JPH01116013A - Gaseous phase chemical reaction apparatus - Google Patents

Abstract

PURPOSE:To prevent the contamination of a constituting material by the powder formed at the time of chemical reaction by constituting an evaporation section and reaction of specific materials. CONSTITUTION:An apparatus constituting body 22, gas introducing pipes 15, 17, an evaporation crucible 19, etc., are respectively formed of graphite or quartz which does not react with an easily evaporatable metal compd. or the same material as the material of the powder to be produced. The easily evaporatable metal compd. charged from an easily evaporatable metal compd. charging pipe 15 into the crucible 19 for evaporation is first fed to the evaporation section 11 and the reaction section 12 without reacting with the constituting materials. A reducing gas is then introduced from the reaction gas introducing pipe 17 to cause the gaseous phase chemical reaction. The reaction gas introducing pipe 17 is sheathed by the inert gas from a sheath introducing pipe 18 at this time. The contamination of the constituting materials by the powder formed of the easily evaporatable metal compd. at the time of the gaseous phase reaction is thereby prevented.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a gas phase chemical reaction device.

[Prior Art] FIG. 4 is a schematic diagram showing a gas phase chemical reaction apparatus for producing fine metal powder, which is described in Japanese Patent Application Laid-Open No. 511-170211. In FIG. 4, 1 is a vaporization section for an easily vaporizable metal compound, 2 is a reaction section, 3 is a powder collection section, 4 is an easily vaporizable metal compound vapor introduction tube, and 5 is a reducing gas introduction tube. Vaporization part 1
The reactor 2 evaporates an easily vaporizable metal compound (for example, a metal halide such as FeCl2, Hie 2, WC 6, etc.), and the reaction section 2 brings the vapor of the easily vaporizable metal compound into contact with a reducing gas and mixes it. Then, a fine metal powder is produced by the progress of a gas phase chemical reaction.

That is, in the above gas phase chemical reaction device, the vaporization section 1
The evaporated metal compound is guided to the reaction section 2 by the carrier gas and reacts with a separately introduced reducing gas. That is, the metal compound is reduced by hydrogen gas or the like to produce metal a fine powder and fine powder, and these ultrafine powder and fine powder are collected in the powder collecting section 3.

[Problems to be Solved by the Invention] In the conventional gas-phase chemical reaction device described above, the inner wall of the device structure constituting the vaporizing section 1 and the reaction section 2 is directly connected to the easily vaporizable metal compound vapor. Since the inner wall material is in contact with the vapor of the easily vaporized metal compound, a reaction may occur between the inner wall material and the vaporized metal compound, and the inner wall material may mix into the product powder and contaminate the product powder.

At least the outermost wall of the installation structure of the vaporization section 1 and the reaction section 2 must be made of a metal material to prevent gas leakage.Therefore, the inner wall of the device structure is made of an easily vaporizable metal such as ceramic It is also possible to use a material that does not easily react with compound vapor, but in this case, cracks will occur in the ceramic due to expansion between the metal and the ceramic, and as a result, the metal and the ceramic will easily form through the fα cracks in the ceramic. Contact with volatile metal compound vapors occurs and contamination of the product powder cannot be avoided.

It is also possible to coat the inner surface of the device structure made of metal material with a material W (ceramics, precious metals, etc.) that does not easily react with vapor of easily vaporized metal compounds, but in this case, unavoidable temperature rise,
Deterioration and peeling occur due to the thermal cycle of decreasing temperature. Also, in the case of noble metals such as platinum, interdiffusion of metals occurs due to high temperatures, and as a result, the entire outer wall is exposed to the surface, making it impossible to avoid contamination of the product powder.

An object of the present invention is to reliably prevent the possibility of contamination of powder produced from an easily vaporizable metal compound with the constituent materials of the device (device structure, gas introduction pipe, vaporization crucible).

