JPS60110803A - Method and device for producing metallic powder - Google Patents

Abstract

PURPOSE:To produce continuously fine and spherical metallic powder at a good yield by blowing a high-pressure gas from the side diagonal with the molten metal directed toward the liquid layer in a rotary drum so as to collide against the rotating liquid layer. CONSTITUTION:Water is supplied at a prescribed flow rate through a water replenishing port 6 into a drum 1 under rotation to form a rotary water layer 5 on the inside circumferential surface of the drum. A molten metal is then ejected from a molten metal ejecting nozzle 3 toward the water layer 5 and at the same time a high-pressure gas is ejected via high-pressure gas ejecting nozzles 4 from the side diagonal with the molten metal so as to collide against the layer 5 after disintegrating the molten metal into fine particles thereby pulverizing and solidifying further the molten metal. The solidified metallic powder deposits on the drum 1 and is rotated together with the drum 1. Such powder is continuously recovered together with the water through a powder recoveing port 7 and is contained into a powder recovering tank 8. The water flowing out through the port 7 is replenished by the water through the port 6 to balance the water flow.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for producing metal powder directly from molten metal, and is particularly designed to continuously produce fine, spherical metal powder with a high yield.

In general, metal powders are used in various shapes depending on the application, and spherical powders are mainly used for conductive coatings, catalysts, powder metallurgy, etc.

Although the gas 71-mize method is the main method for producing such spherical powder, the Omi rotating water atomization method is also being investigated. In this method, water is placed in a rotating drum, the centrifugal force is applied to J, a water layer is formed on the inner wall of the re-drum that rotates with the drum, and the molten metal is spouted toward the water layer and rapidly cooled and pulverized by the rotating water. be.

However, the powder produced by this method has an average particle size of 5.
The particles are coarse, ranging from 0 to 100 μm, and many of them are irregular in shape and not spherical, and depending on the size of the yang, 60 μm or more of flake-like powder may be included, making it extremely difficult to separate these. Not only was it difficult to process, but the yield was also low. Furthermore, the produced powder cannot be collected continuously because it is in the rotating water layer inside the drum.
This significantly hindered productivity.

In view of this, and as a result of various investigations, the present invention has developed a metal powder manufacturing method and a device capable of continuously manufacturing fine, spherical metal powder with good yield.

That is, the manufacturing method of the present invention involves jetting molten metal toward a rotating drum and a fluid layer rotating in the direction of the inner drum, and turning the molten metal into metal 5) powder which is rapidly cooled and pulverized by the rotating fluid. l of
! In the 1'I structure, the molten metal spouted toward the fluid layer is characterized by blowing high-pressure gas diagonally to the side and then thrusting it into the rotating liquid layer by 1Φj.

Furthermore, the apparatus of the present invention jets molten metal toward a liquid layer that rotates with the drum in a rotating drum, and quenches and pulverizes the molten metal into the rotating liquid. A nozzle is provided that spouts a high 11-gas toward the molten metal from an oblique side of the nozzle that spouts the molten metal toward the molten metal, and a recovery pipe is provided in front of the molten metal spouting nozzle to extract the metal powder together with the rotating liquid. It is characterized by the provision of a supply pipe into which liquid equivalent to the amount of liquid taken out is charged.

This will be explained in detail using the drawings.

Figures 1 and 2 are examples of the device of the present invention. In the figures, (1) is a rotating drum, (2) is a rotating shaft, and (3) is a rotating drum.
(4) is a high-pressure gas jet nozzle, (6) is a molten metal jet nozzle, and (6) is a high-pressure gas jet nozzle.
) indicates the supply water port, (7) indicates the powder collection port, and the rotating drum (1) rotates on the side wall 5 of the usage side, leaving the annular wall (1a) projecting inward at -h of the side wall. Set the shaft (2) to rotate at high speed in the direction of the arrow. A nozzle (3) spouts molten metal from the frontage of the drum (1) toward the inner peripheral surface of the drum (1).
) and a nozzle (4) that jets high-pressure gas from the diagonal side toward the molten metal spouted from the nozzle (3). 1) A replenishment water inlet (6) that forms and covers the water layer (6a) on the inner peripheral surface, and a collection port (7) that collects metal powder together with water from the inner peripheral surface of the drum (1) in front of the replenishment water port (6). ).In the teeth, (3a) is a heating high-frequency coil installed around the outer circumference of the molten metal++ (l outlet nostle (33), (6a) is a water supply pipe, and (7a) is gold n1'Yi. 't) Uncollected pipe, (8
) accepts tanks for uncollected metal powder.

Using the above-mentioned agricultural equipment, water is supplied with a specified flow and agitation from the supply water into the rotating drum, and the centrifugal force is applied to form a recirculating water layer on the inner peripheral surface of the re-drum.Next, The molten metal is spouted from the molten metal spouting nozzle toward the water layer, and at the same time, high-pressure gas is spouted from the high-pressure gas spouting nozzle diagonally toward the spouting molten metal to pulverize the molten metal. The solidified metal powder is further pulverized and solidified by colliding with the water layer.The solidified metal powder is transferred to the inner peripheral surface of the 1-ram by centrifugal force and rotates with the drum. It is continuously collected together with water and stored in a powder collection tank.By balancing the amount of water flowing out from the powder collection port with the amount of water supplied from the replenishment water port, the rotating water layer on the inner circumferential surface of the drum is kept at a constant level. It is to be kept as such.

As described above, the present invention employs two-stage spraying in which the molten metal flow ejected from the nozzle is first atomized by a jet of high-pressure gas, and then is sprayed by a rotating water layer. The particle size is 30 μnL, which is about 1/2 to 1/3,
The shape of the powder is also almost spherical, and contains almost no irregular or flaky particles. The size of the metal powder is
The relative positional relationship between the molten metal spout and the high-pressure gas jet, the distance to the rotating water layer, the peripheral speed of the rotating water layer, the temperature of the molten metal, the jet pressure,
It can be changed by adjusting the flow diameter, jetting pressure of high-pressure gas, jetting amount, etc. Therefore, the diameter of the molten metal spouting nozzle is set to 0.3 to 5 mm, and the jetting pressure is set to 0.5 to 10 KfJ.
/trd, and the high pressure gas is air or non-oxidizing gas such as silica, carbon dioxide, argon, etc. depending on the type of molten metal, the ejection pressure is 3#/cd or more, and the rotating drum is Inner diameter 300 mm or more - E, width 50
Use 1B1B or more, and set the circumferential speed to 30TrL/
It is desirable to set it to sec or more.

Although an example using a rotating water layer has been described above, the present invention is not limited to this, and various nonflammable liquids that do not react with the molten metal can be used.

Examples will be described below in order to clarify the effects of the present invention.

Copper powder was produced using the apparatus shown in FIG.

An iron drum with an inner diameter of 400 mm and a width of 60 mm was used as the rotating drum, and the distance between the molten metal spout nozzle and the rotating water layer was 30 mm.
mm, and under the conditions shown in Table 1, the molten metal spouting nozzle J,
The molten metal at 1,300℃ is ejected at a pressure of 1.1<9/c#I, and after being blown with high-pressure nitrogen gas, it collides with a rotating water layer. The grain size distribution of the powder thus obtained was measured. These results are compared with the conventional method that does not use high-pressure nitrogen gas and are also listed in Table 1.

0 -7 male 40c+, +rs, -den 1 →- 1 gl + 田- °゛巳区ゝ＼ ♀Word″-08111 Room! l:! J: It is clear from the table that the average particle size of all the powders produced by conventional methods No. 017 to 9 is 50 to 100 μIn.
Not only are they relatively large and have large variations, but their grain shapes are irregular. In contrast, method No. 1 of the present invention
The powders produced in 4 to 4 had a small average particle size of 22 μm, with little variation, and the particle shape was spherical regardless of the particle size of the powder. Furthermore, as can be seen from Methods No. 35 to 6 of the present invention, even if high-pressure gas is blown into the molten metal flow (= i l), if the gas LE force is small or the circumferential speed of the drum is low, the grain shape will not be nearly spherical. However, the average particle size and dispersion also tend to be less sensitive. Therefore, in order to produce powder with an average particle size of 30 µlrL or less and little variation using the method of the present invention, the ejection pressure of the high-pressure gas must be set at 3 kg/cni, and the circumferential speed of the drum must be set at 30 m/sec or more. I want to be able to pronounce it, and I know what's right.

In the present invention, the 11f1 molten metal flow is atomized with high-pressure gas-C, and then sprayed with a rotating liquid layer to refine the average particle size to 30 μm or less. The powder form is spherical and can be manufactured continuously with good yield, which provides remarkable industrial effects.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of the device of the present invention, and FIG.
FIG. 1 is a perspective view showing a cross section of a main part in the figure. 1. Rotating drum 2, rotating shaft 3, molten metal jetting nozzle 4, high pressure gas jetting nozzle 5, water layer 6, replenishment water port A, metal powder uncollected port Figure 1 Figure 2 ■

Claims (3)

[Claims] (1) In the production of metal powder, the molten metal is quenched and pulverized by the rotating liquid, in which the molten metal is quenched and pulverized by the rotating liquid. A method for manufacturing metal powder that is characterized by blowing high-pressure gas into the molten metal from the side diagonally (=JI) and then avoiding collision with the rotating liquid layer. (2) The method for producing metal powder according to claim 1, wherein the metal powder is continuously collected together with the rotating liquid from inside the rotating drum, and an amount of liquid corresponding to the extracted liquid is supplied into the drum. (3) In the production of metal powder, the molten metal is spouted toward the liquid layer that rotates with the drum in the rotating drum, and the molten metal is rapidly cooled and pulverized by the rotating liquid. A nozzle is installed to eject high-pressure gas toward the molten metal from the diagonal side of the nozzle, and in front of the molten metal ejection nozzle there is a collection pipe that takes out the metal powder along with the rotating liquid, and a supply pipe that charges the liquid equivalent to the amount of liquid taken out. A metal powder manufacturing device characterized by the following: