JPH01207126A - Method for granulating powder or the like - Google Patents

Abstract

PURPOSE:To obtain a granular material having a smooth surface and high sphericity by using a sol in which powder is dispersed as a core liquid, dropping this liquid into a solidified liquid contg. polyvalent metal ions to form the granular material and drying this gel. CONSTITUTION:The core liquid is prepd. by dispersing the powder meeting the purpose of use into the sol which forms a gel by reacting with polyvalent metal ions. This core liquid is dropped into the solidified liquid contg. the polyvalent metal ions to form the granular material. This gel is subjected to a surface treatment at need to eliminate flocculating and sticking properties; thereafter, the gel is dried to obtain the granular material. The above-mentioned granular material is previously immersed into the soln. contg. the poolyvalent metal ions and this soln. is immersed in the sol to effect reaction and to form a coating layer. The granular material having the multilayer structure formed with the many layers on the surface of the grains is thereby obtd.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for granulating powder, etc., and is used in the fields of fine ceramics, catalysts, fertilizers, medicines, agricultural chemicals, seeds, etc. Alternatively, it relates to a granulation method that seeks functionality of the granulation itself, such as compositing specific fine particles, enzymes, microorganisms, cells, etc. with immobilized carriers.

For example, it is a method for producing granules that is used for desulfurization, decolorization, adsorption, deodorization, etc. by forming granules using zeolite, activated carbon, alumina, glass fiber, ceramics, and using the granules as a catalyst. This invention relates to a granulation method that is also applied to granulation methods for ferrite, zirconia, etc.

(Prior Art) In recent years, as new materials have become finer (higher purity), there is a high demand for granulation of wear-resistant materials such as ceramics, composite materials, and metal materials.

According to conventional methods, granulation has so far been entirely carried out by mechanical granulation. Mechanical granulation methods include compression, rolling, extrusion, flow, etc.

Compression molding is the method most commonly used in fields such as medicine, where a powder containing the catalyst to be molded and auxiliary materials such as lubricants and binders are placed in a mortar and compressed with a pestle. Shape.

The transfer granulation method is a method in which a flat, dish-shaped inner cylinder is rotated to cause the powder inside to grow into larger particles in a snowball-like manner. There are types such as type and mixer type.

The mechanism of transfer granulation is that first, wet powder is transferred by transfer or stirring to form core particles.

When water is further replenished, the powder particles combine with the aqueous film to form particles, but the problem is that it is difficult to uniformly replenish water, so particles with a high water content This is a thixotropic phenomenon in which excess water seeps out onto the grain surface, causing the surrounding wet powder to adhere and agglomerate, causing the grains to rapidly grow in a snowball-like manner.

The extrusion granulation method is an extrusion granulation method used in the catalyst industry, but its role is not very large.

The spray granulation method involves catalytic cracking of hydrocarbons such as petroleum, that is, F
It is used as a CC catalyst, and its particle size is approximately 50 to 100 μm on average.

(Problems to be Solved by the Invention) Granulation is a method of combining fine particles to obtain aggregates thereof.

Generally, a binder is used to impart plasticity to the material and granulation is carried out.
Or mold it.

However, in the case of inorganic materials and metals, it is difficult for the binder to penetrate between the powder particles, so it is necessary to use a strong binder.

Even when such a strong binder is mixed, there are many physical properties that do not erode the binder sufficiently, making it difficult to adjust the plasticity.
There are problems with low production per unit of power and high maintenance costs.

In the case of a mechanical granulation method, forming ultrafine powder using a grinding ball is an essential operation for making fine particles.

However, since pulverization is caused by collision and friction between the pulverizing balls, the smoothness of the ball's surface greatly affects the pulverizing efficiency, and at the same time, the unevenness of the ball's surface promotes the friction of the balls themselves, and the metal components created by that friction are transferred. It turns gray and becomes a contaminant that prevents high-purity products from being obtained.

Also, when adding a binder, if the amount is large,
This itself causes contamination, and the surface smoothness of the resulting granules is rough.

゛ In particular, in the transfer and flow method, a binder is sprayed onto the surface of the core material and the powder is allowed to grow while adhering to the core material to form spherical particles.

