JP6751604B2 - Material purification method and equipment, continuous purification system for high-purity substances - Google Patents

Description

The present invention relates to a method and apparatus for purifying substances such as metals and a continuous refining system for high-purity substances. More specifically, the present invention utilizes the principle of segregation and solidification method to contain aluminum, silicon, magnesium, lead and zinc containing eutectic impurities. The present invention relates to a method and an apparatus for producing a high-purity substance by reducing the content of eutectic impurities from the above-mentioned substances to the original substance, and further relates to a continuous purification system for high-purity substances.

When impurities such as Fe, Si, and Cu that form eutectics are contained in a substance such as metal, in order to remove these impurities and obtain a high-purity substance, this substance is melted. It is well known that it is effective to selectively extract primary crystals when cooling and solidifying.

Conventionally, various purification methods using the above principle have been proposed. For example, in Patent Document 1, the concentrated layer of impurities near the solidification interface is thinned by rotating the cooling body so that the relative velocity between the outer peripheral portion of the cooling body and the molten aluminum is 1600 mm / s to 8000 mm / s. However, it has been proposed to increase the purity of purified aluminum.

Further, Patent Document 2 proposes a method of preventing molten aluminum from flowing in the same direction as the cooling body rotates and ensuring a relative speed between the cooling body and the molten aluminum. In this method, a plurality of baffles for reducing the flow velocity of molten aluminum are arranged on the inner peripheral surface of the crucible for holding molten aluminum in the circumferential direction, and the upper ends of the baffles are provided so as to be below the surface of the molten aluminum.

Further, in Patent Document 3, the shortest distance between the inner peripheral surface of the crucible and the outer peripheral surface of the cooling body in the portion where the molten metal exists in the crucible is halved of the longest distance between the inner peripheral surface of the crucible and the outer peripheral surface of the cooling body. It has been proposed that by setting the following and performing purification, the narrow and wide parts of the flow path of the molten metal are intentionally set to slow down the flow velocity in the circumferential direction of the molten metal and increase the relative velocity.
Special Publication No. 61-3385 Special Publication No. 62-235433 Japanese Unexamined Patent Publication No. 2008-163420

However, in the techniques described in Patent Documents 1 and 2, impurities of the obtained substance could not be sufficiently removed, and there was a problem in operation.

That is, in the method as described in Patent Document 1, since the molten metal also flows in the same direction as the cooling body rotates, there is a limit to thinning the impurity concentration layer, and in order to obtain high purification efficiency. If the rotation speed of the cooling body is made too high, there is a problem that the molten material is likely to bounce or fly.

The method described in Patent Document 2 has the effect of suppressing the flow velocity of the entire molten metal or causing turbulence by the baffle plate, but the range of the effect is the range inside from the inner peripheral surface of the crucible by the length of the baffle plate. It is limited to the outer peripheral part of. In order to exert the effect near the outer peripheral surface of the cooling body, it is necessary to extend the baffle plate to the vicinity of the outer peripheral surface of the cooling body, but in that state, the metal lumps that adhere to and grow on the outer peripheral surface of the cooling body come into contact with the baffle plate. , There is a risk that the baffle plate will be damaged. In addition, in order to obtain a crucible with a baffle plate on the inner peripheral surface, a method such as adhering the baffle plate to the inner peripheral surface of the crucible with a separate part or manufacturing a crucible in which the baffle plate exists from the beginning is available. However, there is a problem that it takes time and effort in terms of production and maintenance.

Further, in the method described in Patent Document 3, there is a problem that a trouble that a hot water splash occurs due to a local rise in the hot water level due to a centrifugal force due to a high flow velocity in a narrow part of the flow path. There is.

The present invention has been made in view of such circumstances, and is a substance purification method and apparatus, a high-purity substance, which has high purification efficiency, can suppress hot water splashing, has excellent energy cost, and is not difficult to install. It is an object to provide a continuous purification system of.

The above problem is solved by the following means.
(1) In a substance purification method in which a cooling body is immersed in a molten substance to be purified contained in a molten metal holding container, and crystals of the substance are crystallized on the surface of the cooling body while rotating the cooling body, the cooling body is used. The ratio A / a of the distance A from the bottom surface to the bottom surface of the molten metal holding container and the immersion depth a of the cooling body in the molten substance is 0.3 ≦ A / a ≦ 3.0. Material purification method.
(2) The substance purification method according to item 1 above, wherein the immersion depth a of the cooling body in the molten substance is 150 mm or more and 500 mm or less, and the distance A from the bottom surface of the cooling body to the bottom surface of the molten metal holding container is 700 mm or less.
(3) The substance purification method according to item 1 or 2 above, wherein A / a is 0.5 ≦ A / a ≦ 2.0.
(4) The temperature of the cooling body when immersed in the molten substance while rotating the cooling body so that the peripheral speed of the cooling body is 700 mm / s or more and less than 8000 mm / s is set. The substance purification method according to any one of the above items 1 to 3, wherein the solidus temperature of the substance is 0.7 or more and the solidus temperature or less.
(5) When crystals of the substance are crystallized on the surface of the cooling body and grown, and then the cooling body is pulled up from the molten substance, the peripheral speed of the crystal portion crystallized on the cooling body at the interface with the molten substance is 700 mm. The substance purification method according to any one of the above items 1 to 4, wherein the cooling body is pulled up while rotating so as to be at least / s and less than 8000 mm / s.
(6) The substance purification method according to any one of the above items 1 to 5, wherein the maximum peripheral speed of the cooling body at the initial stage of purification after immersion in the cooling body is higher than the average peripheral speed thereafter.
(7) The substance purification method according to item 6 above, wherein the initial purification period is from the start of purification to the total purification time × 0.1 (however, 10 seconds or more and 120 seconds or less).
(8) The substance purification method according to any one of the above items 1 to 7, wherein the substance is aluminum.
(9) A molten metal holding container for accommodating a molten substance to be purified and a rotatable cooling body immersed in the molten substance contained in the molten metal holding container are provided, and the molten metal holding container is provided from the bottom surface of the cooling body. A substance refining apparatus characterized in that the ratio A / a of the distance A to the bottom surface and the immersion depth a of the cooling body in the molten substance is set to 0.3 ≦ A / a ≦ 3.0. ..
(10) The substance purification according to item 9 above, wherein the immersion depth a of the cooling body in the molten substance is set to 150 mm or more and 500 mm or less, and the distance A from the bottom surface of the cooling body to the bottom surface of the molten metal holding container is set to 700 mm or less. apparatus.
(11) The substance purification apparatus according to item 9 or 10 above, wherein A / a is 0.5 ≦ A / a ≦ 2.0.
(12) A plurality of melts connected in series, which are used in a melting furnace for melting a substance and a substance refining apparatus according to any one of 9 to 11 above, and melts from the melting furnace are sequentially sent. A holding container and a rotatable cooling body used in the substance purification apparatus according to any one of 9 to 11 above, which is paired with each molten metal holding container and for crystallizing a high-purity substance in the molten metal. A series of devices for discharging the molten metal from the final molten metal holding container to the outside of the system are set as one set of lines, and the N-order lines (however, 2 ≦ N) in which a plurality of sets of the lines are used are composed of (n-1). ) The high-purity substance mass adhered to and solidified on the cooling body in the next line (however, 2 ≦ n ≦ N) is melted in the melting furnace of the following nth line, and the molten metal melted in the melting furnace is sequentially discharged. The number of the molten metal holding container and the cooling body arranged in pairs with the molten metal holding container and the holding tank of the nth line is higher than that of the (n-1) order line. A continuous purification system for high-purity substances, characterized by a small amount.
(13) The continuous purification system for high-purity substances according to item 12 above, wherein the order N of the line is 2 or 3.
(14) The continuation of the high-purity substance according to the above item 12 or 13, wherein the substance is aluminum, and boron is added to the melting furnace of one or more of the plurality of lines. Purification system.
(15) A stirring tank capable of adding boron is installed between the melting furnace and the molten metal holding container, and boron is added at any place between the melting furnace and the stirring tank. The continuous purification system for high-purity substances according to item 14 above.
(16) The continuation of high-purity substances according to item 14 or 15 above, wherein a separation tank capable of separating and extracting peritectic impurities as an insoluble boron compound is installed between the melting furnace and the molten metal holding container. Purification system.
(17) A plurality of molten metals connected in series, which are used in a melting furnace for melting a substance and a substance refining apparatus according to any one of 9 to 11 in the preceding paragraph, and molten metal from the melting furnace is sequentially sent. A rotating cooling body used in the holding container and the substance purification apparatus according to any one of 9 to 11 above, which is paired with each molten metal holding container and for crystallizing a high-purity substance in the molten metal. A series of devices for discharging the molten metal from the final molten metal holding container to the outside of the system as one set of lines, and the N-order lines (however, 2 ≦ N) in which a plurality of sets of the above lines are used are composed of (n-). 1) The high-purity material mass adhered to and solidified on the rotary cooling body in the next line (however, 2 ≦ n ≦ N) is melted in the melting furnace of the following nth line, and the molten metal melted in the melting furnace is in order. The molten metal is discharged through the molten metal holding container, and the molten metal discharged in the primary line is discharged outside the line, while the molten metal discharged in the nth line is dissolved in the (n-1) primary line. The number of the cooling bodies to be returned to the furnace and arranged in pairs with the molten metal holding container and the holding tank in the nth line is smaller than that in the (n-1) order line. A continuous purification system for high-purity substances.
(18) The continuous purification system for high-purity substances according to item 17 above, wherein the order N of the line is 2 or 3.
(19) The continuation of the high-purity substance according to the above item 17 or 18, wherein the substance is aluminum, and boron is added to the melting furnace of one or a plurality of lines among the plurality of sets of lines. Purification system.
(20) A stirring tank capable of adding boron is installed between the melting furnace and the molten metal holding container, and boron is added at any place between the melting furnace and the stirring tank. The continuous purification system for high-purity substances according to item 19 above.
(21) The continuation of high-purity substances according to item 19 or 20, wherein a separation tank capable of separating and extracting peritectic impurities as an insoluble boron compound is installed between the melting furnace and the molten metal holding container. Purification system.

