JP3713564B2 - Metal purification equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a purification apparatus that uses segregation solidification to purify a metal such as aluminum or silicon containing eutectic impurities to produce a higher purity metal.
[0002]
[Prior art and problems to be solved by the invention]
For example, as an aluminum refining device, a crucible, a vertical hollow rotating shaft, a hollow rotating cooling body fixed to the lower end of the hollow rotating shaft, a cooling fluid supply pipe arranged in the hollow rotating shaft, and a rotation A hollow cylindrical cooling fluid blowing member disposed in a cooling body and communicated with a cooling fluid supply pipe is provided, and a plurality of cooling fluid blowing ports are formed on the peripheral wall of the cooling fluid blowing member. (See Japanese Patent Publication No. 3-65415). Although not described in the above publication, such a refining apparatus includes a melting furnace that opens upward and includes a heating means and accommodates a crucible, and a rotation driving means that rotationally drives a hollow rotating shaft. The upper end portion of the hollow rotary shaft and the upper end portion of the cooling fluid supply pipe are connected to the rotary joint, and the upper end portion of the cooling fluid supply pipe is communicated with a cooling fluid inlet formed in the body of the rotary joint. This rotary joint is a so-called single hole type having only a cooling fluid inlet in the body. A partition wall is provided at an intermediate portion of the length of the hollow rotary shaft, and the cooling fluid supply pipe penetrates the partition wall in an airtight manner. Further, a cooling fluid delivery port is formed in the peripheral wall of the hollow rotary shaft below the partition wall. Further, below the partition wall, a portion between the inner peripheral surface of the hollow rotary shaft and the outer peripheral surface of the cooling fluid supply pipe is a cooling fluid passage. Then, the hollow rotary cooling body is immersed in the molten metal placed in the crucible, and the hollow rotary cooling body is rotated by rotating the hollow rotary shaft by the rotation driving means, and the cooling fluid supply pipe is used to rotate the cooling fluid blowing member. A cooling fluid is supplied to the inside, and a high-purity metal is crystallized on the outer peripheral surface of the hollow rotating cooling body while blowing the cooling fluid into the hollow rotating cooling body from the cooling fluid outlet of the cooling fluid blowing member. . The cooling fluid blown out from the blowing member is discharged into the atmosphere from the cooling fluid delivery port through the cooling fluid passage.
[0003]
However, in such a refining apparatus, since the melting furnace is opened upward, contamination of the molten metal in the crucible occurs due to dust in the atmosphere, and high purity, for example, a metal having a purity of 99.9999 wt% or more. There was a problem that could not get.
[0004]
Further, for example, as a silicon refining device, a closed melting furnace equipped with a heating means, a molten silicon holding crucible arranged in the melting furnace, a vertical hollow rotating shaft arranged through the top wall of the melting furnace, a hollow A hollow rotary cooling body integrally provided at the lower end of the rotating shaft, and a cooling fluid supply pipe arranged in the hollow rotating shaft, and a large number of peripheral walls of the portion existing in the hollow rotary cooling body in the cooling fluid supply pipe There is known one in which a cooling fluid outlet is formed (see JP-A-63-45112). Although not described in the above publication, such a refining device is provided with a rotational drive means for rotationally driving the hollow rotary shaft, and the upper end portion of the hollow rotary shaft and the upper end portion of the cooling fluid supply pipe are connected to the rotary joint. The upper end of the cooling fluid supply pipe is connected to a cooling fluid inlet formed in the body of the rotary joint. This rotary joint is a so-called single hole type having only a cooling fluid inlet in the body. A partition wall is provided at an intermediate portion of the length of the hollow rotary shaft, and the cooling fluid supply pipe penetrates the partition wall in an airtight manner. Further, a cooling fluid delivery port is formed in the peripheral wall of the hollow rotary shaft below the partition wall. Further, below the partition wall, a portion between the inner peripheral surface of the hollow rotary shaft and the outer peripheral surface of the cooling fluid supply pipe is a cooling fluid passage. Then, in order to prevent oxidation of silicon in the melting furnace, an inert gas atmosphere or a vacuum atmosphere is used, and a hollow rotating cooling body is immersed in molten silicon placed in a crucible, and the hollow rotating shaft is rotated by a rotation driving means. And rotating the hollow rotary cooling body, and blowing out the cooling fluid from the cooling fluid outlet of the cooling fluid supply pipe into the hollow rotary cooling body, and crystallizing high-purity silicon on the outer peripheral surface thereof. . The cooling fluid blown from the cooling fluid outlet of the cooling fluid supply pipe into the hollow rotating cooling body flows upward through the cooling fluid passage and is sent out to the atmosphere from the cooling fluid outlet.
[0005]
Incidentally, Japanese Patent Laid-Open No. 63-45112 does not disclose any sealing device between the top wall of the melting furnace and the outer peripheral surface of the hollow rotating shaft. It is considered that a known packing is generally used as the oil seal. However, there are the following problems in this case. That is, the cooling fluid blown out from the outlet of the cooling fluid supply pipe into the hollow rotary cooling body is heated to a temperature exceeding 200 ° C. by the heat of the molten silicon in the crucible, and thus cooled to a high temperature. Fluid flows upward in the cooling fluid passage. Therefore, there is a problem that the packing provided between the top wall of the melting furnace and the outer peripheral surface of the hollow rotary shaft is damaged by being heated by the heat of the high-temperature cooling fluid and loses the sealing function.
[0006]
An object of the present invention is to provide a metal refining apparatus that solves the above problems all at once.
