JP2016216799A - Method for refining magnesium and magnesium refining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prove a method and device for refining magnesium which can refine high-purity magnesium at a low cost in a shorter time.SOLUTION: A magnesium refining method of the present invention is a method for refining magnesium from raw material magnesium by a vacuum sublimation method and obtains refined magnesium by heating the raw material magnesium by an induction heating method and depositing the magnesium sublimated by the heating on a surface of a deposition part disposed away from the raw material magnesium.SELECTED DRAWING: Figure 1

Description

  The invention according to the present application relates to a magnesium (Mg) purification method and a magnesium purification apparatus by sublimation in a vacuum.

  In the manufacture of semiconductor elements in recent years, the demand for high-purity materials is increasing. For example, in the manufacture of a semiconductor element such as a blue laser diode, high-purity magnesium metal is required because the amount of impurities contained in the magnesium metal material used as the material greatly affects the quality. Impurities contained in the magnesium metal material are generally silicon (Si), manganese (Mn), sulfur (S), phosphorus (P), aluminum (Al), chlorine (Cl), sodium (Na), iron (Fe). , Copper (Cu), nickel (Ni), calcium (Ca), antimony (Sb), potassium (K), fluorine (F), arsenic (As), chromium (Cr), silver (Ag), bismuth (Bi) , Gallium (Ga), lithium (Li), molybdenum (Mo), titanium (Ti), and boron (B). In addition to this, the magnesium metal material contains zinc (Zn). However, when the magnesium metal material is used as a semiconductor material, 100 ppm or less of zinc is not a problem in use, and therefore 100 ppm or less. Zinc is often not treated as an impurity.

  Conventionally, various magnesium purification methods have been employed in order to reduce impurities contained in the magnesium metal material and increase the purity of the magnesium metal. Examples of the magnesium purification method include a zone melting method, an electrorefining method, a thermal reduction method, and a distillation method.

For example, Patent Document 1 states that “a method of purifying magnesium by vacuum distillation of a magnesium raw material, the raw material magnesium charged in the raw material crucible is at a temperature of 600 to 800 ° C., and a degree of vacuum of 1 × 10 ⁻² to 1 By vacuum distillation at × 10 ⁻³ Torr, the evaporated magnesium is condensed above the raw material crucible and recovered in a recovery mold below the raw material crucible to form an ingot. Further, the condensed gas is And a method for purifying magnesium characterized by being cooled and solidified.

  Further, Patent Document 2 states that “in a vacuum atmosphere, the first step of heating the raw material magnesium in the raw material crucible to generate magnesium vapor, the vapor and vent holes are perforated and a plurality of layers are used for condensation. A second step of condensing part of the vapor into the condensation passage formed by the passage plate to generate a condensed solution having a high impurity content; solidifying the vapor that has passed through the condensation passage; Disclosed is a metal refining method characterized by comprising a third step of guiding and cooling into a crucible for use to solidify high-purity magnesium from the steam and a fourth step of repeating the condensed solution in the raw material crucible. Yes.

Japanese Patent No. 3838717 Japanese Patent No. 3857589

  However, in both methods disclosed in Patent Document 1 and Patent Document 2, the raw material crucible containing the raw material magnesium is heated by a heater (electric furnace) to generate magnesium vapor. At this time, since the raw material magnesium is heated by heat conduction from the raw material crucible heated by the heater and a part of the radiant heat, it takes a lot of time to heat the raw material magnesium to the set temperature, There is a problem of poor purification efficiency.

  Further, in the method of conducting heat from the outside toward the inside of the raw material crucible with a heater, it is difficult to uniformly heat the raw material magnesium in the raw material crucible, which is locally higher than the set temperature. May be heated. In this case, in addition to magnesium, impurities contained in the raw material magnesium may also evaporate, and the impurities may be mixed into the magnesium condensed above the raw material crucible.

  Furthermore, in patent document 1 and patent document 2 as described above, high-purity magnesium obtained by purification is accommodated in a recovery mold or a solidification crucible. Therefore, there is a risk of contamination due to impurities when the purified magnesium is taken out.

  Therefore, it has been desired from the market to develop a magnesium purification method and a magnesium purification apparatus that can efficiently purify high-purity magnesium in a shorter time.

  Therefore, as a result of diligent research, the present inventors have made it possible to purify magnesium with high purity efficiently in a short time by employing the magnesium purification method and the magnesium purification apparatus according to the present invention.

  That is, the method for purifying magnesium according to the present invention is a method for purifying magnesium from raw material magnesium by a vacuum sublimation method, in which the raw material magnesium is heated by an induction heating method and is disposed away from the raw material magnesium. Purified magnesium is obtained by evaporating magnesium sublimated by heating on the surface of the part.