At this time, it may be difficult to apply the binder uniformly, and the particle surface becomes uneven, resulting in rough smoothness and poor fluidity.

When trying to obtain spherical particles using a transfer granulator, since the rolling motion rotates in a fixed direction, the particle transfer motion does not necessarily undergo spherical rolling motion, resulting in elliptical granules with low sphericity. Become.

If the sphericity is low, the fluidity will be poor and the particle size will be difficult to control.

Furthermore, alumina, glass fiber, zirconia, etc. have no affinity with the binder and cannot be granulated.

Therefore, in the present invention, these conventional drawbacks, namely the problems of nacreousness, particle size, particle surface smoothness, and contamination due to abrasion, can be solved, powders that could not be granulated at all can be made into spherical shapes, and the particle size can be controlled. The objective is to obtain a granulation method that can easily produce products with uniform particle size with good reproducibility, without contamination due to wear, and with a smooth surface and high sphericity without being affected by powder surface activity. It is something.

(Means for Solving the Problems) In order to achieve the above objects, the present invention uses an encapsulation method that is a part of the conventional submerged coating method, and
, focused on the crosslinking reaction in the method of encapsulation by bringing a polysaccharide solution such as pectin or sodium alginate into contact with a solution containing polyvalent metal ions such as calcium, and utilized this phenomenon. This makes it possible to granulate powders that are not compatible with binders.

That is, the first invention uses a core liquid in which powders according to the purpose of use are dispersed in a sol that reacts with polyvalent metal ions to form a gel, and this is used as a core liquid to coagulate the polyvalent metal ions. This is a method of granulating powder, etc., which is characterized by dropping the gel into a liquid to form granules, treating the surface of this gel as necessary to eliminate cohesive adhesives, and then drying it. The invention involves dropping a solution in which powders are dispersed according to the purpose of use into a gel containing polyvalent metal ions into a sol solution that reacts with polyvalent metal ions to form a gel, thereby producing internally fluid granules. Making,
This is a method for granulating powder, etc., which is characterized in that this gel is surface-treated to eliminate agglomeration and adhesion, if necessary, and then dried.

The third invention is claimed in claim (1), in which powders selected depending on the purpose of use are dispersed in a sol that reacts with polyvalent metal ions to form a gel. (2)
When immersing the granules obtained by the above, the granules may be immersed in a solution containing polyvalent metal ions in advance, or they may be immersed in a single solution without prior immersion, or they may be immersed in a plurality of solutions repeatedly. Dip and react to form a coating layer,
This is a method of forming a plurality of layers on the surface of the granule to obtain a granule with a multilayer structure.

In addition to using a single nozzle, the dripping solution uses a multi-structure nozzle. In the latter case, the solution is a solution in which powder is dispersed in a sol that reacts with polyvalent metal ions to form a gel. , a solution containing polyvalent metal ions in which powder is dispersed, and the powder that reacts with the solution used in the nozzle is dispersed from the inside of the nozzle, and the other from the outside of the nozzle. , or dropped into a solution that does not disperse.

The granules obtained according to the first invention have an internal gel-like structure and are entirely porous.

The polyvalent metal ions used in this method include organic and inorganic salts of polyvalent metals such as calcium chloride, magnesium chloride, barium chloride, aluminum chloride, and iron chloride. Does the coagulating liquid contain such polyvalent metal ions? It's night.

In addition, as the core liquid, multi-I! This is a solution prepared by dissolving a similar solution to a predetermined concentration.

Furthermore, alcohol or the like is used as a treatment agent for the surface treatment of the obtained granules, thereby eliminating agglomeration and adhesion.

Drying is performed by stationary drying, fluidized bed drying, and vibrating fluidized bed drying. In addition, centrifugal drying, solvent replacement, etc. can be considered.

By performing the above operations, agglomeration of the particulate matter is prevented, the necessary spherical shape can be obtained, the spherical shape is maintained, and the sphericity is increased.

Various powders are selected depending on the purpose of use, but they are used as catalysts because they produce porous granules. Therefore, using a catalyst as an example, the explanation is as follows.

In other words, in general, the purpose of catalyst granulation is to improve the flow of reaction gas or liquid, thereby reducing pressure loss, preventing channeling (uneven flow), uniform contact, and supplying the catalyst to the reaction tank. Or ease of discharge from the reaction vessel, dust generation (
For the purpose of preventing dusting, etc., the granulation form is required to be a spherical body with a smooth surface in order to suppress wear and pulverization.