[Means for Solving the Problems] The present invention provides a vaporizing section comprising an input tube for an easily vaporizable metal compound, a carrier gas introduction tube, and a built-in crucible for vaporization;
a reaction part disposed adjacent to the vaporization part and equipped with a reaction gas introduction pipe, the reaction part is arranged adjacent to the vaporization part, and the reaction part is provided with a reaction gas introduction pipe, and the reaction part is arranged adjacent to the vaporization part, and the reaction part is provided with a reaction gas introduction pipe, and the reaction part is arranged adjacent to the vaporization part, and the reaction part is provided with a reaction gas introduction pipe. In a gas-phase chemical reaction device that produces metal or ceramic powder by reaction, a protective inner cylinder made of a material that does not react with easily vaporizable metal compounds is provided inside the device structure that constitutes the vaporization section and the reaction section, and the device structure An inert gas or a reactive gas is passed through the gap between the body and the protective inner cylinder, and any of the easily vaporizable metal compound inlet pipes or gas inlet pipes is present in the high temperature part of the device and comes into contact with the easily vaporizable metal compound. The parts that are likely to be vaporized and the vaporizing crucible are made of a material that does not react with the easily vaporizable metal compound.

[Function] According to the present invention, a material that does not react with an easily vaporizable metal compound (such as graphite, quartz glass, etc. ) is provided to avoid direct contact between the constituent materials of the device structure and the easily vaporizable metal compound. Further, the gas introduction pipe and vaporization crucible disposed within the apparatus are also made of a material (eg, graphite, quartz glass, etc.) that does not react with easily vaporizable metal compounds.

Therefore, the easily vaporizable metal compound charged into the vaporization crucible from the injection pipe for the easily vaporizable metal compound is made of a material that does not react with the easily vaporizable metal compound, such as graphite-1 quartz glass, in the high temperature section of the apparatus. It will be sent to the vaporization section and reaction section without coming into contact with anything other than that. This results in
The present invention can reliably prevent the possibility that powder produced from an easily vaporizable metal compound will be contaminated with the constituent materials of the device (device structure, gas introduction pipe, vaporization crucible).

Further, while using a metal material that easily reacts with easily vaporizable metal compounds as the constituent material of the device structure, such reactions can be avoided. As a result, it is possible to form a device structure that is completely airtight and highly safe in terms of strength, and to produce product powder that is free from contamination due to elution of the metal materials that constitute the device structure.

In addition, as a preferred embodiment of the present invention, if only a portion (for example, one end) in the longitudinal direction of the protective inner cylinder is fixed to the device structure, the protective inner cylinder can be freely moved against the thermal cycle of the device. It can be expanded and contracted to prevent cracks in the protective inner cylinder.
L. The device can be operated stably for a long time.

At this time, the inert gas or reactive gas supplied to the gap between the device structure and the protective inner cylinder is flowed from the fixed part of the protective inner cylinder to the free end side, and the easily vaporized metal compound vapor is transferred to the free end side. can be prevented from entering the above-mentioned gap.

Furthermore, in carrying out the present invention, depending on the operating temperature of the apparatus, the protective inner cylinder, gas introduction pipe, and vaporizing crucible may be made of the same material as the powder to be produced by the apparatus.

[Example] FIG. 1 is a schematic diagram showing a first embodiment of the present invention.

The gas phase chemical reaction device 10 has a vertical shape, and has a vaporization section 1.
1. Reaction section 12) It is composed of a heating device 13 and a cooling section 14, and the flow of gas is set downward.

The vaporization section 11 includes an easily vaporizable metal compound input pipe 15 and a carrier gas inlet 1 for feeding the easily vaporizable metal compound to the reaction section 12.
6. Reaction gas introduction pipe 1, which is equipped with a reaction gas introduction pipe 17, a sheath gas introduction pipe 18, and has a built-in vaporization crucible 19.
7 is disposed penetrating through the center of the double cylindrical vaporizer crucible 19 and is removable. In addition, in a gas phase chemical reaction, it is inevitable that precipitation occurs on the inner wall of the reaction section and the outer wall of the gas introduction tube, but in this reaction section 2110, the sheath gas introduction tube 1
8 makes it possible to sheath the reaction gas introduction pipe 17 with an inert gas and remove it for cleaning after operation. carrier gas inlet 16, reaction gas inlet pipe 17,
The sheath gas introduction pipe 18 is a triple pipe.

The reaction section 12 is connected to the lower part of the vaporization section 11, and has open ends of a reaction gas introduction pipe 17 and a sheath gas introduction pipe 18, which pass through the center of the vaporization crucible 19, arranged therein. Note that the vaporizing section 11 has a cylindrical shape with a large diameter, and the reaction section 12 has a cylindrical shape with a small diameter.

