JPS63123436A - Production of fine powder of metallic compound and apparatus - Google Patents

Abstract

PURPOSE:To produce uniform and high-purity powder of metallic compd. by introducing reaction gas contg. other element into a nozzle for adiabatic expansion at the minimum cross-sectional part of the nozzle or at the position of the upstream side thereof while passing metallic vapor through the nozzle for adiabatic expansion. CONSTITUTION:Jets 74 jetted through a nozzle 48 are led to the space in a cylindrical body 114 and introduced into the space between cylindrical bodies 114, 116 via ventilation pipes 128 and furthermore introduced into the space between cylindrical bodies 116, 118 via the ventilation pipes 128. In this case, fine powder of metallic compd. is stuck on the inner circumferential surface of respective cylindrical bodies, and the fine powder is scraped down with brushes 130-134 and falls to a powder collection funnel 154 via holes 138 and is collected to a conduit part 154a. Then the fine powder in the conduit part 154a is transferred to a hopper 160 by opening an on-off valve 162 and working an exhaust pump 166.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a fine powder of a metal compound, that is, a compound of a metal and another element, and more particularly to a method and apparatus for producing a fine powder of a metal compound. .

Conventional technology As a method for producing fine powder of a metal compound, JP-A-58-150427 and JP-A-60-150828, which were filed by the same applicant as the present applicant, disclose metal vapor and a reaction gas. A method is described which involves passing a gas mixture with or fine particles of a metal compound through a constriction passage and quenching the vapor or particles by adiabatic expansion. According to these methods, it is possible to efficiently produce fine powder of a high-purity metal compound having a substantially uniform particle size and at a low temperature compared to other conventionally known production methods. .

Problems to be Solved by the Invention However, the following problems occur particularly when fine powder of metal carbide is manufactured by the manufacturing method according to the above-mentioned earlier proposal.

In the case of the apparatus shown in FIGS. 3 and 4 of JP-A No. 58-150427: ■ A reaction gas that generates carbon (for example, methane, ethane, propane, etc.) is heated in the gas preheating chamber 4. As a result, the reaction gas causes a crabking phenomenon in the gas preheating chamber and generates carbon. If the flow rate of the reaction gas is increased in order to supply enough reaction gas to sufficiently advance the combination reaction in the metal vapor generation chamber 5, carbon will accumulate in the gas preheating chamber, and in the worst case, the gas preheating chamber will become plugged. As a result, the reaction gas cannot be supplied to the metal vapor generation chamber 5.

■In order to avoid such problems, it is possible to supply the reaction gas directly to the metal vapor generation chamber 5, but if the flow rate of the reaction gas is increased to allow the reaction to proceed sufficiently in the metal vapor generation chamber, A metal carbide film is formed on the surface of the molten metal in the metal vapor generation chamber, which inhibits the generation of metal vapor.

As a result, the production rate of fine metal compound powder decreases, and carbon and metal compounds accumulate in the conduit 10 that has a nozzle 11 at the lower end, and in the worst case, the nozzle becomes plugged, resulting in fine powder of metal compound. It may become impossible to manufacture the product.

In the case of the apparatus shown in FIG. 5 of JP-A-58-150427, since the reaction gas is supplied into the reaction chamber 26, the above-mentioned problems (1) and (2) do not occur. The metal vapor generated in the metal vapor generation chamber 5 is rapidly cooled by adiabatic expansion when passing through the nozzle 11.
Therefore, at the time of introduction into the reaction chamber 26, the metal particles have already cooled to a relatively low temperature, and the metal particles are passed through the reaction chamber at a very high speed by the jet stream ejected from the nozzle 11. Reaction chamber 2
It is difficult to carry out a sufficient compounding reaction in the reactor 6, and therefore it is difficult to produce a fine powder of high purity metal carbide that does not contain unreacted metal.

