JPH08252452A - Method for granulating inorganic compound - Google Patents

Abstract

PURPOSE: To easily granulate an inorganic compound by only mixing, by adding two components of the decomposed substance of starch and polyol at specified ratio in the case of granulating the inorganic compound. CONSTITUTION: In the case of granulating an inorganic compound such as a natural mineral or ferrite, >=3wt.% decomposed substance of starch of DE 2-40 such as potato starch or tapioca starch and 1.5-10wt.% polyol such as glycerol or ethylene glycol are mixed with the inorganic compound. In such a way, the inorganic compound in a wide range is granulated without necessitating a specific device, and also an excess process such as drying is unnecessary because water is not used. Further, substance excepting the inorganic compound may easily be removed by an operation such as burning. The decomposed substance of starch is porous and glycerol or ethylene glycol is desirable as polyol and the mixing ratio of both is preferably (80-55):(20-45) by weight.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for granulating an inorganic compound which can be used in the fields of pigments, metallurgy, ceramics, catalysts and the like.

[0002]

2. Description of the Related Art Inorganic compounds such as naturally occurring minerals and ferrites are widely used in various fields such as pigments, ceramics, ceramics and metallurgical industry. If the inorganic compound contains fine powder or the particle size varies, the following problems occur.

(A) Yield reduction due to powder scattering and adhesion to mechanical equipment, (b) Electronic ceramics such as ferrite and barium titanate when separated during transportation even if raw materials are forcibly mixed in advance. Then, the reaction to obtain the metal oxide by firing becomes non-uniform, and the electrical properties and porcelain properties are hindered. In the case of (C) alloy, the alloy with the target composition cannot be obtained. (D) Ceramic products In the case of products that are manufactured through the molding process as described above, there is a problem that the mechanical strength of the molded product does not become constant due to variations in the filling amount in the mold, or products with high quality cannot be obtained. was there.

In order to improve the above-mentioned problems, a means of granulating an inorganic compound is usually used. For a powder having a strong adhesive property, a binder is not used, and for a powder which is easily dissolved in water, it is granulated only by adding water. In many cases, however, a binder is usually used for an inorganic compound that does not have a binding force by itself and is small.

As a binder used for granulating an inorganic compound, there are cases where a natural or artificial inorganic binder such as clay, bentonite, water glass, etc. is used, but if these remain in the final product, the strength will be weakened, For applications in which functions such as electrical characteristics and porcelain characteristics are impaired, for example, alloys, fine ceramics, new ceramics, etc., organic binders that can remove the binders by treatment such as firing are often used. .

Ethyl cellulose as an organic binder,
There are cases where it is used by dissolving it in an organic solvent such as acetyl cellulose, but it is flammable, has an odor, is a water-soluble polymer for reasons such as high cost, such as polyvinyl alcohol, carboxymethyl cellulose, methyl cellulose, Gelatin and vegetable gums are generally used.

As an example of using a water-soluble polymer for granulating an inorganic compound, for example, in the case of ferrite, a hard agglomerate that has been calcined is crushed in water, and a water-soluble polymer such as polyvinyl alcohol is powdered. Alternatively, it is added as an aqueous solution, mixed and spray-dried or dehydrated as it is, and then appropriately dried to be extrusion-granulated or crush-granulated, but a special machine is required for the granulation.

Further, Japanese Patent Application Laid-Open No. 49-853 discloses a method in which an oxidized magnetic powder and the above water-soluble polymer are mixed in a powder state, and water is added and mixed to granulate the oxidized magnetic powder. However, the process of drying was indispensable because water was used.

In this way, when granulating an inorganic compound, it can be applied to an inorganic compound that cannot be granulated by itself, and can be granulated at low cost without using a special device or a drying step. A method is strongly desired.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method capable of easily granulating an inorganic compound only by mixing when granulating the inorganic compound.

[0011]

Means for Solving the Problems Regarding the method for obtaining granules of inorganic compounds which are widely used in various industries, the inventors of the present invention have earnestly studied, and as a result, added starch decomposition products and polyols to inorganic compounds. , A new method that can granulate an inorganic compound only by mixing was completed.

