JPH1081903A - Production of fine metallic particles and combustion device for producing apparatus of fine metallic particles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently produce fine metallic particles having a uniform high quality in a low cost by individually supplying metallic ion solution and hydrogen into a non-opening type combustion chamber isolated from the atmosphere on the upper part and burning. SOLUTION: The metallic ion solution is supplied from a supplying tube 66 and fed from a spouting hole 69 of the metallic ion toward the combustion device. On the other hand, the hydrogen is supplied from a cylinder 5 and the pressure is adjusted with a pressure adjusting valve 6 and the hydrogen is flowed to a combustion burner 8 through a fuel supplying hole 64 and burnt to form hydrogen flame. The fed metallic ion solution is introduced into the hydrogen flame and thereat, the metallic ions are reduced to produce the metallic fine particles. The produced metallic fine partcles are recovered into recovering solution 27 incorporated in a recovering device 10 thereunder, and the recovering solution 27 is stirred with an electromagnetic stirrer 26. Explosion caused by the clogging, etc., of the atomizing tube, can be reduced by individually supplying the metallic ion solution and the hydrogen, and since the atomizing condition of the metallic ion solution can be controlled, the uniform metallic fine particles can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing fine metal particles and a combustion apparatus for producing fine metal particles. The method for producing metal fine particles and the combustion apparatus according to the present invention,
Any metal that can be ionized can be applied to both heavy metals and light metals. Further, the present invention is applicable to metal fine particles ranging from ultrafine particles that behave as colloids in a solvent to relatively large particles such as metal mud and powder.

[0002] Metal fine particles are useful as a catalyst because of their large surface area. In particular, it has excellent oxidation-reduction ability, and is attracting attention as a catalyst for removing and purifying various harmful gases. Some combinations of metals can also be powerful magnetic materials. Other applications include various sensors and molecular wiring.

[0003]

2. Description of the Related Art Metal fine particles can be produced by physical methods such as gas evaporation method, sputtering method, metal vapor synthesis method, colloid method, alkoxide method, liquid phase method such as coprecipitation method, and metal ion in hydrogen. A gas phase method such as a reduction method and a reduction method of an organometallic compound in hydrogen is known. Among them, the method of producing colloidal metal fine particles can be roughly classified into an arc method in which an electrode is provided in a metal ion solution and electrophoresis is caused by high voltage to generate a metal colloid, and a metal ion solution is placed in a hydrogen flame. There are known two methods of combustion, in which a metal colloid is obtained by supplying and reducing metal ions. As a method for producing colloidal metal fine particles by a combustion method, a method of blowing hydrogen into a metal ion solution container to atomize the metal ion solution and burning the atomized metal ions (Japanese Patent Publication No. 28-1999); A method in which a solution and hydrogen are mixed and then burned (Japanese Patent Publication No. 43801/1990), and a metal ion solution is ejected in a mist state by an atomizing device having an opening diameter adjusting function, and then burned in an atmosphere of hydrogen flame to emit metal ions. (Japanese Patent Laid-Open No. 7-173511) has been proposed.

In each of these methods, a metal ion solution, which is a raw material, is ejected to the atmospheric pressure by pressure, and metal fine particles are produced by using a combustion reaction in an open system under an atmospheric atmosphere. For the recovery of metal fine particles as a reaction product, a method is employed in which a metal fine particle recovery device in which a metal fine particle recovery liquid containing water as a main component is provided immediately below a combustion flame and the metal fine particles are allowed to fall naturally.

