JP2006290695A - Method for manufacturing ceramic raw material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a ceramic raw material having an extremely simple composition and containing inorganic fine foamed hollow spheres effectively and economically. <P>SOLUTION: A ceramic slurry is stirred in a tank and the inorganic fine foamed hollow spheres are charged with pressure in the slurry from the lower part of the tank while stirring in water, mixed and stirred. The mixed fluid is supplied to a spray dryer from the tank for drying and then the ceramic raw material being a specified powdery raw material is manufactured. The content of the inorganic fine foamed hollow spheres is 5-70 wt.% based on 100 wt.% of the ceramic raw material and the inorganic fine foamed hollow spheres can be fly ash balloons. The ceramic raw material can be used as a raw material for tile. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing a ceramic raw material containing inorganic fine foamed hollow spheres.

Conventionally, ceramic products are heavy and easily broken, and handling in manufacturing and transportation has been very difficult. As an example of ceramic products, for example, architectural tiles are used for building exteriors, interiors, floors, etc., and the weight increases in proportion to the number of tiles to be used. It had a major impact on transportation costs.

In recent years, in order to improve the above points, development of weight reduction of ceramic products has been performed. Among them, in reducing the weight of tile products, by incorporating inorganic micro-foamed hollow spheres such as fly ash balloons and silica balloons into ceramic materials that mainly contain clay, feldspar, porcelain stones, silica stones, etc. Lightweight tiles with a specific gravity smaller than that of tile products are manufactured (for example, see Patent Document 1).

However, inorganic micro foamed hollow spheres such as fly ash balloons and silica balloons have a lower specific gravity than clay, feldspar, porcelain stone, etc., which are usually used as raw materials. Thus, even if an attempt was made to prepare the slurry, in practice, there were problems such as the inorganic fine foamed hollow spheres not being uniformly dispersed in the slurry but separated. For this reason, the content of the inorganic fine foamed hollow sphere in the ceramic raw material is often limited.
Japanese Patent Laid-Open No. 11-43381

  Therefore, in view of the above-mentioned problems, an object of the present invention is to provide a method for producing a ceramic raw material containing an inorganic microfoamed hollow sphere efficiently and economically with a very simple configuration.

  That is, the invention of claim 1 stirs the ceramic sludge in the tank, and while stirring the inorganic fine foamed hollow sphere in water, feeds the mixture into the slurry from the bottom of the tank and mixes and stirs it. A mixed fluid of a hollow sphere and a slurry is supplied from a tank to a spray dryer and dried to obtain a predetermined powdery raw material.

  Invention of Claim 2 concerns on the manufacturing method of the raw material for ceramics of Claim 1 whose content of the said inorganic fine foaming hollow sphere is 5-70 weight% with respect to 100 weight% of said raw materials for ceramics.

  Invention of Claim 3 concerns on the manufacturing method of the raw material for ceramics of Claim 1 or Claim 2 whose said inorganic micro foaming hollow sphere is a fly ash balloon.

  Invention of Claim 4 concerns on the manufacturing method of the tile raw material in any one of Claim 1 thru | or 3 whose said ceramic raw material is a tile raw material.

  According to the method for producing a raw material for ceramics according to the invention of claim 1, the slurry for ceramics is stirred in the tank, and the inorganic micro-foamed hollow sphere is stirred into the water while being pumped into the slurry. Stirring and supplying the mixed fluid of the inorganic micro foamed hollow sphere and slurry from the tank to the spray dryer and drying to obtain a predetermined powdery raw material, so that the inorganic micro foam hollow sphere is separated. It is possible to produce a uniformly dispersed raw material for ceramics without having to do so.

  According to the method for producing a ceramic raw material according to the invention of claim 2, the inorganic fine foamed hollow sphere is contained in an amount of 5 to 70% by weight with respect to 100% by weight of the ceramic raw material. By appropriately adjusting the content, it is possible to produce a ceramic raw material for obtaining a ceramic product having desired properties such as weight reduction, water retention or heat insulation.

  According to the method for manufacturing a raw material for ceramics according to the invention of claim 3, since the inorganic microfoamed hollow sphere is a fly ash balloon, the fly ash balloon is usually high in fire resistance and melted at the firing temperature of the ceramic product. Thus, since there is little possibility of large firing shrinkage, a ceramic product with relatively excellent dimensional accuracy can be obtained.

  According to the method for manufacturing a tile raw material according to the invention of claim 4, since the ceramic raw material is a tile raw material, an inorganic micro-foamed hollow sphere is included for use in a lightweight tile, a water retaining tile or a heat insulating tile. A tile raw material having appropriate properties can be produced.

  Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 is a schematic process diagram showing an example of a method for producing a ceramic material according to the present invention, and FIG. 2 is a schematic perspective view showing an example of a method for producing a ceramic material according to the present invention.

  As shown in FIG. 1, the invention according to claim 1 includes a step of stirring in a tank a ceramic sludge obtained by wet-grinding and mixing raw materials such as clay, feldspar, porcelain stone, and silica by a known method. A step of pumping and stirring the inorganic micro-foamed hollow sphere into the slurry from the lower part of the tank while stirring the water in the water, and supplying a mixed fluid of the inorganic micro-foamed hollow sphere and the slurry from the tank to the spray dryer. And drying to obtain a predetermined powdery raw material.

  The slurry for ceramics is obtained by putting raw materials such as clay, porcelain stone and feldspar, water, additives and the like into a ball mill, and wet-grinding and mixing by a known method. As an example, the case of the slurry for tile raw material defined in claim 4 will be described. Raw stone / raw earth, water, solvent, etc. are charged into a ball mill, and wet pulverization / mixing is performed by a known method. In addition, in the case of a tile product that requires coloration, the pigment may be put into the ball mill at the same time. Here, the rough stone / raw earth refers to clay, feldspar, porcelain stone, silica stone and the like that are generally used as tile raw materials. The solvent refers to a solvent that reacts with the product substrate to form a glass layer during firing, and calcium carbonate, talc, dolomite, wollastonite, calcium phosphate, zinc oxide, and the like are mainly used. The raw materials used in the production of ceramic sludge and tile raw material slurries as described above, and their types, contents, etc., are appropriately selected according to the ceramic products such as intended ceramics, porcelain or tiles. .

  The obtained slurry for ceramics is stored in the slurry tank 10 in FIG. 2 by applying a vibration sieve to remove unground material, and stirred by the stirrer 40. In order to prevent the slurry from precipitating, it is desirable to always mix and stir. The tank 10 and the stirrer 40 used here are not particularly limited as long as the slurry for ceramic raw materials can be sufficiently stirred.

  On the other hand, since the inorganic fine foamed hollow sphere has a specific gravity smaller than that of raw materials such as clay, feldspar, and ceramic stone, it is difficult to uniformly disperse them when mixed and stirred together with the raw materials. Therefore, apart from producing the above-mentioned ceramic slurry, the inorganic fine foamed hollow sphere-containing mixed liquid 25 is prepared by stirring and mixing the inorganic fine foamed hollow sphere and water in the tank 20. At this time, in order to uniformly mix the inorganic micro-foamed hollow sphere-containing mixed solution 25 with the inorganic micro-foamed hollow sphere-containing mixture 25, a predetermined amount of water is introduced into the tank 20 in advance and gradually stirred while being stirred by the stirrer 40. It is desirable to introduce inorganic fine foamed hollow spheres. Moreover, since the specific gravity of the inorganic fine foamed hollow sphere is lighter than that of water, it is preferable to always stir in order to maintain the dispersed state in water. The stirrer 40 is not particularly limited, but is preferably a high-speed stirrer using a motor 50 with an inverter 55 in order to uniformly disperse the inorganic fine foamed hollow spheres in water. The solid content concentration of the inorganic micro-foamed hollow spheres in the inorganic micro-foamed hollow sphere-containing mixed solution 25 is 100% by weight of the inorganic micro-foamed hollow sphere-containing mixed solution from the viewpoint of economical acquisition of the powdery raw material during spray dryer drying. The content is preferably 50 to 60% by weight. In order to make it easier to disperse the inorganic fine foamed hollow spheres, for example, a dispersant such as sodium silicate can be added and stirred.

  Here, the inorganic fine foamed hollow sphere is a fine hollow sphere (foam) made of an inorganic material, and examples include a shirasu balloon, a glass balloon, a fly ash balloon, an aluminosilicate balloon, and the like. It is also commercially available for cement, and the particle size, content, etc. of the inorganic microfoamed hollow sphere can be appropriately selected according to the target ceramic product. Further, as defined in claim 2, from the viewpoint of reducing the weight of ceramic products and improving the heat insulation properties, inorganic fine foaming is performed with respect to 100% by weight of the raw material for ceramics obtained after drying the spray dryer. The content of the hollow sphere is preferably 5 to 70% by weight, and more preferably 10 to 60% by weight. In addition, as specified in claim 3, from the viewpoint of the dimensional accuracy of ceramic products, it has excellent fire resistance and does not melt even at the firing temperature of ceramic products such as tiles and ceramics, so fly ash balloons as inorganic micro-foamed hollow spheres Is preferably used. Here, the fly ash balloon refers to a product obtained by separating and refining granular particles collected by a dust collector of a pulverized coal combustion boiler among coal ash generated at a thermal power plant that burns coal. The size, fire resistance, composition, etc. vary depending on the coal production area, composition, combustion method, etc., but for example, the particle size is 1 to 250 μm and the specific gravity is about 0.6 to 0.8. A suitable fly ash balloon can be used.