According to the inventions described in the preceding paragraphs (1) and (9), the ratio A / a of the distance A from the bottom surface of the cooling body to the bottom surface of the molten metal holding container and the immersion depth a of the cooling body in the molten substance is A / a. Since 0.3 ≦ A / a ≦ 3.0, a large amount of molten substance exists between the cooling body and the inner peripheral surface of the molten metal holding container. For this reason, the molten substance itself becomes a resistance, and the swirling flow of the molten substance due to the rotation of the cooling body is sufficiently slowed down, and as a result, the dispersion of the impurity-concentrated layer generated near the solidification interface is promoted, and the purification efficiency of the substance is improved. improves. If the swirling flow of the molten metal is slowed down, purification with suppressed scattering of the molten metal becomes possible.

According to the inventions described in the preceding paragraphs (2) and (10), the immersion depth a of the cooling body in the molten substance is 150 mm or more and 500 mm or less, and the distance A from the bottom surface of the cooling body to the bottom surface of the molten metal holding container is 700 mm. Since it is as follows, productivity and energy efficiency are good, and the difficulty of equipment can be suppressed.

According to the inventions described in the preceding paragraphs (3) and (11), since A / a is 0.5 ≦ A / a ≦ 2.0, higher purification efficiency can be obtained and splashing can be further suppressed.

According to the invention described in the previous section (4), a cooling body having a temperature of the solidus temperature of the molten substance × 0.7 or more is immersed in the molten substance while rotating at a peripheral speed of 700 mm / s or more. From the initial stage of purification, high-purity crystals having good adhesion to the cooling body can be crystallized, peeling from the cooling body can be prevented, and the amount of the purified substance recovered can be increased. Moreover, since the cooling body has a peripheral speed of less than 8000 mm / s, it is possible to prevent operational problems such as scattering of molten substances.

According to the invention described in the preceding paragraph (5), it is possible to prevent a molten substance having a higher impurity concentration from adhering to the surface of the crystallized crystal portion and deteriorating the purification efficiency.

According to the invention described in the previous section (6), since purification is performed by setting the maximum peripheral speed of the cooling body at the initial stage of purification to be higher than the average peripheral speed thereafter, the cooling body is immersed in the molten material to be purified. Even if a crystallized product having a high solidification rate and poor adhesion is purified at the initial stage of purification, it can be positively separated from the rotary cooling body and redissolved in the molten material. In this way, the crystallized substances having poor adhesion to the cooling body are removed at the very early stage, so that it is possible to avoid the situation where the substance crystallized at a high solidification rate grows to some extent and then peels off from the cooling body, and positively peeling off. The later purified substance can be grown without peeling, and the amount of the purified substance recovered can be increased.

According to the invention described in the preceding paragraph (7), since there is a sufficient time to peel off the crystallized product having poor adhesion to the cooling body, the effect of the above (6) can be sufficiently exhibited. ..

According to the invention described in the preceding paragraph (8), high-purity aluminum can be obtained.

According to the invention described in the preceding paragraph (12), a high-purity substance can be purified more efficiently than a serial purification facility. That is, when the recovery rate (recovery weight / original input weight) is the same, higher purity can be obtained. Moreover, since the number of the molten metal holding tank of the nth line and the rotary cooling body arranged in pairs with the holding tank is smaller than that of the (n-1) order line, the molten metal holding tank and the rotary cooling in each line The equipment area is smaller than when the number of bodies is the same.

According to the invention described in the preceding paragraph (13), the desired purity can be obtained more efficiently, and the operability is excellent.

According to the inventions described in the preceding paragraphs (14) and (15), peritectic impurities in the purification of high-purity aluminum can be reduced.

According to the invention described in the preceding paragraph (16), peritectic impurities can be further reduced.

According to the invention described in the preceding paragraph (17), since the discharged molten metal can be reused, energy efficiency and material recovery rate can be improved, and eutectic impurities can be reduced.

According to the invention described in the preceding paragraph (18), a high-purity substance can be efficiently purified, and a system having excellent operability can be obtained.

According to the inventions described in the preceding paragraphs (19) and (20), it is possible to efficiently reduce the peritectic impurities of aluminum when purifying high-purity aluminum.

According to the invention described in the preceding paragraph (21), it is possible to further efficiently reduce peritectic impurities.

It is a figure which shows the structure of the substance purification apparatus which concerns on one Embodiment of this invention. It is a figure which shows the structure of the substance purification apparatus which the cooling body was arranged unevenly. It is a figure which shows the structure of the continuous purification system of a high-purity substance which concerns on other embodiment of this invention. It is a figure which shows the structure of a part of the line of the system of FIG. 2 in detail. It is a figure which shows the structure of the continuous refining system of high-purity material which concerns on still another embodiment of this invention. It is a figure which shows the structure of the continuous purification system used in Example 21. It is a figure which shows the structure of the continuous purification system used in Example 22. It is a figure which shows the structure of the continuous purification system used in Example 23. It is a figure which shows the structure of the continuous purification system used in Example 24. It is a figure which shows the structure of the continuous purification system used in Example 25. It is a figure which shows the structure of the continuous purification system used in Example 27. It is a figure which shows the structure of the continuous purification system used in Example 28. It is a figure which shows the structure of the continuous purification system used in Example 29. It is a figure which shows the structure of the continuous purification system used in Example 30. It is a figure which shows the structure of the continuous purification system used in Example 31.

Hereinafter, an embodiment of the present invention will be described.
[First Embodiment]
FIG. 1 is a diagram for explaining a schematic configuration of a substance purification apparatus according to an embodiment of the present invention and a substance purification method using the same. In this embodiment, a case where the substance is a metal such as aluminum will be described.

In FIG. 1, reference numeral 1 denotes a crucible having a low and low cylindrical shape as a molten metal holding container and having a bottom surface formed on a downward arc surface, and a molten metal (also referred to as molten metal) 6 such as aluminum is housed and held inside the crucible 1. ing. The crucible 1 is composed of a heating furnace, and the molten metal 6 is heated so as to have a constant temperature.

The shape of the crucible 1 is not limited to a crucible 1 having a low and low cylindrical shape and a bottom surface formed on a downward arc surface. It may be a crucible with a flat bottom surface, or a square crucible. A tank made of refractory or the like may be used. Further, the heating method of the furnace constituting the crucible 1 may be electric heating or a gas burner.

The temperature of the molten metal 6 may exceed the solidification temperature, but it is more desirable that the temperature is lower than the temperature at which the solid phase does not exist in the molten metal while the cooling body 2 is immersed in the molten metal 6.

The cooling body 2 is formed in a truncated cone shape with a large diameter on the upper end side, and is installed at the lower end of a rotating shaft 3 that can move up and down. The shape of the cooling body 2 is not limited, and the cooling body 2 may be formed in a cylindrical shape having a constant outer diameter. The rotating shaft 3 has a tubular shape, and a space is also formed inside the cooling body 2. A refrigerant supply pipe 4 and a refrigerant discharge pipe 5 are inserted inside the rotating shaft 3, and air is supplied as a refrigerant. The supplied air is ejected into the internal space of the cooling body 2 through the refrigerant supply pipe 4, and then discharged through the refrigerant discharge pipe 5 inside the rotating shaft 3. The cooling body 2 It is supposed to be able to cool from the inside.

The cooling body 2 has a rotating shaft 3 that moves downward so that it can be immersed and rotated in the molten metal 6. By immersing the cooling body 2 for a certain period of time while circulating air inside the cooling body 2 to cool the cooling body 2. Purified lumps adhere to the outer peripheral surface of No. 2 and grow. After that, the rotating shaft 3 is raised, the cooling body 2 to which the refined mass is attached is pulled up from the molten metal 6, and the rotating shaft 3 is moved to a place where there is a device for scraping the purified mass, and the purified mass is moved to the cooling body 2 by the device. Scrap and collect from.

Here, as shown in FIG. 1A, the ratio A / a of the distance A from the bottom surface of the cooling body 2 to the bottom surface of the crucible 1 and the immersion depth a of the cooling body 2 in the molten metal 6 is 0.3 ≦. Purification is performed with A / a ≦ 3.0. The axis of the cooling body 2 may be deviated from the center of the crucible 1, but at that time, the distance A from the bottom surface of the cooling body 2 to the bottom surface of the crucible 1 is such that the axis of the cooling body 2 is as shown in FIG. 1B. It is the distance from the center of the bottom surface of the cooling body 2 that passes through to the bottom surface of the crucible 1 directly below it.

The ratio A / a of the distance A from the bottom surface of the cooling body 2 to the bottom surface of the crucible 1 and the immersion depth a of the cooling body 2 in the molten metal 6 is set to 0.3 ≦ A / a ≦ 3.0. As a result, a large amount of molten metal 6 exists between the inner peripheral surfaces of the cooling body 2 and the crucible 1, so that the molten metal 6 itself becomes a resistance, and the swirling flow of the molten metal 6 due to the rotation of the cooling body 2 is generated. It is sufficiently slowed down, and as a result, the dispersion of the impurity-concentrated layer generated near the solidification interface is promoted, and the purification efficiency of the metal is improved. If the swirling flow of the molten metal is slowed down, purification with suppressed scattering of the molten metal becomes possible. However, if A / a is less than 0.3, the above effect is poor. On the other hand, even if the A / a is increased to more than 3, the swirling flow of the molten metal 6 is already sufficiently slow, so that further effect of improving the purification efficiency cannot be expected. A particularly preferable value of the ratio A / a of the distance A from the bottom surface of the cooling body 2 to the bottom surface of the crucible 1 and the immersion depth a of the cooling body 2 in the molten metal 6 is 0.5 ≦ A / a ≦ 2. It is 0.