The heating type 5!13 has a vaporization section heating furnace 20 and a reaction section heating furnace 2.
1, the vaporizing section heating furnace 20 is arranged corresponding to the vaporizing section 11, and the reaction section heating furnace 21 is connected to the reaction section 1.
The two heating furnaces 20 and 21 arranged corresponding to the heating elements 2 and 2 have separate heating elements and control systems, so that their temperatures can be controlled independently of each other. When the vaporization temperature of the vaporization section 11 and the reaction temperature of the reaction section 12 are the same, the heating element and control system of the double-jaw thermal furnace 20 and 21 may be unified.

The cooling section 14 is disposed below one reaction section 12, is equipped with a water jacket, and has an outlet connected to a powder recovery device.

The gas phase chemical reaction apparatus 10 is configured to react with metals by a gas phase chemical reaction between an easily vaporizable metal compound introduced from an easily vaporizable metal compound input pipe 15 and a reducing gas introduced from a reaction gas introduction pipe 17. It is possible to produce ultra-fine powder and fine powder. Here, if the easily vaporizable metal compound is continuously added, continuous production of powder becomes possible.

Therefore, in the above-mentioned gas phase chemical reaction device 10, graphite or A protective inner cylinder 23 made of quartz glass or the like is provided. The protective inner cylinder 23 has a large diameter in a portion corresponding to the vaporization section 11 and a small diameter in a portion corresponding to the reaction section 12. The protective inner cylinder 23 has an upper end portion sealed and clamped to the upper end flange portion 22A of the reaction portion 22, and a lower end portion that is free to be released on the lower end side of the reaction portion 12.

Further, a seal gas introduction pipe 24 is connected to the outer circumference of the upper end of the device structure 22, and is configured to supply inert gas or reactive gas as a seal gas to the gap 25 between the device structure 22 and the protective inner cylinder 23. The sealing gas supplied to the zero gap 25, which is 0, flows out from the free end side of the protective inner cylinder 23 into the reaction section 12.

In addition, among the easily vaporizable metal compound input pipe 15, carrier gas inlet 16, and sheath gas inlet pipe 18, the parts that exist in the high temperature part of the device and may come into contact with the easily vaporizable metal compound are It is separated from the internal low-temperature side part and is made of graphite, quartz glass, or the like as a material that does not react with easily vaporizable metal compounds. The hot end portions of the tubes are threaded onto the cold end portions. At this time, the threaded portion does not need to be completely confidential.

Further, the vaporization crucible 19 is also made of graphite, quartz glass, or the like as a material that does not react with the easily vaporizable metal compound.

Next, the operation of the above embodiment will be explained.

According to the above embodiment, the protective inner cylinder 23 made of a material that does not react with easily vaporizable metal compounds (e.g., graphite, quartz glass, etc.) is provided inside the device structure 22 through an inert gas or a reactive gas. Therefore, direct contact between the constituent material of the device structure 22 and the easily vaporizable metal compound can be avoided. In addition, an easily vaporizable metal compound input pipe 15, gas introduction pipes 16, 18, . The vaporizing crucible 19 is also made of a material that does not react with the easily vaporizable metal compound (eg, graphite, quartz glass, etc.).

Therefore, the easily vaporizable metal compound introduced into the vaporizing crucible 19 from the easily vaporizable metal compound input pipe 15 is made of a material that does not react with the easily vaporizable metal compound, such as graphite-1 quartz glass, in the high temperature section of the apparatus. It is sent to the vaporization section 11 and the reaction section 12 without coming into contact with anything other than the above. This ensures that there is no possibility that the powder produced from the easily vaporizable metal compound will contaminate the equipment's constituent materials (package structure 22) input pipe 15, gas introduction pipe 16, 18, and vaporization crucible 19). can be prevented.

Further, while using a metal material that easily reacts with easily vaporizable metal compounds as the constituent material of the device structure 22, such reactions can be avoided. As a result, it is possible to form a device structure 22 that is completely airtight and highly safe in terms of strength, and to produce product powder that is free from contamination due to elution of the metal materials that constitute the device structure 22.