On the other hand, granular catalysts obtained by gripping catalyst components, co-catalyst components, etc., molding, and firing improve basic quality such as catalytic activity (reaction rate, selectivity) and life (chemical deterioration), and improve the reaction mechanism. Depending on the differences, etc., the most suitable form of pore structure, pore distribution, effective surface area, etc. is selected.

Therefore, when performing a granulation operation, it is necessary to adjust the molding pressure to avoid equipment that affects the pore structure (porosity), and at the same time to select operating equipment suitable for the former purpose.

Examples of powders used as raw materials for catalysts include alumina, silica, titania, zirconia, magnesia, glass, activated carbon, pumice, diatomaceous earth, montmorinite, bauxite, and polymers.

The powder used for desulfurization is silica, alumina,
The powders used for adsorption are silica, alumina, glass, zeolite, activated carbon, alumina, cobalt, zirconia, and molybdenum, and the powders used for decolorization are activated carbon and activated clay. The powders used are activated carbon and zeolite.

Granules used in catalysts using powders as described above are:
Uniform particle size can be freely controlled in the range of O01 to 10.0φm111, including granulation in the particle size range of 0.2 to 0.8φ, which cannot be produced using conventional equipment, depending on the purpose of the catalyst.

In other words, the nozzle diameter used, the type and concentration of the core liquid,
Select the powder slurry concentration and adjust the particle size. In addition to the drip nozzle, compressed air is supplied from the outside of the multiple nozzle,
By adjusting the amount of air, the particle size can be reduced to any desired size.

Then, true spherical particles required for a catalyst can be obtained, and a granulated product can be obtained that maintains the characteristics (pore structure, pore distribution) of the carrier raw material without destroying them.

In order to obtain even smoother, uniform, true spherical particles, the phenomenon of pressure loss,
Effects can be seen on quality improvement, such as prevention of dust generation and ease of discharge from the reaction vessel, as well as catalyst activity (reaction rate, selectivity) and life span.

Next, while the first invention uses a polysaccharide solution as the core liquid, the second invention uses a polysaccharide solution or a solution containing polyvalent metal ions. The same one as that of the first invention is used.

The resulting granules have internal fluidity and are dense. Therefore, application to fine ceramics is considered, and the following powders are added depending on the purpose of use.

In the first place, fine ceramics are used as insulating materials, dielectric materials, and semiconductor materials in the electrical and electronic fields, magnetic recording heads, ferrite magnets, and temperature sensors in the magnetic functional field, and gas and temperature sensors, and temperature sensors in the chemical functional field. It is a catalyst carrier and an organic catalyst.

In addition, in the field of mechanical functions, there are cutting materials, wear materials, and heat-resistant materials, and in the field of biological functions, there are artificial tooth roots, artificial bones, and artificial joints.

By the way, if we think about the purpose of granulation of fine ceramics, when molding into shapes suitable for each of the above uses, we can mold ultra-thin plates of several microns such as IC and LSI chips, ultra-small sensors, or wear materials. In the case of molding that requires precision, such as molding or artificial bone, the most important operation is how uniformly the molding mortar is filled, and is a factor that greatly affects the quality after firing.

Therefore, it is desired to improve fluidity as a material characteristic.

Therefore, by granulating particles with high sphericity, fluidity and filling rate are improved.

At the same time, semiconductor materials such as high-purity silicon are required to have eleven nines (99,999999999%), which is unimaginably refined (high purity) compared to conventional ceramics.

Therefore, non-contamination granulation has become a major issue.

In order to solve the above problems, the powders that can be added and their uses are as follows.

Powder Usage As mentioned above, the product of the 1.2 invention allows various powders to be contained in an internally gel-like gel capsule or an internally fluid capsule, but the product of the 3rd invention is 1st
．． 2. The granules obtained according to the invention can be coated with multiple layers.

That is, the granules obtained according to the invention 1.2 are added once to a solution in which powders selected according to each purpose of use are dispersed in a sol that reacts with polyvalent metal ions to form a gel. A granular material with a multilayer structure is obtained by immersion or repeated immersion to react.