Further, it is desirable that the immersion depth a of the cooling body 2 in the molten metal 6 is 150 mm or more and 500 mm or less, and the distance A from the bottom surface of the cooling body 2 to the bottom surface of the crucible 1 is 700 mm or less. If the immersion depth a of the cooling body 2 in the molten metal 6 is less than 150 mm, the total height of the refined lump is low and the lump is light in weight, so that the productivity may not be good. On the contrary, when the immersion depth a of the cooling body 2 in the molten metal 6 exceeds 500 mm, the rotating device of the cooling body 2 becomes large-scale, and the difficulty of equipment installation becomes high. On the other hand, if the distance A from the bottom surface of the cooling body 2 to the bottom surface of the crucible 1 exceeds 700 mm, the amount of molten metal retained in the crucible 1 increases, and a large amount of energy for heating the heater or the like may be required. There is. A more preferable value of the immersion depth a of the cooling body 2 in the molten metal 6 is 200 mm or more and 400 mm or less, and a more preferable value of the distance A from the bottom surface of the cooling body 2 to the bottom surface of the crucible 1 is 600 mm or less.

Further, the shortest horizontal distance L1 between the inner peripheral surface of the crucible 1 and the outer peripheral surface of the cooling body 2 on the surface of the molten metal 6 is 150 mm or more, and the inner peripheral surface of the molten metal holding container covers the entire area where the molten metal exists in the crucible. It is preferable that the horizontal distance L2 at the lowermost end of the cooling body is 100 mm or more. By setting L1 to 150 mm or more and L2 to 100 mm or more, a large amount of molten metal 6 is present between the inner peripheral surfaces of the cooling body 2 and the crucible 1. For this reason, the molten metal itself becomes a resistance, and the swirling flow of the molten metal 6 due to the rotation of the cooling body 2 is sufficiently slowed down, and as a result, the dispersion of the impurity-concentrated layer generated near the solidification interface is promoted, and the metal is purified. Efficiency is improved. If the swirling flow of the molten metal 6 is slowed down, purification with suppressed scattering of the molten metal becomes possible. In particular, ensuring a large horizontal shortest distance L1 between the inner peripheral surface of the upper surface of the molten metal in the crucible 1 and the outer peripheral surface of the cooling body 2 has the effect of slowing the swirling flow of the upper surface of the molten metal 6 and preventing the molten metal from scattering. Is big.

In order to surely exert such an effect, obtain higher purification efficiency, and further suppress splashing, the shortest horizontal direction between the inner peripheral surface of the molten metal 6 surface of the crucible 1 and the outer peripheral surface of the cooling body 2 It is more preferable to set the distance L1 to be 200 mm or more and 500 mm or less, and the horizontal distance L2 between the inner peripheral surface of the crucible 1 and the lowermost end of the cooling body 2 to be 150 mm or more and 500 mm or less. Even if L1 and L2 are set to be larger than 500 mm, it is not possible to obtain a further swirling flow slowing effect of the molten metal 6, and the purification efficiency is saturated, which is wasteful.

Further, in this embodiment, it is desirable that the outer diameter d of the cooling body 2 on the upper surface of the molten metal 6 is 200 mm or more. If the outer diameter d of the cooling body 2 on the upper surface of the molten metal 6 is less than 200 mm, the weight of each mass is reduced, and the productivity is not good. Therefore, by setting the outer diameter d of the cooling body 2 on the upper surface of the molten metal 6 to 200 mm or more, high purification efficiency can be obtained while ensuring productivity.

Further, the outer diameter d of the cooling body 2 on the upper surface of the molten metal 6 is preferably set to 500 mm or less. When the outer diameter d on the upper surface of the molten metal 6 is larger than 500 mm, the rotating device for rotationally driving the cooling body 2 becomes large-scale. However, by setting the outer diameter d on the upper surface of the molten metal 6 to 500 mm or less, the cooling body is cooled. It is possible to prevent the rotating device of No. 2 from becoming large-scale, and it is possible to suppress the difficulty of equipment installation.

When the outer diameter d of the cooling body 2 on the upper surface of the molten metal 6 is 200 mm or more, the shortest horizontal distance L1 between the inner peripheral surface of the upper surface of the molten metal 6 and the outer peripheral surface of the cooling body 2 in the crucible 1 is 150 mm or more. In order to secure a horizontal distance L2 between the inner peripheral surface of the crucible 1 and the lowermost end of the cooling body 2 in the horizontal direction of 100 mm or more, it is desirable that the inner diameter D of the upper surface of the molten metal of the crucible 1 is 500 mm or more. In particular, it is preferably 650 mm or more. By setting the inner diameter D on the upper surface of the molten metal of the crucible 1 to 650 mm or more, even if the outer diameter d of the cooling body 2 on the upper surface of the molten metal 6 is set to 200 mm or more, the inner peripheral surface and the cooling body 2 on the upper surface of the molten metal of the crucible 1 Since the shortest horizontal distance L1 with respect to the outer peripheral surface of the crucible and the horizontal distance L2 between the inner peripheral surface of the crucible 1 and the lowermost end of the cooling body 2 can be secured sufficiently large, productivity can be ensured and excellent purification efficiency can be obtained. Can be done.

However, the inner diameter D on the upper surface of the molten metal of the crucible 1 is preferably 1300 mm or less. If the inner diameter D is larger than 1300 mm, the weight of the molten metal 6 to be maintained at the temperature inevitably increases, so that a large amount of energy for heating the heater or the like is required. Particularly preferably, the inner diameter D on the upper surface of the molten metal of the crucible 1 is preferably 1000 mm or less.

When the cooling body 2 is immersed in the molten metal 6 in the crucible 1 while rotating, and the rotation of the cooling body 2 is continued while supplying air as a cooling fluid to the inside, crystals of the molten metal are formed on the peripheral surface of the cooling body 1. That is, the refined metal crystallizes slowly.

When the cooling body 2 is immersed in the molten metal 6 in the crucible 1, when the cooling body 2 is immersed in the molten metal 6 while rotating as described above, when the cooling body 2 is in contact with the molten metal 6 Since the outer peripheral surface of the cooling body 2 and the molten metal always move relative to each other, a sufficiently purified metal crystallizes on the outer peripheral surface of the cooling body 2.

In this case, the peripheral speed of the outer peripheral surface of the cooling body 2 when the cooling body 2 is immersed in the molten metal 6 is preferably in the range of 700 mm / s or more and less than 8000 mm / s, more preferably 1500 mm / s. As mentioned above, the range is less than 6000 mm / s. The peripheral speed referred to here refers to the moving speed itself of the outer peripheral surface of the cooling body 2, and is a value irrelevant to the moving speed of the molten metal 6.

Further, here, the time from when the lower end of the cooling body 2 touches the molten metal 6 until the cooling body 2 is immersed to the maximum depth is defined as "when immersed". That is, from the time when the lower end of the cooling body 2 touches the molten metal 2 until the cooling body 2 is immersed to the specified depth, the peripheral speed of the outer peripheral surface of the cooling body 2 is set to 700 mm / s or more and less than 8000 mm / s. Good to hold. When the peripheral speed is less than 700 mm / s, the concentration of impurities in the metal crystallized in the vicinity of the outer peripheral surface of the cooling body 2 is high, and as a result, the concentration of impurities in the crystallized metal is high. In order to obtain a high-purity mass, it is preferable that the peripheral speed of the outer peripheral surface of the cooling body 2 is as fast as possible, but at 8000 mm / s or more, the peripheral speed is too fast, and the molten metal on the molten metal surface scatters when the cooling body 2 is immersed. There is a risk of operational problems.

Further, as described above, the shape of the cooling body 2 is not particularly limited, and may be formed into a cylindrical shape having a constant outer diameter, or the outer diameter reaches the lower end as in this embodiment. May be formed in an inverted truncated cone shape (tapered shape) that is continuously reduced, or may have another shape, but in all the parts of the cooling body 2 immersed in the molten metal, the outer peripheral surface It is preferable to keep the peripheral speed at 700 mm / s or more and less than 8000 mm / s.

Further, when immersing the cooling body 2, it is preferable that the temperature of the cooling body 2 is set to be equal to or lower than the solid phase temperature of the metal (470 ° C. or higher in the case of aluminum). If necessary, it may be heated by a heating device such as a heater. If the temperature of the cooling body 2 is less than the solidus temperature of the metal × 0.7, the solidification rate of the molten metal becomes too high, the adhesion to the cooling body 2 is poor, and it is very easy to peel off due to the centrifugal force due to rotation. , The amount of refined metal recovered is reduced. The preferable temperature of the cooling body 2 when immersed in the molten metal 6 is the solidus line temperature × 0.8 or more and the solidus line temperature or less, and more preferably the solidus line temperature × 0.9 or more and the solidus line temperature or less. Is.

Metal crystallizes on the outer peripheral surface of the cooling body 2 due to the rotation of the cooling body 2 immersed in the molten metal 6. If the cooling body 2 is pulled up from the molten metal 6 in a state where the rotation of the cooling body 2 is stopped after the crystallization of a predetermined amount of metal, the following problems may occur.

That is, since the relative motion at the interface between the metal crystallized in the cooling body 2 and the molten metal 6 is stopped, even if the supply of the cooling medium for cooling the cooling body 2 is stopped, the metal crystallizes before the stop. A metal having a high impurity concentration crystallizes on the surface of the refined metal by the time the pulling up is completed after the rotation of the cooling body 2 is stopped, and a molten metal having a higher impurity concentration adheres to the surface of the crystallized metal. Therefore, the purification efficiency may deteriorate.

Therefore, in this embodiment, it is desirable to maintain a state in which the relative movement of the interface between the surface of the crystallized refined metal and the molten metal is always performed by pulling up the cooling body 2 from the molten metal 6 while rotating the cooling body 2. As a result, the impurity concentration in the crystallized refined metal can be lowered, the molten metal is less likely to adhere to the surface of the refined metal, and the overall impurity concentration of the refined metal can be prevented from increasing. ..

From this point of view, it is preferable that the peripheral speed of the cooling body 2 when the cooling body 2 is pulled up from the molten metal 6 is as fast as possible. Specifically, it is preferable to set the peripheral speed at the interface of the refined metal adhering (crystallizing) to the cooling body 2 with the molten metal 6 to 700 mm / s or more. If the peripheral speed is less than 700 mm / s, a metal having a high impurity concentration may crystallize on the surface of the refined metal, and as a result, the impurity concentration of the entire refined metal may increase. More preferably, it is set to 1500 mm / s or more.