In the case of the manufacturing method disclosed in JP-A-60-150828, when the reaction gas is supplied only to the lower chamber 4, the above-mentioned problems (1) and (2) do not occur. However, since the temperature of the metal particles introduced into the lower chamber 4 has already decreased significantly, the metal particles and the reactant gas It is difficult to react quickly, and some of the metal particles remain unreacted. Therefore, the ratio of the amount of fine powder of the metal compound to the amount of metal vapor generated is small, and the production efficiency of the metal compound is poor. There's a problem.

In view of the above-mentioned findings regarding the method for producing fine powder of a metal compound according to the above-mentioned proposal, the present invention provides that even when the metal compound is a metal carbide, the particle size is very small and substantially It is an object of the present invention to provide a method and apparatus that can efficiently produce uniform fine powder of a highly pure metal compound at a low temperature.

Means for Solving the Problems According to the present invention, the above-mentioned object is achieved by passing the vapor of a metal to form a metal compound through a nozzle for adiabatic expansion while containing other elements to form the metal compound. Introducing a reaction gas into the nozzle at a minimum cross-sectional area of the nozzle or a position upstream thereof, and mixing the metal vapor and the reaction gas to cause the metal vapor and the other element to react, A method for producing a fine powder of a metal compound, the method comprising ejecting a mixed gas of the fine particles of the metal compound and residual gas thus generated from the nozzle, thereby rapidly cooling the mixed gas by adiabatic expansion, and a metal vapor generation chamber. , a powder collection chamber, a means for heating the metal vapor generation chamber to a predetermined temperature, and a means for communicating and connecting the metal vapor generation chamber and the powder collection chamber, and providing heat insulation at an end on the side of the powder collection chamber. a throttle passage means having an expansion nozzle; a reaction gas supply means for supplying a reaction gas into the nozzle at a minimum cross section of the nozzle or a position upstream thereof; and a reaction gas supply means at a position receiving a jet from the nozzle. This is achieved by an apparatus for producing fine powder of a metal compound, which has a matrix metal molten metal storage means disposed in the powder collection chamber and a means for reducing the pressure inside the powder collection chamber.

Functions and Effects of the Invention According to the method of the present invention, the metal vapor is mixed with the reaction gas and reacted at a relatively high temperature.
The chemical reaction between the metal vapor and the other elements constituting the metal compound progresses sufficiently, and the resulting mixture of fine particles of the metal compound and residual gas is ejected from the adiabatic expansion nozzle. Since the process is rapidly cooled by adiabatic expansion, it is possible to more efficiently produce a fine powder of a metal compound in a paper box with higher purity than in the conventional production method proposed above.

Furthermore, according to the method of the present invention, the reaction gas is introduced into the nozzle at the minimum cross-section of the nozzle or at a position upstream from it, so that it is possible to It is possible to reduce the occurrence of various problems caused by cracking caused by excessive heating of the reaction gas, which causes carbon to accumulate on the inner wall surface of the nozzle, etc., as in the case of the present invention.

Further, according to the manufacturing apparatus of the present invention, the reactant gas supply means is configured to supply the reactant gas into the nozzle at the minimum cross section of the nozzle or at a position upstream of the minimum cross section, and the restricting passage means is The structure is such that the mixed gas containing fine particles of the metal compound generated by a sufficient reaction in the nozzle is ejected into the powder collection chamber and rapidly cooled by adiabatic expansion, so that the production of the present invention as described above is possible. The method can be carried out easily and reliably.

According to one detailed feature of the method of the invention, the reactant gas is fed into the nozzle at a location spaced from the inner wall of the nozzle; According to the above, the reaction gas supply means includes a conduit having an opening spaced apart from the inner wall surface of the nozzle. According to such a method and apparatus, the mixing of the metal vapor and the reaction gas, and therefore the reaction thereof, can be improved compared to the case where the reaction gas is introduced into the nozzle through a passage opening in the inner wall surface of the nozzle. This makes it possible to improve the purity of the fine powder of the metal compound.

