JPH0971485A - Production of porous ceramic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To freely regulate the pore diameter and porosity and improve the mechanical strength by hardening a compact prepared by forming a mixture of a porous aggregate with a specific binder while passing a gas through the interior of the compact and then baking the hardened compact. SOLUTION: One or more selected from inorganic cellular grains such as porous perlite, vermiculite, glass balloons or pumiceous sand balloons are mixed with one or more binders selected from inorganic substances such as water glass or a silica sol and the resultant mixture is formed into a desired shape to provide a compact 1, which is then placed on a pallet 12 having many bored small through-holes 11 and covered with a gaseous carbon dioxide filling capsule 15 and a sucking capsule 17 through a sealing material 13. Pressurized gaseous carbon dioxide is filled through filling ports 14 in the capsule 15 and a vacuum suction means 19 is operated to suck the interior of the capsule 17. Thereby, the compact 1 is hardened while passing the gaseous carbon dioxide through the interior of the compact 1 and sucking the gaseous carbon dioxide. The resultant compact 1 is subsequently baked at 700-1,300 deg.C for 30min to 72hr.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a porous ceramic, and more specifically, a mixture of porous aggregate and a binder containing water glass is formed into a desired shape and size. The present invention relates to a method for producing a porous ceramic in which a gas is allowed to pass through the inside of the mixture, the entire mixture including the inside is cured by the action of the gas, and then the mixture is fired.

[0002]

2. Description of the Related Art Conventionally, various types of porous ceramics have been developed, and blockages of permeable tiles, permeable blocks, permeable cylinders, permeable casings, aquaculture ponds in pavements, parking lots, entrances, indoors, etc. It is widely used as diffuser plate, diffuser cylinder, filter material, adsorbent material, sound absorbing material, fungal bed material, etc. in natural waters.

In the past, porous ceramics are, for example, porous pearlite, vermiculite, foamed shirasu, which is obtained by heat-foaming pearlite, obsidian, hirucite, shirasu, etc.
It was manufactured as a molded body in which inorganic bubble-containing particles such as glass balloons and silas-baroos, which are fine hollow bodies made of glass, alumina, fly ash, silica sand, shale, etc., are used as an aggregate and are bound with a binder.

A method for producing a lightweight building board by kneading cement and water into a mixture of foam-containing particles such as pearlite and shirasu balloon and inorganic fiber, and molding the mixture by a method such as a papermaking method or a mold casting method (JP-A-48). -59114) or a method using a silicate or the like such as water glass and an appropriate curing agent as a binder (JP-A-51-135924).

Further, a method of using an organic resin alone as a binder (Japanese Patent Laid-Open No. 48-32127) or a method of using it together with an inorganic binder such as water glass or silica gel (Japanese Patent Laid-Open No. 1-290572). ) Is also proposed.

Similarly, a method of foaming and curing using a urethane resin to consolidate the inorganic foam-containing particles (JP-A-61-161).
No. 2016680) is also well known to those skilled in the art.

Recently, a method for producing a porous fired body by effectively utilizing industrial waste has been proposed. For example, JP-A-61-2
In 19776, a method is disclosed in which silica sand sludge discarded as industrial waste is used as an aggregate, and water and a foaming agent are added to this to knead to form a slurry, which is then shaped into a shape and then fired. ing.

Further, in Japanese Unexamined Patent Publication No. 63-176380, a crushed material of a ceramic waste material discarded as an industrial waste is used as an aggregate, and a crushed material of a glass-based waste material discarded as an industrial waste is secondary. The mixture is added as a binder, and a liquid primary binder and water are added and kneaded to form a kneaded product, which is then molded into a desired shape and dimension, and then a gas having a predetermined pressure is blown to the molded product to primarily cure its surface, followed by firing. A method of doing so is disclosed.

