JP2012021185A - Method and apparatus for recovering magnesium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for safely and continuously recovering magnesium, and to provide an apparatus for recovering magnesium that is suitable for the implementation of the method.SOLUTION: The apparatus for recovering magnesium includes: a container that can accommodate granular powder in a vibrating, fluid, or moving manner; a port for supplying the granular powder, which is provided at the upper part of the container; a port for discharging the granular powder, which is provided at the lower part of the container; a port for introducing magnesium vapor into the container; and a device for vibrating, fluidizing, or moving the granular powder accommodated in the container. The apparatus is capable of condensing the introduced magnesium vapor on the granular powder surface.

Description

  The present invention relates to a magnesium recovery method and a magnesium recovery apparatus. More specifically, the present invention relates to a method of recovering magnesium continuously and efficiently and a magnesium recovery apparatus suitable for carrying out the method.

Magnesium is produced by a melt electrolytic method or a thermal reduction method. In the melt electrolysis method, aluminum, silicon, chlorine, iron, manganese and the like are contained as impurities, and the purity of the obtained magnesium is low. For this purpose, magnesium may be purified by distillation.
On the other hand, the thermal reduction method includes a step of reducing dolomite with ferrosilicon and condensing magnesium vapor.
Magnesium is also produced by refining scrap containing magnesium. Distillation is generally used for this purification.

  Magnesium vapor generated in the production or purification of magnesium adheres as fine magnesium powder to the inner wall and lid of the apparatus. If this comes into contact with air, it may ignite and burn. Further, when the device lid is opened and opened, the fine magnesium powder is released out of the system, which may impair the work environment and may ignite and burn. Furthermore, the conventional apparatus has a problem that the magnesium recovery rate from the magnesium vapor is low. Moreover, the work of peeling off the magnesium lump obtained by condensation of magnesium vapor from the condensation surface is required. For this reason, the purity of magnesium may be lowered due to contamination or the like from the condensation surface, or may be left behind on the condensation surface and the recovery rate of magnesium may be lowered.

Under such circumstances, Patent Document 1 and Patent Document 2 cover and seal a crucible for storing a raw material, a heating device for heating and melting the raw material stored in the crucible, and covering the open space of the crucible. A double cylinder composed of an inner sealed cylinder and an outer sealed cylinder, a magnesium condensing device disposed in the inner sealed cylinder and above the crucible, and a cooling means located in the vicinity of the magnesium condensing device, An apparatus for recovering pure magnesium of a magnesium alloy material has been proposed, comprising exhaust means for reducing the pressure inside the double cylinder.
Patent Document 3 discloses an apparatus for producing a pure magnesium lump from magnesium fine pieces, which is a sealed container provided with a heating means for heating the inside, and an inner wall by cooling to a temperature lower than the heating temperature in the sealed container. A recovery container for condensing and adhering vapor; a connection passage for connecting the sealed container and the recovery container to lead magnesium vapor in the sealed container to the recovery container; a decompression means for decompressing the sealed container and the recovery container; There has been proposed an apparatus for producing a pure magnesium lump from a magnesium fine piece, characterized in that it comprises a storage container connected to the lower part for storing oil and water from inside the recovery container.

JP 2002-348621 A JP 2005-126802 A JP-A-6-88148

  An object of the present invention is to provide a method for recovering magnesium continuously and efficiently and a magnesium recovery apparatus suitable for carrying out the method.

As a result of intensive studies to achieve the above object, the present inventor has accommodated powder particles in a container, vibrated, flowed or moved the powder particles, introduced magnesium vapor into the container, It has been found that magnesium can be recovered continuously and with high efficiency.
The present invention has been completed by further studies based on this finding.

That is, the present invention includes the following aspects.
[1] A method for recovering magnesium, comprising storing powder particles in a container, vibrating, flowing or moving the powder particles, and introducing magnesium vapor into the container to condense on the surface of the powder particles.
[2] The method for recovering magnesium according to [1], wherein the powder particles are made of magnesium metal.
[3] The method for recovering magnesium according to [1] or [2] above, wherein the container is filled with a non-oxidizing atmosphere.

