JPH0774361B2 - Device for producing high-purity fine powder of active metal - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for producing high-purity fine powder of active metal,
In particular, active metals that produce hydroxide compounds such as strontium (Sr), barium (Ba), yttrium (Y), etc., which are the raw materials for manufacturing superconducting materials, and hafnium (Hf), which has excellent superhardness and superheat resistance. High-purity fine powder (IIa, IIIa, IV
a, IV b group metal) for producing an active metal high-purity fine powder.

[Prior Art] In recent years, active metals (IIa, IIIa, I
Attention has been paid to the production of high-purity fine powders of V a and IV b metals). The active metal that produces this hydroxide compound increases in surface area with pulverization and causes gas adsorption, occlusion, and surface oxidation. Particularly in the active group IIa metal, it rapidly reacts with water to react with the hydroxide compound. However, these problems have not yet been solved and there has been no prior art for producing high-purity fine powder.

Conventionally, superconducting materials are strontium (Sr), barium (Ba), yttrium (Y), lanthanum (La), copper (C
Conventionally, compound oxides such as u) have been manufactured by using single metal salts or compounds such as oxides as raw materials.

Hafnium (Hf) fine powder, which has excellent superhardness and superheat resistance, reduced Hf salts with hydrogen to generate and carbonize Hf.

However, since metal compounds are used in these production methods, the reaction system is more complicated than that of pure metal fine powder, so that the purity is lowered, which causes the performance of the characteristic value depending on the application to be lowered. There was a problem.

In addition, there is a problem that elements and groups unnecessary for the final product contained in salts are decomposed and escaped during the manufacturing process to become vacancies, which causes disorder in crystals.

Furthermore, since the reaction system is complicated, multiple steps are required, and there is a problem that the cost is large due to the equipment cost during mass production.

Therefore, the applicant can obtain a high-purity fine powder of an active metal (IIa, IIIa, IVa, IVb metal) that produces such a hydroxide compound. Manufacturing method ”was applied separately.

[Problems to be Solved by the Invention] However, since the above-mentioned "method for producing high-purity fine powder of active metal" has not been established in the past, there was no apparatus capable of effectively carrying out this production method.

Therefore, in view of such problems, the present invention provides a high-purity fine powder of an active metal (group IIa, IIIa, IVa, IVb metal) that produces a hydroxide compound. It is an object of the present invention to provide an apparatus for producing fine powder of purity.

[Means for Solving the Problem] In order to achieve the above object, the present invention is to attach a rubber glove to a closed container to which a vacuum evacuation means and an inert gas supply means are connected in order to produce high-purity fine powder of active metal. An opening is formed, the rubber glove is attached to the opening for attaching the rubber glove so as to face the inside of the closed container, and an opening / closing door for blocking the inside of the rubber glove from the outside air is provided. The rubber glove covered by the opening / closing door An inert gas supplied from the inert gas supply means is provided with a communication passage communicating between the inside and the closed container to maintain the same pressure, and the communication passage is opened during vacuum evacuation. Provided with an on-off valve that closes when filled with, further, in an airtight container filled with the above inert gas,
Equipped with a cryogenic cooling means for dew condensation of water in the closed container, the condensed water is brought into contact with the sodium metal mass, and the remaining water in the closed container atmosphere is reacted with sodium metal vapor to form sodium hydroxide. It is provided with a means for removing water.