[0009]

However, in the method for producing a porous fired body described in, for example, JP-A-61-219776, for example, since the molded article after molding is brittle, dehydration for enabling handling, There has been a problem that a complicated process of drying is required, and that an extremely long treatment is required, so that the productivity is poor and the manufacturing cost is high.

In the method for producing a porous ceramic described in Japanese Patent Laid-Open No. 176380/1988, gas (mainly carbon dioxide gas) is blown onto the surface of the molded article to cure it. , As shown by the arrow in FIG.
The gas only comes into contact with the surface of the molded product,
And the floor surface of the molded product that comes into contact with the pallet on which the molded product is placed does not contact. That is, the inside and bottom of the molded product cannot be cured.

Therefore, the molded product is too fragile and cannot be handled, or the molded product is unevenly cured and deformed or deformed, the dimensional accuracy of the molded product is deteriorated, and cracks (scratches) are generated. There is a problem that the yield of the products is deteriorated due to the occurrence of the occurrence, and there is a problem that the production efficiency is lowered and the manufacturing cost is increased.

In this method, when a gas is blown onto the surface of the molded product for a long time to carry out the curing treatment, the production efficiency of the product is deteriorated, and the consumption of expensive carbon dioxide gas is increased to increase the cost. In addition, if the shape of the molded product is large, it is only possible to cure the surface of the molded product even if it is sprayed for a long time. I can't let you do it. That is, when the molded product after curing is too brittle to be handled, a large-sized porous ceramic cannot be manufactured.

The present invention has been made through intensive studies and invented in view of such circumstances, and the problem to be solved is to solve the above-mentioned problems, inconveniences and problems, and the purpose thereof is It is an object of the present invention to provide a method for producing a porous ceramic, which is capable of producing a large-sized porous ceramic, and is capable of mass-producing the porous ceramic efficiently and at low cost.

[0014]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the means adopted by the present invention is that the invention of claim 1 is "represented by a porous aggregate, water glass or silica sol. In the method for producing a porous ceramic, a binder containing at least one kind of a mixture selected from inorganic substances is mixed, and a molded body formed into a desired shape and dimension is fired to produce a porous ceramic. Prior to firing the molded body, a gas is passed inside the molded body, which includes a curing step of curing the entire body including the inside of the molded body. " This is the summary.

Next, the invention of claim 2 is that "a porous aggregate is one or a mixture of two or more selected from organic substances represented by ethyl silicate, phenol isocyanate, carboxymethyl cellulose, starch and the like. In a method for producing a porous ceramic by producing a porous ceramic by mixing a binder containing at least and then firing the molded article into a desired shape and dimensions, before firing the molded article The gist is a method for producing a porous ceramic having a feature of "a hardening step of hardening an entire body including the inside of a molded body by passing a gas".

[0016] Next, the invention of claim 3 is, "The binder is a powdery crushed product obtained by crushing a waste product of a glass product, or a crushed powdery product obtained by crushing a waste product of an enamel product. The method for producing a porous ceramic according to claim 1 or 2, characterized in that any one kind selected from the group of powdery crushed materials or a mixture of two or more kinds thereof is blended. This is the summary.

Next, the invention of claim 4 is characterized in that "the gas is either carbon dioxide gas or a mixed gas containing carbon dioxide gas". The gist of the method is a method for producing a high quality ceramic.

Next, the invention according to claim 5 is that "the aggregate is a porous pearlite, vermiculite, foamed shirasu, glass or alumina, fly ash in which pearlite, obsidian, hirucite, shirasu, etc. are heated and foamed. , One or a mixture of two or more thereof selected from inorganic foam-containing particles such as glass balloons and silas-baroos, which are fine hollow bodies made of natural raw materials such as silica sand and shale. The gist is the method for producing a porous ceramic according to any one of Items 1 to 4.

Next, the invention according to claim 6 is that "the aggregate is any one selected from a crushed material of a burned material waste, or a mixture containing at least one selected from these. The invention is characterized by being "any one".
The gist is the method for producing a porous ceramic according to any one of 4 above.