In addition to a single dropping nozzle, a nozzle with a double or multiple structure can be used for granulation. In that case, the powder is mixed into a sol that reacts with polyvalent metal ions to form a gel. A dispersed solution and a solution in which powder is dispersed in a sol containing polyvalent metal ions may be dropped at the same time, and when either of the solutions is dropped from an external nozzle, this The powder that reacts with the powder is dropped into a solution that is dispersed or not dispersed.

In addition to a double nozzle, a multilayer nozzle such as a triple nozzle may also be used, and between the nozzles, a solution containing different powders that react with each other is used.

When dropping using a multilayer nozzle such as a triple nozzle, the granulation time is short and each layer is difficult to peel off.

Furthermore, when the granules obtained by dripping using a single nozzle are coated with multiple layers, it is suitable for agricultural chemicals and fertilizers due to the problem of peelability.

Conventional multilayer granulation methods are carried out by transfer granulation methods such as a dish granulator, a drum granulator, a rotating disk granulator, and a fluidized bed granulator.

The method is to granulate the powder in advance to form the core, or
Use granules obtained by crushing solids. This is a method in which this is placed in a transfer granulator, and while a binder is being sprayed onto the core material, a powder serving as a coating material is supplied and coated.

Therefore, uniform spraying of the binder is actually extremely difficult, and not only does the particle size become uneven, but also agglomeration of particles occurs during coating granulation.

Furthermore, in the case of multilayer powder coating, a processing time of about 60 to 180 minutes is required, which reduces processing capacity and increases the overall cost.

According to the present invention, the core material and the coating layer can be formed at the same time, and the particle size and coating thickness are uniform. The coating can be formed in 5 to 10 minutes. Furthermore, there is no aggregation of the coatings. Therefore, it is possible to significantly shorten the processing time.

In recent years, along with technological advances in fine ceramics, there has been an extremely high demand for ultra-fine powder and non-contamination of ceramic raw materials.

Currently, mills that can handle these processes include wet and dry methods, both of which use ball grinding methods, but conventional grinding balls include alumina balls, steel balls coated with urethane foam, Agate etc. are commonly used.

However, in order to meet the increasing demand for ultra-fine powder, a ball with a large surface area, smooth surface, and high hardness is desired.

From the above points, according to the third aspect of the present invention, 0.3 to 1
．． A film of extremely hard metal powder such as zirconia can be formed on the surface of a ball with a 0φ diameter alumina core.

In addition, by forming an alumina film on the surface of the magnetic powder ferrite core, it is possible to control the magnetic action and move the ball freely, which greatly increases efficiency while simplifying the shape of the mill body. can be improved.

In addition, multi-layer granulation using various inorganic and organic materials enables control of swelling and disintegration properties of agricultural chemicals, fertilizers, soil conditioners, etc., as well as sustained release and delayed release properties, as well as herbicidal, sterilizing, and insecticidal properties. It is possible to adjust complex pesticides, etc.

Furthermore, by forming a composite layer of catalyst carriers, it is possible to combine uses such as desulfurization, adsorption, decolorization, and deodorization.

In addition, by coating seeds such as radish, carrots, and Chinese cabbage with powders such as diatomaceous earth, talc, clay, and isolac that are easily absorbed by water (and mainly consist of porous fine powder) Not only does it make unit sowing easier, but it also makes it possible to maintain constant germination and uniformly sow the target number of grains when sowing by hand or using a sowing machine, streamlining agricultural work and reducing labor costs. can bring about savings.

In addition, suitable fertilizers and chemicals may be mixed into the covering material to promote and protect early growth.

(Function) As described above, the present invention is a granulation method that utilizes the capsule technology of the submerged effect coating method for the granulation of powders such as metals and ceramics, that is, the spheroidization of powders using a gelation reaction. This is the particle method.

In the first invention, porous spherical granules are obtained by drying particles containing a large amount of powder in a gel, and in the second invention, particles containing a large amount of powder in a gel are dried to form dense particles. Hereinafter, the first invention will be referred to as the gel capsule method, and the second invention will be referred to as the aqua capsule method.

