JPH0268151A - Medium stirring type pulverizer - Google Patents

Abstract

PURPOSE:To pulverize a ceramic powder into fine particles within an extremely short time by constituting the inner surface of a pulverizing container of composite material consisting of a powder of either one of ceramics and metal, and an org. polymer material. CONSTITUTION:In a medium stirring type crusher equipped with a pulverizing container, round balls and a stirrer, at least the inner surface of the pulverizing container is constituted of a composite material consisting of a powder of either one of ceramics (e.g., SiC) and a metal (e.g., Al), and an org. polymer material (e.g., polyurethane). That is, the intermixing of a metal component by abrasion is reduced and heat transfer can be well done because of high heat conductivity. As a result, a pulverizing speed can be markedly increased and a ceramic powder can be pulverized within an extremely short time and the abrasion of round balls can be also reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a media agitation type pulverizer for grinding, mixing, dispersing, homogenizing and similar operations.

2. Prior Art In the present invention, pulverization includes pulverization and mixing in which pulverization and mixing are performed simultaneously.

In recent years, media agitation type pulverizers, which are pulverizers that agitate cobblestones and powder at high speed using a stirring device, have been attracting attention as fine pulverizers for ceramic powder. Conventionally, a media agitation type crusher has a structure consisting of at least a crushing container, cobblestones, and a stirring device, and the inner surface of the crushing container (the part that comes in contact with the cobblestones and ceramic powder) is made of metal such as stainless steel, ceramics, or resin. It consists of one of the following:

Problems to be Solved by the Invention Conventional media agitation type pulverizers and methods of pulverizing ceramic powder using the same take a long time to mix or pulverize ceramic powder into fine particles, especially submicron particle sizes. It takes time. In order to shorten the closing time at this time, the pulverization speed can be increased by increasing the rotational speed and circumferential speed of the stirring device. However, the above-mentioned conventional grinding vessels have various drawbacks, and it has not been possible to increase the grinding speed very much. That is, when the grinding container is made of metal such as stainless steel or chrome plating, there is a drawback that the grinding container is significantly worn, and its components are mixed into the ceramic powder, resulting in deterioration and variation in properties. Furthermore, if the crushing container is made of ceramic such as alumina or zirconia, the wear is relatively less than that of metal, but the grinding container is still considerably worn and mixed with the ceramic powder, resulting in deterioration and variation in properties. Another drawback was that it was relatively expensive.

In the case of resins such as polyethylene and polyurethane, the heat conductivity is low, so increasing the crushing speed causes significant heat generation, so it has been impossible to increase the crushing speed sufficiently.

An object of the present invention is to provide a media agitation type pulverizer that solves the problems of the prior art.

Means for Solving the Problems The present invention provides a medium agitation type pulverizer comprising at least a pulverizing container, cobblestones, and an agitating device, in which at least the inner surface of the pulverizing container contains powder of one or more of ceramics and metals and an organic polymer. The present invention provides a media agitation type pulverizer characterized by being made of a composite with a molecular material.

Specifically, in the above, the present invention is a media agitation type pulverizer characterized in that the boulders are made of ceramics whose main component is zirconia, zircon, or titania.

More specifically, the present invention is a medium agitation type pulverizer characterized in that the diameter of the boulders is 1 mm or less.

Further, in the method of pulverizing at least one type of ceramic powder using a media agitation type pulverizer, at least the inner surface of the pulverizing container is made of a composite of powder of one or more of ceramics and metals and an organic polymer material. This is a method for pulverizing ceramic powder, which is characterized by pulverizing ceramic powder in a pulverizing container.

In addition, in detail, in a method of wet-pulverizing at least one type of ceramic powder using a media agitation type pulverizer, the volume of the liquid is set to four times or less the true volume of the ceramic powder, and a dispersant is added. , further characterized in that the grinding is carried out using cobblestones with a diameter of 1 mm or less in a grinding container in which at least the inner surface of the grinding container is made of a composite of powder of one or more of ceramics and metals and an organic polymer material. This is a method of pulverizing ceramic powder.

More specifically, in the above, the volume of the liquid is within the range of 0.75 times or more and no more than 2 times the true volume of the ceramic powder, and using a cobblestone with a diameter of 0.6 mm or less, pulverization is performed. A method for pulverizing ceramic powder is characterized in that:

Function: According to the above-mentioned pulverizer and the method of pulverizing ceramic powder using the same, at least the inner surface of the pulverizing container in the media agitation type pulverizer is made of a composite of powder of one or more of ceramics and metals and an organic polymer material. By composing it with a solid body, it is possible to combine the features of ceramics, metals, and organic polymer materials. That is, there is little metal component contamination due to wear, and the thermal conductivity is high, allowing for good heat dissipation. Therefore, the pulverizer of the present invention can significantly increase the pulverization speed, and can pulverize ceramic powder into fine particles in an extremely short time. In addition to the above, by setting the diameter of the boulders to 1 mm or less, the grinding speed is high and the grinding into fine particles can be achieved in a short time, and the abrasion of the boulders is significantly reduced.

