JPS62278178A - Manufacture of porous refractory grains - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention (Field of Industrial Application) This invention relates to a method for producing porous refractory granules having a fibrous pore distribution.

(Prior Art) Porous refractory granules have conventionally been produced using a mixture obtained by adding combustible organic matter such as sawdust to a metal salt solution that changes into a refractory metal oxide through heat treatment, or
There is a method in which a mixture obtained by adding flammable organic matter such as sawdust to a slurry of refractory powder is granulated, the resulting granules are heated and calcined, and if necessary, pulverized to a desired particle size. be.

By heating and firing in this conventional method, combustible organic matter in the granulated mixture is burned off and pores and voids are created in the granulated material.

(Problems to be Solved by the Invention) In porous refractory granules produced by conventional methods, the pores, pores, and voids are spherical or lumpy, and are not fibrous, which is considered preferable. Furthermore, it is difficult to obtain spherical porous refractory granules when crushed to the desired particle size after firing.

This invention is in response to the request for the development of a manufacturing method for refractory porous particles that solves the problems of the conventional method described above. Another object of the present invention is to provide a method for producing porous refractory granules having a spherical appearance.

(Means for Solving the Problems) As a result of various tests and research, the present inventors found that if a flammable mm substance is added to a metal salt of a precursor of a refractory oxide and granulated,
We found that it was possible to obtain porous refractory granules with fibrous pores, and as a result of further improving this production method, we found that if we mechanically mix metal salts and fibrous materials and defibrate the fibrous materials. ,
It was discovered that the present invention is effective in achieving the object of the invention, and the present invention was completed.

That is, the method for producing porous refractory granules of the present invention includes mixing a metal salt that produces a refractory metal oxide through heat treatment with a combustible fibrous material, and defibrating the fibrous material;
The method is characterized in that the obtained mixture is granulated to a desired size, and then the granules are heated and fired to produce the metal oxide and to burn off the miscellaneous materials.

This invention will be specifically explained below.

The metal salt used in this invention is one that changes into a refractory oxide by heat treatment.

Specifically, hydrochlorides, sulfates, nitrates, formates, acetates, propionates, butyrates, and alkanoic acids of metals such as aluminum, silicon, magnesium, zirconium, titanium, beryllium, chromium, and yttrium. Examples include salts, lactates, alkoxides, and the like. Particularly in the case of zirconia, zirconium acetate, zirconium chloride, ammonium zirconium carbonate, etc. are advantageous in terms of cost, and their use is preferred.

This metal salt is usually used as a metal salt solution, but if it is insoluble or poorly soluble, it can also be used as a suspension or as a powder.

The combustible fibrous material used in this invention undergoes a reaction such as combustion when heated and fired, and all or most of it is gasified.

For example, there are organic fibers and their Il! Miscellaneous fibers include natural fibers such as plant fibers and animal fibers, cellulose-based and protein-based recycled #JA fibers, semi-synthetic fibers, polyamide, polyvinyl alcohol, polyvinylidene chloride, polyvinyl chloride, polyester, polyacrylonitrile, Examples include synthetic fibers such as polyolefin. In addition, paper
There are fiber processed products such as cloth, and these processed products are made into 11-fiber shapes by defibration processing.

In addition to the above-mentioned metal salts and carbonaceous materials, various additives can be added as necessary. Examples of this additive include organic sizing materials such as polyvinyl alcohol, ethyl cellulose, methyl cellulose, droxypropyl cellulose, carboxymethyl cellulose, and alginate for the purpose of imparting viscosity necessary for granulation.

The mixing ratio of the metal salt and the fibrous material used in this invention is desirably changed as appropriate depending on the desired porosity of the porous refractory granules. The mixing ratio of the metal salt solution and m1In or paper is, for example, in the range of 5:95 to 60:40 by weight.

This is because if the amount of the metal salt solution is less than 5 parts by weight, granulation becomes difficult, whereas if it exceeds 60 parts by weight, granulation becomes similarly difficult.

Next, a method for producing porous refractory granules will be explained. First, a metal salt that produces a refractory metal oxide through heat treatment is mixed with a combustible fibrous material.

Prior to mixing, the metal salt is dissolved into a solution, a suspension, or a powder. Further, the size of the delicate material is adjusted as necessary. In this invention, 11 fibrous materials are defibrated simultaneously with mixing. Specifically, this can be carried out using a mixer that has both mixing and defibrating functions. The degree of mixing and defibration can be changed as appropriate depending on the porosity and performance of the final product.

The resulting mixture is granulated to desired dimensions. Although granulation and defibration cannot be performed with a normal mixer, there are mixers that have granulation and defibration capabilities, such as the Henschel mixer (manufactured by Mitsui Miike Kakoki Co., Ltd.) and the high-speed mixer (manufactured by Fukae Kogyo Co., Ltd.). (manufactured by Co., Ltd.). If a mixer with granulation and defibration functions is used, the speed of 2,00Q rpm to 1
A rotation speed of 0.00 rpm is desirable, and when granulation is intended, a rotation speed of 10 rpm to 200 rpm is suitable.

The obtained granules are heated and fired. It is desirable that the firing temperature and firing time be determined depending on the type of the object to be fired.