In the first invention, for example, when a powder core substance is dispersed as fine particles in a sodium alginate aqueous solution and dropped as small droplets into a coagulation liquid containing polyvalent metal ions such as calcium, the core liquid becomes spherical due to surface tension. Then, an ion exchange reaction occurs from the liquid surface to the inside of the sphere, and the sodium salt of alginic acid turns into calcium salt, becomes insolubilized, and precipitates, producing a spherical gel capsule whose wall material is calcium alginate.

The core material needs to be a mixture of L, M, pectin, sodium alginate, etc., dissolved in a predetermined concentration, and depending on the type of powder added, alumina, aluminum hydroxide, titania, zirconia, zinc oxide, iron oxide,
Talc, silica, pigments, and various metal powders can be encapsulated.

In the gel capsule method according to the first invention, the core liquid is made of a polyester such as sodium alginate! In contrast, the core liquid of the aqua capsule method according to the second invention is an aqueous solution containing polyvalent metal ions such as calcium, L, M, pectin,
This method involves dropping it into a polysaccharide solution such as sodium alginate.

The dropped core liquid forms a gel film from the droplet surface to the film side, forming a capsule. The thickness of the coating increases in proportion to the reaction time.

Further, the thickness of the H coating can be controlled by changing the concentration of calcium and polypropylene 11.

The core material is required to dissolve polyvalent metal ions such as calcium to a predetermined concentration. Then, fine powder particles can be contained in the gel coating by dispersing the fine powder particles in the coating liquid to form a slurry state.

In both inventions 1 and 2, the granules obtained by dropping into the coagulating liquid or the coating liquid are immersed in, for example, alcohol, if necessary, to harden the surface, and then dried. It is something.

The third aspect of the invention is a method for obtaining a granulated product having a multilayer coating structure, and will first be explained from the coating method for the core gel capsule.

In other words, a sol that reacts with polyvalent metal ions to form a gel;
For example, a solution of powder dispersed in an aqueous sodium alginate solution is dropped using a single nozzle into a coagulation liquid containing polyvalent metal ions, such as a coagulation liquid containing calcium chloride, and the resulting granules are washed with water. After that, it is immersed in a solution containing polyvalent metal ions, for example, a solution containing calcium chloride, and then immersed in a sol that reacts with polyvalent metal ions to form a gel, that is, a solution of powder dispersed in an aqueous sodium alginate solution. The process is repeated to obtain spherical multilayer powder-coated capsules with a gel core.

If fine particles are dropped with compressed air from 12 to 2 m in diameter, 2 to 0.3 mm in diameter can be obtained.

As the powder, activated carbon, for example, is used as a catalyst.

The above is a method of dropping using a single nozzle, but multiple nozzles can be used to coat the core gel powder in multiple layers.

That is, using a double nozzle, a sol that reacts with polyvalent metal ions to form a gel, such as a solution of powder such as alumina dispersed in an aqueous sodium alginate solution, is dropped from the inner nozzle, and a polyvalent metal ion is dropped from the outer nozzle. A sol containing metal ions, such as a solution of zeolite powder dispersed in a solution containing calcium chloride, is dropped, and when dropping, it is atomized with compressed air as necessary, and reacts with polyvalent metal ions to form a gel. A core gel spherical two-layer powder-coated capsule is obtained by dropping the gel into a solution, such as an aqueous sodium alginate solution.

This is not immersed in a solution containing polyvalent metal ions, but is immersed in a sol that reacts with polyvalent metal ions to form a gel, such as a solution in which powder, such as activated carbon, is dispersed in an aqueous solution of sodium alginate. A spherical three-layer powder-coated capsule of gel is obtained.

Here, if two kinds of liquids are continuously dropped from a two-fluid nozzle into a solution in which activated carbon is dispersed, a granule having a three-layer structure can be formed at once.

The particle size when not using compressed air is 12 to 2 Ifi in diameter.
I11, if fine particles are dropped using compressed air, particles with a diameter of 2 to 0.2 mm can be obtained.

Next, the coating method for core-internally fluid aqua capsules involves using a single nozzle to apply a polyvalent metal ion-containing solution, such as a solution containing calcium chloride, in which a powder such as calcium carbonate is dispersed. Aqua capsules of spherical powder with internal fluidity are obtained by dropping the powder into a solution that reacts with metal ions to form a gel, such as an aqueous sodium alginate solution, or a solution in which powder is dispersed therein.