In the magnesium purification method according to the present invention, the raw material magnesium is preferably heated to 430 ° C. to 550 ° C. by the induction heating method in a vacuum of 10 Pa to ¹ × 10 ⁻¹ Pa.

  In the method for purifying magnesium according to the present invention, the deposition temperature of magnesium in the condensing part is preferably set to 330 ° C to 410 ° C.

  A magnesium purification apparatus according to the present invention is a magnesium purification apparatus that purifies magnesium from raw material magnesium by a vacuum sublimation method, wherein the inside is evacuated, a vacuum container that contains the raw material magnesium, and the raw material magnesium in the vacuum container An induction heating coil that sublimates magnesium by induction heating from outside the vacuum vessel, and a vapor deposition unit that is disposed in the vacuum vessel apart from the raw material magnesium and deposits magnesium diffused in the vacuum vessel. It is characterized by.

  In the magnesium refining device according to the present invention, it is preferable that the raw material magnesium is accommodated separately from the inner wall surface of the vacuum vessel.

  In the magnesium purification apparatus according to the present invention, the vapor deposition section is preferably adjusted to a magnesium vapor deposition temperature by a vapor deposition section temperature adjusting means using compressed air.

Moreover, the magnesium refinement | purification apparatus which concerns on this invention sets the vacuum degree in the said vacuum vessel to 10 Pa-1x10 < ^-1 > Pa, and the said raw material magnesium and the said vacuum vessel itself are 430 degreeC-550 degreeC with the said induction heating coil. It is preferable to do.

  Moreover, as for the magnesium refinement | purification apparatus which concerns on this invention, it is preferable that the said vapor deposition part is adjusted to 330 to 410 degreeC by the said vapor deposition part temperature adjustment means.

  Further, in the magnesium purification apparatus according to the present invention, the vacuum vessel has an opening and a main body provided with a raw material container for containing the raw material magnesium therein, and a lid that closes the opening of the main body so that the opening can be opened and closed. It is preferable that the lid includes the vapor deposition section facing the inside of the main body.

  Furthermore, in the magnesium purification apparatus according to the present invention, the vacuum vessel includes a cylindrical guide that surrounds a peripheral edge portion of the vapor deposition section via a heat insulating member and extends in a growth direction of the purified magnesium deposited on the vapor deposition section. Is preferred.

  Further, the magnesium refining device according to the present invention includes an inner metal packing and an outer metal packing with a predetermined interval between the main body and the lid, and the inner metal packing and the outer metal packing. It is preferable to fill the space between these metal packings with an inert gas.

  In the magnesium purification method according to the present invention, the raw material magnesium is directly heated without passing through the vacuum vessel by heating the raw material magnesium by the induction heating method. Therefore, unlike the conventional case where the vacuum vessel containing the raw material magnesium is heated by a heater and the raw material magnesium is heated by heat conduction from the vacuum vessel, according to the present invention, the uniform material magnesium can be obtained by induction heating. Heating is possible. Therefore, since this invention can suppress that raw material magnesium is locally heated to high temperature, the impurity contained in raw material magnesium other than magnesium will vapor-deposit with refined magnesium in a vapor deposition part. Inconvenience can be avoided. Moreover, since the raw material magnesium itself can be directly heated by the induction heating method, the raw material magnesium can be heated to the target temperature in a shorter time. Therefore, according to the present invention, high-purity magnesium purification can be realized efficiently in a shorter time.

  Moreover, in addition to the effect by the magnesium purification method mentioned above, the magnesium refinement | purification apparatus which concerns on this invention controls the temperature control by the induction heating of the said raw material magnesium itself by accommodating raw material magnesium spaced apart from the inner wall face of a vacuum vessel. It becomes possible to carry out stably. Therefore, evaporation of impurities contained in the raw material magnesium can be effectively suppressed.

  Furthermore, since the magnesium purification apparatus according to the present invention adjusts the temperature of the vapor deposition part to the vapor deposition temperature of magnesium by the vapor deposition part temperature adjustment means using compressed air, it is not necessary to use liquid or oil as the temperature adjustment means, Workability can be improved.

It is a schematic sectional drawing of the magnesium refinement | purification apparatus which employ | adopted this invention. It is an enlarged view of the vapor deposition part of FIG. It is an exploded view of the vapor deposition part of FIG. It is the elements on larger scale explaining the sealing structure of the magnesium refinement | purification apparatus of FIG.

  Hereinafter, a “magnesium purification method” and a “magnesium purification apparatus” according to the present invention will be described with reference to the drawings.

<Mode of purification of magnesium according to the present invention>
The magnesium purification method according to the present invention is a method for purifying magnesium by sublimating the raw material magnesium in a vacuum. In the method for purifying magnesium according to the present invention, the raw material magnesium is heated by induction heating, and the purified magnesium is vapor-deposited by heating on the surface of the vapor deposition part disposed away from the raw material magnesium. Features.