According to another detailed feature of the apparatus of the present invention, the reaction gas supply means is a conduit having an opening at a position spaced apart from the inner wall surface of the nozzle, and the reaction gas supply means is a conduit having an opening at a position spaced apart from the inner wall surface of the nozzle. It includes a conduit extending into the nozzle from the downstream open end. According to this configuration, the reaction gas is excessively heated before it is discharged into the nozzle, causing cracking, which causes various types of cracking caused by carbon deposits on the inner wall surface of the nozzle, etc. The occurrence of problems can be reduced.

According to yet another detailed feature of the apparatus of the present invention, the reaction gas supply means is a conduit having an opening at a position spaced apart from the inner wall surface of the nozzle, and the reaction gas supply means is a conduit having an opening at a position spaced apart from the inner wall surface of the nozzle, a conduit extending into the nozzle from the downstream open end of the nozzle, the opening extending radially outwardly or inclined downstream relative to the flow direction of the metal vapor; are doing. According to this configuration, the reaction gas can be introduced into the nozzle by the so-called ejector effect in which the reaction gas is sucked out by the flow of metal vapor flowing inside the nozzle, so there is no need to increase the pressure of the reaction gas in the conduit. Therefore, the metal vapor and the reaction gas can be mixed well and reacted well without disturbing the pressure conditions inside the nozzle.

According to yet another detailed feature of the device according to the invention, the reaction gas supply means is constructed such that the position of its opening relative to the smallest cross section of the nozzle can be varied along the flow direction of the metal vapor. According to this configuration, the position of the opening with respect to the minimum cross-section of the nozzle is adjusted so that the combination reaction between the metal vapor and the reaction gas is optimally performed depending on the combination of the metal vapor and the reaction gas and the setting of the operating parameters of the device. can be easily adjusted.

It should be noted that the method and apparatus according to the present invention are suitable for application to the production of fine powder of metal carbide, which is difficult to produce efficiently and in an apparatus using the above-mentioned previously proposed method. The method and apparatus of the present invention include metal oxides,
It may be applied to the production of fine powder of any other metal compound such as metal nitride.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

Embodiment FIG. 1 is a longitudinal sectional view showing one embodiment of the apparatus for producing fine metal compound powder according to the present invention, and FIG. 2 is an enlarged partial longitudinal sectional view showing the main parts of the apparatus shown in FIG. 1. .

In the figure, 10 and 12 indicate an upper housing and a lower housing, respectively. Upper housing 10
It consists of an axially extending body 16 having a substantially integral bottom wall 14 and a lid member 18 closing off the upper end of the body. The lower housing 12 includes a main body 20 that extends along the axis A and has an upper end closed by a bottom wall 14, and a bottom wall member 22 that closes the lower end of the main body. Between the lid member 18 and the upper end of the main body 16, the bottom wall 14 and the main body 20
Seals 24, 26, 28 are disposed between the upper end and the bottom wall member 22, and between the lower end of the main body 20 and the bottom wall member 22,
This isolates the insides of the upper housing and lower housing from the atmosphere. The side walls of the bodies 16 and 20 are double cylindrical and define cooling water passages 30 and 32, respectively.

Inside the upper housing 10 is a meander-shaped gas preheating chamber 3.
4, and a graphite roof 38 having therein a metal vapor generation chamber 36 communicating with the gas preheating chamber. A heater 40 for heating the inside of the crucible to a predetermined temperature is arranged around the crucible 38, and the crucible 38 and the heater 40 are housed in a box-shaped heat insulating material 42 arranged on the bottom wall. A carrier gas introduction conduit 44 communicating with the gas preheating chamber 34 is fixed to the ceiling wall of the crucible 38, and a metal vapor conveying conduit 46 is fixed to the bottom wall of the crucible 38, and the upper part of the conduit is made of metal. Extending upwardly within the steam generation chamber 36, the lower portion of the conduit 46 extends downwardly through the bottom wall 14.

In the illustrated embodiment, the lower end of the conduit 46 is integrally provided with a convergent diverging nozzle 48 having a throat 48a with a parallel section, as shown in detail in FIG. .