  In the tank 20, the mixed liquid 25 containing the inorganic micro-foamed hollow spheres obtained by stirring water and the inorganic micro-foamed hollow spheres at a high speed is added to the slurry tank 10 in which the ceramic slurry 15 has been stirred in advance in the tank lower portion 11. It is pumped through a pipe 35 b provided in the supply port 12. At this time, since the specific gravity of the inorganic microfoamed hollow sphere is small, the inorganic microfoamed hollow sphere is separated and not uniformly dispersed only by adding the inorganic microfoamed hollow sphere-containing mixed solution 25 to the slurry tank 10 from above. . Therefore, by using a pump 30 or the like, the mixed liquid 25 containing inorganic fine foamed hollow spheres is pumped to the slurry tank 10 through the pipe 35b provided in the supply port 12 of the tank lower part 11. Since the ceramic slurry 15 contains a raw material such as clay and has a certain degree of viscosity, once the inorganic fine foamed hollow sphere-containing mixed solution 25 is mixed with the ceramic slurry 15, the inorganic fine foamed hollow sphere Separation is less likely to occur. Therefore, the mixed liquid 25 can be uniformly mixed with the ceramic slurry 15 stirred in the slurry tank 10 by pumping the mixed liquid 25 containing the inorganic fine foamed hollow spheres 25 from the tank lower portion 11.

  In addition, although it is possible to pump the inorganic micro-foamed hollow sphere-containing mixed liquid 25 from the upper part or the central part of the tank itself, in order to disperse the inorganic micro-foamed hollow sphere more uniformly in the ceramic slurry 15. At least, it is preferable to pump the tank 10 from the lower side than the central part in the vertical direction. Further, in the step of pumping the inorganic fine foamed hollow sphere-containing mixed solution 25 to the slurry tank 10 from the lower tank 11, in order to uniformly disperse the inorganic fine foamed hollow sphere-containing mixed solution 25 in the ceramic slurry 15, the slurry tank 10. It is desirable that the slurry 15 for ceramics and the mixed liquid 25 containing inorganic fine foamed hollow spheres are constantly stirred.

  Next, in the slurry tank 10, the mixed liquid 25 containing the inorganic fine foamed hollow spheres and the ceramic slurry 15 are stirred by the stirrer 40, so that the obtained mixed fluid passes through the pipe 35 a provided at the discharge port 13 of the tank 10. Supplied to spray dryer. The position of the mixed fluid discharge port 13 in the slurry tank 10 is not particularly limited. In this embodiment, the supply port 12 for feeding the mixed liquid 25 containing inorganic fine foamed hollow spheres 25 to the slurry tank 10, and the slurry 15 for ceramics and the mixed liquid 25 containing inorganic fine foamed hollow spheres are stirred and mixed in the tank 10. Although the case where the discharge port 13 for supplying the obtained mixed fluid to the spray dryer is separately provided is shown, a switching valve or the like is provided in the pipe 35b arranged in the supply port 12 of the mixed liquid 25 containing the inorganic fine foamed hollow spheres. Can also be used as a discharge port. In the step of supplying the mixed fluid to the spray dryer through the pipe 35a provided at the discharge port 13 of the lower portion 11 of the slurry tank, the mixed fluid in the slurry tank 10 is constantly stirred so that the mixed fluid does not settle. It is desirable that

  The mixed fluid is dried by a spray dryer to produce a powdery ceramic material. The particle size and water content of the powdery ceramic raw material obtained are not particularly limited, and conditions such as the drying temperature of the spray dryer can be appropriately adjusted according to the target ceramic product. When manufacturing the tile raw material defined in claim 4, the conditions of the spray dryer can be set according to the use of the tile product, but the particle size is preferably about 400 μm and the water content is preferably 5 to 8% by weight. . It should be noted that the powdery ceramic material can be mechanically compressed and pulverized and re-granulated into a certain size depending on the application.