[0005] Since the temperature rises during the combustion of metal ions, the specific gravity of the surrounding gas becomes small, and the generated fine metal particles rise and diffuse into the atmosphere. For this reason, the generated solid matter such as metal fine particles adheres to the vicinity of the spraying part of the atomizing device for atomizing the metal ion solution, and gradually grows. With the growth of the adhered solid, the diameter of the metal ion solution spray port changes, and the atomization state of the metal ion solution changes. Further, the atomization state of the metal ion solution changes with time due to the atomization device atomization part being exposed to high temperature and being worn. For these reasons, the generated metal fine particles become non-uniform. Increasing the flame increases the risk of burns to the operator, clogs the spray tube and also risks explosion. Furthermore, since combustion is performed in the open to the atmosphere, the generated fine metal particles are scattered into the atmosphere, and the recovery rate of the fine metal particles is reduced.

Further, since metal ions are burned in the atmosphere, a temperature distribution is generated from the center of the combustion flame to the periphery thereof, and the speed at which the atomized raw material solution changes into fine metal particles is varied, which causes a problem. As a result, the particle size of the generated metal fine particles becomes non-uniform, which further reduces the yield of the metal fine particles having a desired particle size.

As described above, the method for producing metal fine particles by the combustion method is difficult to obtain uniform metal fine particles, has a low recovery rate of metal fine particles, has a risk of explosion due to easy blockage of the metal ion solution outlet, In addition, problems such as low burn efficiency and burns to workers due to the rising hydrogen flame are recognized.

[0008]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and provides a method for efficiently producing uniform, high-quality metal fine particles at low cost and a combustion apparatus used in a metal fine particle producing apparatus. It is intended to do so.

[0009]

SUMMARY OF THE INVENTION The gist of the present invention is to provide a method for producing fine metal particles, in which a metal ion solution and hydrogen are separately placed in a non-open type combustion chamber having at least an upper part isolated from the atmosphere. A method for producing metal fine particles, comprising supplying and burning. Further, in the method for producing metal fine particles, when the metal ions are burned in a non-open type combustion chamber in which at least the upper part is isolated from the atmosphere, the medium is caused to flow down along the combustion chamber wall surface. This is a method for producing metal fine particles. Then, in the method for producing metal fine particles, a gas is blown onto a combustion flame to induce the combustion flame below the combustion chamber. Further, in the method for producing metal fine particles, when metal ions are burned in a non-open combustion chamber isolated from the atmosphere, a gas is blown on the combustion flame to induce the combustion flame below the combustion chamber. A method for producing metal fine particles, characterized by passing a metal fine particle recovery liquid together with generated metal fine particles, a combustion flame, and a combustion product.

Next, in a combustion apparatus for producing metal fine particles, a partition wall is provided at least at an upper portion of the combustion apparatus for isolating the combustion atmosphere from rising, and a metal ion solution supply port and a hydrogen supply port are provided. This is a non-open type combustion apparatus for producing metal fine particles, which is provided with a mouth. Also,
In a combustion device for producing fine metal particles, at least an upper portion of the combustion device, a partition wall for isolating the combustion atmosphere from rising, and a medium for flowing a medium down the inner wall of the combustion device. This is a non-open type combustion apparatus for producing fine metal particles, which is provided with a supply port. And, in a combustion device for producing metal fine particles, at least an upper portion of the combustion device for isolating the combustion atmosphere from an atmospheric air for suppressing the rise of the combustion flame, and for guiding the combustion flame below the combustion device. A non-open type combustion apparatus for producing fine metal particles, wherein a gas blowing port for blowing gas is provided. Further, in a combustion device for producing metal fine particles, at least an upper portion of the combustion device, a partition wall for isolating from an atmospheric atmosphere for suppressing a rise of a combustion flame, and a medium for flowing down a medium along an inner wall of the combustion device. A non-open type combustion apparatus for producing metal fine particles, comprising a medium supply port and a gas blowing port for blowing a gas for guiding a combustion flame below the combustion apparatus.

A conventional method for producing metal fine particles by a combustion method employs a method in which a metal ion solution is atomized and reduced in a reducing flame such as hydrogen. At this time, since the burning treatment with the reducing flame is performed in the atmosphere, the burning flame rises and damages the metal ion spray tube or causes a phenomenon such that solid matter adheres to the metal ion spray tube. There is also a problem that the generated metal fine particles dissipate into the atmosphere. In addition, workers may be burned by the rising combustion flames or cause health problems with substances such as metal particulates that escape into the atmosphere.