[0007]
[Means for Solving the Problems]
  In the metal refining device according to the first aspect of the present invention, a crucible in which molten metal is placed is disposed in a melting furnace, a vertical hollow rotating shaft is passed through the top wall of the melting furnace, and a lower end of the hollow rotating shaft is provided. Dipped in the molten metalTapered cylindrical shape that narrows downwardA metal refining apparatus is provided with a hollow rotary cooling body, and rotates the hollow rotary cooling body and crystallizes the metal on the outer peripheral surface of the hollow rotary cooling body while supplying a cooling fluid to the inside. Thus, the cooling fluid is supplied into the hollow rotary cooling body through the outer portion in the hollow rotary shaft, and is discharged through the inner portion.
[0008]
  According to a second aspect of the present invention, there is provided the metal refining device according to the first aspect, wherein a cooling fluid discharge pipe is disposed in the hollow rotary shaft, and an inner peripheral surface of the hollow rotary shaft and the cooling fluid discharge pipe are disposed. This portion serves as a cooling fluid passage, and the cooling fluid is supplied into the hollow rotary cooling body through the cooling fluid passage and discharged through the cooling fluid discharge pipe.
  According to a third aspect of the present invention, there is provided the metal refining device according to the first or second aspect, wherein the hollow rotary cooling body sends the cooling fluid fed into the cooling fluid passage toward the peripheral wall of the hollow rotary cooling body. A cooling fluid blowing member for blowing is provided.
  According to a fourth aspect of the present invention, there is provided a metal refining apparatus comprising: a melting furnace having a molten metal holding crucible disposed therein; a vertical hollow rotating shaft disposed through the top wall of the melting furnace; and the hollow rotating shaft being driven to rotate. A rotary driving means, a packing that seals between an outer peripheral surface of the hollow rotary shaft and a portion around the rotary shaft penetrating portion in the top wall of the melting furnace, and an inner space is formed at the lower end of the hollow rotary shaft Provided to communicate with the internal space of the rotating shaftTapered cylindrical shape that narrows downwardA hollow rotary cooling body and a means for supplying a cooling fluid into the hollow rotary cooling body are provided. The hollow rotary cooling body is immersed in a molten metal placed in the crucible, and the hollow rotary cooling body is rotated. And a metal refining device for crystallizing metal on the outer peripheral surface of the hollow rotary cooling body while supplying the cooling fluid to the inside of the hollow rotary cooling body by the cooling fluid supply means. A cooling fluid discharge member in which a cooling fluid discharge pipe located in a hollow rotary cooling body is disposed, and a number of cooling fluid discharge ports are formed on a peripheral wall between a lower end of the hollow rotation shaft and a lower end of the cooling fluid discharge pipe Is disposed in the hollow rotary cooling body, and the portion between the hollow rotary shaft and the inner peripheral surface of the cooling fluid outlet member and the outer peripheral surface of the cooling fluid discharge pipe is a cooling fluid passage.The cooling fluid is blown out from the cooling fluid blowing port of the cooling fluid blowing member toward the peripheral wall of the hollow rotating cooling body.It has been made.
  According to a fifth aspect of the present invention, there is provided the metal purifying apparatus according to the fourth aspect, wherein the cooling fluid inlet port is formed such that the upper end portion of the cooling fluid passage and the conduit of the cooling fluid discharge pipe are respectively formed in the body of the rotary joint. And communicated with the outlet.
  According to the metal refining device, the cooling fluid fed into the cooling fluid passage from the cooling fluid inlet of the rotary joint flows downward through the cooling fluid passage inside the hollow rotary shaft, and is blown out by the cooling fluid blowing member. It blows out toward the peripheral wall of a rotary cooling body from an opening | mouth, and cools the outer peripheral surface of a hollow rotary cooling body. Next, the cooling fluid heated by the heat of the molten metal in the crucible held in the crucible enters the inside through the lower end opening of the cooling fluid discharge pipe, flows upward in the cooling fluid discharge pipe, and flows into the rotary joint. It is sent out through the cooling fluid delivery port. Therefore, the packing provided between the outer peripheral surface of the hollow rotary shaft and the portion around the rotary shaft penetrating portion on the top wall is not affected by the heat of the cooling fluid heated to a high temperature.
[0009]
According to a sixth aspect of the present invention, there is provided the metal purification apparatus according to the fourth or fifth aspect, wherein the cooling fluid blowing member is formed of graphite or ceramics, and a lower end portion of the cooling fluid discharge pipe is the cooling fluid blowing member. It is inserted in the through hole formed in the bottom wall of.In this case, the cooling fluid discharge pipe penetrates the partition wall without interposing a seal between the outer peripheral surface of the lower end portion of the cooling fluid discharge pipe and the inner peripheral surface of the through hole formed in the bottom wall of the cooling fluid blowing member. It can be fitted in the hole in a rotatable and airtight manner. Therefore, the number of parts is reduced.