Next, an example when a tile product is manufactured using the method for manufacturing a raw material for ceramics in the present invention will be described. A fly ash balloon was used as the inorganic microfoamed hollow sphere. Here, the fly ash balloon is made by SHIJIAZHUANG CENOSPHORE FACTORY, the particle size is 40 mesh (screen opening 425 μm) 95% by weight, the specific gravity is 0.35 to 0.55, the melting point is 1700 ° C., and the component composition is SiO ₂ is 52 to 54 wt%, Al ₂ O ₃ is 36 to 40 wt%, CaO is 2 wt%, Ig. Loss of 1.9% by weight was used. Separately, the slurry for tile raw material having the predetermined composition shown below was stirred in a tank, and separately, water and a fly ash balloon were stirred using a high-speed stirrer to prepare a mixed solution. Next, while stirring the slurry for tile raw material in the tank, the mixed liquid containing fly ash balloon was pumped from the lower part of the slurry tank and stirred with the slurry for tile raw material to prepare a mixed fluid.

[Formulation Example 1]
The raw material is 27.8% by weight of Sasame clay, 19.0% by weight of Kibushi clay, 1.0% by weight of silica and 52.2% by weight of feldspar, and 3.5% by weight of the solvent for 100% by weight of the raw material Was added, and wet milling was performed by a known method in a ball mill, and the slurry for tile raw material was stirred in a slurry tank. Separately, 40% by weight of water and 60% by weight of fly ash balloon were used to prepare a mixed solution using a high-speed stirrer. In addition, 0.2 weight% of sodium silicate was added as a dispersing agent with respect to 100 weight% of the said liquid mixture. The mixed liquid was prepared by pumping the fly ash balloon-containing mixed solution into the slurry tank so that the fly ash balloon was 20% by weight with respect to 100% by weight of the solid content of the tile raw material slurry.

[Formulation Example 2]
The raw material is 27.8% by weight of Sasame clay, 19.0% by weight of Kibushi clay, 1.0% by weight of silica and 52.2% by weight of feldspar, and 4.5% by weight of the solvent for 100% by weight of the raw material Was added, and wet milling was performed by a known method in a ball mill, and the slurry for tile raw material was stirred in a slurry tank. Separately, 40% by weight of water and 60% by weight of fly ash balloon were used to prepare a mixed solution using a high-speed stirrer. In addition, 0.2 weight% of sodium silicate was added as a dispersing agent with respect to 100 weight% of the said liquid mixture. The mixed liquid was prepared by pumping the fly ash balloon-containing mixed solution into the slurry tank so that the fly ash balloon was 50% by weight with respect to the solid content of 100% by weight of the slurry for tile raw material.

The mixed fluid prepared by the predetermined composition was dried by a spray dryer, and the obtained powdery ceramic raw material was molded at a pressure of 200 kg / cm ² . The molded body was fired at 1250 ° C., and the water absorption, specific gravity, and thermal conductivity were measured. The results are shown in Table 1 below. As a comparison, Table 1 also shows the specific gravity and thermal conductivity of a porcelain tile of a conventional product that does not contain inorganic microfoamed hollow spheres. As is apparent from Table 1, in Formulation Examples 1 and 2 containing 20% by weight or 50% by weight of fly ash balloons, the specific gravity is small as compared with the conventional porcelain tiles that do not contain inorganic micro-foamed hollow spheres. A low thermal conductivity value was obtained, and a light and heat-insulating tile product was obtained.

It is a schematic process drawing which shows an example of the manufacturing method of the raw material for ceramics of this invention. It is a schematic perspective view showing one Example of the manufacturing method of the raw material for ceramics of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Slurry tank 11 Lower tank 12 Supply port 13 Discharge port 15 Slurry for ceramic industry 20 Tank 25 Mixed liquid containing inorganic micro foam hollow sphere 30 Pump 35a, 35b Pipe 40 Stirrer 50 Motor 55 Inverter

Claims (4)

While stirring the ceramic slurry in the tank,
While stirring the inorganic microfoamed hollow sphere in water, it is pumped into the slurry from the bottom of the tank and mixed and stirred.
Supplying a mixed fluid of the inorganic micro-foamed hollow sphere and the slurry from the tank to the spray dryer;
A method for producing a ceramic raw material, wherein the raw material is dried to obtain a predetermined powdery raw material. For 100% by weight of the ceramic raw material,
The method for producing a raw material for ceramic industry according to claim 1, wherein the content of the inorganic fine foamed hollow sphere is 5 to 70% by weight. The method for producing a raw material for ceramics according to claim 1 or 2, wherein the inorganic fine foamed hollow sphere is a fly ash balloon. The method for manufacturing a tile material according to any one of claims 1 to 3, wherein the ceramic material is a tile material.

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