[4] Container that can accommodate powder particles so that they can vibrate, flow, or move, a port that supplies powder particles to the top of the container, a port that discharges powder particles to the bottom of the container, and magnesium vapor introduced into the container And a means for vibrating, flowing, or moving the powder contained in the container, and the introduced magnesium vapor can be condensed on the surface of the powder.
[5] The magnesium recovery apparatus according to [4], further including means for classifying discharged particles.
[6] The magnesium recovery apparatus according to [4] or [5], wherein the powder particles are made of magnesium metal.
[7] The magnesium recovery apparatus according to any one of [4] to [6], wherein the inside of the container can be made into a non-oxidizing atmosphere.

The magnesium recovery apparatus suitably used for the magnesium recovery method according to the present invention has a container that can accommodate powder particles so as to be able to vibrate, flow, or move. The container has a mouth for supplying powder to the top, a mouth for discharging powder to the bottom of the container, and a mouth for introducing magnesium vapor into the container.
Such a container may be a tower or tank type chemical device known as a moving bed or fluidized bed. As the moving bed device, for example, a hopper or conveyor for supplying new powder particles to the upper part of the container is provided, and a vibratory feeder, rotary feeder, table feeder for discharging a fixed amount of powder particles to the lower part of the container Etc. are provided, and the powder particles can move from top to bottom in the container (see FIG. 3). The moving bed apparatus can include a so-called simulated moving bed apparatus in which a plurality of fixed layers are moved in a pseudo manner by switching valves. In addition, as the fluidized bed apparatus, for example, a hopper for supplying new powder particles is provided at the top of the container, and a device that generates sufficient vibration to fluidize the powder particles in the container is provided in the container. A feeder for discharging a certain amount of powder particles at the bottom of the container (see Fig. 1); A hopper for supplying new powder particles is provided at the top of the container, and the powder in the container is disposed at the bottom of the container A device (see FIG. 2) in which a device for feeding airflow sufficient to fluidize the particles is provided, and a feeder for discharging a certain amount of powder particles at the lower portion of the container is provided. Moreover, the apparatus which forms the fluidized bed by combining the fluidization by mechanical vibration and the fluidization by airflow may be used.

And magnesium vapor | steam is introduce | transduced into the said container, it is made to contact with the granule currently vibrated, fluidized, or moved, and is condensed on the surface of this granule. When the introduced magnesium vapor condenses on the surface of the particles, the particles are coated with magnesium, and the particles become larger. In the present specification, “condensation” implies both rearrangement from the gas phase to the liquid phase (condensation in a narrow sense) and rearrangement from the gas phase to the solid phase (condensation in a narrow sense). In addition, “condensation” in the present specification also implies rearrangement from the gas phase to the liquid phase and then rearrangement from the liquid phase to the solid phase.
The magnesium vapor may be a vapor generated by heating and melting a magnesium material, or a vapor generated by a thermal reduction method. Examples of the magnesium material include scraps containing magnesium such as defective moldings, biscuits, sprues, runners, overflows, burrs, cutting powders, and chips. The magnesium material may be pure magnesium or a magnesium alloy. Magnesium vapor can also be generated by sending magnesium oxide vapor into the furnace and irradiating it with a laser. The temperature of the magnesium vapor can be set as appropriate in consideration of the recovery rate of magnesium, thermal energy, costs for equipment, and the like. In addition, according to the dictionary of metallic materials and processing processes (edited by Kawaguchi et al., Maruzen, published on March 15, 2001), magnesium has a melting point of 650 ° C. and a boiling point of 1120 ° C.
Magnesium vapor may be brought into countercurrent contact or cross-contact with the powder particles. FIG. 3 shows the case of countercurrent contact in which magnesium vapor flows from bottom to top and powder particles move from top to bottom.