[Operation] Since the cryogenic cooling means is provided on one side wall of the closed container having the rubber gloves facing the inside so as to perform the internal work in the inert gas atmosphere, the cooling means is used for the sealing. When the cryogenic refrigerant is brought into contact with the container, the residual water in the atmosphere gas is condensed on the inner wall of the container. The condensed water is removed by adopting the water trap technology disclosed in “Method for removing residual water in atmospheric gas” filed separately. This is because sodium lumps of metal are brought into contact with the dewed water to act as a so-called solid-phase getter to produce sodium hydroxide, and the residual water is decomposed as hydroxyl groups.
To remove. Further, the atmospheric gas still contains a residual trace amount of moisture that is not condensed. In this regard, using the device disclosed in “Sodium Vapor Generator” filed separately, metallic sodium is heated in the atmospheric gas containing the residual trace amount of water to generate and disperse sodium vapor. Then, the sodium vapor dispersively contacts with the residual trace moisture contained in the atmosphere gas, acts as a so-called vapor phase getter to generate sodium hydroxide, and the residual trace moisture that cannot be removed by the solid phase getter is extremely converted into a hydroxyl group. It is decomposed and removed to low concentrations (10-100W / Vppb).

Then, the active metal which forms the hydroxide compound is pulverized in the inert gas atmosphere from which the residual water is thus removed.
This pulverization is performed by mechanically crushing the active metal by the crushing method while reducing the ductility by using the cryogenic cooling device.

Then, the pulverized product is hermetically stored in the storage container under the above-mentioned atmosphere to maintain high purity during storage.

Further, an opening / closing door is provided at the attachment opening of the rubber glove so as to cover it from the outside, and the opening / closing door is provided with the pressure equalizing means. However, the inside of the glove covered by the opening / closing door is maintained at the same atmospheric pressure as the inside of the container, and the rubber glove is not damaged.

[Embodiment] A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in FIGS. 1 to 3, a container 1 for producing a high-purity fine powder of active metal according to this embodiment is provided with three hermetically sealed containers 2a, 2b, 2c which are connected in series. These closed containers 2a, 2b, 2c
The rubber gloves 3 for operation are attached to the front of each of them. This rubber glove 3 is attached by a guide ring 4 so as to face the inside as shown in FIG. 7 in order to perform internal work while maintaining the inside of the containers 2a, 2b, 2c in an inert gas atmosphere. An opening / closing door 5 is attached to the rubber glove mounting opening 3a of the rubber glove 3 through an O-ring 6 so as to cover the opening from the outside as shown in FIGS. 7 to 8. There is. The opening / closing door 5 is provided with a pressure equalizing means 7. The pressure equalizing means 7 is a pressure-resistant hose 8 that serves as a communication passage for communicating the inside of the rubber glove 3 covered by the opening / closing door 5 with the closed containers 2a, 2b, 2c so as to maintain the same pressure. The hose 8 includes an electrically operated on-off valve 9 provided on the container side mounting portion. Above the rubber glove mounting opening 3a is a viewing window for observing the inside of the container.
10 are provided respectively. Further, an exhaust nozzle 11 is provided on the top of the closed container 2b located in the center, and a vacuum pump 13 for exhausting the inside of the container as shown in FIG.
The vacuum evacuation means 14 connected to is connected. A vacuum gauge 15, a main switching valve 16 and an exhaust switching valve 17 are provided in this vacuum evacuation means 14 in order. The vacuum gauge 15 and the main switching valve 16 are branched to form a pressure regulating system 18, and an accumulator 20 is connected via an electric opening / closing valve 19 to make the internal pressure of the container equal to the atmospheric pressure. The electrically operated on-off valve 19 is provided with a foot pedal 21, and when the pedal is depressed, the electrically operated on-off valve 19 is opened. The pressure adjusting system 18 is connected by a flange joint 22 with an O-ring, and the accumulator 20 at the tip thereof is also connected by a flange joint 23 with an O-ring as shown in FIG. As shown in the figure, the accumulator 20 is a pressure-resistant mesh vinyl hose 25 attached to the tip of a backflow shock absorber 24 immersed in oil (kerosene) 27 contained in a glass bottle 26. Further, inert gas pipe connection ports 28 for introducing an inert gas into the inside are respectively provided in the lower front portion of the closed containers 2a, 2b, 2c, and these inert gas pipe connection ports 28 are, An inert gas supply means (not shown) for supplying an inert gas is connected to each of the closed containers 2a, 2b, 2c. Furthermore, a cryogenic cooling means 29 is provided on one side wall of the closed vessels 2a, 2b, 2c to condense water remaining in these vessels. This cryogenic cooling means
29 is for accommodating a cryogenic condensation plate 30 formed as a part of the back wall of the container body, and a cryogenic refrigerant formed integrally with this to cool the cryogenic condensation plate 30. Cooling box
The box 31 includes a funnel-shaped inlet 32 for supplying a cryogenic refrigerant into the box 31, and an automatic temperature controller 33 for adjusting a cooling temperature by heating a heat pipe. The cryogenic condensation plate 30 is attached to the container body via a double seal 34. Further, the cryogenic condensation plate 30 and the box body 31 formed integrally with the cryogenic condensation plate 30 are made of copper, and these are heat insulating materials 35.
Is covered by. Then, the closed container 2a, 2b, 2c
Lighting lamps 36 are attached to the ceiling portions of the respective.