Usually, the granules are heated and fired at a firing temperature of 500 to 2000°C and a firing time of 1 to 100 hours. This heating burns out the fibrous material in the granules and imparts porosity to the granules. Furthermore, the gold F4 salt is transformed into a refractory metal oxide.

The porous refractory granules obtained by firing can be used as fragrance carriers, bacteria carriers, filters, adsorbents, raw materials for lightweight refractory materials, and the like.

(Function) In this invention, the metal salt is changed into a refractory metal oxide by heating, thereby imparting fire resistance to the product. In this invention, the combustible fibrous material is mixed and defibrated into fine fibrous materials, and the fine fibrous materials are dispersed in the granules. By heating and firing, the dispersed male substances are gasified, oxidized, or burned, and removed from the granules.

Since many elongated I male substances are dispersed in the granules, the generated gas is easily removed from the granules through other adjacent fibrous substances, voids, and pores.

Since the dispersion in the granules is mu-shaped, the pores formed also have long and complex cavities.

(Effects of the Invention) Based on the above-mentioned effects, the following effects can be obtained by the present invention.

(1) This method does not involve obtaining porous blocks by firing and then pulverizing them to produce porous refractory granules of the desired particle size, as in the conventional method, but granulating them to produce starting material particles of the desired particle size. Therefore, there is no need for pulverization, and therefore, spherical porous refractory granules can be easily obtained.

(2) Since fibrous pores and pores along a relatively spherical surface are obtained, fire-resistant porous particles with a large specific surface area can be produced.

(3) Since inexpensive materials such as old newspapers can be used as organic tJ & fiber raw materials, fire-resistant porous particles can be produced relatively inexpensively.

(4) The diameter of the pores of the porous refractory granules can be adjusted by appropriately selecting the diameter of the organic fibers used, and a desired pore diameter can be easily obtained.

(Example) This invention will be specifically explained by the following examples.

Example 1 50 parts by weight of 30% concentration zirconium acetate, 2 parts by weight of calcium chloride, and 48 parts by weight of polyester l1Iff with a diameter of 5μ and a length of 20-1 m/m were charged into a Henschel mixer, and the mixture was rotated at a rotation speed of 500 orpm for 10 minutes. After kneading, the mixture was kneaded at 150 rpm for 10 minutes to produce a granulated product. The granulated product is relatively spherical, close to □, and its diameter is approximately 511 mm.
It was III. This granulated product was fired at 1500° C. for 2 hours to obtain porous refractory granules.

Table 1 shows the properties of the obtained porous refractory granules.

Example 2 70 parts by weight of basic aluminum chloride at a concentration of 50%, 3 parts by weight of silica gel, and 27,000 parts by weight of waste paper were put into a high-speed mixer, kneaded at a rotation speed of 300 rpm for 15 minutes, and then kneaded at 50 ppm for 3 minutes. A granulated product was produced. The diameter of the spherical granulated product is approximately 10 m, and this granulated product is
Table 1 shows the characteristics of the porous refractory grains obtained by firing at 400°C for 2 hours.

Example 3 1 part of 60 [ff] of hydrolyzed solution of ethersilicate and 1 part of cellulose m-fiber (40 mff) were put into a Henschel mixer and kneaded for 10 minutes at 500 rpm.Then, the number of revolutions was lowered to 100 rpm and kneaded for 5 minutes until the diameter Five spherical granules were produced. This granulated product was fired at 900° C. for 2 hours to obtain porous refractory granules.

Table 1 shows the properties of the obtained porous refractory granules.

Comparative Example 70 parts by weight of basic aluminum chloride with a concentration of 50%, 3 parts of dried silica gel, and 27 parts by weight of sawdust were put into a high-speed mixer, kneaded at 300 rpm for 15 minutes, and then kneaded at 50 ram for 5 minutes. A granulated product was produced by this process. The diameter of this granulated product was about 20a+, and this granulated product was fired at 1400'C for 2 hours to produce porous refractory granules. Table 1 shows the properties of the obtained refractory granules.

The refractory grains were not spherical but had a round and flat shape, and the pores were not continuous m-male pores but were close to independent closed pores.

Table 1 Quality characteristics of porous refractory granules

Claims (1)

[Claims] 1. Mixing a metal salt that produces a refractory metal oxide through heat treatment with a combustible fibrous material, defibrating the fibrous material, and shaping the resulting mixture into desired dimensions. A method for producing porous refractory granules, which comprises granulating and then heating and baking the granules to generate the metal oxide and burn and remove the fibrous material. 2. The metal salt is aluminum, silicon, magnesium,
At least one selected from hydrochlorides, nitrates, formates, acetates, propionates, butyrates, alkanoates, lactates, and alkoxides of metals selected from zirconium, titanium, beryllium, chromium, and yttrium. The manufacturing method according to claim 1, which is a salt of. 3. The manufacturing method according to claim 1 or 2, wherein the metal salt is a metal salt solution. 4. The manufacturing method according to claim 1, 2 or 3, wherein the combustible fibrous material is paper or cloth. 5. The manufacturing method according to any one of claims 1 to 4, wherein granulation and mixing are performed using a mixer having defibration and granulation functions.