[0012]

In the present invention, the term "inorganic compound" refers to a compound excluding compounds commonly called organic compounds (carbon compounds other than a relatively small number of simple carbon compounds).
In the present invention, a substance composed only of carbon and carbon and a carbonate are included. In other words, it is a generic term for a substance that is composed only of carbonates and carbon, and a substance that includes three substances other than those that are called ordinary organic compounds. Specifically, metals such as iron, nickel and copper and metal compounds such as chlorides of metals, silicon compounds such as silicon, silica sand, silica and zeolite, carbonates such as calcium carbonate, clay minerals such as kaolin, graphite and coal. Examples include carbon, such as coke, coke, and activated carbon.

At this time, as the particle size of the inorganic compound, a particle size of submicron to 100 μm can be used, and it is possible to manufacture a wide range of granulated products ranging from several tens of microns to about 1000 μm. The particle size of the product should be selected according to the type of inorganic compound and the purpose of use.

The starch decomposition product referred to in the present invention is (a) roasted by commonly used starch or processed starch thereof roasted to a DE of 2 or more at high temperature in the presence or absence of an acid in the powder state. Dextrin, British gum, (b) the above starch or modified starch thereof is heated in the presence of an acid and / or an enzyme to be hydrolyzed to a DE of 2 or more, preferably 2 to 40, and dried.

As the starch at this time, usual potato starch,
Examples of tapioca starch, corn starch and the like, and examples of the modified starch thereof include modified starch obtained by subjecting it to etherification, esterification, oxidation treatment and the like according to a conventional method.

In the case of the above hydrolysis, acid or (and)
Add an enzyme and heat in an autoclave or continuous hydrolysis device to obtain a predetermined DE, neutralize after hydrolysis reaction, purify if necessary, concentrate to the required extent, spray drying and other suitable methods It is dried at. Hydrogenated reduced starch degradation products also have the same effect, and are therefore included.

At this time, if the DE is less than 2, granulation becomes difficult, and conversely, if it exceeds 40, agglomerates are more likely to be generated and the hygroscopicity of the granulated product tends to increase, so that it is preferably 2.
-40, more preferably 4-30. The DE means the content of reducing sugar (as glucose) per reducing sugar content per solid content in the starch decomposition product.

As the decomposed product of starch, a porous product having a large number of voids on the surface or (and) inside of the powder has a good granulation effect and an effect that a small addition amount thereof is required. As the decomposed product of the porous starch, the decomposed product of DE2 to 40 is supplied in a liquid state to a drum dryer and dried, or the decomposed product of starch of DE30 or less, raw starch, and oxidized starch is mildly decomposed. For example, an amorphous granular or powdery substance obtained by high temperature and high pressure treatment using a device such as an extruder without water or water can be exemplified. The apparent specific volume at this time is 6 to 20.
It is preferably about cc / g. The apparent specific volume is
It means the apparent non-volume of 1 g of the starch decomposition product, and is a value obtained from the volume when 10 g of the powdered base was gently filled in a graduated cylinder of 200 to 300 mL without tapping.

The polyol used in the present invention has 2 units in the molecule.
Substances having at least one hydroxyl group and being liquid at room temperature, such as glycerin, ethylene glycol, and propylene glycol, are collectively referred to, and glycerin and ethylene glycol are more preferable from the viewpoint of fluidity of the granulated product.

The amount of the starch decomposition product used in the present invention is
It depends on the type of inorganic compound, DE of starch decomposition product, whether it is porous, etc., but if it is less than 3% by weight with respect to the inorganic compound, granulation becomes impossible, so it is necessary to add 3% by weight or more. . Further, it is possible to granulate even if the addition amount of the starch decomposition product is equal to or more than that of the inorganic compound, and it is not necessary to limit the upper limit of the addition amount, but if the addition amount is increased too much, the cost becomes high, and the range of the inorganic compound is increased. For reasons such as limitation, it is preferable to keep the content of the inorganic compound up to about 30% by weight.