The nozzle 48 is connected to the powder collection chamber 5 at its downstream opening end 48b.
It communicates with 0.

Inside the nozzle 48, there is a throat portion 48a extending from the downstream opening end 48b.
Reactant gas introduction conduit 5 to a position substantially in the longitudinal center of
2 is extended. The conduit 52 is supported by a support device 53 supported on the side wall of the main body 20 of the lower housing 12 so that its position can be adjusted along an axis in the vertical direction in the figure. A cap 54 is fixed to the tip of the conduit 52. The cap 54 includes a conical head portion 54a and a substantially cylindrical body portion 54b having a plurality of circumferentially spaced apart and axially extending tongues 56. There is. A male thread is formed on the outer surface of each tongue in the radial direction, and the male thread engages with a female thread formed on the inner surface of the tip of the conduit 52. The distal end of the conduit 52 and the lower end of the cap body 54b have frusto-conical surfaces 52b and 58, respectively, which open toward the downstream open end 48b of the nozzle, and these frusto-conical surfaces provide a connection between the conduit 52 and the cap 54. An annular opening 62 having a diverging cross section is defined in the reaction gas supply means 6o.

An on-off valve 6 is located in the lower part of the side wall of the lower housing 20.
4 is connected to one end of a conduit 66, and a vacuum pump 68 is connected to the other end of the conduit, thereby reducing the pressure in the powder collection chamber 50 and the like to a predetermined pressure. . A water-cooled steel pipe 70 is disposed in the powder collection chamber 50 below the nozzle 48, and the steel pipe extends spirally along the axis A.

Next, an embodiment of the manufacturing method of the present invention, which is carried out using the metal compound fine powder manufacturing apparatus configured as described above, will be described.

First, a solid or liquid metal to form a metal compound is charged into the metal vapor generation chamber 36, and the vacuum pump 68 is operated while a carrier gas is introduced from the carrier gas introduction conduit. Next, while flowing cooling water into the cooling water passages 30 and 32,
The heater 40 is energized to heat the metal vapor generation chamber to a predetermined temperature.

At this stage, the metal charged into the metal vapor generation chamber becomes molten metal 72, and metal vapor is generated from the liquid surface, although not shown in the figure. Next, reaction gas supply means 60
The reaction gas is then introduced into the nozzle 48.

In this case, the metal vapor generated from the molten metal 72 is mixed with the carrier gas in the metal vapor generation chamber, and the mixed gas passes through the conduit 46 to the nozzle 48 without substantially decreasing the temperature.
The metal vapor flows into the nozzle and is mixed with the reaction gas introduced into the nozzle through the reaction gas supply means 60, whereby the metal vapor and the reaction gas react to form fine particles of a high-temperature metal compound, and a mixed gas containing such fine particles. is the downstream opening end 48b of the nozzle
The metal compound is ejected as a jet 74 and rapidly cooled by adiabatic expansion when passing through the nozzle, and fine powder 76 of the metal compound adheres to the surface of the water-cooled copper tube 70 and the inner surface of the inner side wall of the main body 2o.

In this case, by adjusting the flow rate of the carrier gas, the flow rate of the reaction gas, the pressure inside each chamber, etc., the size of the fine powder of the metal compound to be generated can be changed, and the temperature inside the metal vapor generation chamber can be changed. By adjusting the flow rate of the reaction gas, etc., the amount of fine metal compound powder produced per unit time can be changed.

Next, some specific examples of the manufacturing method of the present invention performed using the metal compound fine powder manufacturing apparatus shown in FIG. 1 will be described.

Specific Example 1 A molten silicon metal was selected as the molten metal 72, argon was selected as the carrier gas, and methane gas was selected as the reaction gas.
Fine powder of silicon carbide was produced by operating the apparatus shown in the figure.