[0010]
  According to a seventh aspect of the present invention, there is provided a metal refining apparatus comprising a melting furnace having a molten metal holding crucible disposed therein, a vertical hollow rotating shaft disposed through the top wall of the melting furnace, and a rotary drive of the hollow rotating shaft. A rotary driving means, a packing that seals between an outer peripheral surface of the hollow rotary shaft and a portion around the rotary shaft penetrating portion in the top wall of the melting furnace, and an inner space is formed at the lower end of the hollow rotary shaft A hollow rotary cooling body provided so as to communicate with the internal space of the rotary shaft, and means for supplying a cooling fluid into the hollow rotary cooling body, the hollow rotary cooler being inserted into the molten metal placed in the crucible A metal refining apparatus that immerses a cooling body, rotates the hollow rotary cooling body, and crystallizes metal on the outer peripheral surface of the hollow rotary cooling body while supplying the cooling fluid to the inside of the hollow rotary cooling body. So ,
  A partition wall is provided at an intermediate portion of the length of the hollow rotary shaft, and a lower end portion is rotatably fitted in a through hole formed in the partition wall at a portion above the partition wall in the hollow rotary shaft. A cooling fluid discharge pipe is disposed, and a portion between an inner peripheral surface of a portion above the partition wall in the hollow rotary shaft and an outer peripheral surface of the cooling fluid discharge pipe is an upper cooling fluid passage,The upper cooling passage is in communication with the cooling fluid supply means;
  A cooling fluid blowing member having a lower portion positioned in the hollow rotating cooling body is disposed in a portion below the partition in the hollow rotating shaft, the cooling fluid blowing member is composed of an inner and outer double pipe, and both inner and outer pipes A lower cooling fluid passage is formed between the lower cooling fluid passage, and a lower end of the lower cooling fluid passage is closed by a closing wall connecting a lower end of the inner tube and a lower end of the outer tube, and the outer portion of the cooling fluid blowing member is A cooling fluid outlet is formed in the tube,
  The upper cooling fluid passage and the lower cooling fluid passage are communicated with each other through a through hole formed in the partition wall, and the inner pipe of the cooling fluid blowing member is communicated with the cooling fluid discharge pipe. Is.
[0011]
According to an eighth aspect of the present invention, there is provided the metal refining device according to the seventh aspect of the present invention, wherein an expansion portion is provided in a portion of the outer pipe of the cooling fluid blowing member located in the hollow rotating cooling body. In this case, the distance between the outlet and the peripheral wall of the rotating cooling body is reduced, and the cooling efficiency of the outer peripheral surface of the rotating cooling body is improved.
According to a ninth aspect of the present invention, there is provided the metal refining device according to the seventh or eighth aspect, wherein the upper end portion of the upper cooling fluid passage and the pipe line of the cooling fluid discharge pipe are respectively connected to The cooling fluid is communicated with a cooling fluid inlet and a delivery outlet formed in the body of the rotary joint.
UpMoneyAccording to the genus purification apparatus, the cooling fluid fed into the upper cooling fluid passage from the cooling fluid inlet of the rotary joint flows downward through the upper cooling fluid passage and further passes through the through hole formed in the partition wall. Into the lower cooling fluid passage, further flows downward in the lower cooling fluid passage, and is blown out from the outlet of the outer pipe of the cooling fluid blowing member toward the peripheral wall of the rotary cooling body. Cool down. Next, the cooling fluid heated by the heat of the molten metal in the crucible held in the crucible enters the inner pipe of the cooling fluid blowing member, flows upward in this, and further flows into the cooling fluid discharge pipe. It flows upward in the lever tube and is sent to the outside through the cooling fluid outlet of the rotary joint. Therefore, the packing provided between the outer peripheral surface of the hollow rotary shaft and the portion around the rotary shaft penetrating portion on the top wall is not affected by the heat of the cooling fluid heated to a high temperature.
[0012]
According to the invention of claim 10Metal purification equipmentThe invention of any one of claims 7-9InSaidThe lower end of the cooling fluid discharge pipe passes through a graphite or ceramic ring.SaidIt is inserted into the through hole formed in the partition wall of the hollow rotary shaftIs a thing. In this case, the graphite or ceramic ring serves as a seal between the outer peripheral surface of the lower end portion of the cooling fluid discharge pipe and the inner peripheral surface of the through hole formed in the partition wall of the hollow rotary shaft. Can be inserted into the through hole of the partition wall in a rotatable and airtight manner. Therefore, a separate seal is not required and the number of parts is reduced.
[0013]
According to the invention of claim 11Metal purification equipmentThe invention of claim 5 or 9InSaidA rotary joint, a cylindrical body whose upper end is closed and whose lower end is open;SaidWith a rotating tube supported rotatably in the body,SaidThe upper end of the rotating tubeSaidThe lower end of the body is positioned below the lower surface of the upper end closing wall, and the lower end isSaidProtruding below the body,SaidOn the peripheral wall of the bodySaidIn the upper part of the rotating tubeSaidA cooling fluid inlet is formed,SaidA cooling fluid delivery port is formed in the top closed wall of the body,SaidThe upper end of the hollow rotating shaftSaidConnected to the lower end of the rotating tube,SaidThe upper end of the cooling fluid discharge pipe is connected to the cooling fluid delivery portIs a thing.
[0014]
A metal purification method according to the invention of claim 12 is a metal purification method using the apparatus according to any one of claims 4 to 6,
While immersing the hollow rotating cooling body in the molten crude metal placed in the crucible, sending the cooling fluid into the cooling fluid passage and blowing out the cooling fluid from the outlet of the cooling fluid blowing member toward the peripheral wall of the hollow rotating cooling body , The rotary rotating cooling body is rotated by the rotation driving means through the hollow rotating shaft, and thereby high purity purified metal is crystallized on the outer peripheral surface of the hollow rotating cooling body, and is blown out toward the peripheral wall of the hollow rotating cooling body. The cooling fluid which cooled the outer peripheral surface of the lever is discharged through a cooling fluid discharge pipe.