On the other hand, if the peripheral speed at the interface of the refined metal adhering (crystallizing) to the molten metal 6 when the cooling body 2 is pulled up is 8000 mm / s or more, the centrifugal force is too large, so that the surface of the refined metal is exposed to the surface. The adhered molten metal 6 may scatter above the liquid surface. Preferably, it is preferably set to less than 7000 mm / s.

Here, the period from when the uppermost portion of the refined metal crystallized in the cooling body 2 is pulled up from the molten metal 6 until the lowermost end of the refined metal is separated from the molten metal 6 is defined as "when pulling up". That is, the peripheral speed at the interface of the refined metal with the molten metal 6 is maintained at 700 mm / s or more and less than 8000 mm / s from the time when the uppermost portion of the refined metal is pulled up from the molten metal 6 until the lowermost end of the refined metal is separated from the molten metal 6. It is desirable to do.

Further, in this embodiment, the peripheral speed of the cooling body 2 is intentionally increased at the initial stage of purification to increase the centrifugal force, so that the mass having weak adhesion with the cooling body 2 can be obtained in a short time at the initial stage of purification. It is better to actively peel off. That is, during the initial purification period immediately after the immersion of the cooling body 2, it is preferable to set the maximum peripheral speed of the cooling body 2 to be larger than the average peripheral speed of the cooling body 2 after the initial purification process. Specifically, it is preferable to set the maximum peripheral speed of the cooling body at the initial stage of purification to 1.1 times or more the average peripheral speed of the cooling body 2 after the initial stage of purification. If it is less than 1.1 times, a sufficient centrifugal force may not be obtained and the purified metal having weak adhesion to the cooling body 2 may not be sufficiently peeled off.

The initial stage of purification means the time from the start of purification to 0.1 times the total purification time. However, the range is 10 seconds or more and 120 seconds or less. The term “start of purification” as used herein means that the cooling body 2 is immersed in the molten metal 6 to a specified depth. Even if the peripheral speed of the cooling body 2 is increased after exceeding 0.1 times the total purification time or after exceeding 120 seconds from the start of purification, the peeling timing of the purified metal is too late and purification is performed in a certain time. It is not preferable because it causes a decrease in the amount of metal recovered. Further, if the time for increasing the peripheral speed of the cooling body 2 is less than 10 seconds from the start of purification, the purified metal having weak adhesion to the cooling body 2 cannot be sufficiently peeled off, which is not preferable.

As shown in FIG. 1A, the crucible 1 has a depth H of the crucible, a length A from the bottom of the crucible to the bottom of the cooling body 2, a depth of immersion in the molten metal 6 in the cooling body 2, and a depth of immersion of the crucible 1. It is desirable that the relationship of the opening inner diameter (equal to the inner diameter of the crucible 1 on the upper surface of the molten metal in this embodiment) D satisfies the condition of H ≧ A + 2a−D / 20 (H = 1000 mm). When such a condition is satisfied, the length from the surface of the molten metal 6 to the upper part of the crucible 1 is sufficiently secured with respect to the immersion depth a in the molten metal 6 in the cooling body 2, so that the crucible is satisfied. 1 It is possible to further suppress the scattering of the molten metal to the outside. When H is 1000 mm or more, it is desirable that H ≧ A + 2a-D / 20-200. If A + 2a-D / 20 is 1000 mm or more, the crucible height becomes excessive with respect to the scattering of the molten metal, which causes an increase in the crucible cost. Therefore, a value of −200 mm is an appropriate value.

In this embodiment, examples of the substance to be purified include metals containing eutectic impurities and metals such as silicon, magnesium, lead and zinc, but substances other than metals may be used.

Since the substance purified by the above has high purity, it can exhibit excellent properties and functions by being used for various processing and applications. For example, when the substance to be purified is a metal, the refined metal may be used for casting to produce a cast product, or the cast product may be rolled and used as various metal plates or metal foils. .. Further, this metal foil may be used as an electrode material of, for example, a metal electrolytic capacitor.

In addition, when the purified metal is aluminum, it contains aluminum and a peritectic element that forms peritectic and boron, and boron is 5 to 80 mass ppm more than the total chemical equivalent calculated as a metal boroide with the peritectic element. In the melting step of melting the contained aluminum refining raw material to make a molten metal, and moving the molten metal obtained in the melting process to a reaction chamber, the peritectic element and boron are reacted in the molten metal in the reaction chamber. The reaction step of removing the peritectic element by producing the metal boron and the metal boron produced in the dissolution step and the molten metal obtained in the reaction step are moved to the purification chamber. Then, in the purification chamber, it is desirable to carry out an segregation solidification step of crystallizing high-purity aluminum from which unreacted eutectic elements including boron have been removed by segregation solidification from the molten metal obtained in the reaction step. Further, it is more desirable that the peritectic element in the aluminum refining raw material is at least one selected from the group consisting of Ti, Zr and V.

According to this method, the boron concentration in the raw material for aluminum purification is 5 to 80 mass ppm more than the total chemical equivalent calculated as a metal boride with the peritectic element, so it is packaged from the stage of the dissolution step. The crystallization element and boron react with each other, and a longer reaction time can be secured in combination with the reaction step to generate more metal borides, and the peritectic element can be removed to obtain high-purity aluminum. Moreover, since the thermal energy of dissolution is used for the reaction, the energy cost can be reduced. Then, by performing segregation solidification after the reaction step of removing the metal boride, unreacted eutectic elements containing boron can be removed from the molten metal, and aluminum having a higher purity can be obtained.

Further, since the molten metal obtained in the melting step is moved to the reaction chamber to carry out the continuous treatment in which the reaction step is performed, the productivity of high-purity aluminum is good. Further, since the molten metal obtained in the reaction step is moved to the purification chamber to carry out a continuous treatment in which the segregation solidification step is performed, the productivity of high-purity aluminum is good.

Further, Ti, Zr and V are major peritectic elements in aluminum, and these elements are removed by purification.

[Second Embodiment]
Next, a continuous purification system for high-purity substances according to another embodiment of the present invention will be described. In this system, the case where the high-purity substance is high-purity aluminum will be described as an example.

As the crucible and the cooling body used in this system, the same crucible and the cooling body as described in the above-mentioned [first embodiment] are used. Further, the conditions for purifying a substance such as a metal using each crucible and a cooling body are the same as the purification conditions described in the above-described [first embodiment].

1) Primary line The continuous purification apparatus for high-purity aluminum according to this embodiment is provided with a melting furnace for melting aluminum, and molten metal from the melting furnace is sequentially sent to a plurality of crucibles connected in series to make a final. First, a primary line is configured with a series of devices for discharging molten metal from the crucible to the outside of the system as a set of lines. At this time, it is assumed that each crucible is paired with a rotatable cooling body for crystallizing high-purity aluminum in the molten metal.

At this time, for a plurality of crucibles, for example, one large tank may be divided into a plurality of sections by a partition wall, each section may be used as a crucible, and a communication port may be provided in the partition wall so that the molten metal passes through each crucible. .. Further, a plurality of crucibles may be arranged in series, and each crucible may be connected by a gutter.

When the cooling body paired with each crucible rotates in the molten metal, high-purity aluminum is crystallized on its peripheral surface. The crystallization of aluminum on the peripheral surface of the cooling body occurs when the cooling body is immersed in the molten aluminum in the crucible while rotating, and is cooled by a cooling fluid such as air or steam.

Aluminum is crystallized on the peripheral surface of the cooling body for a predetermined time while removing impurities from the molten metal, and then pulled up while rotating to recover the aluminum from the cooling body outside the crucible.

The greater the cooling capacity of the cooling body, the higher the productivity. On the other hand, since the solidification rate increases, the purification purity decreases. Therefore, it is preferable to set the optimum conditions in consideration of the balance between the purity of the aluminum ingot to be purified and the time required for extraction.

When recovering the crystallized and purified aluminum ingots in the cooling body immersed in each crucible, they may be recovered all at once, but it is desirable to recover them sequentially in consideration of continuous production.

2) Combined line 1. Similar to the primary line, a melting furnace for melting aluminum, a plurality of crucibles connected in series to which molten metal from the melting furnace is sent in order, and a pair of each crucible. One or more sets of lines consisting of a cooling body for crystallizing high-purity aluminum in the molten metal and a series of devices for discharging the molten metal from the final crucible to the outside of the system are further combined. Therefore, an Nth-order line (however, 2 ≦ N) is formed.

2. The aluminum ingots crystallized on the cooler in each crucible in the primary line and collected / purified are continuously melted in the melting furnace of the secondary line and then sent to each crucible in the same manner as in the case of the primary line. Then, in each crucible, it crystallizes into a cooling body and is collected and purified.

3. 3. The purification system specified in the present embodiment consists of an Nth-order line (however, 2≤N) provided with two or more sets of the above-mentioned lines, and a (n-1) -order line (however, 2≤n≤N) is a cooling body. The high-purity aluminum ingot recovered by adhering to and solidifying in the crucible is melted in the melting furnace of the nth order line, and the molten metal is sent to a plurality of crucibles connected in series through a gutter, a communication hole, etc., and in each crucible. , Aluminum is crystallized on the cooling body again, and recovery and purification are repeated.

4. The number of crucibles and paired coolers in the nth line needs to be less than the number of crucibles and paired coolers in the (n-1) next line.

The reasons for this are the four points a to d described below.