In the above embodiment, only one end of the protective inner cylinder 23 is fixed to the device structure 22. Therefore, the protective inner cylinder can be freely expanded and contracted in response to the thermal cycle of the device, preventing cracks and the like in the protective inner cylinder 23, and allowing the device to operate stably for a long time. At this time,
The inert gas or reactive gas supplied to the gap 25 between the device structure body 22 and the protective inner cylinder 23 is caused to flow from the fixed part of the protective inner cylinder 23 to the free end side, and the easily vaporized metal compound vapor is transferred to the free end side. Intrusion into the gap from the end can be prevented.

FIG. 2 is a schematic diagram showing a second embodiment of the present invention.

This gas phase chemical reaction device 30 is the gas phase chemical reaction device lO
The difference is that it is vertical with the gas flowing upward.

The gas phase chemical reaction device 30 has a vaporization section 3 similar to the device IO.
1. Reaction section 32) It has a heating device 33 and a cooling section 34. In addition, the vaporization section 31 includes an easily vaporizable metal compound input pipe 35.
, a carrier gas introduction pipe 36, and a vaporization crucible 37. Further, the reaction section 32 includes a reaction gas introduction pipe 38 and a sheath gas introduction pipe 39.

In addition, similar to the device 10, the gas phase chemical reaction device 30 is provided with a protective inner cylinder 41 made of a material that does not react with easily vaporizable metal compounds inside the device structure 40, and a seal gas introduction pipe 42 is connected to the device structure 40. An inert gas or a reactive gas is allowed to accumulate in the gap 43 between the protective inner cylinder 41 and the protective inner cylinder 41. Further, the gas phase chemical reaction device 30 has an input pipe 3 similar to the device 2110.
5. The part of the gas introduction pipe 36.39 that exists in the high temperature part of the device and may come into contact with easily vaporizable metal compounds;
The vaporizing crucible 37 is made of a material that does not react with easily vaporizable metal compounds.

Therefore, even in this gas phase chemical reaction apparatus 30, the powder produced from the easily vaporizable metal compound is used as the constituent material of the apparatus (apparatus structure 40, input pipe 35, gas introduction pipe 36, 39).
, the possibility of contamination of the vaporization crucible 37) can be reliably prevented.

FIG. 3 is a schematic diagram showing a third embodiment of the present invention.

This gas phase chemical reaction device 50 is the gas phase chemical reaction section ff1.
The difference from IO is that it is a horizontal bottle in which the gas flow is set horizontally.

The gas phase chemical reaction device 50 is similar to the device 10.

Vaporization section 51, reaction section 52) heating device 53. It has a cooling section 54. The vaporization section 51 also includes an easily vaporizable metal compound input pipe 55, a carrier gas introduction pipe 56, and a vaporization crucible 57.
It is equipped with The reaction section 52 also has a reaction gas introduction pipe 58.
．． A sheath gas introduction pipe 59 is provided.

Further, similar to the device 10, the gas phase chemical reaction device 50 is provided with a protective inner cylinder 61 made of a material that does not react with easily vaporizable metal compounds inside the device structure 60, and a seal gas introduction pipe 62 is connected to the device structure 60. Inert gas or reducing gas is allowed to flow into the gap 63 between the protective inner cylinder 61 and the protective inner cylinder 61. In addition, the gas phase chemical reaction apparatus 50 includes an easily vaporizable metal compound input pipe 55, a carrier gas introduction pipe 56, and the like in the device 2f10. The part of the sheath gas introduction pipe 59 that exists in a high temperature part of the apparatus and may come into contact with the easily vaporizable metal compound, and the vaporizer crucible 57 are made of a material that does not react with the easily vaporizable metal compound. .

Therefore, even in this gas phase chemical reaction apparatus 50, the powder produced from the easily vaporizable metal compound is used as the constituent material of the apparatus (device structure 60, input pipe 55, gas introduction pipe 56, 59).
, the possibility of contamination in the vaporization crucible 57) can be reliably prevented.

Hereinafter, specific implementation results of the present invention will be explained.

(Example 1) Copper a fine powder was prepared using the apparatus 10 shown in FIG.