A metal purification method according to the invention of claim 13 is a metal purification method using the apparatus according to any one of claims 7 to 11,
A hollow rotary cooling body is immersed in a molten crude metal placed in a crucible, and a cooling fluid is fed into the upper cooling fluid passage and the lower cooling fluid passage from the outlet of the outer pipe of the cooling fluid outlet member. While the cooling fluid is blown out toward the peripheral wall, the rotary rotary cooling body is rotated by the rotation driving means via the hollow rotary shaft, thereby crystallizing high-purity purified metal on the outer peripheral surface of the hollow rotary cooling body. The cooling fluid that is blown out toward the peripheral wall of the rotating cooling body and cools the outer peripheral surface thereof is discharged through the inner pipe and the cooling fluid discharge pipe of the cooling fluid blowing member.
The metal according to the invention of claim 14 is purified by the method of claim 12 or 13.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the refining device according to the present invention is applied to a method for producing high-purity silicon having a purity of 99.9 wt% or more by refining crude silicon.
[0016]
Embodiment 1
This embodiment is shown in FIGS. FIG. 1 shows the overall configuration of a metal refining apparatus according to the present invention, and FIGS. 2 and 3 show the configuration of the main part thereof.
[0017]
1 to 3, a metal refining apparatus includes a closed melting furnace (1), a molten silicon holding crucible (2) disposed in the melting furnace (1), and a top wall of the melting furnace (1) ( 1a) A vertical hollow rotary shaft (3) arranged through and a lower end of the hollow rotary shaft (3) in a fixed manner so that the internal space communicates with the internal space of the hollow rotary shaft (3). A hollow rotary cooling body (4) provided.
[0018]
The melting furnace (1) is formed of a refractory. A heater (5) (heating means) is disposed along the inner peripheral surface of the peripheral wall (1b) of the melting furnace (1). A through hole (6) is formed at the center of the top wall (1a) of the melting furnace (1). The top wall (1a) of the melting furnace (1) has an inert gas supply pipe (7) for supplying an inert gas such as nitrogen gas and argon gas into the melting furnace (1), and a melting furnace (1 A vacuum exhaust pipe (50) for evacuating the inside is attached in a penetrating manner.
[0019]
The molten silicon holding crucible (2) is formed of a material that has little reaction with silicon, such as graphite or alumina, and is less contaminated with molten silicon. The crucible (2) is placed on a mounting table (8) made of a refractory placed on the bottom wall (1c) of the melting furnace (1).
[0020]
The hollow rotating shaft (3) is made of, for example, graphite. The hollow rotary shaft (3) is passed through a through hole (6) formed in the top wall (1a). The outer peripheral surface of the hollow rotary shaft (3) and the inner peripheral surface of the through hole (6) are sealed with, for example, a packing (9) using a synthetic rubber used as an oil seal. A taper portion (3a) spreading downward is formed at the lower end portion of the hollow rotary shaft (3), and a screw portion (3b) is formed at a portion below the taper portion (3a). A female thread portion (3c) is formed on the inner peripheral surface of the lower end portion of the hollow rotary shaft (3). Such a hollow rotary shaft (3) is rotatable above a melting furnace (1) via a bearing (not shown) on a holding member (11) provided to be movable up and down with respect to the fixed portion (10). It is supported by. The hollow rotating shaft (3) is rotated by the rotation driving means (12). The rotation drive means (12) includes an electric motor (13) mounted upward on the holding member (11), a belt wheel (14) fixed around the shaft (13a) of the electric motor (13), and a hollow rotary shaft. A belt wheel (15) fixed around (3) and a belt (16) stretched over both belt wheels (14) and (15).
[0021]
The hollow rotary cooling body (4) has a tapered cylindrical shape having a bottom and narrowing downward. The hollow rotating cooling body (4) is formed of a material that has good thermal conductivity and does not react with molten silicon and does not contaminate it, such as silicon nitride or graphite. A large-diameter portion is formed on the inner peripheral surface of the hollow rotary cooling body (4) via a step portion, and a female screw portion (4a) is formed on the large-diameter portion. Then, the male screw part (3b) of the hollow rotary shaft (3) is screwed into the female screw part (4a) of the hollow rotary cooling body (4), so that the hollow rotary cooling body (4) becomes a hollow rotary shaft ( It is fixed to 3). The outer diameter of the upper end portion of the hollow rotary cooling body (4) is equal to the large end diameter of the tapered portion (3a) of the hollow rotary shaft (3), and the lower end surface of the hollow rotary shaft (3) is hollow. While being in contact with the upper surface of the stepped portion of the rotating cooling body (4), the upper end surface of the hollow rotating cooling body (4) is in contact with the lower end surface of the tapered portion (3a) of the hollow rotating shaft (3).
[0022]
At the lower end of the hollow rotating shaft (3), a cooling fluid blowing member (17) that is cylindrical with a bottom and has a taper shape that narrows downward is attached so that it is located in the hollow rotating cooling body (4). It has been. A male thread part (17a) is formed at the upper end of the outer peripheral surface of the peripheral wall of the cooling fluid blowing member (17), and this male thread part (17a) is screwed onto the female thread part (3c) of the hollow rotary shaft (3). By fitting, the blowing member (17) is attached to the hollow rotating shaft (3). The cooling fluid blowing member (17) is made of graphite, and a number of cooling fluid blowing ports (18) are formed in the peripheral wall (17b), and a through hole (19 is formed in the center of the bottom wall (17c). ) Is formed.
[0023]
A cooling fluid discharge pipe (21) having a lower end located in the cooling fluid blowing member (17) and an upper end protruding above the upper end of the hollow rotating shaft (3) is disposed in the hollow rotation shaft (3). ing. The portion between the inner peripheral surface of the hollow rotary shaft (3) and the outer peripheral surface of the cooling fluid discharge pipe (21), and the inner peripheral surface of the cooling fluid outlet member (17) and the outer peripheral surface of the cooling fluid discharge pipe (21) The portion between the two is a cooling fluid passage (22).