The ratio of the total recovery weight SW2 of the refined high-purity aluminum mass to the input aluminum raw material weight SW1 is defined as the recovery rate (SW2 / SW1).
a: The recovery rate (SW2 / SW1) is always less than 1, and it is necessary to lower the recovery rate in order to reduce the impurity concentration from the recovered aluminum ingot. As a result, in order to link the time required for the cooling body to extract the aluminum ingot on the nth-order line and the time required for the aluminum ingot to be extracted on the (n-1) next line, the number of crucibles is n. In the next line, it must be reduced according to the recovery rate than (n-1).
b: When the number of crucibles in the nth-order line is smaller than the number of crucibles in the n-1st-order line, the smaller the ratio of the recovered weight of the n-th-order line to the recovered weight of the n-1st-order line, the higher the purity. An aluminum crucible is obtained.
c: As described above, by installing purification lines in which the crucible is reduced according to the order up to the nth order line, energy efficiency is improved in a small facility area, and eutectic impurities are conventionally disclosed. Equipment / systems that can be further reduced than equipment can be obtained. At this time, for the purpose of comprehensively increasing the energy efficiency of this line, it is desirable that the intervals between the lines are as close as possible.
d: At this time, the molten metal discharged in the second or higher order nth line may be immediately returned to the melting furnace of the (n-1) order line without being cooled or solidified and reused. By this reuse, in the melting furnace of the (n-1) next line, a raw material having the same level of purity as the melting raw material can be used without requiring melting energy, and the energy efficiency is further improved.

3) Line order The line order (N order) is preferably secondary or tertiary. Even if the equipment is constructed beyond the third order, the complexity of the equipment will increase, and the superiority in terms of operation and economy will be poor.

Further, the impurity concentration of the molten metal in the crucibles continuously connected in series in each of the primary to nth orders increases sequentially from the first holding tank toward the final holding tank. Therefore, the more crucibles connected by one line, the higher the recovery efficiency of the refined mass (Al purity for the same recovery weight), but if it is excessive, it becomes difficult to control the molten metal temperature and the like.

Therefore, the number of crucibles that are continuous in series is 8 to 25 in the primary line, and the ratio of the number of n-th order crucibles to the number of (n-1) next-order crucibles is 0.5 to 0.8. It is preferable to set to.

4) Addition of Boron In at least one of the N-order lines, boron may be added to the melting furnaces 11, 21, and 31 to react boron with peritectic impurities such as Ti, Zr, and V. Further, a stirring tank capable of adding boron may be installed between the melting furnace and the crucible with the cooling body. By adding boron in this stirring tank, boron can be reacted with peritectic impurities such as Ti, Zr, and V. Further, boron may be added not only in the melting furnace and the stirring tank but also in the gutter connecting the melting furnace and the stirring tank. Boron is generally, but is not limited to, added as an Al-B (boron / boron) mother alloy. As a method of accelerating the reaction between peritectic impurities and boron after addition, there are a non-contact type molten metal stirring with a permanent magnet, stirring with a graphite rotor, and a method of blowing a processing gas into the molten metal.

5) Separation of peritectic impurities Perforated crystals are removed from the molten metal by reacting peritectic elements such as Ti, Zr, and V with boron to generate and remove insoluble boron compounds by adding and stirring the above-mentioned boron. Impurities can be removed. At this time, the separation of the insoluble boron compound can be mechanically removed as a slag on the surface of the stirring tank.

Further, it is also effective to construct a separation tank between the melting and stirring tank crucibles. In this separation tank, in order to separate the slag floating on the surface of the molten metal into a system other than the crucible, a partition wall is provided between the separation tank and the surface of the molten metal, and a gutter of a different route is provided so that the waste can be discharged. Further, since the insoluble boron compound is an insoluble compound, it may be removed by installing a filter.

[Specific Embodiment]
2 and 3 show a purification system for high-purity aluminum according to an embodiment of the present invention.

In FIG. 2, the aluminum refining system consists of a plurality of consecutive lines consisting of a device for refining aluminum to continuously obtain high-purity aluminum.

In the first primary line, a melting furnace 11 for melting aluminum to be purified containing eutectic impurities and peritectic impurities, and preferably, a stirring tank 12 is continuously arranged in the melting furnace 11. In the stirring tank 12, after adding boron as an Al—B mother alloy into the molten aluminum received from the melting furnace 11, bubbles such as Ar gas are released, the disperser is lowered, and the mixture is immersed in the molten aluminum in the stirring tank 12. Then, air bubbles are released by the driving means and rotated. This state will be described in detail in FIG.

Following the stirring tank 12, a plurality of crucibles 13, 13 ... (10 in this example) are continuously arranged in series. The melting furnace 11, the stirring tank 12, the crucibles 13, 13 ... Are each connected by a gutter 15 for sending the molten metal.

When the molten metal is sent from the stirring tank 12 into the crucibles 13, 13 ... And the predetermined amount is filled, the inside of the molten aluminum of the crucibles 13, 13 ... Is filled with air, gas, steam, etc. Immerse the cooling bodies 130, 130 ... Cooled with the cooling fluid of. When the temperature of the molten aluminum of the crucibles 13, 13 ... Is kept heated to a temperature exceeding the freezing point, the purity to be purified on the surface of each of the cooling bodies 130, 130 ... By the principle of segregation solidification. High aluminum crystallizes to form high purity aluminum crucibles. The molten aluminum having a high impurity concentration in the crucibles 13, 13 ... Is discharged to the discharged molten metal receiver 14.

The aluminum ingot crystallized and extracted on the surface of each of the cooling bodies 130, 130 ... Is pulled up while rotating, and after the rotation is stopped, it is mechanically recovered from the cooling bodies 130, 130 ....

The cooling fluid supplied to each of the cooling bodies 130, 130, ... The higher the cooling capacity, the higher the productivity. On the other hand, when the solidification rate becomes excessively high, the concentration of impurities in the recovered aluminum mass is high. Become. Therefore, it is necessary to consider the optimum purification conditions for the balance between the recovered weight suitable for the purity of the aluminum ingot to be purified and the impurity concentration.

The recovered refined mass is put into the melting furnace 21 of the subsequent secondary line, and the molten metal is sent from the melting furnace 21 to the stirring tank 22 and the continuous crucibles 23, 23, ... As in the primary line. When collecting the purified lumps on the primary line, a method of collecting the purified lumps from all the cooling bodies 130, 130, ... At the same time may be used, but a method of sequentially collecting them in order to maintain continuity in the operation is preferable. In the example shown in FIG. 1, the number of crucibles 23 in the secondary line is set to 5, which is smaller than the number of crucibles 13 in the primary line.

The molten metal having a low impurity concentration dissolved in the melting furnace 21 of the secondary line is stirred in the stirring tank 22 after adding boron in the melting furnace 21 or the stirring tank 22 as in the primary line. Similar to the primary line, the molten metal from the stirring tank 22 is sent to the continuous crucibles 23, 23, ... In series, and when a predetermined amount is filled, the inside is filled with air, gas, steam, etc. The cooling bodies 230, 230 ... Cooled by the cooling fluid are immersed in the molten aluminum of the crucibles 23, 23 ... On the surfaces of the cooling bodies 230, 230, ..., Aluminum crystallized higher than the purity obtained in the primary line to form a lump. The molten aluminum having a high impurity concentration in the crucible is discharged to the discharged molten metal receiver 24.

The refined lumps crystallized on the surfaces of the cooling bodies 230, 230, ... Of the secondary line are pulled up while rotating, stopped rotating, and then collected.

The recovered refined mass is put into the melting furnace 31 of the subsequent tertiary line, and the molten metal is sent from the melting furnace 31 to the stirring tank 32 and the continuous crucibles 33, 33 ... Like the primary line. Purified lumps are sequentially collected by the cooling bodies 330, 330 ... Corresponding to the crucibles 33, 33 ... In the example shown in FIG. 2, the number of crucibles 33 in the tertiary line is set to three, which is smaller than the number of crucibles 13 in the secondary line.

In all lines or some lines, a separation tank capable of removing the insoluble boron compound purified in the stirring tank may be provided between the stirring tank crucibles. In the example shown in FIG. 2, a separation tank 35 is provided between the stirring tank 32 and the crucible 33 of the tertiary line.

The separation tank 35 not only separates the insoluble boron compound floating and separated by bubbles, but also removes the insoluble boron compound that settles in the molten metal. Therefore, a filter may be installed in the separation tank. At this time, the molten aluminum having a high impurity concentration in the crucibles 33, 33 ... Is discharged to the discharged molten metal receiver 34.

FIG. 3 describes the configurations of the melting furnace 31, the stirring tank 32, the crucible 33, and the like in the tertiary line, but the configurations of the melting furnace, the stirring tank, and the crucible in the other lines are the same.

A connecting gutter 36 as a receiving gutter for receiving the molten metal supplied from the melting furnace 31 is provided at the upper end of the stirring tank 32, and a connecting gutter 36 as a molten metal discharge gutter is provided at the upper end of the crucible 33 farthest from the melting furnace 31. Is provided, and the space between the stirring tanks 32 and the crucibles 33 and the crucibles 33 are connected by a connecting gutter 36.

In the stirring tank 32, a disperser including a rotating shaft 321 which is driven up and down by a driving means (not shown) and is rotated, and a rotating body 322 for dispersion provided fixedly at the lower end of the rotating shaft 321. 320 is arranged. A processing gas passage extending in the length direction is formed inside the rotating shaft 321, and a processing gas outlet (not shown) communicating with the processing gas passage is provided on the lower end surface of the dispersion rotating body 322. At the same time, a plurality of protrusions for promoting stirring are formed at intervals in the circumferential direction. Then, when the processing gas is supplied to the processing gas passage while rotating the rotating shaft 321, the stored molten metal is agitated and the processing gas is released from the processing gas outlet into the molten metal as fine bubbles, and the molten metal 60 It is distributed throughout.

Further, at a position corresponding to the hot water outlet 323 of the stirring tank 32, the horizontal cross section is substantially U-shaped vertical so as to cover the inner end of the stirring tank 32 of the hot water outlet 323 and the portion of the inner surface of the stirring tank 32 that is connected to the lower side of the hot water outlet 323. A partition wall 324 is provided. The vertical partition wall 324 can prevent the insoluble boron compound produced by the reaction of boron and the peritectic element from flowing out to the crucible on the downstream side thereof.