Next, after washing with water, it is immersed in a polyvalent metal ion solution, such as a calcium chloride solution, and then a sol that reacts with the polyvalent metal ions to form a gel, such as a solution of powder, such as titanium dioxide, dispersed in an aqueous sodium alginate solution. By repeating the immersion operation, spherical multilayer powder-coated aqua capsules with core internal flowability are obtained.

If fine particles are dropped using compressed air, particles with a diameter of 2 to 0.3+ nm can be obtained, but if not used, particles with a diameter of 12 to 2 nm can be obtained.

Next, multilayer coating of core fluid powder using multiple nozzles is as follows.

That is, using a double nozzle, a sol containing polyvalent metal ions, such as a solution containing powder, such as talc, dispersed in a solution containing calcium chloride is supplied from the inner nozzle, and a solution containing powder, such as talc, which reacts with polyvalent metal ions is supplied from the outer nozzle. A sol, such as a powder such as alumina dispersed in an aqueous sodium alginate solution, is dropped into a coagulating liquid containing polyvalent metal ions, such as a solution containing calcium chloride, to form a gel with a fluid core inside. A two-layer powder-coated aqua capsule is obtained, and the powder, such as zirconia, is dispersed in a sol, such as a sodium alginate aqueous solution, which reacts with polyvalent metal ions to form a gel without immersing it in a solution containing polyvalent metal ions. The capsules are immersed in a solution containing three layers of powder to obtain flowable core spherical three-layer powder-coated aqua capsules. The particle size is similar to that described above.

In addition, in some cases, a triple nozzle is used to drop two kinds of powders that react with each other and a solution in which different powders are dispersed at the same time, and the droplets are dropped while jetting compressed air from an outer nozzle.

For example, a solution of talc dispersed in a sodium alginate aqueous solution is injected through a central nozzle with a diameter of 1.5 am, and a solution of talc dispersed in a sodium alginate aqueous solution is
．． A solution of alumina dispersed in a calcium chloride solution was simultaneously dropped from a 2 mm intermediate nozzle, and dropped into a sodium alginate aqueous solution while blowing compressed air from an outer nozzle with a diameter of 3 mm, resulting in 1.5 mm gel beads. is,
When dried, it becomes a 1mm gel ball.

As described above, multilayer coating is possible by reacting granules produced by the gel capsule method or aqua capsule method with a coating liquid in a slurry state.

Therefore, a highly hard ceramic film can be formed by coating a talc sphere with alumina and zirconia, and the fired product can be used as a grinding ball.

(Example) First, the first invention will be explained in detail.

As a typical example, powder is mixed into an aqueous sodium alginate solution to form a slurry. This is used as a core liquid to perform vacuum defoaming and deaeration.

While stirring the degassed core liquid, supply it to the spray nozzle using a metering pump.

The core liquid discharged from the nozzle hole is reduced in diameter using compressed air and dropped into a coagulating liquid consisting of an aqueous calcium chloride solution. The dropped core liquid is completely gelled in the coagulation liquid.

The gelled spheres are taken out and impregnated with alcohol to solidify the surface. The surface-solidified spherical granules are left to dry or dried in a fluidized bed.

Since there are many types of sodium alginate used in the core liquid depending on the viscosity or degree of polymerization, the sodium alginate is selected depending on the physical properties and particle size of the powder to be dispersed.

As for particle size adjustment, by adjusting the diameter of the nozzle used and the amount of compressed air, the particles can be reduced to an arbitrary particle size and dropped.

If the nozzle diameter is, for example, 1φ, a nozzle with a diameter of about 2 to 0.5φ can be manufactured.

Hereinafter, specific examples will be described.

Example 1 B Aluminum hydroxide 20% 15% Sodium alginate 1.0 1.0 Peptizer 0
．． A slurry consisting of 5.0.5 is used as a core liquid and is degassed under vacuum. While stirring the degassed core liquid, it is dripped into a coagulation liquid containing 1% calcium chloride using a metering pump from a two-fluid nozzle with an inner cylinder of 1 mm, 0 trn and an outer cylinder of 1.3 mm.

The dropped core liquid is completely gelled in the coagulation liquid.