On the other hand, if the addition amount of the polyol exceeds 10% by weight with respect to the inorganic compound, the hygroscopicity becomes so strong that blocking and the like are likely to occur, so it is necessary to suppress it to less than 1.5% by weight. In that case, granulation cannot be performed, so 1.5 to 10 wt% is used.

In the present invention, it is an essential condition to add two components, a starch decomposition product and a polyol, when granulating an inorganic compound, and if either one is missing, granulation of the inorganic compound becomes impossible. An inorganic compound can be granulated very easily by adding 3% by weight or more of a starch decomposition product and 1.5 to 10% by weight of a polyol to an inorganic compound and mixing them, but the starch decomposition product and the polyol are 80 to 55: When added in a weight ratio of 20 to 45, the granulated state becomes even better.

According to the granulation method of the present invention, components other than inorganic compounds, that is, decomposed products of starch and polyols can be removed by calcination and the like. Among the granulated products of inorganic compounds, alloy and electronic products are calcinated. Even if there are such steps, it is possible to easily control the chemical reaction during the steps and to reduce the amount of components other than inorganic compounds as much as possible in order to increase the purity of the inorganic compounds in the final product. In such a case, it is more preferable to use a porous starch decomposition product as the starch decomposition product.

There are a wide variety of inorganic compounds that require granulation, and the components contained in them are various. In the present invention, it is essential to add a starch decomposition product and a polyol. Glucose, maltose, lactose and other oligosaccharides, HAP, HVP and other protein degradation products, gum arabic, guar gum, xanthan gum, alpha starch, CM
Water-soluble polymers such as C and alginic acid may be further added.

The present invention is characterized in that when the inorganic compound is granulated, the inorganic compound, the starch decomposition product and the polyol are mixed. However, there is no problem in the order, and for example, the inorganic compound and the starch decomposition product are mixed. The post-polyol may be mixed, the starch decomposition product and the polyol may be mixed and then the inorganic compound may be mixed, and further, the three may be simultaneously mixed. In this way, the order is not a problem, but the point is 3
It is essential to mix the components uniformly.

On the other hand, as equipment used for mixing and granulating,
For example, ribbon mixer, screw mixer, dough mixer, Ken mixer, silent cutter, food processor, high speed mixer, super mixer,
A general mixer, kneader, or the like which is normally used such as a vertical granulator can be used and is not particularly limited. However, the mixing time should be appropriately selected according to the type of equipment, the type of raw materials, the throughput, and the like.

In order to explain the granulation method of the present invention more specifically, a granulation method using silica as an inorganic compound using a mixing device having a high stirring speed, such as a food processor, will be described below.

3 to 30 parts by weight of a decomposed product of starch having a DE of 2 to 40 was added to a food processor, 1.5 to 10 parts by weight of glycerin was added as a polyol, and a stirring speed was 500 to
A granulated product with good fluidity can be obtained by stirring and mixing at 4000 rpm for 20 seconds to 2 minutes to homogenize, and adding 100 parts of silica and further mixing for 1 to 3 minutes. On this occasion,
Although not an essential condition, if left as it is, a granulated product with better fluidity can be obtained. In addition, a mixture of starch decomposition product and silica in a powder state is put into a food processor,
Glycerin may be added and mixed for granulation, but in this case, it is more desirable to carry out by adding glycerin little by little, preferably by spraying.

Granulation can be performed in the same manner using a mixing device having a slow stirring speed, such as a ribbon mixer, but the mixing time needs to be longer than in the above case.

The method for granulating an inorganic compound according to the present invention enables granulation of a wide range of inorganic compounds without requiring a special apparatus for granulation. Since water is not used, extra steps such as drying are unnecessary. Ceramics that are unnecessary and can easily remove substances other than inorganic compounds by operations such as firing when removing substances other than inorganic compounds from granulated products, and require high performance such as electrical and magnetic properties. It also enables the manufacture of products.

[0031]

EXAMPLES The present invention will be described in detail below with reference to reference examples and examples, and parts in the examples indicate parts by weight.