The molten metal that has passed through the stirring tank 32 flows into the separation tank 35. A partition wall 351 is provided in the separation tank 35, and the molten metal 60 from which the insoluble boron compound and the insoluble boron compound settling in the molten metal have been removed flows into the crucible 33 in the next stage.

The above-mentioned cooling bodies 330, 330 ... Are arranged in the crucibles 33, 33 ... By being connected to a rotating shaft 331 that is vertically driven and rotationally driven by a driving means (not shown). Each rotating shaft 331 is internally formed with a cooling fluid passage (not shown) extending in the length direction. Further, each cooling body 330 has a bottomed inverted truncated cone shape in which the cross-sectional area decreases downward, an internal space communicating with the cooling fluid passage is formed, and the cooling fluid is passed through the cooling fluid passage to the internal space. The outer peripheral surface in contact with the molten metal can be maintained at a predetermined temperature by supplying the fluid. Therefore, the cooling body 330 is preferably formed of a material having good thermal conductivity, for example, graphite, as well as not contaminating the molten metal by reacting with the molten aluminum. Further, the cooling body 330 is set to a height at which a portion excluding the upper end portion is immersed in the molten aluminum.

FIG. 4 shows another embodiment. In this example, the system is composed of tertiary lines as in the system shown in FIG. 2, and the configuration of the device in each line is shown in FIG. 2 except that the separation tank 35 in the tertiary line is not installed. It is the same as the one.

The system shown in FIG. 4 has an opening in which an Al-B alloy or a boron-containing material equivalent thereto can be appropriately charged in the melting furnace 21 and the stirring tank 22 in the secondary line. The molten metal received from the melting furnace 21 in the gutter reaches the stirring tank 22.

Thus, in the example of FIG. 4, the excess molten metal that has passed through the crucibles 23, 23, ... Is returned from the crucible 23 in the final stage to the melting furnace 11 of the primary line by the return device 27. It is supposed to be a crucible.

Further, the excess molten metal that has passed through the crucibles 33, 33, ... Of the tertiary line is also returned from the final crucible 33 to the melting furnace 21 of the secondary line by the return device 37. ..

In this way, by returning the excess molten metal from the final crucible to the melting furnace in the previous line, the molten metal can be used efficiently, and the system has excellent operability.

[Example according to the first embodiment]
(Example 1)
An aluminum molten metal (former molten metal) made of an aluminum raw material having an impurity concentration (mass ppm) shown in Table 1 was placed in a crucible 1 and refined. The purification equipment and purification conditions are as follows.

As shown in FIG. 1, the crucible 1 is a bottomed cylinder having an inner diameter (same as the inner diameter of the opening) D of 480 mm and a depth H of 850 mm on the upper surface of the molten metal, and the bottom surface is formed in a downward arc surface. There was. The cooling body 2 was made of graphite having a truncated cone shape with a large diameter on the upper end side and an outer diameter d of 180 mm on the upper surface of the molten metal.

Then, 1500 liters / minute of compressed air was circulated inside the cooling body 2 as a cooling medium, and the cooling body 2 was purified at a constant rotation speed of 4000 mm / s for 6 minutes.

At this time, the shortest horizontal distance L1 between the inner peripheral surface of the molten metal upper surface of the crucible 1 and the outer peripheral surface of the cooling body 2 in the horizontal direction is 150 mm, and the inner peripheral surface of the crucible 1 and cooling are performed over the entire area where the molten aluminum exists in the crucible 1. The horizontal distance L2 at the lowermost end of the body 2 is 100 mm, the distance A from the bottom surface of the cooling body 2 to the bottom surface of the crucible 1 is 430 mm, and the immersion depth a of the cooling body 2 in the molten aluminum 6 is 200 mm. The value of A / a was 2.15.

Further, the temperature of the cooling body 2 was set to 350 ° C. when immersed in the molten metal 6, and the cooling body 2 was not rotated when immersed in the molten metal 6 and when withdrawn from the molten metal after purification for 6 minutes.

(Examples 2 to 10, Comparative Examples 1 and 2)
Under the same conditions as in Example 1 except that the distance A from the bottom surface of the cooling body 2 to the bottom surface of the crucible 1 and the value of the immersion depth a of the cooling body 2 in the molten aluminum 6 were changed as shown in Table 1. , Purified. The impurity concentrations of the molten aluminum are as shown in Table 1.

(Example 11)
Under the conditions of Example 4, when immersing in the molten metal 6, the temperature of the cooling body 2 is set to 470 ° C. (solid phase line temperature of aluminum × 0.7), and the smallest diameter portion of the portion immersed in the molten metal 6 is set. The cooling body 2 was immersed while rotating at a peripheral speed of 5000 mm / s, and the peripheral speed was maintained from the start of purification to the total purification time × 0.1. After that, the peripheral speed was set to 4000 mm / s.

After crystallizing the refined aluminum for 6 minutes, the peripheral speed of the surface of the lowermost end of the purified aluminum crystallized in the cooling body 2 is set to 2500 mm / s, and the lowermost end of the cooling body 2 is completely separated from the molten aluminum. The rotation speed was maintained until it was pulled up.

Table 1 shows the weight, impurity concentration and purification efficiency of the refined aluminum mass obtained as described above. The purification efficiency is calculated by the ratio of the impurity concentration of the obtained refined aluminum mass to the impurity concentration contained in the original molten aluminum.

Table 1 also shows the quality of energy efficiency and equipment difficulty. Regarding energy efficiency, ◎ indicates extremely good, 〇 indicates good, Δ indicates normal, and regarding equipment difficulty, ◎ indicates low, 〇 indicates slightly low, and Δ indicates normal. About molten metal splash ◎ indicates no, and 〇 indicates almost none.

As can be understood from the results in Table 1, the purification efficiency of Examples 1 to 11 was higher than that of Comparative Example 1. Further, in Example 11, the purification efficiency was higher than that in Example 4, the weight of the purified lump was large, and the splashing of the molten metal could be suppressed. Further, it can be seen that the purification efficiency is saturated in Comparative Example 2.

[Example according to the second embodiment (Example according to the system shown in FIG. 2)]
Table 2 shows the composition of the aluminum raw material used in the refining system and the aluminum ingot after refining, and Table 3 shows each refining condition.

Furthermore, the purification contents under each condition and examples of comparative examples will be described in detail after the table.

(Example 21)
As shown in FIG. 5, aluminum is refined by a continuous double refining system in which the number of crucibles 13 and 23 in which the cooling bodies 130 and 230 are arranged is set to 10 in the primary line and 5 in the secondary line. did. The composition contained in the original aluminum is Fe 0.04%, Si 0.02%, Ti 0.001%, V 0.003% by weight.

The rotation speed of the carbon cooling body was 400 rpm, air was flowed to cool the inner surface, and the mixture was purified in a molten metal for 8 minutes, and the crystallized high-purity aluminum was pulled up and recovered. This operation was repeated for more than a day, and during the operation, the original aluminum was always melted and supplied, and consideration was given to maintaining a constant water level at all times. Both the primary line and the secondary line were carried out under the same conditions.

Further, as the crucibles 13, 23 and the cooling bodies 130, 230, those having the same specifications as those of the first embodiment in the first embodiment were used. However, a communication hole is formed in each crucible so that the value of A + a, which is the height of the liquid level of the molten metal, is the same as that of the first embodiment, and the molten metal is sent from the upstream side beyond the liquid level at that height. In the case of a crucible, the molten metal is discharged to the downstream side through the communication hole. The recovery rate (total recovered weight of refined high-purity aluminum mass / weight of input aluminum raw material) is 33%.

At this time, the average composition of the high-purity aluminum ingots obtained on the secondary line was Fe0.0016%, Si0.0023%, Ti0.002%, and V0.005%.

(Example 22)
As shown in FIG. 6, aluminum is refined by a continuous double refining system in which the number of crucibles 13 and 23 in which the cooling bodies 130 and 230 are arranged is set to 10 in the primary line and 5 in the secondary line. did. The composition contained in the original aluminum is Fe 0.04%, Si 0.02%, Ti 0.001%, and V 0.003%. Boron was added to the stirring tanks 12 and 22 arranged in the next stage of the melting furnaces 11 and 21 in the primary line and the secondary line so as to have a concentration of 0.007%.

The rotation speed of the cooling body (material carbon) was 400 rpm, and air was flowed to cool the inner surface, purified in a molten metal for 8 minutes, and crystallized high-purity aluminum was pulled up and recovered. This operation was repeated for more than a day, and during the operation, the original aluminum was always melted and supplied, and consideration was given to maintaining a constant water level at all times. Both the primary line and the secondary line were carried out under the same conditions.

Further, as the crucibles 13, 23 and the cooling bodies 130, 230, those having the same specifications as those of the first embodiment in the first embodiment were used. However, a communication hole is formed in each crucible so that the value of A + a, which is the height of the liquid level of the molten metal, is the same as that of the first embodiment, and the molten metal is sent from the upstream side beyond the liquid level at that height. In the case of a crucible, the molten metal is discharged to the downstream side through the communication hole. The recovery rate is 33%.

At this time, the average composition of the high-purity aluminum ingots obtained on the secondary line was Fe0.0015%, Si0.0022%, Ti0.0001%, V0.0003%, and B0.0015%.

Under the same conditions as above, except that boron was added to the melting furnaces 11 and 21 in the primary line and the secondary line so that the concentration was 0.007% without providing the stirring tanks 12 and 22. As a result of the test, the same results as above were obtained in terms of the recovery rate and the average composition of the high-purity aluminum ingots obtained in the secondary line.

(Example 23)
As shown in FIG. 7, the number of crucibles 13, 23, 33 in which the cooling bodies 130, 230, and 330 are arranged is set to 10 in the primary line, 5 in the secondary line, and 3 in the tertiary line. Aluminum was purified in a continuous three-time purification system. The composition contained in the original aluminum is Fe 0.04%, Si 0.02%, Ti 0.001%, and V 0.003%. Boron was added to the stirring tanks 12, 22 and 32 arranged in the next stage of the melting furnaces 11, 21 and 31 in the primary line, the secondary line and the tertiary line so as to have a concentration of 0.006%.