  In the present invention, the raw material magnesium is silicon (Si), manganese (Mn), sulfur (S), phosphorus (P), aluminum (Al), chlorine (Cl), sodium (Na), iron (Fe), copper (Cu ), Nickel (Ni), calcium (Ca), antimony (Sb), potassium (K), fluorine (F), arsenic (As), chromium (Cr), silver (Ag), bismuth (Bi), gallium (Ga) ), Lithium (Li), molybdenum (Mo), titanium (Ti), boron (B), etc. It is preferable to use high-purity magnesium having a total content of impurities of 1000 ppm or less. This is because the present invention is suitable for a method of further purifying magnesium having a higher purity by further purifying high-purity magnesium having a total impurity content of 1000 ppm or less. In addition, although raw material magnesium contains zinc (Zn), when refined magnesium is used as a semiconductor material, the zinc is often not treated as an impurity if it is 100 ppm or less. Accordingly, here, zinc of 100 ppm or less is not treated as an impurity.

As vacuum conditions which refine | purify the said raw material magnesium, it is preferable that it is 10 Pa-1x10 < ^-1 > Pa. The gas remaining in the vacuum atmosphere may be air, but more preferably an inert gas such as argon. Although there is no particular limitation on the method for forming the vacuum atmosphere, it is possible to form the vacuum atmosphere under the above-described vacuum conditions by sucking air or inert gas from a vacuum container filled with air or inert gas by a vacuum pump or the like. preferable.

  And in the purification method of magnesium in this invention, the raw material magnesium is heated to the temperature of 430 degreeC-550 degreeC higher than the sublimation temperature of magnesium metal on the said vacuum condition, and the magnesium contained in the said raw material magnesium is sublimated. Is preferred.

  The heating method employs the induction heating method as described above, and induces an eddy current in the raw material magnesium by the induction heating coil to cause the raw material magnesium to self-heat. At this time, the vacuum vessel in which the raw material magnesium is accommodated is preferably induction-heated by the induction heating coil together with the raw material magnesium in order to prevent magnesium sublimated by heating from being deposited on portions other than the vapor deposition portion. .

  It is preferable to heat the raw material magnesium to 430 ° C. to 550 ° C., which is higher than the sublimation temperature of magnesium metal under the vacuum conditions, by adjusting the frequency of the current supplied to the induction heating coil and the supply power. Thus, impurities having a lower vapor pressure than magnesium contained in the raw material magnesium can remain in the raw material magnesium without evaporating. Therefore, lithium (Li), antimony (Sb), bismuth (Bi), aluminum (Al), manganese (Mn), gallium (Ga), boron (B), silver (Ag), which are impurities whose vapor pressure is lower than that of magnesium. ), Titanium (Ti), chromium (Cr), copper (Cu), silicon (Si), iron (Fe), nickel (Ni), molybdenum (Mo), calcium (Ca), etc. are left in the raw material magnesium, It can be separated from the sublimated magnesium.

  In the method for purifying magnesium according to the present invention, the vapor deposition section is disposed in the vacuum container in which the raw material magnesium is stored, away from the raw material magnesium. This vapor deposition section is for sublimation of magnesium that has been sublimated by heating by an induction heating coil and diffused in a vacuum atmosphere, and is temperature controlled to a predetermined vapor deposition temperature lower than the inner wall surface of the vacuum vessel.

  Specifically, the deposition temperature of magnesium in the deposition section is preferably set to 330 ° C. to 410 ° C. that enables magnesium to be deposited under the above-described vacuum conditions. By adjusting the vapor deposition portion to a temperature at which magnesium can be vapor deposited, it is possible to suppress the disadvantage that impurities having a higher vapor pressure than magnesium contained in the raw material magnesium are vapor deposited on the vapor deposition portion. Therefore, zinc (Zn), sodium (Na), arsenic (As), potassium (K), phosphorus (P), sulfur (S), chlorine (Cl), fluorine (F), which are impurities whose vapor pressure is higher than that of magnesium. ) And the like can be prevented from adhering to the vapor deposition part and separated from the magnesium adhering to the vapor deposition part.

  In the vapor deposition section, magnesium that has been further diffused in a vacuum atmosphere is deposited on the surface of the magnesium that has already been vapor deposited, so that magnesium purified to a high purity gradually grows.

