum lump. Applicant for the above patent: Showa Aluminum Co., Ltd. W, Figure 1 Figure 2 Figure 4 March 2, 1988 1. Display of the case 1986 Patent Application No. 313249 2, Q Ming's name Metal refining method 3, Person making the amendment Relationship to the case Patent applicant 4 - Agent address 57, Ugidani Nishinocho, Minami-ku, Osaka City No. 6 Inaba Building, 6th floor, No. 06-252-24365, date of amendment order Showa year, month, day 6, number of inventions increased by amendment Contents of amendment (1) From page 2, line 8 to page 5, line 2 of the specification: for example·
There is... ” should be corrected as follows. "For example, there is a known method of refining aluminum that contains impurities that form eutectic with aluminum to a higher purity by utilizing the principle of segregation solidification. The method involved in the patent application is that after the aluminum to be purified is melted, the molten aluminum is placed in a crucible and kept heated at a temperature that always exceeds its solidification temperature. A hollow rotary cooling body with a tapered cylindrical shape tapered downward from the upper end is immersed in the cooling body, and cooling fluid is fed into this cooling body to maintain its surface temperature below the solidification temperature while rotating this cooling body. By dispersing and mixing the impurities discharged near the solidification interface when aluminum crystallizes on the outer peripheral surface of the cooling body into the entire liquid phase, the thickness of the impurity-concentrated layer near the solidification interface in the liquid phase is reduced. As a result, there is a method of refining aluminum by crystallizing aluminum of higher purity from the circumferential surface of the cooling body while increasing the temperature gradient in the liquid phase in the impurity-concentrated layer (Japanese Patent Publication No. 61-3385). In the above method, in order to reduce the thickness of the impurity-concentrated layer near the solidification interface in the liquid phase, thereby increasing the temperature gradient and improving the purification efficiency, it is necessary to One condition is to increase the relative speed with aluminum.
It is one. However, as the cooling body rotates, the molten aluminum also flows in the same direction as the rotational direction of the cooling body, creating a vortex, so there is a limit to the increase in the relative speed, and there is also a limit to the improvement in refining efficiency. Moreover, if the number of revolutions of the cooling body is increased, centrifugal force increases, making it difficult for crystallized high-purity aluminum to adhere to the circumferential surface of the cooling body, resulting in a decrease in productivity. In addition, when the rotation speed of the cooling body is increased, the area around the cooling body tries to involve the molten aluminum, and air is drawn into the molten aluminum.
This air and aluminum react to generate a large amount of slag made of A/203. Moreover, since the cooling body used in the above-mentioned conventional method has a tapered cylindrical shape that tapers downward from the upper end, when it is rotated, the circumferential speeds of the upper and lower parts will be different. The circumferential speed at the top becomes larger than the circumferential speed at the bottom, creating a flow with an upward velocity component in the molten aluminum.As a result, the surface of the molten aluminum ripples and air is drawn into the molten aluminum. This air reacts with aluminum, producing a large amount of slag made of A/203. therefore,
Not only does slag removal work become necessary, but the ring also scatters and adheres to the inner surface of the crucible, impeding the work. Furthermore, a large amount of slag is generated, which may reduce purification efficiency. The above-mentioned ripples become more likely to occur after aluminum lumps begin to crystallize on the circumferential surface of the rotary cooling body. In addition, the present applicant also proposed that a plurality of baffles for reducing the flow rate of molten aluminum be provided on the inner peripheral surface of the crucible at predetermined intervals in the circumferential direction in order to reduce the flow rate of the vortex flow of the molten aluminum. I was worried (Jitko Sho 61-38912
(see publication). In this case, it is possible to increase the relative speed between the cooling body and molten aluminum without increasing the rotational speed of the cooling body, further improving the refining efficiency. The presence of the plates causes the flow velocity of the molten aluminum to differ locally, with the result that near the top of the subsurface portion of the cooling body, the molten aluminum has a greater flow with an upward velocity component. Therefore, the surface of the molten aluminum will ripple even more violently, and the negative effects of the ripples will become even more severe." (2) The difference between "method" and "and" on page 7, line 7 of the same book. In between, ``a method of covering the inner circumferential surface of the refined metal crystallization area with a heat insulating material and making the thickness of the heat insulating material thinnest at the upper end and gradually thickening toward the bottom.'' (3) Ibid. "Crystallization part (B)" on page 9, line 16 is corrected as "crystallization part (8)". 4) "Crystallization part (6)" on page 10, line 19 of the same book is changed to "crystallization part (8)". ” he corrected. 5) "Crystalization part (6)" in lines 1-2 and 4, page 11 of the same book.