The purification conditions such as the rotation speed of the cooling body (material carbon), the cooling conditions, and the immersion time of the molten metal are the same as those in Example 21. This operation was repeated for more than a day, and during the operation, the original aluminum was always melted and supplied, and consideration was given to maintaining a constant water level at all times. The primary line, secondary line, and tertiary line were all carried out under the same conditions.

Further, as the crucibles 13, 23, 33 and the cooling bodies 130, 230, 330, those having the same specifications as those of the first embodiment in the first embodiment were used. However, a communication hole is formed in each crucible so that the value of A + a, which is the height of the liquid level of the molten metal, is the same as that of the first embodiment, and the molten metal is sent from the upstream side beyond the liquid level at that height. In the case of a crucible, the molten metal is discharged to the downstream side through the communication hole. The recovery rate is 18%.

At this time, the average composition of the high-purity aluminum ingots obtained in the tertiary line was Fe0.0005%, Si0.0011%, Ti0.0001%, V0.0002%, and B0.0012%.

(Example 24)
As shown in FIG. 8, the number of crucibles 13, 23, 33 in which the cooling bodies 130, 230, and 330 are arranged is set to 10 in the primary line, 5 in the secondary line, and 3 in the tertiary line. Aluminum was purified in a continuous three-time purification system. The composition contained in the original aluminum is Fe 0.04%, Si 0.02%, Ti 0.001%, and V 0.003%. Boron was added to the stirring tanks 12, 22 and 32 arranged in the next stage of the melting furnaces 11, 21 and 31 in the primary line, the secondary line and the tertiary line so as to have a concentration of 0.006%.

At this time, separation tanks 16, 26, and 35 were installed between the stirring tanks 12, 22, and 32 crucibles 13, 23, and 33 to which B was added in each line. The purification conditions such as the rotation speed of the cooling body (material carbon), the cooling conditions, and the immersion time of the molten metal are the same as those in Example 21. This operation was repeated for more than a day, and during the operation, the original aluminum was always melted and supplied, and consideration was given to maintaining a constant water level at all times. The primary line, secondary line, and tertiary line were all carried out under the same conditions.

Further, as the crucibles 13, 23 and the cooling bodies 130, 230, those having the same specifications as those of the first embodiment in the first embodiment were used. However, a communication hole is formed in each crucible so that the value of A + a, which is the height of the liquid level of the molten metal, is the same as that of the first embodiment, and the molten metal is sent from the upstream side beyond the liquid level at that height. In the case of a crucible, the molten metal is discharged to the downstream side through the communication hole. The recovery rate is 18%.

At this time, the average composition of the high-purity aluminum ingots obtained in the tertiary line was Fe0.0005%, Si0.0010%, Ti0.0001%, V0.0001%, and B0.0011%.

(Example 25)
As shown in FIG. 9, the number of crucibles 13, 23, 33, 43 in which the cooling bodies 130, 230, 330, and 430 are arranged is 10 in the primary line, 5 in the secondary line, and 3 in the tertiary line. Aluminum was refined by a continuous four-time purification system set to two in the quaternary line. The composition contained in the original aluminum is Fe 0.04%, Si 0.02%, Ti 0.001%, and V 0.003%. The concentration of boron in the stirring tanks 12, 22, 32, and 42 arranged in the next stage of the melting furnaces 11, 21, 31, and 41 in the primary line, secondary line, tertiary line and quaternary line is 0.005%. It was added so as to become.

The purification conditions such as the rotation speed of the cooling body (material carbon), the cooling conditions, and the immersion time of the molten metal are the same as those in Example 21. This operation was repeated for more than a day, and during the operation, the original aluminum was always melted and supplied, and consideration was given to maintaining a constant water level at all times. The primary line, secondary line, tertiary line, and quaternary line were all carried out under the same conditions.

Further, as the crucibles 13, 23, 33, 43 and the cooling bodies 130, 230, 330, 430, those having the same specifications as those of the first embodiment in the first embodiment were used. However, a communication hole is formed in each crucible so that the value of A + a, which is the height of the liquid level of the molten metal, is the same as that of the first embodiment, and the molten metal is sent from the upstream side beyond the liquid level at that height. In the case of a crucible, the molten metal is discharged to the downstream side through the communication hole. The recovery rate is 12%.

At this time, the average composition of the high-purity aluminum ingots obtained in the fourth line was Fe0.0003%, Si0.0006%, Ti0.0001%, V0.0001%, and B0.0009%.

(Comparative Example 26)
Purification was performed under the same conditions as in Example 21 except that the crucibles 13 and 23 and the cooling bodies 130 and 230 had the same specifications as in Comparative Example 1 in the first embodiment.

The recovery rate at this time was 33%, and the average composition of the obtained high-purity aluminum ingot was Fe0.0022%, Si0.003%, Ti0.002%, and V0.005%.

As can be seen from Table 2, the concentration of each element was lower in the method of the example than in the comparative example.

[Example according to the second embodiment (Example according to the system shown in FIG. 4)]
Table 4 shows the composition of the aluminum base material used in the refining system and the aluminum ingot after refining, and Table 5 shows each refining condition.

Furthermore, the purification contents under each condition and examples of comparative examples will be described in detail after the table.

(Example 27)
As shown in FIG. 10, aluminum is refined by a continuous double refining system in which the number of crucibles 13 and 23 in which the cooling bodies 130 and 230 are arranged is set to 10 in the primary line and 5 in the secondary line. did. The composition contained in the original aluminum is Fe 0.04%, Si 0.02%, Ti 0.001%, V 0.003% by weight.

At this time, it was assumed that the molten metal was returned from the crucible 23 at the end of the secondary line to the melting furnace 11 of the primary line through the molten metal returning device 27.

The rotation speed of the carbon cooling body was 400 rpm, air was flowed to cool the inner surface, and the mixture was purified in a molten metal for 8 minutes, and the crystallized high-purity aluminum was pulled up and recovered. This operation was repeated for more than a day, and during the operation, the original aluminum was always melted and supplied, and consideration was given to maintaining a constant water level at all times. Both the primary line and the secondary line were carried out under the same conditions.

Further, as the crucibles 13, 23 and the cooling bodies 130, 230, those having the same specifications as those of the first embodiment in the first embodiment were used. However, a communication hole is formed in each crucible so that the value of A + a, which is the height of the liquid level of the molten metal, is the same as that of the first embodiment, and the molten metal is sent from the upstream side beyond the liquid level at that height. In the case of a crucible, the molten metal is discharged to the downstream side through the communication hole. The recovery rate (total recovered weight of high-purity aluminum ingot / original aluminum supply amount) is 75%.

At this time, the average composition of the high-purity aluminum ingots obtained in the secondary line was Fe0.0015%, Si0.0022%, Ti0.002%, and V0.005%.

(Example 28)
As shown in FIG. 11, aluminum is refined by a continuous double refining system in which the number of crucibles 13 and 23 in which the cooling bodies 130 and 230 are arranged is set to 10 in the primary line and 5 in the secondary line. did. The composition contained in the original aluminum is Fe 0.04%, Si 0.02%, Ti 0.001%, and V 0.003%. Boron was added to the stirring tanks 12 and 22 arranged in the next stage of the melting furnaces 11 and 21 in the primary line and the secondary line so as to have a concentration of 0.007%.

At this time, the molten metal is returned from the crucible 23 at the end of the secondary line to the melting furnace 11 of the primary line through the molten metal returning device 27.

The rotation speed of the cooling body (material carbon) was 400 rpm, and air was flowed to cool the inner surface, purified in a molten metal for 8 minutes, and crystallized high-purity aluminum was pulled up and recovered. This operation was repeated for more than a day, and during the operation, the original aluminum was always melted and supplied, and consideration was given to maintaining a constant water level at all times. Both the primary line and the secondary line were carried out under the same conditions.

Further, as the crucibles 13, 23 and the cooling bodies 130, 230, those having the same specifications as those of the first embodiment in the first embodiment were used. However, a communication hole is formed in each crucible so that the value of A + a, which is the height of the liquid level of the molten metal, is the same as that of the first embodiment, and the molten metal is sent from the upstream side beyond the liquid level at that height. In the case of a crucible, the molten metal is discharged to the downstream side through the communication hole. The recovery rate is 75%.

At this time, the average composition of the high-purity aluminum ingots obtained on the secondary line was Fe0.0015%, Si0.0021%, Ti0.0001%, V0.0003%, and B0.0012%.

(Example 29)
As shown in FIG. 12, the number of crucibles 13, 23, 33 in which the cooling bodies 130, 230, and 330 are arranged is set to 10 in the primary line, 5 in the secondary line, and 3 in the tertiary line. Aluminum was purified in a continuous three-time purification system. The composition contained in the original aluminum is Fe 0.04%, Si 0.02%, Ti 0.001%, V 0.003% by weight. Boron was added to the stirring tanks 12, 22 and 32 arranged in the next stage of the melting furnaces 11, 21 and 31 in the primary line, the secondary line and the tertiary line so as to have a concentration of 0.006%.

At this time, from the crucible 23 at the end of the secondary line to the melting furnace 11 of the primary line through the molten metal return device 27, from the crucible 33 at the end of the tertiary line through the melt return device 37, the secondary line The molten metal is returned to the melting furnace 21. The purification conditions such as the rotation speed of the cooling body (material carbon), the cooling conditions, and the immersion time of the molten metal are the same as those in Example 21. This operation was repeated for more than a day, and during the operation, the original aluminum was always melted and supplied, and consideration was given to maintaining a constant water level at all times. The primary line, secondary line, and tertiary line were all carried out under the same conditions.

Further, as the crucibles 13, 23, 33 and the cooling bodies 130, 230, 330, those having the same specifications as those of the first embodiment in the first embodiment were used. However, a communication hole is formed in each crucible so that the value of A + a, which is the height of the liquid level of the molten metal, is the same as that of the first embodiment, and the molten metal is sent from the upstream side beyond the liquid level at that height. In the case of a crucible, the molten metal is discharged to the downstream side through the communication hole. The recovery rate is 75%.