  In this case, in the method for purifying magnesium according to the present invention, the raw material magnesium is directly heated without passing through the vacuum vessel by heating the raw material magnesium by the induction heating method. Therefore, unlike the conventional case where the vacuum vessel containing the raw material magnesium is heated by a heater and the raw material magnesium is heated by heat conduction from the vacuum vessel, the induction heating method enables uniform heating of the raw material magnesium. Become. Therefore, according to the magnesium purification method of the present invention, since the raw material magnesium can be suppressed from being locally heated to a high temperature, impurities contained in the raw material magnesium other than magnesium are contained in the vapor deposition section. The inconvenience of vapor deposition with purified magnesium can be avoided. In addition, heating of raw material magnesium by the induction heating method, unlike heating by heat conduction from a vacuum vessel, can directly heat the raw material magnesium itself, so that the raw material magnesium is heated to the target temperature in a shorter time. be able to. Therefore, according to the magnesium purification method of the present invention, high-purity magnesium purification can be achieved efficiently in a shorter time.

<Mode of Magnesium Purification Apparatus According to the Present Invention>
Next, the magnesium purification apparatus of the present invention will be described. A magnesium purification apparatus according to the present invention purifies magnesium from raw material magnesium by a vacuum sublimation method, the inside is made into a vacuum, a vacuum vessel containing the raw material magnesium, and the raw material magnesium in the vacuum vessel is the vacuum vessel An induction heating coil that sublimates magnesium by induction heating from the outside, and a vapor deposition section that is disposed apart from the raw material magnesium in the vacuum vessel and deposits magnesium diffused in the vacuum vessel. And Hereinafter, specific embodiments of the magnesium purification apparatus of the present invention will be described with reference to FIGS. First, a schematic configuration of the magnesium purification apparatus 1 according to the present embodiment will be described with reference to a schematic sectional view of the magnesium purification apparatus 1 of FIG.

  The magnesium purification apparatus 1 according to the present embodiment includes a vacuum vessel 10 including a main body 11 having an opening, a lid body 12 that closes the opening of the main body 11 so as to be freely opened and closed, and the inside of the vacuum vessel 10 is evacuated. And vacuum means 13 for setting the atmosphere.

  The main body 10 constituting the vacuum vessel 10 has a bottomed cylindrical shape made of SUS304, and includes a raw material storage portion 21 that stores the raw material magnesium 2 at the lower portion. An induction heating coil 22 for inductively heating the raw material magnesium 2 is wound around the lower portion of the main body 10 corresponding to the raw material container 21 so as to face the outer periphery of the lower portion of the main body 10. The induction heating coil 22 is connected to a power supply device (not shown), and a current having a predetermined frequency is applied by the power supply device.

  The raw material container 21 formed in the main body 10 is provided with a raw material holding mechanism 23 for suspending and holding the raw material magnesium 2 in the raw material container 21. The raw material holding mechanism 23 is located above the raw material container 21 and is suspended in the main body 10. The raw material holder 23 is suspended from the suspended support part 24 into the raw material container 21. Part 25. When the raw material magnesium 2 is held in the raw material holding part 25, the suspension support part 24 holds the raw material holding part 25, so that the raw material magnesium 2 is suspended and held in the raw material container 21.

  In the present invention, the raw material magnesium 2 held in the raw material storage unit 21 by the raw material holding mechanism 23 is preferably stored separately from the inner wall surface of the main body 11 of the vacuum vessel 10. This is because the conduction heat is applied to the raw material magnesium 2 from the induction-heated vacuum vessel 10 by energization of the induction heating coil 22, and the raw material magnesium is effectively suppressed from being locally heated to a high temperature. . However, considering the induction heating efficiency of the raw material magnesium 2 by the induction heating coil 22, it is preferable to be closer to the induction heating coil 22 wound around the vacuum vessel 10. Therefore, it is preferable that the raw material magnesium 2 and the inner wall surface of the vacuum vessel 10 are arranged to be separated from each other by 0.5 mm to 3 mm.

  In the present embodiment, the main body 10 includes a raw material magnesium temperature sensor (raw material magnesium temperature detecting means) 26 for detecting the temperature of the raw material magnesium 2 housed in the raw material container 21. The induction heating coil 22 heats the raw material magnesium 2 to an arbitrary set temperature within the range of 430 ° C. to 550 ° C. based on the temperature detected by the raw material magnesium temperature sensor 26.

  Moreover, although the vacuum vessel 10 is heated by the induction heating coil 22 by the induction heating coil 22, the auxiliary | assistant which assists the said heating capability in order to suppress that a sublimation magnesium vapor-deposits on the inner wall surface which the vacuum vessel 10 does not intend. A heater 27 may be provided. Although not shown, an auxiliary heater may be provided on the outer surface of the vacuum vessel 10 for the same purpose.