The gelled spheres are taken out and impregnated with alcohol to solidify the surface. The surface-solidified spherical granules are left to dry or dried in a fluidized bed.

In the above items, the amount of compressed air per unit is 1 to 5 N.
j! /+ain, the distance from the nozzle to the coagulation liquid was changed to 15 to 27IIIl, where particle formation was possible, and granulation was carried out.

The particle size after alcohol dehydration and drying is A: 0.7 nm, B
; 0.5 mm was obtained.

And the concentration of aluminum hydroxide in the slurry liquid is 1
At 5%, a ball close to a true sphere was obtained.

The purpose of adding a deflocculant is to improve the dispersibility of the powder.

Example 2 A slurry consisting of sodium alginate 1.0% ^zoR material 15.0 deflocculant 0.5 water 83.5 was used as a core liquid, and this was vacuum defoamed and degassed in the same manner as in Example 1. While stirring the core liquid, it is dripped into a coagulating liquid containing 1% calcium chloride using a metering pump through a single nozzle tube with an inner diameter of 4.4 am and an outer diameter of 5.0 mm.

The dropped core liquid is completely gelled in the coagulation liquid. Hereinafter, the same process as in Example 1 is carried out.

The above yellow pigment AZo pigment contained 66.2% water and was dropped at a distance of 15 mm from the nozzle to the coagulation liquid. The particle size in the coagulation liquid was approximately 5 mm.

The above is a case of an internal gel capsule, but a case where it is made into a multilayered capsule will be described.

Example 3 The first stage core liquid slurry formulation was sodium alginate 1.0%, talc 40.0%, peptizer 0.1%, water 58.9%, and this was mixed in the same manner as in Example 1. % calcium chloride solution.

The core liquid was mixed well and dropped into the coagulation liquid from a 3φ carp nozzle.

Allow reaction time of 10 minutes.

A spherical capsule of talc having a diameter of approximately 3φ■ is prepared.

The second stage and above are considered as the first stage, and the product produced in this step is put into the next coating solution.

Coating liquid Sodium alginate 1.0% Alumina 20.0% Deflocculant 0.1% Water 79.1% The talc sphere, which is the core produced in the first step, is removed from the coagulation liquid and attached to the sphere surface. The coagulation liquid is wiped off with water and then poured into the coating liquid.

After adding the talcum sphere, a reaction time of 5 minutes is allowed and the talcum is separated from the coating liquid.

A capsule body was prepared by coating alumina on a talc sphere having a diameter of about 4 mm.

This is again impregnated into the first stage coagulation liquid.

Third step: Remove the capsule body prepared in the second step from the coagulation solution.
Rinse with water and add to the next coating solution.

Coating liquid Sodium alginate 1.0% Zirconia 20.0% Peptizer o, i% Water 78.9% Reaction time 5
Wait for a minute and separate from the coating liquid. Therefore, a second-stage capsule body having a diameter of approximately 5 φ is made with a zirconia coating film.

Next, the capsule body as described above was dried with hot air at 105°C. On the surface of a talcum sphere with a diameter of about 311 IIl,
A granule consisting of three layers was produced, in which the surface of the sphere coated with 50 μm of alumina was further coated with 50 μm of zirconia.

The difference between steps 1 and 2 of the capsule described above is whether alumina or zirconia is mixed into the coating liquid, and by repeating this process, a multilayer coating can be formed.

Next, an example of the aqua capsule method, that is, the internal flow capsule method will be described.

Hereinafter, processes not specifically described are the same as those in the first embodiment.

Example 4 Core liquid slurry combination Calcium chloride 2.0% Gelatin 2.0% Alumina 35.0% Deflocculant 2.1% Water 60.9% Coating liquid Sodium alginate 0.5% Water 99.5% Core liquid were mixed well and dripped into the coating liquid from a 3φ■ nozzle.

A reaction time of 5 minutes was allowed, and the capsule was separated from the coating liquid to produce a spherical alumina capsule of about 4φ■.

Then, it is dried with hot air at 105°C. Alumina spheres with a diameter of about 2φmm were produced.