At this time, the average composition of the high-purity aluminum ingots obtained in the tertiary line was Fe0.0005%, Si0.0011%, Ti0.0001%, V0.0002%, and B0.0010%.

(Example 30)
As shown in FIG. 13, the number of crucibles 13, 23, 33 in which the cooling bodies 130, 230, and 330 are arranged is set to 10 in the primary line, 5 in the secondary line, and 3 in the tertiary line. Aluminum was purified in a continuous three-time purification system. The composition contained in the original aluminum is Fe 0.04%, Si 0.02%, Ti 0.001%, and V 0.003%. Boron was added to the stirring tanks 12, 22 and 32 arranged in the next stage of the melting furnaces 11, 21 and 31 in the primary line, the secondary line and the tertiary line so as to have a concentration of 0.006%.

At this time, the separation tanks 16, 26, and 35 were installed and used between the stirring tanks 12, 22, and 32 crucibles 13, 23, and 33 to which B was added in each line. The purification conditions such as the rotation speed of the cooling body (material carbon), the cooling conditions, and the immersion time of the molten metal are the same as those in Example 21. This operation was repeated for more than a day, and during the operation, the original aluminum was always melted and supplied, and consideration was given to maintaining a constant water level at all times. The primary line, secondary line, and tertiary line were all carried out under the same conditions.

Further, as the crucibles 13, 23, 33 and the cooling bodies 130, 230, 330, those having the same specifications as those of the first embodiment in the first embodiment were used. However, a communication hole is formed in each crucible so that the value of A + a, which is the height of the liquid level of the molten metal, is the same as that of the first embodiment, and the molten metal is sent from the upstream side beyond the liquid level at that height. In the case of a crucible, the molten metal is discharged to the downstream side through the communication hole. The recovery rate is 75%.

At this time, the average composition of the high-purity aluminum ingots obtained in the tertiary line was Fe0.0005%, Si0.001%, Ti0.0001%, V0.0001%, and B0.0010%.

(Example 31)
As shown in FIG. 14, the number of crucibles 13, 23, 33, 43 in which the cooling bodies 130, 230, 330, and 430 are arranged is 10 in the primary line, 5 in the secondary line, and 3 in the tertiary line. Aluminum was refined by a continuous four-time refining system set to two in the quaternary line. The composition contained in the original aluminum is Fe 0.04%, Si 0.02%, Ti 0.001%, and V 0.003%. The concentration of boron in the stirring tanks 12, 22, 32, and 42 arranged in the next stage of the melting furnaces 11, 21, 31, and 41 in the primary line, secondary line, tertiary line and quaternary line is 0.005%. It was added so as to become.

The purification conditions such as the rotation speed of the cooling body (material carbon), the cooling conditions, and the immersion time of the molten metal are the same as those in Example 21. This operation was repeated for more than a day, and during the operation, the original aluminum was always melted and supplied, and consideration was given to maintaining a constant water level at all times. The primary line, secondary line, tertiary line, and quaternary line were all carried out under the same conditions.

Further, as the crucibles 13, 23, 33, 43 and the cooling bodies 130, 230, 330, 430, those having the same specifications as those of the first embodiment in the first embodiment were used. However, a communication hole is formed in each crucible so that the value of A + a, which is the height of the liquid level of the molten metal, is the same as that of the first embodiment, and the molten metal is sent from the upstream side beyond the liquid level at that height. In the case of a crucible, the molten metal is discharged to the downstream side through the communication hole. The recovery rate is 75%.

At this time, the average composition of the high-purity aluminum ingots obtained in the fourth line was Fe0.0003%, Si0.0006%, Ti0.0001% or less, V0.0001%, and B0.0008%.

11, 21, 31, 41 Melting furnace 12, 22, 32, 42 Stirring tank 1, 13, 23, 33, 43 Crucible (molten metal holding container)
2,130,230,330 Cooler 16,26,35 Separation tank 15,25,36,46 Gutter 27,37,47 Melt return device 6,60 Molten

Claims (21)

In a substance purification method in which a cooling body is immersed in a molten substance to be purified contained in a molten metal holding container, and crystals of the substance are crystallized on the surface of the cooling body while rotating the cooling body.
The ratio A / a of the distance A from the bottom surface of the cooling body to the bottom surface of the molten metal holding container and the immersion depth a of the cooling body in the molten substance, which is the distance from the liquid surface of the molten material to the bottom surface of the cooling body, is , 0.3 ≦ A / a ≦ 3.0. The substance purification method according to claim 1, wherein the immersion depth a of the cooling body in the molten substance is 150 mm or more and 500 mm or less, and the distance A from the bottom surface of the cooling body to the bottom surface of the molten metal holding container is 700 mm or less. The substance purification method according to claim 1 or 2, wherein A / a is 0.5 ≦ A / a ≦ 2.0. The temperature of the cooling body when the cooling body is immersed in the molten substance while rotating so that the peripheral speed of the cooling body is 700 mm / s or more and less than 8000 mm / s is set to the substance. The substance purification method according to any one of claims 1 to 3, wherein the solidus temperature of 0.7 or more and the solidus temperature or less. When crystals of the substance are crystallized on the surface of the cooling body and grown, and then the cooling body is pulled up from the molten substance, the peripheral speed of the crystal portion crystallized on the cooling body at the interface with the molten substance is 700 mm / s or more. The substance purification method according to any one of claims 1 to 4, wherein the cooling body is pulled up while rotating so as to be less than 8000 mm / s. The substance purification method according to any one of claims 1 to 5, wherein the maximum peripheral speed of the cooling body at the initial stage of purification after immersion in the cooling body is higher than the average peripheral speed thereafter. The substance purification method according to claim 6, wherein the initial purification period is from the start of purification to the total purification time × 0.1 (however, 10 seconds or more and 120 seconds or less). The substance purification method according to any one of claims 1 to 7, wherein the substance is aluminum. A molten metal holding container for containing a molten substance to be purified and a rotatable cooling body immersed in the molten substance contained in the molten metal holding container are provided.
The ratio A / a of the distance A from the bottom surface of the cooling body to the bottom surface of the molten metal holding container and the immersion depth a of the cooling body in the molten substance, which is the distance from the liquid surface of the molten material to the bottom surface of the cooling body, is , 0.3 ≦ A / a ≦ 3.0. The substance refining apparatus according to claim 9, wherein the immersion depth a of the cooling body in the molten substance is set to 150 mm or more and 500 mm or less, and the distance A from the bottom surface of the cooling body to the bottom surface of the molten metal holding container is set to 700 mm or less. The substance purification apparatus according to claim 9 or 10, wherein A / a is 0.5 ≦ A / a ≦ 2.0. A plurality of series-connected molten metal holding containers used in a melting furnace for melting a substance and the substance refining apparatus according to any one of claims 9 to 11, in which molten metal from the melting furnace is sequentially fed. And a rotatable cooling body used in the substance purification apparatus according to any one of claims 9 to 11, which is paired with each molten metal holding container and for crystallizing a high-purity substance in the molten metal. , A series of devices for discharging molten metal from the final molten metal holding container to the outside of the system is made into one set of lines.
The high-purity material mass was recovered by adhering to and solidifying the cooling body in the (n-1) order line (however, 2 ≦ n ≦ N), which consisted of N-order lines (where 2 ≦ N) in which a plurality of sets of the above lines were used. Is melted in the melting furnace of the nth order line, and the molten metal melted in the melting furnace is sequentially passed through the molten metal holding container and discharged.
In addition, the number of the molten metal holding container and the cooling body arranged in pairs with the holding tank of the nth line is smaller than that of the (n-1) order line, which is a continuous purification system for high-purity substances. .. The continuous purification system for high-purity substances according to claim 12, wherein the order N of the line is 2 or 3. The continuous purification system for a high-purity substance according to claim 12 or 13, wherein the substance is aluminum, and boron is added to a melting furnace of one or more of the plurality of lines. .. A stirring tank capable of adding boron is installed between the melting furnace and the molten metal holding container, and boron is added at any place between the melting furnace and the stirring tank. The continuous purification system for high-purity substances according to claim 14. The continuous purification system for high-purity substances according to claim 14 or 15, wherein a separation tank capable of separating and extracting peritectic impurities as an insoluble boron compound is installed between the melting furnace and the molten metal holding container. .. A plurality of series-connected molten metal holding containers used in a melting furnace for melting a substance and the substance refining apparatus according to any one of claims 9 to 11, in which molten metal from the melting furnace is sequentially fed. And a rotatable cooling body used in the substance purification apparatus according to any one of claims 9 to 11, which is paired with each molten metal holding container and for crystallizing a high-purity substance in the molten metal. In preparation, a series of devices for discharging molten metal from the final molten metal holding container to the outside of the system is made into one set of lines.
A high-purity substance in which a plurality of sets of the above lines are used (however, 2 ≦ N), and the (n-1) order line (however, 2 ≦ n ≦ N) is adhered to and solidified on the rotary cooling body and recovered. The lump is melted in the melting furnace of the subsequent n-th order line, and the molten metal melted in the melting furnace is sequentially passed through the molten metal holding container and discharged.
The molten metal discharged in the primary line is discharged outside the line, while the molten metal discharged in the nth line is returned to the melting furnace of the (n-1) primary line.
In addition, the number of the molten metal holding container and the cooling body arranged in pairs with the holding tank of the nth line is smaller than that of the (n-1) order line, which is a continuous purification system for high-purity substances. .. The continuous purification system for high-purity substances according to claim 17, wherein the order N of the line is 2 or 3. The continuous purification system for a high-purity substance according to claim 17 or 18, wherein the substance is aluminum, and boron is added to a melting furnace of one or more of the plurality of lines. .. A stirring tank capable of adding boron is installed between the melting furnace and the molten metal holding container, and boron is added at any place between the melting furnace and the stirring tank. The continuous purification system for high-purity substances according to claim 19. The continuous purification system for high-purity substances according to claim 19 or 20, wherein a separation tank capable of separating and extracting peritectic impurities as an insoluble boron compound is installed between the melting furnace and the molten metal holding container. ..

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