" is corrected to "Crystallization part (8)". In line 7 of the same page, between ``therefore'' and ``cooling body'', ``the circumferential speed of the lower part of the high-purity aluminum ingot (1) becomes greater than the circumferential speed of the upper part'' is added. Add the following sentence between lines 13 and 14 on the same page. In the above, the high-purity aluminum lump (1) is crystallized on the outer circumferential surface of the lower sandwich-shaped high-purity aluminum crystallization part (8), so when collecting the high-purity aluminum lump (1), the lower The aluminum lump (1) can be easily removed from the outer circumferential surface of the cooling body (2) by scraping it off.Also, the aluminum lump (1) can be removed only from the outer circumferential surface of the high-purity aluminum crystallization part (8) in the shape of a lower sandwich. Since the aluminum lump (1) is crystallized not only on the outer peripheral surface of the high-purity aluminum product part (8) but also on the outer peripheral surface of the amorphous part (7), the aluminum ingot (1) has a higher In other words, near the liquid surface, the temperature of the molten aluminum (4) is lower than that of other parts due to the influence of the atmospheric temperature, and the amorphous part (2) of the cooling body (2) This is because the crystallization speed of 7) on the outer peripheral surface may be faster than on other parts, and the aluminum purity of the obtained lump (1) may decrease.In addition, in the above, in the initial stage of the operation, That is, even before high-purity aluminum (+) begins to crystallize in the above shape, the cylindrical part of the cooling body (2) generates a flow of molten aluminum (4) having an upward velocity component in the vicinity thereof. In other words, the circumferential velocities at the upper and lower parts of the cylindrical part become equal, and the flow of molten aluminum (4) around them is balanced.Therefore, the upward velocity component near the cylindrical part This prevents the flow of molten aluminum (4) having a "I will show you." On line 20 of the same page, between “describe” and “rotary cooling body”, there is a “
In the device shown in Fig. 5, a rotary cooling body (20) immersed in molten aluminum (4) in a crucible (1) has a tapered shape that gradually becomes thinner from the upper end downward. . Add this. (7) On page 15, line 5 of the same book, between ``therefore'' and ``cooling body,'' it says, ``Until the aluminum lump (1) crystallizes, the circumferential speed of the lower part of the amorphous part (12) is lower than that of the upper part. A flow of molten aluminum (4) with a downward velocity component that is higher than the circumferential velocity is generated, and after the aluminum lump (1) crystallizes, the amorphous portion (12) and the aluminum lump (1) form a flow. A flow of molten aluminum (4) with a downward velocity component is generated." (8) In the same book, p. 18, line 19, "using" is replaced with "using," so if the metal amorphous part spreads upward, the circumferential speeds of the upper and lower parts will be different, and the lower part The circumferential velocity of the upper part becomes larger than that of the upper part, and a molten metal flow with a downward velocity component is generated in the vicinity.Also, if the metal amorphous part is cylindrical, the peripheral velocity of the upper part and the lower part become equal, and the flow of molten metal around it is balanced.Therefore, the generation of a flow of molten metal with an upward velocity component near the amorphous metal part is prevented, and the violent ripples on the liquid surface are prevented. This will prevent this from happening.Moreover,
I am corrected. (9) In the same book, page 19, line 7, between ``later'' and ``rotation,'' it says, ``The circumferential speeds of the upper and lower parts of the crystallized metal lump will be different, and the circumferential speed of the lower part will be different from that of the upper part. Add ``Grow bigger than speed''. (lO) "Implementation of conventional method" on page 20, lines 12-13 of the same book
is corrected to read "Comparative example implementation with respect to the example performed using the apparatus shown in FIG. 1."that's all

Claims (1)

[Claims] Molten metal is placed in a crucible, a rotary cooling body is immersed in the molten metal, and as the rotary cooling body is rotated, purified metal with high purity is crystallized from its circumferential surface. The upper part of the metal amorphous part is the metal amorphous part, and the lower part is the purified metal crystallized part. By using a cylindrical shape and making the temperature of at least the upper outer circumferential surface of the refined metal crystallization part highest at the upper end and decreasing toward the bottom, the temperature of the metal to the refined metal crystallization part is reduced. The crystallization rate is slowest at the upper end and becomes faster toward the bottom, and the shape of the crystallized metal lump is such that the outer diameter at the upper end is larger than the metal amorphous part and spreads downward. A method for refining metals.