The present invention is intended to suppress the rise of the combustion flame by performing combustion in a non-open type combustion chamber at least an upper part of which is isolated from the atmosphere. That is, by providing a partition at the upper portion of the combustion chamber, the combustion flame does not rise at least above the partition. In addition, since the combustion is performed in a non-released state by providing a partition, the temperature in the combustion chamber becomes uniform. As a result, it is possible to prevent the diffusion of the metal fine particles as a reaction product, to suppress the temporal change of the spray state of the metal ion solution as the raw material, and to stably obtain uniform metal fine particles for a long time. As a result, the recovery rate of the generated metal fine particles is improved, and a high yield can be secured. Further, since the combustion is performed in an open system by providing the partition walls, the amount of metal fine particles scattered into the atmosphere is reduced, which greatly contributes to an improvement in the recovery rate of metal fine particles.

Japanese Patent Publication No. 28-1999 describes that the combustion of hydrogen is carried out in a bell-shaped protective jacket. In this technique, a metal ion solution is atomized with hydrogen gas, and hydrogen and the atomized metal ion solution are ejected together and burned. In addition, since there is no air inlet, continuation of combustion is difficult. In the method of the present invention, the hydrogen and metal ion solution are fed separately to the combustion chamber. By supplying hydrogen and the metal ion solution separately, explosion due to blockage of the spray tube can be reduced, and the atomization state of the metal ion solution can be controlled. Can be done.

Since the temperature rises due to the combustion, the combustion products including the generated metal fine particles move upward. Further, since convection is accompanied at the same time, combustion products including the generated metal fine particles convection or float in the combustion device. At this time, the generated metal fine particles adhere to the inner wall of the combustion device. In the present invention, the medium is caused to flow down along the inner wall of the combustion device. In this case, the medium acts as a refrigerant and can prevent overheating of the combustion device. In addition, when a medium such as water is used, it acts as a liquid for collecting metal fine particles, prevents a reaction product containing the metal fine particles from adhering to and growing on the inner wall of the combustion device, and improves the collection efficiency of the metal fine particles. Prevents abnormal growth of metal particles on the inner wall of the combustion device,
In addition, it is possible to prevent foreign substances from being mixed.

As a medium flowing down to the inner wall of the combustion device,
Liquid or gas can be used. Water is the most common liquid. Of course, fresh water can be used, but it is also possible to circulate and use the metal fine particle recovery liquid. If necessary, water may contain an inorganic component or an organic component as appropriate. In addition to liquids, gases can also be used. Air, carbon dioxide,
Nitrogen gas or the like can be used as appropriate.

Further, in the present invention, a gas is blown to forcibly guide the atomized metal ion solution and combustion flame in a certain direction of the metal fine particle recovery device, that is, below the combustion device. By directing the combustion flame downwardly of the combustion device, the rise of the combustion flame is suppressed. When the rise of the combustion flame is suppressed, overheating of the spray tube of the metal ion solution is reduced, and deformation of the spray tube and adhesion of solid matter to the spray tube are reduced. Air is generally used as the blowing gas. However, it is not limited to air alone. Nitrogen, carbon dioxide, argon, or a mixture thereof or other gases can be used.

According to the present invention, a partition is provided on an upper portion of the combustion device,
Since the medium is caused to flow down or the gas is blown down along the inner wall of the combustion device to guide the combustion flame or the like downward, the combustion flame does not spread to the atmosphere. As a result, the risk of the operator being burned or injured is extremely small.