[0032]

[Reference Example 1] Tapioca starch was suspended in water and baume 18
Of milk, calcium carbonate is added to the emulsion to adjust the pH to 5.8, and then Crystase KD (α-amylase manufactured by Daiwa Kasei Co., Ltd.) is added at 0.1% by weight per solid content.
The resulting mixture is added to an onrator (starch continuous liquefaction device manufactured by Sakura Seisakusho Co., Ltd.) having a content of 10 L at a rate of 5 L per minute. Effluent from the onrator (85-87
(° C) was collected in a stainless steel pot and hydrolyzed by keeping it in a constant temperature bath adjusted to 85 to 86 ° C for 3 minutes, and 1% hydrochloric acid was added dropwise to lower the pH to 3.8 to deactivate the enzyme. , Calcium carbonate is added to this, and the pH is returned to 5.8. The obtained liquid was transferred to an autoclave, pressure-cooked at 140 ° C. for 10 minutes, cooled to 86 ° C., and then 0.06 to 0.
13% by weight of Crystase KD (trade name: α-amylase manufactured by Daiwa Kasei Co., Ltd.) is added, and the hydrolysis reaction is performed again, and the reaction is stopped by pressure steaming. To this liquid, 0.5% by weight of solid content of Radiolite # 800 (trade name: Showa Co., Ltd. filter aid) was added, and the liquid temperature was 70 to 8
After suction filtration at 0 ° C., the filtrate was desalted, concentrated, and spray-dried to obtain a starch decomposition product. The addition amount (% by weight) of krystase KD per solid content used for the second stage liquefaction and the DE of dried starch hydrolyzate are shown below.

[0033]

[0034]

[Reference Example 2] 2000 kg of cornstarch was added to 4000 of water.
Dispersed in L, added 7 to 13 kg of oxalic acid, poured into 500 L of hot water at 85 ° C., and kept the temperature at 85 ± 1 ° C. After allowing this temperature to stand for 25 minutes, the pressure was raised to 1.2 kg, and the mixture was steamed under pressure for 25 minutes, then released under normal pressure and neutralized to pH 5.5 with calcium carbonate to obtain a liquefied liquid. The obtained liquefied liquid was treated in the same manner as in Reference Example 1 to obtain a starch decomposition product. The oxalic acid used for liquefaction and the DE of the dried starch hydrolyzate are shown below.

[0035]

[0036]

[Reference Example 3] Sample No. of Reference Example 1 A liquefied product of the starch decomposition product of No. 3 was concentrated to a solid content concentration of 53%, and a double drum dryer (steam internal pressure; 5.0 kg / cm ² , drum diameter 1.2).
m, rotation speed: 0.92 rpm), dried, coarsely pulverized, and passed through a 20-mesh sieve to obtain a porous starch having an apparent specific volume of 8.5 (cc / g). Sample No. 7

[0037]

[Reference Example 4] Instead of tapioca starch, hydroxypropylated tapioca starch (substitution degree of about 0.06) was used, and the addition amount of secondary liquefaction of klyase KD was 0.1 per liquid solid content.
The hydroxypropylated tapioca starch hydrolyzate was decomposed in the same manner as in Reference Example 1 to give DS4.6 hydroxypropylated tapioca starch hydrolyzate.

[0038]

[Example 1] Food processor (D manufactured by Cuisinart Co., Ltd.
LC-7S type) with dextrin (DE4.5 roasted dextrin manufactured by Matsutani Chemical Co., Ltd.), Sample N of Reference Example 1
o. Sample Nos. 1 and 3 of Reference Example 2; 14 parts of each of 4, 5, and 6 starch decomposition products were added, and the stirring speed was 1500 rpm.
After adding 6 parts of glycerin and mixing for 30 seconds, 100 parts of "Roleoseal QS-10" (manufactured by Tokuyama Soda Co., Ltd., silica having primary particles of about 16 µm) was added and mixed for 2 minutes to obtain a powder. The conditions are shown in Table 1. In addition, as a control example, there is no hydrolysis of starch, and matsunoline M is soluble in cold water.
(Alpha starch manufactured by Matsutani Chemical Co., Ltd.) was used instead of the decomposed product of starch.