Table 1 Temperature of Sl molten metal: 2000°C Argon flow rate = 1i/11n CH4 gas flow rate: 20. i'/1n Pressure crab in metal vapor generation chamber 8 Torr Pressure crab in powder collection chamber 2T
orr As a result, the average particle size of silicon carbide fine powder of about 400
It was possible to collect the particles at a rate of 0z/hr4, and the silicon carbide fine powder could be produced for about 100 hours without any trouble in the operation of the apparatus due to carbon accumulation, etc.

Specific Example 2 Pure aluminum molten metal was selected as the molten metal 72, argon was selected as the carrier gas, methane gas was selected as the reaction gas, and the conditions shown in FIGS. 1 and 2 were carried out under the conditions shown in Table 2 below. Fine powder of aluminum carbide was produced by operating the equipment as described above.

Table 2 Temperature of A1 molten metal: 1800°C Argon flow rate: Ii/a+1n CH4 gas flow rate: 25. i'/1n Pressure crab in metal vapor generation chamber 9 Torr Pressure crab in powder collection chamber 3T
As a result, fine aluminum carbide powder with an average particle size of about 400 particles can be collected at a rate of about 60 g/hr, and for about 100 hours without any operational problems due to carbon accumulation etc. It was possible to produce fine aluminum carbide powder over the period.

FIG. 3 is an enlarged partial sectional view showing a powder collecting section of the apparatus for producing fine metal compound powder according to the present invention, which is configured to continuously collect fine powder of metal compound. Furthermore, in Figure 3,
Parts that are substantially the same as those shown in FIG. 1 are designated by the same reference numerals as shown in FIG.

In FIG. 3, an annular plate 100 is fixed to the inner side wall of the lower housing 12 at its outer peripheral edge. Annular plate 10
A cylindrical body 102 is fixed along the axis A to the inner peripheral edge of the annular plate, and cylindrical bodies 104 and 106 are fixed concentrically to the cylindrical body 102 on the lower surface of the annular plate. spaced in the direction. An annular plate 108 is fixed to the upper end of the cylindrical body 102, and the inner peripheral edge thereof is fixed to the conduit 46 at the nozzle 48 portion. The conduit 52 extends through the cylindrical body 102 and is movable relative to the cylindrical body in the vertical direction.

A powder collection drum 110 is arranged below the annular plate 100. In the illustrated embodiment, the powder collection drum 11
0 has a triple cylindrical structure and includes three cylindrical bodies 114, 116, and 118 disposed on the bottom plate 112 concentrically and spaced apart from each other in the radial direction. Each cylindrical body includes an inner cylinder 120 and an outer cylinder 122 which are fixed to the bottom plate 112 at their lower ends and spaced apart from each other, and an annular ceiling plate 124 which is fixed to their upper ends. inner cylinder 120,
The outer cylinder 122), the ceiling wall 124, the bottom plate 112) and fins (not shown) fixed to the inner cylinder or the outer cylinder cooperate with each other to define a cooling water passage 126. Further, a ventilation vibrator 128 extending in the radial direction is fixed to each cylindrical body, and each ventilation pipe is offset in the vertical and horizontal directions from the ventilation pipe of the adjacent cylindrical body.

A brush 130.132.134 is fixed to the outer peripheral surface of each cylindrical body 102.104.106, and each brush is in contact with the inner peripheral surface of the upper end of the corresponding cylindrical body 114.116.118. .

Further, each brush has a part extending to the vicinity of the bottom plate 112, and although this part is not shown in the figure, a corresponding cylindrical body 114.166.1 is formed by an elastic rod-shaped core material.
This scrapes off the fine powder 136 adhering to the inner peripheral surface of the cylindrical body, and the bottom plate 11
It is designed to fall downward through a hole 138 provided in 2.