[0024]
The upper end of the hollow rotary shaft (3) and the upper end of the cooling fluid discharge pipe (21) are connected to the rotary joint (23), and the upper end of the cooling fluid passage (22) and the cooling fluid discharge pipe (21) The pipe lines communicate with a cooling fluid introduction port (25) and a delivery port (26) formed in the body (24) of the rotary joint (23), respectively. The rotary joint (23) has a cylindrical body (24) whose upper end is closed and whose lower end is open, and a vertical shape made of stainless steel, for example, which is rotatably supported by a bearing (27) in the body (24). And a rotary tube (28). Although not shown, the inner peripheral surface of the body (24) and the outer peripheral surface of the rotary tube (28) are sealed by a moving surface sealing device such as a mechanical seal using a bellows. . The upper end of the rotary tube (28) is located below the lower surface of the upper end closing wall (24a) of the body (24), and the lower end protrudes downward from the body (24). A threaded portion is formed on the outer peripheral surface of the portion protruding downward from the body (24), and this male threaded portion is formed on the inner peripheral surface of the upper end portion of the hollow rotary shaft (3). The upper end portion of the hollow rotary shaft (3) is connected to the lower end portion of the rotary tube (28). A cooling fluid introduction port (25) is formed in a portion of the peripheral wall (24b) of the body (24) above the rotary tube (28), and a cooling fluid delivery port (26) is formed on the upper end closing wall (24a) of the body (24). ) Is formed. The rotary joint (23) is a so-called double hole type having a cooling fluid introduction port (25) and a cooling fluid delivery port (26) in the body (24). The upper end of the cooling fluid discharge pipe (21) is inserted and fixed to the cooling fluid delivery port (26). An elbow (29) communicating with the cooling fluid outlet (26) is attached to the upper end of the body (24) of the rotary joint (23). Although not shown, the cooling fluid supply pipe (25) is connected to the cooling fluid inlet (25) of the body (24) of the rotary joint (23), and the cooling fluid discharge pipe (21) is connected to the elbow (29). .
[0025]
Purification of silicon using such a purification apparatus is performed as follows.
[0026]
The crude silicon to be purified is placed in the crucible (2) in advance, and the melting furnace (1) is evacuated by the vacuum exhaust pipe (50), and then the melting furnace (1 ) Is supplied with an inert gas to create an inert gas atmosphere in the melting furnace (1). In this way, a perfect inert gas atmosphere can be created in the melting furnace (1). Then, the crude silicon is heated and dissolved by the heater (5) to form molten crude silicon (S), which is heated and held at a temperature exceeding the solidification temperature. The molten crude silicon (S) is placed in an inert gas atmosphere. The molten crude silicon (S) may be separately dissolved and then put into the crucible (2).
[0027]
Next, a cooling fluid inlet (25) formed in the body (24) of the rotary joint (23) from the cooling fluid supply pipe, and a cooling fluid passage (22) in the hollow rotary shaft (3) through the body (24). The cooling fluid is fed into the hollow rotating shaft (12) by the rotation driving means (12) while blowing the cooling fluid from the outlet (18) of the cooling fluid blowing member (17) toward the peripheral wall of the hollow rotating cooling body (4). The hollow rotary cooling body (4) is rotated through 3), and high purity purified silicon is crystallized on the outer peripheral surface of the hollow rotary cooling body (4) by the principle of segregation solidification. At this time, the cooling fluid blowing member (17) also rotates with the hollow rotating shaft (3) relative to the cooling fluid discharge pipe (21). By rotation of the hollow rotary cooling body (4), solidification can proceed while dispersing impurities discharged from the solidification interface into the liquid phase throughout the liquid phase. Accordingly, solidification proceeds under the control of a segregation coefficient close to the equilibrium segregation coefficient, and high-purity purified silicon crystallizes in a short time on the outer peripheral surface of the hollow rotary cooling body (4). In addition, it is preferable that the peripheral speed at the time of rotation of a hollow rotary cooling body (4) is 500-6000 mm / sec, especially 500-4000 mm / sec. This is because if it is less than the lower limit value, the effect of purification is small, and if the upper limit value is exceeded, the silicon solid phase may be difficult to adhere to the outer peripheral surface of the hollow rotary cooling body (4).
[0028]
The cooling fluid heated by the heat of the molten crude silicon (S) held in the crucible (2) is cooled by being blown out toward the peripheral wall of the hollow rotary cooling body (4) to cool the outer peripheral surface. The fluid discharge pipe (21) enters the inside from the lower end opening, flows upward in the cooling fluid discharge pipe (21), passes through the cooling fluid delivery port (26) of the body (24) of the rotary joint (23), and is elbowed. It is sent to the cooling fluid delivery pipe via (29). Accordingly, the packing (9) provided between the outer peripheral surface of the hollow rotary shaft (3) and the portion around the through hole (6) in the top wall (1a) of the melting furnace (1) is heated to a high temperature. It is not affected by the heat of the cooling fluid.
[0029]
Embodiment 2
This embodiment is shown in FIGS.
[0030]
In this case, the hollow rotating shaft (31) is passed through the through hole (6) of the top wall (1a) of the melting furnace (1) from above, and the lower component is located in the melting furnace (1). (32) and a lower component member (33) fixed to the lower end of the upper component member (32). The upper component member (32) is made of a metal such as stainless steel. The lower component member (33) is made of, for example, graphite.