When the gas is blown, the entire combustion chamber may be made a closed system, and the blown gas may be directly immersed in the metal fine particle recovery liquid. That is, the product / combustion product outlet of the combustion chamber is installed so as to be immersed in the metal particulate recovery liquid.
As a result, the generated metal fine particles, combustion products, combustion flames, and the like pass through the metal fine particle recovery liquid together with the necessarily blown gas. By passing through the metal fine particle recovery liquid, the recovery rate of the generated metal fine particles is improved. Furthermore, impurities in the combustion products are also collected by the metal fine particle collection liquid at the same time,
The amount of harmful substances released into the atmosphere is also reduced.

Further, a combustion device is used to realize the present invention. The combustion device of the present invention has a partition at least at an upper portion of the combustion device, which is isolated from the atmosphere to suppress the rise of the combustion flame. Even if only the partition is provided on the upper part of the combustion chamber, the effect produced by this is extremely large. Further, a medium supply port for flowing the medium down along the inner wall of the combustion device can be provided. Further, a gas blowing port for blowing a gas for guiding a combustion flame below the combustion device can be provided. The components of the combustion apparatus of the present invention described above may be used independently or in combination.

First, an embodiment of a conventional method for producing metal fine particles by a combustion method will be described. FIG. 4 shows a conventional method for producing fine metal particles by a typical combustion method. Metal ion solution 12
Is supplied by compressed air 16 pressurized by the compressor 13. The flow rate of the ionic solution 12 is adjusted by the solution flow rate control valve 18, sent to the spray pipe 53, and ejected from the ejection port 55. On the other hand, hydrogen is supplied from a hydrogen cylinder 5 and burns in a combustion burner 8. The ejected metal ions are reduced in a hydrogen flame to become metal fine particles. The generated metal fine particles are
It is collected by the metal fine particle collection liquid 27. At this time, the metal fine particle recovery liquid 27 is stirred by the electromagnetic stirrer 25 and the stirrer 26. In this embodiment, the hydrogen flame rises and the spray pipe 5
3 is wrapped in flame, and solid matter adheres to the spout 55,
The generated metal fine particles dissipate into the atmosphere, the resulting metal fine particles have a non-uniform particle size, a short continuous operation time, an explosion easily occurs, and the operator is easily burned.

[0021]

Next, an embodiment of the present invention will be described. FIG. 5 is a simplified example of an embodiment of the present invention. The combustion device 1 has a partition on the top and side surfaces of the combustion device 1. While isolated from the air atmosphere, the metal ions are reduced by a reducing flame such as a hydrogen flame to become metal fine particles.
The metal ion solution is hydrogen gas supplied from the metal ion solution supply port 66 and separately supplied from the fuel supply port 67,
It is burned and reduced in the combustion device 1. Since the combustion device 1 has partitions on the top and side surfaces, the generated metal fine particles do not dissipate into the atmosphere, and the combustion flame does not rise to the outside of the combustion device 1. Therefore, the recovery rate of the metal fine particles is high, and the particle diameter of the obtained metal fine particles tends to be uniform. In addition, the operator is less likely to be injured such as a burn. The air or the like for continuing the combustion may be supplied by being mixed with the combustion gas, or may be supplied separately from the combustion gas by providing a separate supply port (not shown).

In the prior art invention of Japanese Patent Publication No. 28-1999, hydrogen and metal ion solution are ejected together, which causes various problems, that is, the atomization nozzle is liable to be clogged and an explosion is likely to occur. There are problems such as the inability to independently control the state of hydrogenation and hydrogen combustion, and the resulting non-uniform particle size of the fine metal particles. In this regard, in the present invention, since hydrogen and the metal ion solution are separately supplied, there is no problem of explosion, and the combustion of hydrogen and the atomization state of the metal ion solution can be controlled independently. The particle size becomes uniform.