A cooling water supply conduit 140 and a cooling water discharge conduit 142 are connected to the cooling water passage of each cylindrical body, and some of these conduits extend concentrically with each other along the axis A, and are connected to the powder collection drum. A drive shaft 144 for rotating the drive shaft 110 is configured. The drive shaft 144 extends downward through the bottom wall member 22 and is supported by a bearing 146 fixed to the bottom wall member. The lower end of the drive shaft is a coupling 148
The powder collecting drum 110 is connected to a motor 150 via a motor 150 so that the powder collecting drum 110 is rotationally driven around an axis A. The cooling water supply conduit 140 and the cooling water discharge conduit 142 communicate with a cooling water supply source and a cooling water drain, respectively, which are not shown in the drawings, via a plenum device 152.

Below the powder collection drum 110 are holes 138 in the bottom plate 112.
A powder collection funnel 154 is disposed to collect the fine powder that has fallen further, and a conduit portion 154a thereof is fixed to the bottom wall member 22 and extends downward through the bottom wall member 22. The lower end of the conduit portion 154a is connected to a hopper 160 via an on-off valve 156 and a conduit 158. The exhaust pump 16 is connected to the conduit 158 by a conduit 164 having an on-off valve 162 in the middle.
6 and also has an on-off valve 170
68 for selective release to the atmosphere. An on-off valve 172 is provided at the lower end of the hopper 160 for taking out the fine metal compound powder 136 from inside the hopper.

Thus, in this embodiment, the jet stream 74 ejected from the nozzle 48 is guided into the space within the cylinder 114, passes through the ventilation vibrator 128, flows into the space between the cylinders 114 and 116, and then flows through the ventilation pipe 128. through cylinders 116 and 118
It flows into the space between. In this case, the fine powder of the metal compound adheres to the inner circumferential surface of each cylindrical body, and the fine powder is scraped off by the brushes 130 to 134, falls into the powder collection funnel 154 through the hole 138, and is collected in the conduit portion 154a. be done. When a predetermined amount of fine powder is collected in the conduit section 154a, the on-off valve 162 is opened and the exhaust pump 166 is turned on.
By operating the on-off valve 1, the pressure inside the hopper 160 is reduced to be equal to the pressure inside the powder collection chamber 50.
62 is closed and the exhaust pump 166 is stopped, the on-off valve 156 is opened, thereby moving the fine powder in the conduit portion 154a to the hopper 160. When taking out the fine powder in the hopper 160, the on-off valve 170 is opened with the on-off valves 156 and 162 closed, thereby increasing the pressure inside the hopper to atmospheric pressure, and in that state. Open/close valve 172
Open the door.

Although in the embodiment described above, the nozzle 48 is a tapered-divergent nozzle, the nozzle provided at the lower end of the conduit 46 may be, for example, a tapered nozzle. Further, the blowing direction of the reaction gas by the reaction gas supply means is preferably radially outward inclined toward the downstream opening end of the nozzle as in the illustrated embodiment, or radially outward, but in the direction of the flow of metal vapor. It may be radially outward inclined toward the upstream side when viewed from above.

In this case, means for preventing metal particles from entering the conduit 52 is arranged at a position upstream from the tip of the conduit.