The powder used in the magnesium recovery apparatus according to the present invention is not particularly limited as long as magnesium can be condensed on the surface. From the viewpoint of easy recovery of high-purity magnesium, the powder is preferably made of metallic magnesium. The shape of the powder is not particularly limited, but a spherical shape is preferable from the viewpoint of easy vibration, flow, or movement in the container.
The size of the powder is not particularly limited as long as it can be vibrated, flowed or moved. The size of the powder particles is, for example, 10 μm to 10 mm, preferably 50 μm to 1 mm. If the powder is too large, the magnesium recovery rate may be low. If the powder is too small, there is a high risk of ignition, combustion, etc., and agglomeration may make it difficult to vibrate, flow or move in the container.
The powder is preferably cooled in order to facilitate condensation of magnesium vapor on the surface. The powder particles can be cooled by a known cooling means. For example, in the moving bed apparatus shown in FIG. 3 or the fluidized bed apparatus shown in FIG. 1, a heat exchanger or the like can be provided on the upper part of the container 311 or the container 111 to cool the particles. Further, in the fluidized bed apparatus shown in FIG. 2, the powder particles can be cooled by lowering the temperature of the gas introduced for fluidization.

  The atmosphere in the container is not particularly limited, but is preferably a non-oxidizing atmosphere. In an oxidizing atmosphere, magnesium produced by condensation of magnesium vapor is likely to be oxidized. In order to obtain a non-oxidizing atmosphere, an inert gas such as nitrogen gas or argon gas can be introduced into the container. Further, the operation temperature can be lowered by reducing the pressure in the container.

  The powder covered with magnesium is taken out from the powder outlet provided in the lower part of the container. The means for taking out the powder particles is not particularly limited. For example, a vibration feeder, a rotary feeder, a table feeder, a screw feeder, etc. are mentioned. And the taken-out powder grain can be classified. Classification means is not particularly limited. Examples thereof include a sieve, a centrifugal classifier, a gravity classifier, and an inertia classifier. Powder particles having a predetermined size or less can be supplied again from the upper part of the magnesium recovery apparatus according to the present invention.

According to the magnesium recovery method and the magnesium recovery apparatus of the present invention, magnesium can be recovered continuously and with high efficiency. When the introduced magnesium vapor is condensed on the surface of the particles, the particles are coated with magnesium, and the particles become larger. The magnesium recovery method according to the present invention does not require handling of the magnesium fine powder generated by the condensation of magnesium vapor as in the conventional method, so that it is excellent in work environment and can avoid problems such as ignition and combustion. By using the powder particles, the contact area with the magnesium vapor increases, so that high condensation efficiency can be obtained with a small device. Since the powder coated with magnesium can be continuously taken out of the container by using a vibration feeder, a rotary feeder or the like, the productivity of magnesium can be increased. When magnesium powder is used as the powder, it is not necessary to peel off the magnesium obtained by condensation of magnesium vapor from the magnesium powder. Therefore, high purity magnesium can be recovered with high efficiency.
In addition, the powder coated with magnesium is classified, and the powder of a predetermined size or less is supplied again from the upper part of the magnesium recovery device and used until it reaches a predetermined size, thereby reducing the manufacturing cost. Can be lowered.

The conceptual diagram which shows the magnesium collection | recovery apparatus concerning Embodiment 1. FIG. The conceptual diagram which shows the magnesium collection | recovery apparatus which concerns on Embodiment 2. FIG. The conceptual diagram which shows the magnesium collection | recovery apparatus which concerns on Embodiment 3. FIG.

  Next, an embodiment of the magnesium recovery apparatus according to the present invention will be shown to describe the present invention more specifically. The scope of the present invention is not limited by these embodiments.

Embodiment 1
FIG. 1 is a conceptual diagram showing a vibration / fluidized bed type magnesium recovery apparatus using mechanical vibration. In addition, in FIG. 1, drawing of the powder grain of a container center part is abbreviate | omitted.
The collection device includes a container 111 and a vibrator 110 attached to the lower part of the container 111. The container 111 is a cylindrical tower, a magnesium powder supply port 113 at the top of the tower, a powder discharge port 114 coated with magnesium at the bottom of the tower, a magnesium vapor inlet 115 at the bottom of the tower, And an exhaust port 116 at the top of the tower. The supply port 113, the discharge port 114, the introduction port 115, and the exhaust port 116 are connected to an external pipe or the like via a flexible tube. The flexible tube prevents vibrations from being transmitted to external piping.