In the figure, 37 is an operation panel, 38 is an in-container power connector, and 39 is a container cleaning port.

An active metal (II) for producing a hydroxide compound is prepared by the separately-applied "method for producing high-purity fine powder of active metal" using the container 1 for producing high-purity fine powder of active metal configured as described above (II
a, IIIa, IVa, IVb metal) is produced. Active metals (IIa, IIIa, I
Examples of the Va and IVb metals) include strontium (Sr), barium (Ba), yttrium (Y), lanthanum (La), zirconium (Zr), which are raw materials for superconducting materials,
Hafnium (Hf) is used as a raw material for super hard and super heat resistant materials.

First, active metals (IIa, III
The inside of the closed containers 2a, 2b, 2c for producing high-purity fine powder of (a, IVa, IVb metal) is discarded by the vacuum pump 13 of the vacuum evacuation means 14 to create a vacuum atmosphere. Then, the inert gas supply means supplies and replaces the inert gas from the inert gas pipe connection port 28 into the containers 2a, 2b, 2c. The evacuation and the inert gas replacement are repeated 3 to 4 times. The degree of vacuum is measured by a vacuum gauge 15 provided in the vacuum evacuation means 14. Then, the exhaust system 14
The pressure of the inert gas atmosphere is made the same as that of the atmosphere by the accumulator 20 of the pressure regulating system 18 formed by branching into the container so that the work in the container can be performed. For vacuum exhaust, the main switching valve 16
Also, manually open and close the exhaust switching valve 17. The pressure adjustment by the accumulator 20 is performed by opening and closing the electric on-off valve 19 by the foot pedal 21. The closed containers 2a, 2b, 2c can be observed inside through a viewing window 10 and are provided with rubber gloves 3 that can be worked from the outside without impairing the sealing property. When the inside of the containers 2a, 2b, 2c is evacuated and an inert gas atmosphere is provided, the opening / closing door 5 which is openably / closably attached to the attachment opening of the rubber glove 3 is closed, and the opening / closing door 5 is provided. The inside of the glove covered with the opening / closing door 5 and the inside of the container are kept at the same atmospheric pressure by the pressure equalizing means 7, and the rubber glove 3
To prevent damage.

Even if the atmosphere to which the active metal that produces the hydroxide compound is exposed to vacuum or an inert gas atmosphere as described above, water remains in the atmosphere. Method to remove residual water. A cryogenic condensation device 29 is provided on one side wall of the closed containers 2a, 2b, 2c, and a cryogenic refrigerant is supplied from an inlet 32 into the box body 31, and the cryogenic condensation plate 30. Contact.
Liquid nitrogen, for example, is used as the cryogenic refrigerant and is cooled to -150 ° C or lower. Then, the residual moisture in the atmosphere gas is condensed on the inner walls of the containers 2a, 2b, 2c. Then, the rod-shaped metallic sodium lump is brought into contact with the condensed water. Since this rod-shaped metallic sodium lump is used under the above-mentioned inert gas atmosphere, it does not ignite and acts as a so-called solid phase getter. This metal sodium lump is immersed in oil such as petroleum to prevent ignition, and thus the containers 2a, 2b,
It is housed in 2c. When the metallic sodium lump (Na) acts as a solid phase getter on the condensed water (H ₂ O), a reaction occurs as in 2Na + 2H ₂ O → 2NaOH + H ₂ to generate sodium hydroxide (NaOH), and the residual water is It is decomposed and removed as a hydroxyl group.