[0031]
The lower end opening of the upper component member (32) is closed by a closing wall (34). A through hole (35) is formed in the central portion of the closed wall (34), and a graphite ring (36) is fitted into the through hole (35). Further, a plurality of arc-shaped elongated holes (37) are formed on the same circumference in a portion around the through hole (35) in the closed wall (34). An outward flange (38) is integrally formed at the lower end of the upper component (32). The upper end portion of the upper component member (32) is connected to the lower end portion of the rotary pipe (28) of the rotary joint (23) in the same manner as the upper end portion of the hollow rotary shaft (3) of the first embodiment.
[0032]
A closing member (39) made of a metal such as stainless steel is fitted on the upper end of the lower component member (33). A through hole (40) having a diameter larger than the inner diameter of the graphite ring (36) is formed in the central portion of the closing member (39), and the upper component member (32) is formed around the through hole (40). A plurality of arc-shaped elongated holes (41) communicating with the arc-shaped elongated hole (37) are formed on the same circumference. In addition, an outward flange (42) is integrally formed on the peripheral portion of the closing member (39), and the outward flange (42) and the outward flange (38) of the upper component member (32) are illustrated. The lower component member (33) is fixed to the lower end of the upper component member (32) by being connected by tightening means such as bolts and nuts. The closing wall (34) and the closing member (39) serve as a partition wall in the middle of the hollow rotary shaft (31), and the arc-shaped elongated holes (37) and (41) formed in these walls serve as partition walls. It is a through hole. In the same way as the lower end portion of the hollow rotary shaft (3) of the first embodiment, a lower expanding taper portion (33a) is formed at the lower end portion of the lower component member (33), and is formed from the taper portion (33a). Also, a screw part (33b) is formed in the lower part. Then, the male screw part (33b) of the lower component member (33) is screwed into the female screw part (4a) of the hollow rotary cooling body (4), so that the hollow rotary cooling body (4) becomes the lower component member ( It is fixed to 33).
[0033]
The cooling fluid discharge pipe (43) disposed in the hollow rotary shaft (31) is shorter than the cooling fluid discharge pipe (21) of the first embodiment, and the upper end thereof is the cooling fluid delivery port (26) of the rotary joint (23). ), And the lower end portion is rotatably passed through the graphite ring (36) to reach the upper end portion in the lower component member (33). The portion between the inner peripheral surface of the upper component member (32) and the outer peripheral surface of the cooling fluid discharge pipe (43) is an upper cooling fluid passage (44), and the upper end of the upper cooling fluid passage (44). The cooling fluid discharge pipe (43) and the cooling fluid discharge pipe (43) are connected to a cooling fluid inlet (25) and a sending outlet (26) formed in the body (24) of the rotary joint (23), respectively.
[0034]
In the lower component member (33), a cooling fluid blowing member (45) having a lower portion located in the hollow rotary cooling body (4) is disposed. The cooling fluid blowing member (45) is composed of an inner and outer double pipe, and a portion between the inner and outer pipes (46) and (48) is a lower cooling fluid passage (49). The lower end of the lower cooling fluid passage (49) is closed by a closing wall (50) connecting the lower end of the inner pipe (46) and the lower end of the outer pipe (48). In the outer pipe (48) of the cooling fluid blowing member (45), a narrowed and tapered widened portion (48a) is formed in a portion located in the hollow rotary cooling body (4), and a large number of widened portions (48a) are formed. The cooling fluid outlet (51) is formed. The upper end portion of the cooling fluid blowing member (45) is fixed to the closing member (39) at the upper end of the lower component member (33), and the upper cooling fluid passage (44) and the lower cooling fluid passage (49) are closed walls ( 34) and arcuate elongated holes (37) and (41) formed in the closing member (39). The upper end of the inner pipe (46) of the cooling fluid outlet member (45) surrounds the lower end of the cooling fluid discharge pipe (43), and the inner pipe (46) communicates with the cooling fluid discharge pipe (43). It has been made.
[0035]
Other configurations are the same as those of the first embodiment, and the same portions are denoted by the same reference numerals.
[0036]
Purification of silicon using such a purification apparatus is performed as follows.
[0037]
In the same manner as in the first embodiment, the molten crude silicon (S) in the crucible (2) is heated and held at a temperature exceeding the solidification temperature by the heater (5).
[0038]
Next, the cooling fluid inlet (25) formed in the body (24) of the rotary joint (23) from the cooling fluid supply pipe, and the upper component (32) of the hollow rotary shaft (31) through the body (24) Cooling fluid is fed into the upper cooling fluid passage (44). This cooling fluid flows downward through the upper cooling fluid passageway (44) and blows out the cooling fluid through arcuate slots (37) (41) formed in the closing wall (34) and the closing member (39). It enters into the lower cooling fluid passage (49) in the member (45) and flows downward in the lower cooling fluid passage (49), and the expanded portion in the outer pipe (48) of the cooling fluid blowing member (45) ( The air is blown out from the blowout port (51) of 48a) toward the peripheral wall of the hollow rotary cooling body (4). Then, in the same manner as in Embodiment 1, high purity purified silicon is crystallized on the outer peripheral surface of the hollow rotary cooling body (4).
[0039]
The cooling fluid heated by the heat of the molten crude silicon (S) held in the crucible (2) is cooled by being blown out toward the peripheral wall of the hollow rotary cooling body (4) to cool the outer peripheral surface. It enters the inside through the lower end opening of the inner pipe (46) of the fluid blowing member (45), flows upward in this, and further flows into the cooling fluid discharge pipe (43) and flows upward in this pipe (43). Then, it passes through the cooling fluid delivery port (26) of the body (24) of the rotary joint (23), and is sent to the cooling fluid delivery pipe through the elbow (29). Therefore, the packing (9) that seals between the outer peripheral surface of the hollow rotary shaft (3) and the portion around the through hole (6) in the top wall (1a) of the melting furnace (1) was heated to a high temperature. Not affected by the heat of the cooling fluid.