  The lid 12 constituting the vacuum vessel 10 is a plate-like member made of SUS304, and magnesium diffused in the vacuum vessel 10 is deposited on the inner surface side of the lid 12 facing the inside of the vacuum vessel 10. A vapor deposition unit 30 is provided. In the present embodiment, the vapor deposition section 30 is positioned above the raw material storage section 21 disposed in the lower part of the main body 10 and is spaced apart from the raw material magnesium stored in the raw material storage section 21. The vapor deposition part 30 is adjusted to the vapor deposition temperature of magnesium by the vapor deposition part temperature adjustment means. In this invention, it is preferable that the vapor deposition part temperature adjustment means which controls the temperature of the vapor deposition part 30 uses compressed air. This is because the compressed air does not need to use liquid or oil, and is easy to handle, so that purification work and maintainability are easy. Below, the vapor deposition part 30 which used compressed air as a vapor deposition part temperature adjustment means is demonstrated with reference to the elements on larger scale of FIG. 2, and the exploded sectional view of FIG. In the present embodiment, three vapor deposition units 30 are provided on the lid 12, and two vapor deposition units 30 are illustrated in the cross-sectional view of FIG. 1.

  The vapor deposition section 30 in the present embodiment includes a temperature adjustment container 33 having a bottomed cylindrical shape, and a columnar pressure adjustment member 34 having an external shape along the internal shape of the temperature adjustment container 33, and the temperature Compressed air is retained between the inner peripheral surface of the adjustment container 33 and the outer peripheral surface of the pressure adjustment member 34, or the outer bottom surface of the temperature adjustment container 33 serving as a magnesium vapor deposition surface or the outer bottom surface of the temperature adjustment container 33. The vapor deposition plate 31 disposed in close contact with is adjusted to a magnesium vapor deposition temperature. At this time, the inner diameter dimension of the temperature adjustment container 33 is preferably formed to be slightly larger than the outer dimension of the pressure adjustment member 34. This is because the compressed air press-fitted into the temperature adjustment container 33 via the pressure adjustment member 34 can be appropriately released to the outside from between the inner periphery of the temperature adjustment container and the outer periphery of the pressure adjustment member 34. . The magnesium vapor deposition surface may be constituted by the outer bottom surface of the temperature control vessel 33. However, in consideration of the ease of taking out the evaporated and grown refined magnesium 3, the magnesium vapor deposition surface is closely attached to the temperature control vessel 33. The inner surface of the vacuum vessel 10 of the deposited plate 31 is preferably a magnesium deposition surface.

  The temperature adjustment container 33 according to the present embodiment is inserted through the vapor deposition portion attachment hole 12 </ b> A formed through the lid body 12 from the outside, with the pressure adjustment member 34 accommodated therein. The pressure adjusting member 34 is in a state where it is accommodated in the temperature adjusting container 33, and is connected to the outside and the temperature adjusting container 33 to insert a compressed air introduction nozzle 36 for introducing compressed air from the outside. A hole 35 is formed. A recess 37 for retaining the compressed air introduced through the compressed air introducing nozzle 36 is formed on the bottom surface side of the temperature adjusting container 33 of the nozzle mounting hole 35 formed in the pressure adjusting member 34. Yes. The recess 37 is formed larger than the cross-sectional area of the nozzle 36.

  The pressure adjusting member 34 has a bottomed temperature sensor insertion hole 38 formed therein. The temperature sensor insertion hole 38 is used for detecting the temperature of the bottom surface of the temperature adjustment container 33 that becomes the vapor deposition surface of magnesium, or the bottom surface of the pressure adjustment member 34 that approximates the temperature of the vapor deposition plate 31 that is closely attached to the bottom surface. The vapor deposition part temperature sensor (vapor deposition part temperature detection means) 39 is inserted and held. The supply amount of the compressed air supplied into the temperature adjustment container 33 through the compressed air introduction nozzle 36 is adjusted based on the temperature detected by the vapor deposition section temperature sensor 39, and the temperature of the vapor deposition surface of magnesium is the vapor deposition of magnesium. It heats so that it may become arbitrary temperature in the range of the temperature, for example, 330 degreeC-410 degreeC.

  In the present embodiment, the temperature adjustment member 34 fixes the fixing plate 40 to the lid body 12 by screwing while being accommodated in the temperature adjustment container 33. With this configuration, the temperature adjustment member 34 can be prevented from coming out of the temperature adjustment container 33 due to the introduction of compressed air, and can be used safely. A communication hole 41 is formed in the fixed plate 40 at a position where the compressed air introduction nozzle 36 is inserted and a position where the vapor deposition section temperature sensor 39 is inserted, and from between the temperature adjustment container 33 and the pressure adjustment member 34. A communication hole 42 for discharging the discharged compressed air to the outside is formed.