FIG. 6 shows an embodiment in which the combustion device has a gas blowing function. The combustion device 1 has partitions on the upper and side surfaces of the combustion device 1, and further has a product / combustion product outlet 63, a metal ion solution spray pipe 53, and a gas
2. A fuel supply port 67 and a combustion burner 8 are provided.
While isolated from the air atmosphere, the metal ions are reduced by a reducing flame such as a hydrogen flame to become metal fine particles. The metal ion solution is supplied from the metal ion solution supply port 66, and is burned and reduced in the combustion device 1 by hydrogen gas separately supplied from the fuel supply port 67. Air is blown from the gas inlet 62 to guide combustion flames, products, and the like toward the product / combustion product outlet 63. The generated metal fine particles do not dissipate into the atmosphere, and the combustion flame goes to the lower part of the combustion device. Therefore, the rise of the combustion flame is reduced, the deformation of the ejection port 55 due to the heating is small, and the adhesion of solid matter around the ejection port 55 is reduced. Therefore, the recovery rate of the metal fine particles is increased, and the particle diameter of the obtained metal fine particles becomes uniform. In addition, the operator is less likely to be injured such as a burn.

In the embodiment of FIG. 6, the combustion burner 8
Is one, but the number of combustion burners is not limited to one, and plural burners may be used. An embodiment using two combustion burners 8 is shown in FIG. The effect is similar.

FIG. 2 shows an example of an embodiment of the combustion apparatus 1 of the present invention. The combustion device 1 includes a spray pipe 53, a fuel supply port 67, a gas blowing port 62 for blowing gas,
A combustion burner 8 is provided at the end of a product / combustion product outlet 63, a medium supply port 68 for flowing down a medium along the inner wall of the combustion device, and a fuel supply port 67.

The metal ion solution is supplied to a metal ion supply port 66.
And is discharged from the injection port 69 toward the combustion chamber. On the other hand, the hydrogen gas is supplied from the fuel supply port 67, reaches the combustion burner 8 via the fuel passage 65, and is ignited and burns here. The sent out metal ion solution undergoes a reduction treatment in a hydrogen flame to become metal fine particles. The generated metal fine particles fly into the combustion device, and a part thereof collides with and adheres to the wall of the combustion device. Let water flow down along the walls of the combustion chamber. Water is supplied from the medium supply port 68 and flows down along the wall of the combustion chamber through the medium passage. The outlet for the medium may have a slit shape or a plurality of holes. Since water flows down along the wall of the combustion chamber, the collision of metal fine particles against the wall of the combustion device is considerably prevented, and the metal fine particles and the like that collide with the wall of the combustion device are washed away by the water, and eventually It is collected by merging with the metal fine particle collection liquid. The air required for hydrogen combustion is
2, or a separate supply port may be provided and supplied from there.

Air is blown into the combustion device from the gas blowing port 62. As a result, the hydrogen flame is generated at the product / combustion product outlet 6.
3, the rise of the hydrogen flame is suppressed, the adhesion of solid matter at the metal ion solution ejection port 69 can be suppressed, and the deformation and damage due to overheating of the metal ion solution ejection tube are reduced. be able to.

From the product / combustion product outlet 63, the generated fine metal particles and other substances are not shown in the figure.
It is discharged to the collection device. Combustion is performed in a space isolated from the atmosphere.Water flows down along the inner wall of the combustion chamber to wash away metal fine particles and the like adhering to the inner wall of the combustion device, and further blows air to forcibly generate a combustion flame.・ It is guided in the direction of the combustion product outlet. Therefore, the metal fine particles dissipated in the atmosphere can be almost completely reduced to zero, and the rise of the combustion flame can be suppressed. As a result, effects such as high uniformity of the obtained metal fine particles, high recovery rate, high productivity, and no burn or health problem of the operator are exhibited.

FIG. 3 shows an example of another embodiment. In this example, the combustion chamber has two stages, and there is a hydrogen flame in the upper combustion chamber, where metal ions are reduced. At the bottom,
There is a medium supply port 68 for water or the like, from which a medium is supplied and serves to increase the recovery rate of the generated metal fine particles.