[0040]
In the above two embodiments, the inside of the melting furnace (1) is an inert gas atmosphere, but instead of this, a vacuum atmosphere may be used. In this case, a vacuum pulling tube is fixed to the lid of the melting furnace (1) in place of the inert gas supply pipe (7) in a penetrating manner, and the melting furnace (1) is evacuated by an appropriate vacuum pump. A vacuum atmosphere.
[0041]
In the above two embodiments, the purification apparatus according to the present invention is applied to the purification of silicon. For example, it is applied to the purification of aluminum for producing ultra-high purity aluminum having a purity of 99.9999 wt%. You can also
[0042]
【The invention's effect】
This inventionGoldAccording to the genus refining apparatus, as described above, the packing that seals between the outer peripheral surface of the hollow rotary shaft and the portion around the rotary shaft penetrating portion in the top wall of the melting furnace is a cooling fluid heated to a high temperature. Therefore, the performance of the packing is maintained for a long time. Further, since the melting furnace is hermetically sealed, contamination of the molten metal in the crucible due to dust in the atmosphere is prevented.
[Brief description of the drawings]
FIG. 1 is a partially cutaway front view showing the overall configuration of Embodiment 1 of an apparatus according to the present invention.
FIG. 2 is an enlarged vertical sectional view showing the structure of the lower part.
FIG. 3 is an enlarged vertical sectional view showing the configuration of the upper part.
FIG. 4 is an enlarged vertical sectional view showing the structure of the lower part of Embodiment 2 of the apparatus according to the present invention.
FIG. 5 is a partially enlarged view of FIG. 4;
6 is a cross-sectional view taken along line VI-VI in FIG.
[Explanation of symbols]
(1) Closed melting furnace
(1a) Top wall
(2) Molten metal holding crucible
(3) Hollow rotating shaft
(4) Hollow rotating cooling body
(5) Heater (heating means)
(9) Packing
(12) Rotation drive means
(17) Cooling fluid outlet
(18) Cooling fluid outlet
(19) Through hole
(21) Cooling fluid discharge pipe
(22) Cooling fluid passage
(23) Rotary joint
(24) Body
(25) Cooling fluid inlet
(26) Cooling fluid outlet
(31) Hollow rotating shaft
(32) Upper component
(33) Lower component
(34) Closure wall
(35) Through hole
(37) Arc-shaped slot
(39) Closing member
(41) Arc-shaped slot
(43) Cooling fluid discharge pipe
(44) Upper cooling fluid passage
(45) Cooling fluid outlet
(46) Inner pipe
(48) Outer pipe
(49) Lower cooling fluid passage
(50) Closed wall
(51) Cooling fluid outlet

Claims (14)

A crucible into which the molten metal is placed is placed in the melting furnace, a vertical hollow rotating shaft is passed through the top wall of the melting furnace, and the lower end of the hollow rotating shaft is directed downwardly immersed in the molten metal. A tapered cylindrical hollow rotating cooling body is provided, and while rotating the hollow rotating cooling body and supplying a cooling fluid to the inside thereof, a metal is crystallized on the outer peripheral surface of the hollow rotating cooling body. A metal refining device,
A metal refining device in which the cooling fluid is supplied into the hollow rotary cooling body through an outer portion in the hollow rotary shaft and is also discharged through an inner portion.   A cooling fluid discharge pipe is disposed in the hollow rotary shaft, and a portion between an inner peripheral surface of the hollow rotary shaft and the cooling fluid discharge pipe serves as a cooling fluid passage, and the cooling fluid passes through the cooling fluid passage. The metal refining device according to claim 1, wherein the metal refining device is supplied to the hollow rotary cooling body through the cooling fluid discharge pipe and discharged through the cooling fluid discharge pipe.   The metal refining device according to claim 1, wherein the hollow rotary cooling body includes a cooling fluid blowing member that blows the cooling fluid fed into the cooling fluid passage toward a peripheral wall of the hollow rotary cooling body. . A melting furnace having a molten metal holding crucible disposed therein, a vertical hollow rotating shaft disposed through the top wall of the melting furnace, a rotation driving means for rotating the hollow rotating shaft, and an outer peripheral surface of the hollow rotating shaft And a packing that seals between the periphery of the rotating shaft penetrating portion on the top wall of the melting furnace, and an inner space is provided at the lower end of the hollow rotating shaft so as to communicate with the inner space of the hollow rotating shaft. A hollow rotary cooling body having a tapered cylindrical shape narrowed downward , and means for supplying a cooling fluid into the hollow rotary cooling body, and the hollow rotary cooling is contained in the molten metal placed in the crucible. A metal refining apparatus for immersing a body, rotating the hollow rotary cooling body, and crystallizing metal on the outer peripheral surface of the hollow rotary cooling body while supplying the cooling fluid to the inside of the hollow rotary cooling body by the cooling fluid supply means There
A cooling fluid discharge pipe having a lower end located in the hollow rotary cooling body is disposed in the hollow rotary shaft, and a large number of cooling fluid outlets are provided on a peripheral wall between the lower end of the hollow rotary shaft and the lower end of the cooling fluid discharge pipe. A cooling fluid blowing member having a mouth is disposed so as to be positioned in the hollow rotary cooling body, and is provided between the hollow rotary shaft and the inner circumferential surface of the cooling fluid blowing member and the outer circumferential surface of the cooling fluid discharge pipe. The metal refining device is configured such that the portion is a cooling fluid passage, and the cooling fluid is blown out from the cooling fluid blowing port of the cooling fluid blowing member toward the peripheral wall of the hollow rotating cooling body .   