  The container 111 is installed on the base via a spring 117. The container 111 is vibrated by the vibrator 110. Due to this vibration, magnesium powder particles (particle size: about 150 μm) supplied from the supply port 113 are vibrated and fluidized in the container 111. In addition, a vibration plate such as a spiral plate or a cross-shaped plate is installed in the container 111, and the vibration generated by the vibrator is transmitted to the vibration plate, so that the vibration and fluidization of the powder particles are performed throughout the container. Can get up easily.

  Magnesium vapor introduced from the inlet 115 contacts the fluidized magnesium powder and condenses on the surface of the powder. The surface of magnesium powder particles is coated with magnesium by condensation. The height of the magnesium powder fluidized in the tower is high enough that almost all of the introduced magnesium vapor condenses on the surface of the magnesium powder and does not contain magnesium vapor in the exhaust at the exhaust port. To. This height can be calculated by a method similar to a design method in a fluidized bed adsorption device, a fluidized bed gas absorption device, or the like. The powder coated with magnesium is discharged from the discharge port 114. The discharge amount is adjusted by the discharge device 112. Moreover, in order to promote condensation of magnesium vapor | steam, a heat exchanger (not shown) etc. can be provided in the upper part of the container 111, and magnesium powder can be cooled using it. In order to prevent the magnesium vapor from condensing on the inner wall surface of the container 111, the inner wall can be kept higher than the condensation temperature of the magnesium vapor.

  When the magnesium recovery apparatus shown in FIG. 1 is used, the magnesium vapor introduced from the introduction port 115 is almost completely removed from the airflow, so that the magnesium vapor hardly comes out from the exhaust port 116. Magnesium condensed on the surface of the magnesium powder is in the form of a film and is difficult to peel off from the powder. The powder coated with magnesium discharged from the discharge port 114 has an appropriate size and is easy to handle. In addition, although the inlet 115 is arrange | positioned so that magnesium vapor | steam blows down in the container 111, it is not limited to this.

  Magnesium vapor is generated as follows. Magnesium oxide and nitrogen gas are sent together into the furnace and irradiated with a laser. This laser irradiated part becomes a high temperature of about 20,000 ° C. Under this high temperature, magnesium oxide separates into magnesium and oxygen and becomes pure magnesium. Since the partial pressure of the separated oxygen is lowered by nitrogen gas, recombination with magnesium hardly occurs. A mixture of nitrogen gas and magnesium vapor generated by the method is fed into the introduction port 115.

[Embodiment 2]
FIG. 2 is a conceptual diagram showing a fluidized bed type magnesium recovery apparatus using an air flow. In addition, in FIG. 2, drawing of the powder grain of a container center part is abbreviate | omitted.
The collection device has a container 211. The container 211 is a cylindrical tower, a magnesium powder supply port 213 at the top of the tower, a powder discharge port 214 coated with magnesium at the bottom of the tower, a magnesium vapor inlet 215 at the bottom of the tower, An exhaust port 216 and a blower port 218 for feeding gas are provided at the top of the tower. The supply port 213, the discharge port 214, the introduction port 215, the exhaust port 216, and the blower port 218 are connected to external piping through a flexible tube.

  The gas sent from the blower port 218 is dispersed by the dispersion plate 219 so that an even upward air flow is generated in the container 211. The amount of gas is adjusted so that the ascending airflow is not less than the fluidization start speed and not more than the particle end speed. Due to this updraft, the magnesium particles (particle size: about 150 μm) supplied from the supply port 213 are fluidized in the container 211. In order to accelerate the condensation of magnesium vapor, the fed gas can be cooled by a heat exchanger (not shown) provided in front of the air blowing port. Nitrogen gas can be used as the gas for generating the updraft.

Magnesium vapor introduced from the inlet 215 contacts the fluidized magnesium powder and condenses on the surface of the powder. The surface of magnesium powder particles is coated with magnesium by condensation. The height of the magnesium particles that are fluidized in the tower is high enough so that the magnesium vapor is condensed almost entirely on the surface of the magnesium particles and the magnesium vapor is not contained in the exhaust at the exhaust port. This height can be calculated by a method similar to a design method in a fluidized bed adsorption device, a fluidized bed gas absorption device, or the like. In addition, although the inlet 215 is arrange | positioned so that magnesium vapor | steam blows down in the container 211, it is not limited to this.
The powder coated with magnesium is discharged from the discharge port 214. The discharge amount is adjusted by the discharge device 212. The exhaust port 216 can be provided with a filter such as a wire mesh or a classification device such as a cyclone so that magnesium powder particles do not come out with the rising air current. Magnesium vapor is generated in the same manner as in the first embodiment.