FIG. 1 shows an example of an embodiment of the production of fine metal particles using the combustion apparatus of the present invention. The metal ion solution is supplied from a metal ion solution supply pipe 66 and is sent out from the metal ion ejection port 69 toward the combustion device 1. Alcohols may be added to the metal ion solution in the sense of assisting combustion. The supply of the metal ion solution is not limited to the pressure feeding, but may be supplied by a pump or the like.

On the other hand, hydrogen is supplied from a hydrogen cylinder 5,
The pressure is adjusted by the pressure adjusting valve 6 and reaches the combustion burner 8 through the fuel supply port 64. In the combustion burner, the hydrogen burns to form a hydrogen flame. The sent metal ion solution is guided into the hydrogen flame generated by the combustion burner 8, where the metal ions are reduced to generate metal fine particles. The generated metal fine particles are recovered by a metal fine particle recovery liquid 27 stretched on a metal fine particle recovery apparatus 10 provided thereunder. The metal fine particle recovery liquid 27 is stirred by the electromagnetic stirrer 26.

The metal fine particle recovery liquid 27 is appropriately replaced depending on the condition of use. Further, since the temperature of the metal fine particle recovery liquid increases, it may be cooled by passing through water, or the metal fine particle recovery liquid 27 may be circulated through a heat exchanger 70 for use. In order to improve the recovery rate of metal fine particles, a metal fine particle recovery liquid 2
7 is stirred by, for example, an electromagnetic stirrer 26. The stirring means is not limited to the electromagnetic stirrer.

A part of the metal fine particles reduced in the hydrogen flame collides with the wall of the combustion chamber and adheres to the wall. To prevent this, a cooling liquid is caused to flow down along the wall of the combustion chamber. The cooling liquid is supplied from the cooling liquid supply port 68 and flows down to the combustion chamber wall surface through the cooling liquid passage 65. The metal fine particles that are going to collide with the combustion chamber wall surface are washed away by the cooling liquid flowing down along the wall surface, and finally merge with the metal fine particle recovery liquid 27 and are collected. It is convenient to circulate and use the metal fine particle recovery liquid 27 as the cooling liquid. Of course, it does not matter if water is used separately.

The generated metal fine particles and the like are supplied to the combustion chamber outlet 63.
Is discharged from The discharge destination is the metal fine particle collection device 10 into which the metal fine particle collection liquid 27 has been applied. The product / combustion product outlet 63 may be provided on the metal fine particle recovery liquid 27, but may be immersed in the metal fine particle recovery liquid, though not shown. From the viewpoint of increasing the recovery rate of metal fine particles, it is preferable to immerse the product / combustion product outlet 63 in the metal fine particle recovery liquid. By blowing gas, the substance in the combustion chamber containing the generated metal fine particles is brought into contact with the metal fine particle recovery liquid 27 and then discharged outside the room.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
Platinum colloid was produced using the apparatus shown in FIG. The preparation conditions of the used solution and the like, and the manufacturing conditions such as the combustion condition are as follows. Dissolve 10 g of platinum in 50 ml of aqua regia,
To this, 120 ml of 95% ethanol was added, and distilled water was further added to make the whole 300 ml, and the platinum ion solution was adjusted. The metal fine particle recovery liquid was prepared by adding 1 g of a surfactant to 5 l of distilled water. On the other hand, hydrogen has a combustion temperature of 6
The hydrogen flow rate was adjusted to be in the range of 20 to 680 ° C.
The manufacturing operation was performed according to the procedure already described. The recovery rate of the metal fine particles was 90 as an average value of 50 experiments.
９５95%. On the other hand, in a comparative example in which metal fine particles were manufactured according to FIG.
It was as low as 5%.