[0039]

[Table 1]

⊚: A very uniform granulated product. ◯: Granulated product that is slightly uneven. Δ: A part of lumps is contained in addition to the granulated product. X: Granulation is not possible or the ratio of lumps is very large.

[0041]

[Example 2] Sample N of Reference Example 1 in a food processor
o. 14 parts of the starch decomposition product of No. 3 (DE8.1) was added, 6 parts each of glycerin, ethylene glycol, and propylene glycol were added at a stirring speed of 1500 rpm, mixed for 40 seconds, and then "Reorosil QS-20" (Tokuyama Soda) (Silica with a primary particle size of about 12 μm manufactured by KK) 1
00 parts was added and stirring was continued for 1.5 minutes to obtain a very uniform granulated product. Moreover, all the granulated products showed good fluidity, but the granulated products to which glycerin and ethylene glycol were added exhibited particularly good fluidity.

[0042]

[Example 3] Reference Example 1 was added to 100 parts of "Roleoseal QS-30" (produced by Tokuyama Soda Co., Ltd., having a primary particle diameter of about 7 µm).
Sample No. 30 parts of the starch decomposition product (DE4.8) of 2 and 8 parts of glycerin were added, and silica was granulated according to Example 1 to obtain a uniform granulated product.

[0043]

[Example 4] Reference Example 1 was added to 100 parts of "Reorosil QS-40" (produced by Tokuyama Soda Co., Ltd., having a primary particle size of about 5 µm).
Sample No. 3 (spray-decomposed starch decomposition product of DE8.1), or sample No. 3 of Reference Example 3. Table 2 shows the results of granulating silica according to Example 1 using 7 (DE8.1 porous starch hydrolyzate dried with a drum dryer) and glycerin in a weight ratio of 2/1. The granulated state was judged according to the same criteria as in Example 1.

[0044]

[Table 2]

[0045]

Fifth Embodiment Sample No. of Reference Example 1 As shown in Table 3, using the starch decomposed product of No. 3 and glycerin in a specific weight ratio, "Roleoseal QS-40" was granulated according to Example 1, and allowed to stand for 2 hours as it was. A uniformly granulated product was obtained.

[0046]

[Table 3]

[0047]

Example 6 Kaolin (manufactured by Matsumura Sangyo Co., Ltd., containing about 20% of particles of 2 μm or more and having an average particle size of about 0.5 μm) 1
Sample No. of Reference Example 4 in 00 parts. Using 14 parts of a hydrolyzed product of hydroxypropylated tapioca starch of 8 and 6 parts of glycerin,
Kaolin was granulated according to Example 1 to obtain a very uniform granulated product with good fluidity.

[0048]

Example 7 Alumina (made by Sumitomo Chemical Co., Ltd., activated alumina having an average particle size of about 35 μm) was used in a Hobart mixer.
Part and sample No. 14 parts of the starch decomposition product of No. 2 was added, and 7 parts of glycerin was sprayed on the mixture stirred at 100 rpm for 15 minutes, and then stirred for 10 minutes to obtain a highly uniform granulated product with good fluidity.

[0049]

Example 8 Sample No. was added to 100 parts of alumina of Example 7.
Using 5 parts of the decomposed product of starch of 7 and 2 parts of gum arabic and 3.5 parts of glycerin, alumina was granulated according to Example 4 to obtain a very uniform granulated product having extremely good fluidity.

Claims (4)

[Claims] 1. A method for granulating an inorganic compound, which comprises mixing 3% by weight or more of a starch decomposition product of DE2-40 with 1.5 to 10% by weight of a polyol with respect to the inorganic compound. 2. A starch decomposition product and a polyol are 80 to 55: 2.
The method of claim 1, wherein the weight ratio is 0 to 45. 3. The method according to claim 1, wherein the decomposed product of starch is porous. 4. The method according to claim 1, wherein the polyol is glycerin or ethylene glycol.