However, a trace amount of water that does not condense even when cooled to an extremely low temperature remains in the atmospheric gas. The solid phase getter can only remove the condensed water.

Therefore, next, add metallic sodium in the containers 2a, 2b, 2c.
It is heated and melted at 600 ℃ to generate sodium vapor.
Similarly, this metallic sodium is stored in the above-mentioned containers 2a, 2b, 2c in a state of being immersed in oil such as petroleum so as to prevent ignition, and taken out by an inert gas. This sodium vapor disperses in the closed containers 2a, 2b, 2c and acts as a vapor phase getter for removing water. Residual trace moisture (H ₂ O) in atmospheric gas
When sodium vapor (Na) acts as a gas-phase getter, it reacts like 2Na + 2H ₂ O → 2NaOH + H ₂ to produce sodium hydroxide (NaOH), and the residual water as a hydroxyl group has an extremely low concentration (10-100W / Vppb). )
Will be disassembled and removed.

The water removal method in which the sodium vapor (Na) acts as a vapor phase getter is performed by using the device disclosed in “Sodium vapor generator” filed separately.

It is necessary to confirm whether the residual water in the inert gas atmosphere has been removed to an extremely low concentration (10 to 100 W / Vppb) by such a residual water removal method. However, even if "a method for removing residual moisture in atmospheric gas" was established, it would be
There has been no conventional technique for simply and qualitatively detecting water present at ~ 100W / Vppb). Therefore, the present applicant has created a separate application for a “method and detector for detecting trace moisture in atmospheric gas”. This method for detecting a small amount of water in atmospheric gas is to detect a small amount of water in the atmospheric gas by bringing the atmospheric gas into contact with black barium powder, and by changing the color of the black barium powder, the presence or absence of a small amount of water in the atmospheric gas. Is detected. Further, the trace moisture detector in the atmosphere gas, a cylinder through which the contents can be seen through, a black barium powder contained in the cylinder, and a black barium powder held in the cylinder to hold it, And a breathable member for introducing the atmospheric gas to be measured, a lid body detachably provided at both open ends of the cylinder body to prevent the gas from entering the cylinder body, the lid body and the cylinder body. It is composed of a sealant for sealing the gap with the body. In this way, using black barium powder as an indicator of an extremely small amount of water, the remaining minute amount of water is confirmed by the change of color from black to white, and when the above-mentioned extremely low concentration is not reached, the water removal by steam sodium vapor is repeated. .

When the residual water content in the containers 2a, 2b, 2c reaches the extremely low concentration, an active metal (IIa, IIIa, I
V a, IV b group metal) is pulverized. First, coarsely crush the activated pure metal ingot, but especially for coarse crushing of hafnium (Hf) crystal bars, we adopted the method and device disclosed in “Coarse crushing method of hafnium crystal bars and its apparatus” filed separately. This is what you do. Then, the coarsely crushed product is immersed in a cryogenic refrigerant such as liquid nitrogen,
Keeping the temperature below ℃, and reducing the ductility by cryogenic cooling.
Further, in order to mechanically pulverize this, the crushing container and the vibrator are similarly kept at -150 ° C. or less with a cryogenic refrigerant such as liquid nitrogen, and pulverized to 5 μm or less by a vibration type crusher. This pulverization process may be performed by a method other than the crushing method, but it does not impair the purity as compared with pulverization by other methods and makes the apparatus compact.