The metal purifier according to claim 4, wherein an upper end portion of the cooling fluid passage and a pipe line of the cooling fluid discharge pipe are communicated with a cooling fluid inlet and a outlet formed in a body of a rotary joint, respectively. .   6. The cooling fluid blowing member is formed of graphite or ceramics, and a lower end portion of the cooling fluid discharge pipe is fitted into a through hole formed in a bottom wall of the cooling fluid blowing member. Metal purification equipment. A melting furnace having a molten metal holding crucible disposed therein, a vertical hollow rotating shaft disposed through the top wall of the melting furnace, a rotation driving means for rotating the hollow rotating shaft, and an outer peripheral surface of the hollow rotating shaft And a packing that seals between the periphery of the rotating shaft penetrating portion on the top wall of the melting furnace, and an inner space is provided at the lower end of the hollow rotating shaft so as to communicate with the inner space of the hollow rotating shaft. A hollow rotary cooling body, and means for supplying a cooling fluid into the hollow rotary cooling body, and the hollow rotary cooling body is immersed in a molten metal placed in the crucible, A metal refining device that rotates and supplies a cooling fluid to the inside of the hollow rotary cooling body by the cooling fluid supply means, and crystallizes metal on an outer peripheral surface thereof,
A partition wall is provided at an intermediate portion of the length of the hollow rotary shaft, and a lower end portion is rotatably fitted in a through hole formed in the partition wall at a portion above the partition wall in the hollow rotary shaft. cooling fluid discharge pipe is disposed, the portion between the inner peripheral surface and the outer peripheral surface of the cooling fluid discharge pipe in the upper portion than the partition wall in the hollow rotating shaft made and upper cooling fluid passages, the upper cooling passage channel Is communicated with the cooling fluid supply means,
A cooling fluid blowing member having a lower portion positioned in the hollow rotating cooling body is disposed in a portion below the partition in the hollow rotating shaft, the cooling fluid blowing member is composed of an inner and outer double pipe, and both inner and outer pipes A lower cooling fluid passage is formed between the lower cooling fluid passage, and a lower end of the lower cooling fluid passage is closed by a closing wall connecting a lower end of the inner tube and a lower end of the outer tube, and the outer portion of the cooling fluid blowing member is A cooling fluid outlet is formed in the tube,
The upper cooling fluid passage and the lower cooling fluid passage are communicated with each other through a through hole formed in the partition wall, and the inner pipe of the cooling fluid blowing member is communicated with the cooling fluid discharge pipe. Metal purification equipment.   The metal purifier according to claim 7, wherein an expansion portion is provided in a portion of the outer pipe of the cooling fluid blowing member located in the hollow rotating cooling body.   The metal according to claim 7 or 8, wherein an upper end portion of the upper cooling fluid passage and a pipe line of the cooling fluid discharge pipe are communicated with a cooling fluid inlet and a delivery outlet formed in a body of a rotary joint, respectively. Purification equipment.   The lower end part of the said cooling fluid discharge pipe is inserted in the through-hole formed in the partition of the said hollow rotating shaft through the ring made from graphite or ceramics, The metal in any one of Claims 7-9 Purification equipment. The rotary joint includes a cylindrical body whose upper end is closed and whose lower end is open, and a rotating tube rotatably supported in the body, the upper end of the rotating tube being an upper end closing wall of the body The cooling fluid inlet is formed in a portion of the peripheral wall of the body above the rotating tube, and the lower end of the cooling fluid introduction port is formed at the upper end of the body. A cooling fluid delivery path is formed in the closed wall;
The metal purifier according to claim 5 or 9, wherein an upper end portion of the hollow rotary shaft is connected to a lower end portion of the rotary tube, and an upper end portion of the cooling fluid discharge pipe is connected to the cooling fluid delivery port. . A method for purifying a metal using the apparatus according to any one of claims 4 to 6,
While immersing the hollow rotating cooling body in the molten crude metal placed in the crucible, sending the cooling fluid into the cooling fluid passage and blowing out the cooling fluid from the outlet of the cooling fluid blowing member toward the peripheral wall of the hollow rotating cooling body , The rotary rotating cooling body is rotated by the rotation driving means through the hollow rotating shaft, and thereby high purity purified metal is crystallized on the outer peripheral surface of the hollow rotating cooling body, and is blown out toward the peripheral wall of the hollow rotating cooling body. A method for purifying a metal, characterized in that a cooling fluid having cooled the outer peripheral surface thereof is discharged through a cooling fluid discharge pipe. A metal purification method using the apparatus according to any one of claims 7 to 11,
A hollow rotary cooling body is immersed in a molten crude metal placed in a crucible, and a cooling fluid is fed into the upper cooling fluid passage and the lower cooling fluid passage from the outlet of the outer pipe of the cooling fluid outlet member. While the cooling fluid is blown out toward the peripheral wall, the rotary rotary cooling body is rotated by the rotation driving means via the hollow rotary shaft, thereby crystallizing high-purity purified metal on the outer peripheral surface of the hollow rotary cooling body. A method for purifying a metal, characterized in that a cooling fluid blown toward a peripheral wall of a rotary cooling body and cooled on an outer peripheral surface thereof is discharged through an inner pipe and a cooling fluid discharge pipe of a cooling fluid blowing member.   A metal purified by the method according to claim 12 or 13.

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