[0036]

In the production of the metal fine particles of the present invention,
Reduction of metal ions in a combustion device isolated from the atmosphere, blowing gas to forcibly induce a combustion flame below the combustion device to suppress the rise of the combustion flame, and metal adhering to the inner wall of the combustion device It is characterized in that fine particles and the like are washed away with a medium such as water. As a result, effects such as high uniformity of the obtained metal fine particles, high recovery rate, high productivity, and no burn or health problem of the operator are exhibited.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of an embodiment of the present invention.

FIG. 2 is a diagram showing an example of the combustion device of the present invention.

FIG. 3 is a diagram showing another example of the combustion device of the present invention.

FIG. 4 is a diagram showing an example of an embodiment in the conventional production of metal fine particles.

FIG. 5 is a diagram showing another example of the combustion device of the present invention.

FIG. 6 is a diagram showing another example of the combustion device of the present invention.

FIG. 7 is a diagram showing another example of the combustion device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustion apparatus 5 Fuel cylinder 6 Pressure control valve 7, 72 Pressure gauge 8 Combustion burner 9 Thermometer (thermocouple) 10 Metal fine particle recovery apparatus 11 Metal ion solution container 12 Metal ion solution 13 Compressor 16 Compressed air 17 Pressure regulator 18 Solution Flow control valve 19 Pressure gauge 23 Recovered liquid outlet 24 Recovered liquid inlet 25 Electromagnetic stirrer 26 Stirrer 27 Metal fine particle recovered liquid 53 Spray tube 54 Needle valve 55 Spouting outlet 62 Gas inlet 63 Product / combustion material outlet 64 Medium passage 65 Fuel path 66 Metal ion solution supply port 67 Fuel supply port 68 Medium supply port 69 Spout port 70 Heat exchanger 71 Flow control valve 73 Liquid feed pump

Claims (8)

[Claims] 1. A method for producing metal fine particles, wherein a metal ion solution and hydrogen are separately supplied and burned into a non-open type combustion chamber at least in the upper part of which is isolated from the atmosphere. A method for producing metal fine particles. 2. A method for producing metal fine particles, wherein when a metal ion is burned in a non-open type combustion chamber at least of which an upper part is isolated from the atmosphere, a medium flows down along the wall surface of the combustion chamber. A method for producing metal fine particles, comprising: 3. The method for producing metal fine particles according to claim 1, wherein a gas is blown onto the combustion flame to induce the combustion flame below the combustion chamber. Manufacturing method. 4. In a method for producing metal fine particles, when metal ions are burned in a non-open type combustion chamber isolated from the atmosphere, a gas is blown onto the combustion flame to lower the combustion flame in a lower part of the combustion chamber. A method for producing metal fine particles, characterized by passing a metal fine particle recovery liquid together with generated metal fine particles, a combustion flame, and a combustion product. 5. A combustion apparatus for producing metal fine particles,
A non-opening for producing fine metal particles, characterized in that at least an upper part of the combustion device has a partition wall for isolating from an atmospheric atmosphere for suppressing a rise of a combustion flame, and a metal ion solution supply port and a hydrogen supply port are provided. Type combustion device. 6. In a combustion apparatus for producing metal fine particles,
A metal, characterized in that at least an upper part of the combustion device is provided with a partition wall for isolating the combustion atmosphere from rising from the atmosphere and a medium supply port for flowing down a medium along the inner wall of the combustion device. A non-open type combustion device for producing fine particles. 7. A combustion apparatus for producing metal fine particles,
At least at the upper part of the combustion device, a partition wall for isolating the combustion flame from rising to the atmosphere, and a gas inlet for blowing gas for guiding the combustion flame below the combustion device are provided. Closed combustion device for producing fine metal particles. 8. A combustion apparatus for producing metal fine particles,
At least at the upper part of the combustion device, a partition wall for isolating the combustion atmosphere from rising to the atmosphere, a medium supply port for flowing a medium down the inner wall of the combustion device, and the combustion flame below the combustion device. A non-open type combustion apparatus for producing fine metal particles, comprising a gas blowing port for blowing a gas for guiding the gas to the combustion chamber.