  In the present embodiment, the magnesium is disposed on the outer bottom surface of the temperature adjustment container 33 serving as the magnesium vapor deposition surface of the vapor deposition section 30 or the vapor deposition plate 31 disposed in close contact with the outer bottom surface of the temperature adjustment container 33. A cylindrical guide 46 extending in the purification direction of the refined magnesium 3 deposited and grown on the deposition surface is provided. As shown in FIG. 2, the cylindrical guide 46 abuts on the inner surface of the lid 12 and is attached to the vacuum container 10 with a part of the temperature adjustment container 33 entering the cylindrical guide 46. A peripheral edge portion of the outer bottom surface of the temperature adjustment container 33 serving as a magnesium vapor deposition surface, or a peripheral edge portion of the vapor deposition plate 31 disposed in close contact with the outer bottom surface of the temperature adjustment container 33, and the cylindrical guide 46. It is preferable that a heat insulating ring (heat insulating member) 45 for performing heat cutting is interposed therebetween. This is to prevent magnesium from being deposited on the cylindrical guide 46.

  Further, the magnesium purification apparatus 1 according to the present embodiment is configured so that the magnesium sublimated from the raw material magnesium 2 in the raw material container 21 in the vacuum vessel 10 is guided into the cylindrical guide 46. It is preferable to partition the cylindrical guide 46 other than the opening on the raw material container 21 side by the partition plate 47.

Next, the vacuum structure of the vacuum vessel 10 including the main body 11 and the lid body 12 will be described. The vacuum vessel 10 includes a vacuum pump 13 as vacuum means for forming a vacuum atmosphere in the vacuum vessel 10. In the magnesium purification apparatus of the present invention, the degree of vacuum in the vacuum vessel 10 is preferably set to 10 Pa to ¹ × 10 ⁻¹ Pa by the vacuum pump 13. The gas remaining in the vacuum atmosphere may be air, but is preferably an inert gas such as argon. In the present embodiment, as a method of forming a vacuum atmosphere in the vacuum vessel 10, a method of using the vacuum pump 13 to suck the gas filled in the vacuum vessel 10 and maintain a negative pressure up to a predetermined degree of vacuum. However, it is not limited to this.

  Further, in order to maintain the vacuum atmosphere in the vacuum vessel 10, the main body 11 and the lid 12 constituting the vacuum vessel 10 are separated from each other by an inner metal packing made of a metal such as copper at a predetermined interval. It is preferable to employ a sealing structure including an outer metal packing. Specifically, as shown in the enlarged view of the circle S in FIG. 1 shown in FIG. 4, a flange portion 11A is provided at the opening edge of the main body 11, and two packing receiving grooves are formed on the end surface of the flange portion 11A that overlaps the lid body 12. 14 and 15 are formed, the inner metal packing 16 is disposed in the packing receiving groove 14 positioned on the inner side, and the outer metal packing 17 is disposed in the packing receiving groove 15 positioned on the outer side. Between these packing accommodating grooves 14 located on the inner side and the packing accommodating grooves 15 located on the outer side, an anti-oxidation vacuum pump 19 (vacuum means) for sucking gas between the packing accommodating grooves 14 and 15 is provided. An antioxidant passage 18 to be connected is formed. The means for preventing oxidation is not limited to the oxidation-preventing vacuum pump 19, and an inert gas filling means for filling an inert gas such as argon between the packing housing grooves 14 and 15. May be used. By adopting these configurations, it is possible to greatly suppress the inconvenience that the metal packings 16 and 17 housed in both packing housing grooves 14 and 15 are oxidized, thereby extending the life of the metal packing. it can.

Next, the magnesium purification operation of the magnesium purification apparatus 1 according to the present embodiment will be described. First, the raw material magnesium 2 is stored in the raw material storage part 21 of the vacuum vessel 10. The raw material magnesium 2 is stored in the raw material holding unit 25 while being separated from the inner wall surface of the vacuum vessel 10 by, for example, 1 mm. And the upper surface opening of the main body 11 of the vacuum vessel 10 is obstruct | occluded with the cover body 12, and it fixes with a screw etc., for example. And the vacuum degree in the vacuum vessel 10 is adjusted with the vacuum pump 13 to the arbitrary vacuum degree in the range of 10 Pa- ¹ * 10 < ^-1 > Pa.

  Thereafter, a current having a predetermined frequency is applied to the induction heating coil 22 to perform induction heating of the raw material magnesium 2 housed in the raw material housing portion 21 of the vacuum vessel 10. At this time, the raw material magnesium 2 is heated to an arbitrary set temperature within a range of 430 ° C. to 550 ° C. by the induction heating coil 22 based on the temperature detected by the raw material magnesium temperature sensor 26 as described above. At this time, the vacuum vessel 10 itself is also induction-heated by the induction heating coil 22, but further, the heating capacity of the auxiliary heater 27 is supplementarily used, and the vacuum vessel 10 itself is set to any setting equal to or higher than the heating temperature of the magnesium raw material. Heat to temperature.