The reaction conditions using cuprous chloride as an easily vaporizable metal compound and hydrogen as a reducing gas were as follows: vaporization temperature 1000°C, reaction temperature 4000°C, carrier gas (argon) flow rate 8 exchanges/min, hydrogen gas 1i, amount 5 per minute, seal gas (argon) flow 111/min, sheath gas (argon) flow 311/min
It's a minute. Cupric +11 oxide was stratified at a rate of 2 g/min, and copper powder of approximately 0.2 p, m was obtained at a reaction rate of 86%. Stainless steel was used for the outer wall components of the reactor structure. Graphite was used for the protective inner cylinder. No impurities other than chlorine due to unreacted copper chloride mixed in and oxygen due to contact with air were detected in the obtained copper powder, indicating that there was no contamination.

(Example 2) - The constituent material of the protective inner cylinder in Example 1 was replaced with quartz glass, and the other apparatus configuration and reaction conditions were as described in Example 1.
We conducted an experiment exactly the same as in . the result,
The properties of the copper powder were also completely unchanged from the results of Example 1, and no contamination was observed.

(Comparative Example 1) Copper powder was produced under the same reaction conditions using the same apparatus as in Example 1 except for the protective inner cylinder provided in Example 1. As a result, in addition to copper, chlorine, and oxygen, the copper powder contained 2.34% Fe, Cr 0
．． Corrosion was also confirmed by examining the inner wall of the device structure after the zero reaction, which contained metal components originating from stainless steel of 32% NiO, 28% Mn, and 0.08% Mn.

(Comparative Example 2) 1- Copper powder was produced under the same reaction conditions as in Example 1 using a reaction apparatus in which the protective inner cylinder in Example 1 was not provided and the apparatus structure was made of pure nickel.

As a result, in addition to copper, chlorine, and oxygen, the copper powder contains Ni.
It contained 0.54%.

[Effects of the Invention] As described above, according to the present invention, the powder produced from the easily vaporizable metal compound is not contaminated by the constituent materials of the device (device structure, gas introduction pipe, vaporization crucible). f@ characteristics can be reliably prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a first embodiment of the present invention, FIG. 2 is a schematic diagram showing a second embodiment of the present invention, and FIG. 3 is a schematic diagram showing a third embodiment of the present invention.
A schematic diagram showing an embodiment, and FIG. 4 is a schematic diagram showing a conventional example. 1O130,50... Gas phase chemical reaction device, 11.31
．． 51... Vaporization section, 12.32.52... Reaction section, 15.35.55... Easily vaporizable metal compound input pipe, 1
6.36.56...Carrier gas introduction pipe, 17.38
．． 58...Reaction gas introduction pipe, 18.39.59...
Sheath gas introduction pipe, 19.37.57... Crucible for vaporization. 22.40.60...Device structure, 23.41.61...Protection inner cylinder, 24.42.62...Seal gas introduction pipe, 25.43
．． 63... Gap. Agent Patent Attorney Shuji Shiokawa γTI drawing (no changes to the text) Part 1
Diagram 2 Diagram 4 (irti"a'r1 4nη Procedural amendment dated January 2, 1989)

Claims (2)

[Claims] (1) A reaction comprising a vaporization section that is equipped with an input tube for easily vaporizable metal compounds, a carrier gas introduction tube, and a built-in crucible for vaporization, and a reaction gas introduction tube that is disposed adjacent to the vaporization section. In a gas phase chemical reaction apparatus for producing metal or ceramic powder by a gas phase chemical reaction between an easily vaporizable metal compound and a reaction gas for the easily vaporizable metal compound, A protective inner cylinder made of a material that does not react with the easily vaporizable metal compound is provided inside the apparatus structure constituting the reaction part and the reaction part, and an inert gas or reactive gas is flowed into the gap between the apparatus structure and the protective inner cylinder, and , parts of the easily vaporizable metal compound input pipe or gas inlet pipe that exist in the high temperature part of the device and may come into contact with the easily vaporizable metal compound, and the vaporization crucible that react with the easily vaporizable metal compound. A gas phase chemical reaction device characterized in that it is formed of a material that does not contain (2) The gas phase chemical reaction device according to claim 1, wherein the protective inner cylinder is fixed only partially to the device structure in the longitudinal direction.