After that, the process moves to a storage process to store the finely divided active pure metal. This storage step prevents adsorption, occlusion, and surface oxidation of gas with an increase in surface area to be pulverized, and removes the above residual water to an extremely low concentration in order to prevent formation of a hydroxide compound. Store tightly in a storage container in a gas atmosphere. This storage container has a double seal to ensure airtightness in order to prevent contamination by oxygen and moisture in the atmosphere.

In addition, the active metal (II
a, IIIa, IVa, IVb group metal), in the production of high-purity fine powder, three closed containers to which the above-mentioned rubber gloves 3 were attached were provided so as to communicate with each other. Since separate work can be performed individually, flow work can be performed. The closed container may be provided with only one group and the same container may be used for all the steps.

In addition, a conveyor (for moving and transporting semi-finished products, products, crushers, etc.) installation module,
Kneading work module, powder metallurgy molding press module,
Modules according to the purpose such as a sintering furnace module, a weighing / packing module, a raw material preparation module, a crushing work module, and the like are conceivable, and these can be set in any combination.

[Effects of the Invention] In short, according to the present invention, since the inside of the rubber glove and the inside of the closed container are always kept at the same pressure even when the pressure inside the closed container is increased or decreased, the rubber glove mounting opening is provided. It is possible to prevent the rubber gloves from being damaged by the fluctuation of the pressure in the closed container. In addition, since water in the closed container can be removed to an extremely low concentration, high-purity active metal fine powder can be produced.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a container for producing high-purity fine powder of active metal according to the present invention, FIG. 2 is a back view of FIG. 1, FIG. 3 is a right side view of FIG. FIG. 1 is a schematic side view showing a cryogenic cooling device for producing a high-purity fine powder of active metal of the present invention,
FIG. 5 is a system diagram for mounting an actuator of a high-purity fine powder production container of active metal of the present invention, FIG. 6 is a schematic view showing an actuator of a high-purity fine powder production container of active metal of the present invention, and FIG. FIG. 8 is a schematic view showing a rubber glove, a door for opening and closing, and a pressure equalizing means of the container for producing a high-purity fine powder of active metal according to the present invention.
FIG. 9 is a schematic view showing a rubber glove and an opening / closing door of a container for producing high-purity fine powder of active metal of the present invention, and FIG. 9 shows an opening / closing door and a pressure equalizing means of a container for producing high-purity fine powder of active metal of the present invention. It is a schematic diagram. In the figure, 1 is a container for producing high-purity fine powder of active metal, 2 is a closed container, 3 is rubber gloves, 5 is an opening / closing door, 7 is a pressure equalizing means, 20 is an accumulator, and 29 is a cryogenic cooling means.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Hideo Nakazawa Inventor Hideo Nakazawa 3-15-15 Toyosu, Koto-ku, Tokyo Inside Ishikawajima Master Metal Co., Ltd. (56) References JP 61-19594 (JP, A) 62-198094 (JP, U)

Claims (1)

[Claims] 1. A rubber glove mounting opening is formed in a closed container to which a vacuum evacuation means and an inert gas supply means are connected in order to produce a high-purity fine powder of an active metal, and the rubber glove mounting opening is To attach the rubber gloves facing the inside of the closed container, and to provide an opening / closing door that shuts off the inside of this rubber glove from the outside air, in order to keep the inside of the rubber gloves covered by this opening / closing door at the same pressure. A communication passage that connects these is provided, and this communication passage is provided with an opening / closing valve that opens during vacuum evacuation and closes when the closed container is filled with the inert gas supplied from the inert gas supply means.
The closed container filled with the inert gas is provided with a cryogenic cooling means for dew condensation of water in the closed container, and the condensed water is brought into contact with the metallic sodium lump, and the remaining moisture in the closed container atmosphere. An apparatus for producing a high-purity fine powder of active metal, comprising: a water removing unit that reacts with sodium vapor of sodium to remove it as sodium hydroxide.