Example The present invention will be explained in detail below.

Example 1 Pb3O4, ZnO5SnO2, Nb in ceramic powder
2O5, TiO2 and Zr02 (the average particle size of these powders is 2.3 μm), these were
(Zn+z3Nb2z3)s, 59(Sn+)aN
b2/3) e, esTis, n2Zre, m1Iss
After weighing to the component ratio of the composition represented by Type dispersant (Ceramo Old 34 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
After pre-mixing with a mixer, the slurry is 40-80%
cc to medium agitation type crusher with an internal volume of 40 to 50 cc (Engineering Link Limited (EIGE)
M50 type motor mill made by RENGINERING LIMITED) - The material of the grinding container is hard chrome plating on the inside, polyurethane, polyethylene, epoxy resin, a composite of metal A1 powder and epoxy resin, ratio 1:1, A1 particles. Diameter is 0, 2~0, 5mm
) and a composite of SiC ceramic powder and polyurethane resin (ratio 1:1, SiC particle size 0.2-0.
5 mm), the circumferential speed of the stirrer was 10 m/see, and the mixture was pulverized and mixed for 20 minutes using a cobblestone filling of 80%. The outline of the structure of the media agitation type pulverizer used is given in Japanese Patent Publication No. 63-5.
This is shown in Publication No. 139. The stirring device was made of zirconia ceramics (partially stabilized zirconia containing yttria). The stones used were zirconia ceramics (partially stabilized zirconia containing ittria), titania ceramics, and zircon. The particle diameter of the obtained powder was measured using a sedimentation type particle size distribution analyzer (Sedaygraph 5000, manufactured by Shimadzu Corporation). The particle size was measured by sampling slurry at regular intervals during pulverization and mixing.

From this data, the time required to form a powder of 0.2 μm was determined. The times in the table are the average residence time of the slurry in the crushing container. The amount of wear of the cobblestone is determined from the change in its weight before and after use, and the table shows that the particle size of the powder is 0.2 μm.
It is shown as the value at the time when .

Table 1 shows the amount of wear of the boulders as a percentage of the weight of the ceramic powder.

Margin table below 1 This mark is in the column of the diameter of the cobblestone in Comparative Example Table 1, and the # mark is the titania cobblestone.
The & symbol is a zircon boulder, and the unmarked one is a zirconia boulder.

Example 2 After drying the slurries No. 6 of Example 1, they were placed in an alumina porcelain crucible and calcined at 850° C. for 2 hours to obtain a single-phase ceramic powder having an approximately perovskite structure. This was coarsely ground using an agitator and crusher. This powder was mixed with pure water in a volume 1.7 times the true volume of the powder and 1w of the weight of the ceramic powder.
After pre-pulverizing in a ball mill (average particle size: 1.1 μm) with t% (solid content equivalent) of a polycarboxylic acid type dispersant (Ceramo 0134 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), 40 to 80 cc of this slurry was It was placed in the media agitation type pulverizer of Example 1 and pulverized for 20 minutes. Thereafter, the grinding time and the amount of wear of the cobblestones were measured in the same manner as in Example 1. The results are shown in Table 2.

(The following is a margin) (The following is a margin) Table 2 The * mark is a comparative example (The following is a margin) In Table 2, in the column of the diameter of the cobblestone, the # mark is a titania boulder,
The & symbol is a zircon boulder, and the unmarked one is a zirconia boulder.

As is clear from the above examples, the inner surface of the grinding container was A
Composed of a composite of gold metal SiC ceramic powder dispersed in an organic polymer material such as polyurethane or epoxy resin, the amount of wear on the cobblestones is significantly reduced, and the heat dissipation of the crushing container is excellent, making the slurry abnormal. It was possible to grind for a long time without generating heat. At the same time, the diameter of the boulder is 1m.
A pulverizer with a diameter of less than m has a high pulverizing speed and can be pulverized into fine particles in a short period of time, and the wear of the boulders is extremely low. In addition, when the grinding container was made of hard chrome plating, heat dissipation during grinding was good and continuous use for 20 minutes was possible, but the abrasion of the stones was significant. The grinding container was also considerably worn. On the other hand, when the inner surface of the grinding container is made of only organic polymer materials such as polyurethane, polyethylene, and epoxy resin, heat dissipation during grinding is extremely poor and the slurry generates abnormal heat, with the temperature of the slurry reaching 80°C in about 5 minutes of operation. Continuous use was impossible because it exceeded the limit. Ceramic powder, which is pulverized or mixed by a media agitation type pulverizer using a dispersant with a water volume of 4 times or less than that of ceramic powder, and using cobblestones with a diameter of 1 mm or less, has a significantly small sedimentation volume, and Average particle size is small.