[Embodiment 3]
FIG. 3 is a conceptual diagram showing a moving bed type magnesium recovery apparatus. In addition, in FIG. 3, drawing of the powder grain of a container center part is abbreviate | omitted.
The collection device has a container 311. The container 311 is a cylindrical tower, a magnesium particle supply port 313 at the top of the tower, a powder discharge port 314 coated with magnesium at the bottom of the tower, a magnesium vapor inlet 315 at the bottom of the tower, And an exhaust port 316 at the top of the tower.

  Magnesium particles (particle size: about 150 μm) supplied from the supply port 313 are filled into the tower. A vibration feeder 312 having a vibrator 310 is installed at the discharge port 314 so that particles coated with magnesium can be discharged at a constant flow rate. Due to the discharge of the powder particles from the discharge port, the magnesium powder particles supplied from the supply port 313 sequentially move from the upper part to the lower part in the tower by gravity. A heat exchanger (not shown) or the like is provided on the upper portion of the container 311 and the magnesium powder can be cooled using the heat exchanger. The supply amount of the magnesium particles at the supply port 313 is adjusted according to the discharge amount of the powder particles at the discharge port 314.

  On the other hand, the magnesium vapor introduced from the introduction port 315 comes into countercurrent contact with the magnesium particles moving downward and condenses on the surface of the particles. The surface of magnesium powder particles is coated with magnesium by condensation. The height of the magnesium particles filled in the tower is set high enough that the magnesium vapor is condensed almost entirely on the surface of the magnesium particles and the magnesium vapor is not contained in the exhaust at the exhaust port. This height can be calculated by a method similar to the design method in a moving bed adsorption device, a moving bed gas absorption device, or the like. The inlet 315 is arranged so that magnesium vapor blows upward in the container 311. A perforated plate or the like is attached to the outlet of the inlet 315 so that the powder particles do not enter the inlet 315. Then, an inert gas or the like contained in the introduced magnesium vapor is exhausted from the exhaust port 316. The powder coated with magnesium is discharged from the discharge port 314. Magnesium vapor is generated in the same manner as in the first embodiment.

  According to the magnesium recovery apparatus according to the above embodiment, magnesium can be recovered continuously and with high efficiency. When the magnesium recovery apparatus according to this embodiment is used, the magnesium vapor introduced from the introduction port is almost completely removed from the airflow, so that the magnesium vapor hardly comes out from the exhaust port. When the introduced magnesium vapor is condensed on the surface of the particles, the particles are coated with magnesium, and the particles become larger. Since the powder coated with magnesium can be continuously taken out of the container, the productivity of magnesium can be increased. In addition, the powder coated with magnesium is classified, and the powder of a predetermined size or less is supplied again from the upper part of the magnesium recovery device and used until it reaches a predetermined size, thereby reducing the manufacturing cost. Can be lowered.

Claims (7)

Contains powder in a container,
Vibrate, flow or move the particles;
A method for recovering magnesium, comprising introducing magnesium vapor into the container and condensing on the surface of the particles.   The method for recovering magnesium according to claim 1, wherein the powder particles are made of magnesium metal.   The method for recovering magnesium according to claim 1 or 2, wherein the container is filled with a non-oxidizing atmosphere. A container that can accommodate powder particles so that they can vibrate, flow or move,
There are a mouth for supplying the granules to the top of the container, a mouth for discharging the grains to the bottom of the container, and a mouth for introducing magnesium vapor into the container,
And having means for vibrating, flowing or moving the powder particles contained in the container,
A magnesium recovery apparatus capable of condensing introduced magnesium vapor on the surface of the powder particles.   The magnesium recovery apparatus according to claim 4, further comprising means for classifying the discharged powder particles.   The magnesium recovery apparatus according to claim 4 or 5, wherein the powder particles are made of magnesium metal.   The magnesium recovery apparatus according to any one of claims 4 to 6, wherein the inside of the container can be made into a non-oxidizing atmosphere.

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