JPS63183109A - Apparatus for producing metal powder - Google Patents

Abstract

PURPOSE:To efficiently produce fine metal powder having low apparent density and high flowability by installing a mixing chamber contg. a collision body under a nozzle for jetting a liq. so as to increase cooling rate. CONSTITUTION:A mixing chamber 8 is installed under a nozzle body and a collision body 9 is set in the chamber 8. A flow of molten metal flowing down from a tundish passes through the nozzle body and is atomized by jets of a liq. such as water. The resulting particles of the molten metal collide against the collision body 9. The particles are further pulverized and cooled by mixing with the liq. such as water. Thus, fine metal powder having irregular shape, low apparent density and high flowability is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a powder manufacturing apparatus used for manufacturing metal powder used as a raw material for powder metallurgy-4 electric materials and the like.

[Conventional technology]

Conventionally, powder manufacturing equipment for powder metallurgy, electrical materials, etc., has often used powder manufacturing equipment using electrolytic methods, mechanical pulverization methods, spraying methods, rotating electrode methods, etc., and the spraying method is particularly suitable for mass production. For example, in FIG. 1, 1 is a tongue, 2 is a molten metal, 3 is a molten metal flow, 4 is a nozzle body, and 5 is a metal liquid. 6 is a container, 7 is a liquid stream such as water, and this liquid stream is ejected at a high speed, for example, 100 m/s, so as to be focused at an angle θ.

When molten metal is sprayed using such a device, metal droplets are instantaneously formed and cooled at the same time, so a simple container is required, which has the advantage of low manufacturing costs and high productivity. .

Conventional spraying equipment has the advantage of being easy to powder, but at the same time, the liquid stream and the powdered particles are not sufficiently mixed, and cooling is required. The drawback was that it was less effective.

If the cooling effect is low, for example, in the case of copper powder, the apparent density is 3
．． Only heavy powders of 0 to 3.5 g/cc can be obtained, and if the particle size of the powder is made even finer, it is necessary to increase the pressure of the spray medium such as water, which has the disadvantage of contributing to increased costs. . Furthermore, when the apparent density is lowered by increasing the liquid flow rate and flow rate in order to increase the cooling rate, there is a drawback that only a powder with poor fluidity is obtained.

[Problem that the invention seeks to solve]

It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a powder manufacturing apparatus that can efficiently produce fine powder with low apparent density and good fluidity.

[Means for solving problems]

That is, the present invention uses a nozzle having an annular slit for spouting water or other liquid, and a device for spraying and pulverizing molten metal by flowing down the center of the nozzle, in which a collision chamber 9 is provided at the bottom of the nozzle. This powder manufacturing apparatus is characterized by being provided with a mixing chamber 8 with an attached mixing chamber 8.

[Effect]

In this invention, a mixing chamber is provided at the bottom of a nozzle that spouts a liquid, and the powdered particles are sufficiently mixed with a liquid such as water, and by increasing the cooling rate, they are prevented from becoming spherical due to surface tension, and are formed into irregular shapes. This mixing chamber is used to generate particles and obtain a powder with good fluidity and low apparent density.
It is characterized in that an impactor is provided inside thereof so as to have the above-mentioned quenching action as well as a certain degree of crushing action at the same time.

The shape of this colliding body is flat, dish-shaped, umbrella-shaped, or lattice-shaped, but it may be screw-shaped as long as it can stir the liquid flow and particles.

〔Example〕

FIG. 2 is a diagram showing an embodiment of the present invention, and the same reference numerals are used for the same components as in FIG. 1, and the explanation thereof will be omitted.

The powder manufacturing apparatus of the present invention shown in FIG. 2 is provided with a mixing chamber 8 in the lower part of the nozzle body 5, and an impactor 9 is attached inside the mixing chamber 8. Molten metal flow 3 (
(in this example, molten copper was used) passes through a nozzle body 4, is powdered into metal droplets 5 by a liquid stream 7 (in this example, water is used), and is further collided with an impactor 9 to be crushed. At the same time, it is vigorously mixed with liquid such as water and cooled. For this reason, the obtained powder had an irregular shape and a low apparent density, but had good fluidity and was fine.

Table 1 shows the spraying conditions of this example and the powder characteristics (particle size distribution, apparent density, fluidity) of the obtained powder.

Table 1 also shows the powder properties as a comparative example when the spraying conditions were the same as in the previous example except for the mixing chamber 8 and the collision body 9 in the apparatus of the present invention shown in FIG. .

As is clear from Table 1, the powder obtained using the apparatus of the present invention has fine particle size, low apparent density, and good fluidity.

Table 1 [Effects of the Invention] The present invention collides and mixes a mixed flow of atomized metal droplets and a water chef inside a mixing chamber equipped with a collision body, thereby making metal droplets even finer. By increasing the cooling effect, we were able to obtain a metal powder with good fluidity and low apparent density.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing an example of a conventional powder manufacturing device;
The figure is an explanatory diagram showing an example of the powder manufacturing apparatus of the present invention. 1, tundish 2, molten metal 3, molten metal flow 4, nozzle body 5, droplet 6, container 7, liquid flow 8, mixing chamber 9, colliding body

Claims (1)

[Claims] (1) In a device that uses a nozzle that has an annular slit to spout water or other liquid and causes molten metal to flow down the center of the nozzle to atomize and powderize the metal, an impactor 9 is attached to the lower part of the nozzle. A powder manufacturing apparatus characterized in that a mixing chamber 8 is provided.