  When the raw material magnesium 2 is induction-heated to a temperature equal to or higher than the sublimation temperature of magnesium, the magnesium contained in the raw material magnesium 2 is sublimated. The sublimated magnesium is indicated by a black circle in FIG. At this time, a substance having a lower vapor pressure than magnesium contained in the raw material magnesium 2 remains in the raw material magnesium. Impurities having a lower vapor pressure than magnesium include lithium (Li), antimony (Sb), bismuth (Bi), aluminum (Al), manganese (Mn), boron (B) gallium (Ga), silver (Ag), Examples include titanium (Ti), chromium (Cr), copper (Cu), silicon (Si), iron (Fe), nickel (Ni), molybdenum (Mo), and calcium (Ca).

  Magnesium sublimated from the raw material magnesium 2 diffuses into the vacuum vessel 10. At this time, the vacuum vessel 10 itself is set to a temperature higher than the vapor deposition temperature of magnesium by the induction heating coil 22 and the auxiliary heater 26, and the vapor deposition unit 30 disposed above the raw material storage unit 21 is compressed air. Is set to an arbitrary temperature within a range of 330 ° C. to 410 ° C. that allows magnesium to be deposited. Therefore, the magnesium diffused into the vacuum vessel 10 is deposited on the vapor deposition unit 30 disposed above the raw material storage unit 21 without adhering to the inner wall surface of the vacuum vessel 10. In the present embodiment, magnesium diffused in the vacuum vessel 10 is guided to the cylindrical guide 46 provided in the vacuum vessel 10 and is deposited in close contact with the outer bottom surface of the temperature adjustment vessel 33. Vapor deposition is performed on the plate 31. Since the purified magnesium 2 deposited on the surface of the vapor deposition plate 31 has a temperature close to the surface temperature of the vapor deposition plate 31, magnesium is deposited one after another on the surface of the magnesium vapor deposited on the surface of the vapor deposition plate 31. On the plate 31, the purified magnesium 2 grows in an icicle shape.

  At this time, among impurities contained in the raw material magnesium 2, a substance having a vapor pressure higher than that of magnesium evaporates into the vacuum container 10 by being heated together with magnesium. However, since the temperature of the vapor deposition part 30 (evaporation plate 31) is set to the high temperature of 330 degreeC-410 degreeC as mentioned above, an impurity vapor-deposits on the vapor deposition part 30, and the purity of refined magnesium 2 falls. Can be suppressed. As impurities having higher vapor pressure than magnesium, zinc (Zn), sodium (Na), arsenic (As), potassium (K), phosphorus (P), sulfur (S), chlorine (Cl), fluorine (F) Can be mentioned.

  Thus, in the magnesium purification apparatus according to the present invention, the raw material magnesium 2 can be directly heated without going through the vacuum vessel 10 by heating the raw material magnesium 2 by the induction heating method. Therefore, unlike the conventional case where the vacuum vessel 10 containing the raw material magnesium 2 is heated by a heater and the raw material magnesium 2 is heated by heat conduction from the vacuum vessel 10, the raw material magnesium 2 itself is heated uniformly. Can do.

  Therefore, the impurity contained in the raw material magnesium evaporated from the raw material magnesium 2 is locally heated to a high temperature to evaporate, thereby avoiding the disadvantage of being evaporated together with the purified magnesium 3 in the vapor deposition section 30. . In addition, the heating of the raw material magnesium 2 by the induction heating method can directly heat the raw material magnesium 2 itself, unlike the heating by the heat conduction from the vacuum vessel 10, so that the raw material magnesium 2 is aimed at a shorter time. Can be heated to temperature. Therefore, highly purified magnesium can be purified efficiently in a shorter time.

  Moreover, the magnesium purification apparatus 1 in the present embodiment can stably control the temperature of the raw material magnesium 2 itself by induction heating by housing the raw material magnesium 2 apart from the inner wall surface of the vacuum vessel 10. It becomes possible. Therefore, when the raw material magnesium 2 is partially heated to a high temperature, evaporation of impurities contained in the raw material magnesium 2 can be effectively suppressed.

  Furthermore, since the magnesium purification apparatus 1 in this embodiment adjusts the temperature of the vapor deposition part 30 to the vapor deposition temperature of magnesium using compressed air, it becomes unnecessary to use liquid, oil, etc. as a temperature adjustment means, and workability | operativity is improved. Improvements can be made.

  Moreover, when taking out the refined magnesium 2 deposited on the deposition unit 30 in the present embodiment, the lid 12 is opened, and the deposition plate 31 disposed on the bottom surface of the temperature adjustment container 33 of the deposition unit 30 is removed. Thus, purified magnesium 2 is taken out. At this time, since the vapor deposition plate 31 is a simple plate-like member, purified magnesium can be easily taken out, and it is possible to effectively avoid the inconvenience that impurities are mixed during the extraction.

  In the above-described embodiment, the raw material magnesium 2 is disposed in the lower portion of the vacuum vessel 10 and the vapor deposition section 30 is disposed in the upper portion of the vacuum vessel 10, but the present invention is not limited to this. However, the vapor deposition unit 30 for vapor deposition of the raw material magnesium 2 and the purified magnesium 3 may be arranged separately.

  In the magnesium purification method and the magnesium purification apparatus according to the present invention, for example, when purifying 99.9 wt% or more of raw material magnesium, impurities contained in the raw material magnesium are efficiently heated by induction heating. This is particularly effective when purifying purified magnesium having a higher purity without mixing any of the above.

DESCRIPTION OF SYMBOLS 1 Magnesium refinement | purification apparatus 2 Raw material magnesium 3 Purified magnesium 10 Vacuum container 11 Main body 12 Cover body 12A Deposition part attachment hole 13 Vacuum pump (vacuum means)
14, 15 Packing receiving groove 16 Inner metal packing 17 Outer metal packing 18 Antioxidation passage 19 Antioxidation vacuum pump (vacuum means)
DESCRIPTION OF SYMBOLS 21 Raw material accommodating part 22 Induction heating coil 23 Raw material holding | maintenance mechanism 24 Suspension support part 25 Raw material holding | maintenance part 26 Raw material magnesium temperature sensor (raw material magnesium temperature detection means)
27 Auxiliary heater 30 Vapor deposition section 31 Vapor deposition plate 33 Temperature adjustment container 34 Temperature adjustment member 35 Nozzle insertion hole 36 Compressed air introduction nozzle 37 Recess 38 Temperature sensor insertion hole 39 Vapor deposition temperature sensor (vapor deposition temperature detection means)
40 fixed plate 41 communication hole 42 communication hole 46 cylindrical guide

Claims (11)

A method of purifying magnesium from raw material magnesium by a vacuum sublimation method,
A method for purifying magnesium, comprising heating the raw material magnesium by an induction heating method, and depositing magnesium sublimated by heating on a surface of a vapor deposition part disposed away from the raw material magnesium to obtain purified magnesium. The method for purifying magnesium according to claim 1, wherein the raw material magnesium is heated to 430 ° C. to 550 ° C. by the induction heating method in a vacuum of 10 Pa to ¹ × 10 ⁻¹ Pa.   The magnesium purification method according to claim 2, wherein a deposition temperature of magnesium in the deposition section is set to 330 ° C. to 410 ° C. A magnesium purifier for purifying magnesium from raw material magnesium by a vacuum sublimation method,
A vacuum container that contains a raw material magnesium;
An induction heating coil that sublimates magnesium by induction heating the raw material magnesium in the vacuum vessel from the outside of the vacuum vessel;
A magnesium refining apparatus comprising: a vapor deposition section that is disposed in the vacuum vessel apart from the raw material magnesium and deposits magnesium diffused in the vacuum vessel.   The magnesium purification apparatus according to claim 4, wherein the raw material magnesium is stored separately from the inner wall surface of the vacuum vessel.   The said vapor deposition part is a magnesium refinement | purification apparatus of Claim 4 or Claim 5 adjusted to the vapor deposition temperature of magnesium by the vapor deposition part temperature adjustment means using compressed air. The degree of vacuum in the vacuum container is 10 Pa to ¹ × 10 ⁻¹ Pa, and the raw material magnesium and the vacuum container itself are set to 430 ° C. to 550 ° C. by the induction heating coil. The magnesium refinement | purification apparatus of description.   The said vapor deposition part is a magnesium refinement | purification apparatus of Claim 7 adjusted to 330 to 410 degreeC by the said vapor deposition part temperature adjustment means. The vacuum vessel has an opening and a main body provided with a raw material container for containing the raw material magnesium therein, and a lid that closes the opening of the main body so that the opening can be opened and closed.
The said lid is a magnesium refinement | purification apparatus in any one of Claims 4-8 provided with the said vapor deposition part which faces the inside of a main body.   The said vacuum vessel surrounds the peripheral part of the said vapor deposition part via a heat insulation member, and is provided with the cylindrical guide extended in the growth direction of the refined magnesium vapor-deposited on the said vapor deposition part. Magnesium purification equipment.   Between the main body and the lid body, an inner metal packing and an outer metal packing are provided at a predetermined interval, and a vacuum is provided between the inner metal packing and the outer metal packing, or between these metal packings. The magnesium purification apparatus according to claim 9 or 10, wherein an inert gas is filled in the container.

Images