Although the present invention has been described above in detail with respect to specific embodiments and some specific examples, the present invention is not limited to these embodiments and specific examples, and can be applied within the scope of the present invention. It will be apparent to those skilled in the art that various other embodiments are possible.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of the apparatus for producing fine metal compound powder according to the present invention, FIG. 2 is an enlarged longitudinal cross-sectional view of a main part of the apparatus shown in FIG. 1, and FIG. FIG. 2 is an enlarged partial sectional view showing a powder collecting section of the metal compound fine powder manufacturing apparatus according to the present invention, which is configured to continuously collect fine metal compound powder. DESCRIPTION OF SYMBOLS 10... Upper housing, 12... Lower housing, 14... Bottom wall, 16... Main body, 18... Lid member, 20... Main body, 22... Bottom wall member, 24. 26
．． 28...Seal, 30.32...Cooling water passage, 3
4... Gas preheating chamber, 36... Metal vapor generation chamber, 38
... Crucible, 40... Heater, 42... Insulation material,
44...Carrier gas introduction conduit, 46...Metal vapor transport conduit, 48...Tapered divergent nozzle, 48a...Groat, 48b...Downstream open end, 50...Powder collection chamber , 52... Reaction gas introduction conduit, 54... Cap, 56... Tang, 58... Truncated conical surface, 60...
- Reaction gas supply means, 62...opening. 64...Opening/closing valve, 66...Conduit, 68...Vacuum pump. 70... Water-cooled steel pipe, 72... Molten metal, 74...
Jet stream. 76... Fine powder of metal compound, 100... Annular plate,
102.104.106... Cylindrical body, 108... Annular plate. 110... Powder collection drum, 112... Bottom plate, 11
4.116.118... Cylindrical body, 120... Inner cylinder,
122...Outer cylinder, 124...Ceiling plate, 126...
Cooling water passage. 128...Vent pipe, 130.132.134...
・Brush, 136... Fine powder, 138... Hole, 14
0... Cooling water supply conduit, 142... Cooling water discharge conduit, 144... Drive shaft, 146... Bearing, 148...
- Coupling, 150... Motor, 152... Blenheim device, 154... Powder collection funnel, 156...
・Opening/closing valve, 158... Conduit, 160... Hopper, 1
62... Opening/closing valve, 164... Conduit, 166... Exhaust pump, 168... Conduit. 170...Opening/closing valve, 172...Opening/closing valve patent issued
Applicant: Representative of Toyota Motor Corporation
Patent Attorney Masatake Akashi Figure 1 10... Upper housing 46... Metal vapor conveying conduit 12... Lower housing 48... Taper-widening nozzle 34... Gas preheating chamber 50...
Powder auxiliary chamber 36...Metal vapor generation chamber 52...
Reaction gas introduction conduit 38...crucible
60...Reaction gas supply raw/kill 40...Heater Fig. 2 48...Tapered divergent nozzle 48&... Throat 52...Reaction gas introduction groove pipe 60...Reaction gas supply means 62...Opening

Claims (5)

[Claims] (1) While passing the vapor of the metal to form the metal compound through an adiabatic expansion nozzle, the reactive gas containing other elements to form the metal compound is passed through the minimum cross-section of the nozzle or at a position upstream from it. The metal vapor is introduced into the nozzle and mixed with the reaction gas to cause the metal vapor to react with the other element, and the resulting mixed gas of the fine particles of the metal compound and the residual gas is introduced into the nozzle. A method for producing a fine powder of a metal compound, the method comprising: ejecting the mixed gas from a metal compound, thereby rapidly cooling the mixed gas by adiabatic expansion. (2) In the method for producing fine powder of a metal compound according to claim 1, the reaction gas is introduced into the nozzle at a position spaced apart from the inner wall surface of the nozzle. A method for producing fine powder of a metal compound. (3) A metal vapor generation chamber, a powder collection chamber, a means for heating the metal vapor generation chamber to a predetermined temperature, and a means for communicating and connecting the metal vapor generation chamber and the powder collection chamber to collect the powder. a throttle passage means having a nozzle for adiabatic expansion at the end on the chamber side; a reaction gas supply means for supplying the reaction gas into the nozzle at a minimum cross-section of the nozzle or a position upstream thereof;
An apparatus for producing fine powder of a metal compound, comprising: a matrix metal molten metal storage means disposed within the powder collection chamber at a position receiving a jet stream from the nozzle; and means for reducing the pressure inside the powder collection chamber. (4) In the apparatus for producing fine powder of a metal compound according to claim 3, the reaction gas supply means includes a conduit having an opening at a position spaced apart from the inner wall surface of the nozzle. Features: A device for producing fine powder of metal compounds. (5) In the apparatus for producing fine powder of a metal compound as set forth in claim 4, the conduit is located within the nozzle from the downstream opening end of the nozzle when viewed in the flow direction of the metal vapor flowing within the nozzle. 1. An apparatus for producing fine powder of a metal compound, characterized in that: