JPH07100403A - Method and apparatus for producing fine powder - Google Patents

Abstract

PURPOSE:To produce a fine powder material without generating aggregation at the time of heat treatment operation and the trouble caused by the generation of aggregation. CONSTITUTION:In the production of a fine powder, a fine powder raw material L is dropped on tumbling media 1 heated while mixed mutually or a heated container 2 in which the tumbling media 1 are received by small quantity. A fine powder producing apparatus is equipped with a large number of the mutually mixed tumbling media 1, the container 2 having the tumbling media 1 received therein, the heating means 5 heating the tumbling media 1 and the container 2 and the raw material supply means 8 dropping the flowable fine powder raw material L on the heated tumbling media 1 or the container 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing fine powder, and more particularly to a method and apparatus for obtaining a solid fine powder material by subjecting a fluid fine powder raw material to a heat treatment operation. Regarding

[0002]

2. Description of the Related Art Conventionally, a fluid fine powder material mixed by adding a solution such as water or an organic solvent, for example, a clay or a slurry (hereinafter referred to as a ceramic slurry) which is a mixture of a ceramic and a solution. On the other hand, when obtaining a solid fine powder material that has been treated by a heat treatment operation such as drying or calcination, that is, a ceramic material, a heat treatment furnace of a well-known structure called a batch type or a continuous type ( It is common to use (not shown). And in the batch type heat treatment furnace,
After injecting the ceramic slurry into the box that is a box-shaped container made of ceramics or heat-resistant metal, and placing the box into which the ceramic slurry has been poured in the heating chamber, at the required temperature for a predetermined time It has been practiced to obtain a treated ceramic material in a solid state by performing a heat treatment operation such as drying and calcination by heating over, or a drying or calcination alone.

Further, a pusher type tunnel furnace or a rotary kiln is generally used as a continuous heat treatment furnace. In the pusher type tunnel furnace, the box into which the ceramic slurry is injected is sequentially transferred from the inlet side to the outlet side for heating. And, a ceramic material is obtained by cooling. Furthermore, in the rotary kiln, while heating a cylindrical furnace core tube made of ceramic or heat-resistant metal to a required temperature and rotating it, the ceramic slurry that is dripped from the inlet side of the furnace core tube and supplied in the furnace core tube. Heating is performed, and the treated solid ceramic material is discharged from the outlet side of the furnace core tube. The ceramic material, which is the finely powdered material thus treated, is crushed by using a ball mill or a crusher and then sent to the main firing step.

[0004]

By the way, the ceramic material, which is a fine powder material, causes agglomeration with the heat treatment operation for the ceramic slurry, which is a fine powder raw material, and the porous material has a certain size. It is usually obtained as a secondary particle body that is a lump. Therefore, even if the ceramic material obtained as the secondary particles is subjected to post-treatment such as pulverization, it is difficult to pulverize it into a fine powder state, and furthermore, the pores generated during the heat treatment operation are completely eliminated. The inconvenience that it cannot be lost will occur. Then, it is unavoidable that pores remain in the ceramic sintered body obtained by the main firing of the crushed ceramic material and it becomes difficult to densify, which leads to deterioration of characteristics in the final product. Was the reality.

The present invention was devised in view of such inconveniences, and provides a fine powder material which can prevent the occurrence of agglomeration during the heat treatment operation and which does not cause any inconvenience due to the agglomeration. An object of the present invention is to provide a manufacturing method and a manufacturing apparatus for fine powder that can be obtained.

[0006]

The method for producing fine powder according to the present invention is a method for obtaining a solid fine powder material by subjecting a fluid fine powder raw material to a heat treatment operation. In order to achieve this, it is characterized in that the fine powder raw material is dropped little by little into a rolling medium that is heated while being mixed with each other or a container that contains these rolling media and is heated. Further, the fine powder manufacturing apparatus according to the present invention includes a large number of rolling media mixed with each other, a container for containing these rolling media, a heating means for heating the rolling media and the container, and a heated rolling medium. And a raw material supply means for dropping a fluid fine powder raw material into a moving medium or a container.