Note that the average particle size was also reduced by simply using cobblestones with a small diameter without a dispersant, but in this case, the sedimentation volume of the powder was large and the dispersibility of the powder was poor. Simply reducing the amount of water will cause the slurry to lose its fluidity and will not be pulverized at all. The amount of wear on the cobblestones is large for cobblestones with a diameter of 1.2 mm, but decreases dramatically when the diameter is less than 1 mrn. The diameter of the boulder is 1 mm or less, and the smaller the diameter, the more suitable it is for fine pulverization. When the diameter of the cobblestones is 0.6 mm or less, the effect of fine pulverization becomes very large and the amount of wear of the cobblestones is small. Note that the size of the boulders is the average diameter, which is distributed from front to back, and is an average value.

Further, in order to make the pulverization effective, it is preferable to make the ceramic powder in advance sufficiently smaller than the size of the cobblestone. The minimum required amount of water may be such that the slurry has fluidity. Note that when the amount of water is less than 0.75 times, the fluidity of the slurry tends to decrease. In addition, cobblestones made of zirconia, titania, and zircon had very little wear, while alumina cobbles wore significantly, more than 10 times as much as titania and zircon. Further, it was effective when the amount of the dispersant was 0.5 to 2 wt% (in terms of solid content) based on the weight of the ceramic powder. Incidentally, it is necessary to select an appropriate amount of the dispersant depending on the particle size of the powder, etc.

Note that the scope of the present invention is not limited to the above-mentioned examples, and the metal powder, ceramic powder, and organic polymer material constituting the composite may be raw materials to be crushed and may be other than those in the examples. . In addition, the shape of the powder is granular, flat, acicular,
It may be m-male or the like.

Furthermore, the liquid may be other liquids than water, such as ethanol and trichloroethane. Various dispersants can be used depending on the type of liquid and ceramic powder. In the above embodiments, a flow tube type media agitating type pulverizer was used for the pulverization, but other types of media agitating type pulverizers such as a base type, a stirring tank type, an annular type, etc. may be used. The material of the boulders is not limited to the scope of the examples and may be other materials such as silicon carbide,
It may also be silicon nitride, a material whose main component is the raw material powder itself, or the like.

As explained above, in the present invention, by setting the diameter of the boulders to 1 mm or less, the grinding speed is high and the grinding into fine particles can be achieved in an extremely short period of time, and the wear of the boulders is extremely low.

In addition, in the case of ceramics whose main component is zirconia, or one of zircon and titania, the cobblestones are less likely to wear, and contamination of the ceramic raw material powder with impurities can be reduced.

The volume of the liquid is reduced to a fraction of the conventional volume, that is, the volume of the liquid is less than four times the true volume of the powder, and a dispersant is used, and a cobblestone containing 11 or less zirconia, zircon, or titania as a main component is used. By pulverizing, it can be pulverized into submicron particles in an extremely short time.

Furthermore, since the slurry has excellent dispersibility, the mixing effect is also large. That is, in pulverizing and mixing two or more types of ceramic powder, not only the effect of fine pulverization but also the effect of homogeneous mixing can be obtained.

Furthermore, since the amount of liquid used in the pulverization method of the present invention is extremely small, there is also the effect that when two or more types of ceramic powders are pulverized and mixed, separation of the ceramic powders during slurry drying is difficult. Furthermore, since the amount of liquid used in the method of the present invention is significantly smaller, the volume of slurry is less than 1/2 to 1/4 for the same amount of powder compared to conventional methods. For this reason, a mill with the same capacity can provide several times the throughput compared to conventional milling methods. Furthermore, since the amount of liquid used is small, the powder can be dried in a short time and the energy required for drying can be significantly reduced.

In the present invention, since the boulder is made of zirconia, titania, or zircon, and the stirrer is made of zirconia, there is little contamination due to abrasion. In the case of mixing or pulverizing powder, the influence of compositional fluctuations due to the mixing of abrasive components can be ignored compared to the case of using cobblestones or stirrers made of other materials.

As is clear from the detailed description of the invention, the media agitation type pulverizer according to the present invention has at least the inner surface of the pulverizing container made of a composite of powder of one or more of ceramics and metals and an organic polymer material. By configuring it, there is less mixing of metal components due to wear, and the thermal conductivity is high, so that heat dissipation can be improved. As a result, the pulverization speed can be significantly increased, ceramic powder can be pulverized into fine particles in an extremely short period of time, and wear of the boulders is also reduced.

Claims (4)

[Claims] (1) In a media agitation type pulverizer equipped with a pulverizing container, boulders, and an agitating device, at least the inner surface of the pulverizing container is composed of powder of one or more of ceramics and metals and an organic polymer material. A media agitation type crusher characterized by consisting of a composite body. (2) A media agitation type pulverizer equipped with a pulverizing container, boulders, and an agitating device, characterized in that at least the inner surface of the pulverizing container is made of a composite of ceramic powder and an organic polymer material. A media agitation type crusher. (3) A media stirring type pulverizer equipped with a pulverizing container, boulders, and an agitating device, characterized in that at least the inner surface of the pulverizing container is made of a composite of metal powder and an organic polymer material. A media agitation type crusher. (4) The media agitation type pulverizer according to claim 1, wherein the boulders are made of ceramics containing either zirconia, zircon, or titania as a main component.