Example 5 Core liquid slurry blend Calcium chloride 2.0% Gelatin 2.0% Calcium carbonate 40.0% Deflocculant 0.1% Water 55.9% Coating liquid Sodium alginate 0.5% Titanium dioxide 20.0% A core solution containing 0.1% deflocculant and 79.4% or more water was mixed well and dropped into the coating solution through a 2φ nozzle.

A reaction time of 5 minutes is allowed to separate from the coating liquid.

A capsule body was prepared by coating a calcium carbonate sphere with a diameter of about 3φ with titanium dioxide.

Next, after impregnating this in alcohol for 5 minutes, it was heated to 105°C.
dried with hot air.

In this way, a titanium dioxide coated sphere with a calcium carbonate core having a diameter of about 2φ was obtained.

(Effects of the Invention) According to the present invention, powders that could not be granulated at all by conventional granulation methods can be spherical.

In addition, the particle size can be easily controlled, and products with uniform particle size can be produced with good reproducibility.

Moreover, since it is not subjected to mechanical shearing force, it is possible to produce granules with a smooth surface and highly spherical properties without being affected by contamination problems due to wear or the surface activity of the powder.

Therefore, a material with excellent fluidity without wear can be obtained. It can also be used as a surface modification method, such as coating the capsule surface with various powders or creating a multi-layered capsule.

Furthermore, when mixing submicron particles, various types of metals can be mixed uniformly, and the particle size range is 0.1 to 5M in a single layer.
It is wider than the conventional method.

In the present invention, solidification and drying, particularly in the final step, has the effect of preventing particles from agglomerating together, maintaining particle size, and increasing sphericity.

From the above, problems with compression molding method (1)
The processing power is extremely low and the overall cost is high (.

(2) Pore structure and pore distribution are destroyed due to molding compression.

(3) If the diameter of the tablet is less than 4φ, it is difficult to mold it.
Also, the processing capacity is significantly inferior.

Problems with the transfer granulation method (1) The yield is extremely poor, and when the operation is aimed at granulation of 3φ or less, the yield is about 20 to 30%, and even when the grain size is 4φ or more, the yield is 40 to 30%. The efficiency is low at around 50%.

Problems with spray granulation method (1) It is used as a specific catalyst and is not universally used.

Furthermore, it is necessary to improve the pore structure.

(2) It is difficult to granulate particles with a particle size of 1OOμ or more.

(3) Energy costs are high.

All of the above problems can be solved by the present invention.

The granules obtained according to the first invention can be used for catalyst granulation because porous granules can be obtained, and the granules obtained according to the second invention can be used as dense granules. , used for fine ceramics granulation.

Further, since the granules obtained in the third invention can be multilayer coated granules, they can be used, for example, in complex agricultural chemicals for weeding, sterilization, and insecticide.

Claims (4)

[Claims] (1) In the sol that reacts with polyvalent metal ions to form a gel,
The core liquid is made by dispersing powder according to the purpose of use.
The gel is dropped into a coagulating liquid containing polyvalent metal ions to form granules, and the gel is surface-treated as necessary to eliminate agglomeration and adhesion, and then dried. Granulation method. (2) A solution of powders dispersed according to the purpose of use in a sol containing polyvalent metal ions is dropped into a sol solution that reacts with polyvalent metal ions to form a gel to form internally fluid granules. A method for granulating powder, etc., which comprises preparing the gel, subjecting the gel to surface treatment to eliminate agglomeration and adhesion as necessary, and then drying the gel. (3) In the sol that reacts with polyvalent metal ions to form a gel,
When immersing the granules obtained according to claims (1) and (2) in one or more solutions in which powders selected depending on the purpose of use are dispersed, polyvalent metal ions are added in advance. A coating layer is formed by immersing the granule in the single solution or repeatedly immersing it in a plurality of solutions to form a coating layer, thereby forming a coating layer. A method for granulating powder, etc., which forms multiple layers on the surface to obtain a granulated product with a multilayer structure. (4) In the sol that reacts with polyvalent metal ions to form a gel,
Either a solution containing powder dispersed or a solution containing powder dispersed in a solution containing polyvalent metal ions is applied from the inside of the multi-nozzle, and the other from the outside, which is used for the outer nozzle. A claim for obtaining a multilayered granulated product that reacts with a solution and is dropped into a solution in which powder is dispersed or not dispersed (
3) Method of granulating powder, etc.