[0007]

According to the manufacturing method of the present invention, the solution content such as water contained in the fine powder raw material dropped into the rolling medium or the container being heated is contacted with the rolling medium or the like. As a result, the fine powder component in the fine powder raw material adheres and remains on the surface of the rolling medium or the like. Since these rolling media are mixed with each other, the remaining fine powder component is crushed as the rolling media collide with each other and rub against each other. As a result, the fine powder component finely crushed after losing the solution content gradually becomes lighter in weight, and floats upward along the container wall.

Since the fine powder raw material supplied newly by dropping contains a solution and is heavy in weight, it is sunk into the lower side of the container, and the sunk fine powder raw material is The above operation is repeated by contact with a rolling medium or the like. Further, according to the apparatus for producing fine powder according to the present invention, the above production method can be realized very easily.

[0009]

EXAMPLES Examples of the present invention will be described below.

In the method for producing fine powder according to this example, a heat treatment operation such as drying or calcination is performed on a ceramic slurry which is a fluid fine powder raw material mixed by adding a solution such as water or an organic solvent. It is a method of obtaining a ceramic material as a fine powder material that has been treated and is in a solid state by being applied. And, this manufacturing method is characterized in that the fluidized fine powder raw materials are dropped little by little into the rolling medium which is heated while being mixed with each other or the container which contains these rolling medium and is heated. There is.

On the other hand, in the apparatus for producing fine powder according to the present embodiment, as shown in simplified form in FIG. 1, a large number of rolling media 1 called media (cobblestones) and the like are mixed with each other.
And a container 2 which accommodates these rolling media 1 and is driven to rotate about a vertical axis P, and a support shaft 3 which is vertically arranged and supports the container 2 from below. An electric motor 4 that rotates at a low speed is connected to the lower end of the. The rolling medium 1 here is made of ceramic or heat-resistant metal and has a spherical shape or a cylindrical shape with a diameter of about 1 to 50 mm, and the internal volume of the container 2 and the characteristics of the ceramic material S are taken into consideration. On the other hand, the container 2 is made of thin plate-shaped ceramic or heat-resistant metal, and is made in the shape of a truncated cone with its upper surface facing outward. It is considered to be an open surface.

The manufacturing apparatus further comprises an electric heater 5 as a heating means for heating the rolling medium 1 and the container 2, and a heat insulating member 6 having a predetermined thickness in which each of the electric heaters 5 is built. Each of the heat insulating members 6 is arranged so as to surround the side surface and the open surface of the container 2 with a gap set as a predetermined dimension interposed therebetween. Then, a through hole 7 penetrating the heat insulating member 6 along the thickness direction is formed at a predetermined position of the heat insulating member 6 arranged at a position facing the open surface of the container 2 from the vertical axis P. Has been done.

Further, the manufacturing apparatus is provided with a raw material supply means 8 for dropping and supplying the ceramic slurry L which is a fluid fine powder raw material onto the rolling medium 1 or the container 2 heated by the electric heater 5. The raw material supply means 8 is composed of a slurry storage container 9 in which the prepared ceramic slurry L is stored, and a slurry pipe 10 extended from the slurry storage container 9. The discharge port of the slurry pipe 10 is arranged at a position facing the through hole 7 formed in the heat insulating member 6 that covers the open surface of the container 2. Although not shown, it is needless to say that it is desirable to provide a valve for controlling the supply amount of the ceramic slurry L or the like at a midway position of the slurry pipe 10 or the like. Further, reference numeral 11 in the figure denotes a recovery container for storing the treated solid ceramic material S, and the ceramic container L is supplied to the recovery container 11 in the shape of an annular box. It is installed at a lower position corresponding to the outer peripheral edge of the container 2.

Next, a procedure for obtaining the ceramic material S from the ceramic slurry L by performing a heat treatment operation using the manufacturing apparatus according to this embodiment will be described.

First, while preparing a ceramic slurry L in which components have been prepared by adding and mixing a solution such as water or an organic solvent, a container 2 accommodating a large number of rolling media 1 is rotated by an electric motor 4 to generate electric heat. By using the heater 5, the rolling medium 1 and the container 2 are heated to the required temperature. The rolling medium 1 and the container 2 are heated to about 500 ° C. when the ceramic slurry L is dried, and to about 1000 ° C. when calcination is performed. Then, the ceramic slurry L stored in the slurry storage container 9 constituting the raw material supply means 8 is discharged little by little from the slurry pipe 10 and is passed through the through hole 7 of the heat insulating member 6 arranged on the upper side. It is dripped onto the rolling medium 1 which has been heated in advance and supplied. It goes without saying that the ceramic slurry L may be dropped onto the container 2.

Then, the solution such as water contained in the ceramic slurry L supplied by the dropping is evaporated by coming into contact with the rolling medium 1 and the like, and the surface of the rolling medium 1 and the like is evaporated. Only the ceramic component in the ceramic slurry L adheres and remains on the top. However, since these rolling media 1 are mixed with each other as the container 2 rotates, the rolling media 1
The ceramic components remaining on the respective surfaces in a spread state are crushed by the rolling media 1 colliding with each other and rubbing against each other. Then, as a result of losing the solution content and finely crushing the ceramic component, the weight thereof gradually becomes lighter, and as a result, the ceramic component floats upward along the wall surface of the container 2. At this time, since the newly dropped ceramic slurry L contains a solution and is heavy, the ceramic slurry L is sunk into the lower side of the container 2, and the sunk ceramic slurry L rolls. The contact with the medium 1 or the like causes the solution component to be evaporated, and then the operation of crushing by the rolling medium 1 is repeated.

As a result, the treated solid ceramic material S gradually accumulates in the upper side of the container 2 which is rotating after accommodating the rolling medium 1.
The accumulated ceramic material S is discharged by the action of centrifugal force from the gap provided between the open surface of the container 2 and the heat insulating member 6 arranged on the upper side. Then, these discharged ceramic materials S are collected by the collecting container 11 installed at the lower position corresponding to the outer peripheral edge of the container 2, and then sent to the main firing step.

In the present embodiment, the fluid fine powder material is the ceramic slurry L and the solid fine powder material is the ceramic material S, but the fine powder is not limited to ceramic. Needless to say, existing equipment such as a ball mill, a rod mill, and a horizontal conical pot may be used as the container 2 that stores the rolling medium 1 and is rotated and heated. Further, in this embodiment, a large number of rolling media 1 are mixed by rotating the container 2,
For example, it is possible to provide a stirring member (not shown) separate from the container 2 and mix the rolling medium 1 housed in the fixedly supported container 2 with the stirring member. .

[0019]

As described above, according to the method and apparatus for producing fine powder of the present invention, the fine powder loses the solution content by being dropped onto the heated rolling medium or container. The fine powder component in the raw material adheres and remains on the surface of the rolling medium and is crushed by rubbing these rolling mediums together. Therefore, in spite of the heat treatment operation performed on the fine powder raw material, the fine powder as a primary particle body that does not cause aggregation at all, rather than the secondary particle body that has caused aggregation due to the heat treatment operation in the conventional example. A body material is obtained.

As a result, when the fine powder material thus obtained is used, it becomes possible to produce a product having a density close to the theoretical density, and it is possible to improve the characteristics and stabilize the quality of the final product. The effect of being able to do is obtained.

[Brief description of drawings]

FIG. 1 is a structural diagram showing a simplified apparatus for producing fine powder according to the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rolling medium 2 container 5 electric heater (heating means) 8 raw material supply means L ceramic slurry (fine powder raw material) S ceramic material (fine powder material)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiko Takami 2 26-10 Tenjin, Nagaokakyo, Kyoto Prefecture Murata Manufacturing Co., Ltd. (72) Inventor Takahiro Yamamoto 2 26-10 Tenjin, Nagaokakyo, Kyoto Stock Company Murata Manufacturing

Claims (2)

[Claims] 1. A method of producing fine powder, wherein a solid fine powder material (S) is obtained by subjecting a fluid fine powder raw material (L) to a heat treatment operation, which comprises heating while being mixed with each other. A method for producing fine powder, characterized in that the fine powder raw material (L) is dropped little by little into a moving medium (1) or a container (2) which contains and heats these rolling media (1). 2. A large number of rolling media (1) to be mixed with each other, and a container (2) for containing these rolling media (1).
A heating means (5) for heating the rolling medium (1) and the container (2), and a fluid fine powder raw material (L) for the heated rolling medium (1) or the container (2). An apparatus for producing fine powder, comprising: a raw material supply means (8) for dropping.