Next, the invention according to claim 7 is that "the aggregate is any one selected from a slag, a waste foundry sand, a waste cement, a sand figure, a powdery and granular waste represented by kira, etc. Alternatively, it is a mixture containing at least one selected from these ", and the gist is the method for producing a porous ceramic according to any one of claims 1 to 4.

[0021] Next, the invention of claim 8 is that "the aggregate is a mixture of selben and powdery or granular waste such as slag, waste casting sand, waste cement, sand form, and kira." The gist is the method for producing a porous ceramic according to any one of claims 1 to 4, which is characterized by the above.

Next, a ninth aspect of the present invention is that "the porous ceramic is a diffuser plate, a diffuser cylinder, a mortar or the like in a water-permeable tile, a water-permeable block, a water-permeable cylinder, a water-permeable casing, a closed pond such as a culture pond. Material, adsorbent, sound absorbing material, fungal bed material, planting block ". The method of manufacturing a porous ceramic according to any one of claims 1 to 8, has as its gist.

Next, the invention of claim 10 is characterized in that "the porous ceramic has at least two layers having different contents of the aggregate". The manufacturing method of the porous ceramic is as the gist.

Next, in the invention of claim 11, "carbon dioxide gas is added to the inside of the molded body before firing the molded body in which water glass is mixed at least as a binder with the aggregate and molded into a desired shape and size. It includes a step of allowing the aggregates adjacent to each other to be bonded by silica gel produced by the reaction of water glass and carbon dioxide gas, and hardening the whole including the inside of the molded body. The manufacturing method of is made into the gist.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The aggregate for producing the porous ceramic of the present invention is an inorganic aggregate composed of an inorganic material, and examples of the inorganic aggregate include pearlite, obsidian, and hirucite,
Porous perlite or vermiculite obtained by heat-foaming shirasu, foamed shirasu, glass balloons made of glass, alumina, fly ash, quartz sand, shale, etc. Any one of them or a mixture of two or more of them can be used, and it is preferable to be a natural stone other than sedimentary rock in which cracks and the like are less likely to occur during subsequent firing.

Further, as the aggregate, for example, it is generally called selben by crushing ceramic waste materials such as tableware, kitchen appliances, sanitary appliances, defective products such as insulators and waste materials into fine particles. Crushed materials and concrete cement generated by demolition of concrete cement structures and buildings are crushed into fine particles, crushed waste foundry sand is crushed into fine particles and waste generated during clay refining. Particles such as crushed materials that are generally called fine particles, crushed waste that is produced by metal refining and crushed to fine particles that are generally called slag, and crushed materials that are crushed to fine particles by crushing waste foundry sand Shaped waste can also be used.

Further, as the aggregate, two or more kinds selected from the group of the natural stones may be mixed, and two or more kinds selected from the group consisting of the powder-grain-shaped wastes may be mixed. Alternatively, one or more kinds selected from the group of natural stones and one or more kinds selected from the group consisting of the waste in the form of powder and granules may be used in combination.

Fine aggregates generally called calcined aggregates and aggregates such as crushed substances generally obtained by crushing incinerated ash into fine granules are at least already fired and therefore are not included in the aggregates. Since water of crystallization is not contained, for example, so-called cutting is good and the secondary shrinkage is small, which is preferable in that the burden of drying can be reduced and energy efficiency can be improved.

The primary binder referred to in the present invention is a liquid,
The purpose is to coat the surface of the aggregate and to temporarily bond the aggregate to prevent the kneaded product from being deformed or broken during handling or firing. Generally, water glass is used. Alternatively, an organic material typified by ethyl silicate or phenol / isocyanate can be used, and it is preferable to add 2 to 25% to the aggregate 100.

Also, as the primary binder, a sizing agent typified by carboxymethyl cellulose, starch or the like can be used.

Next, the secondary binder referred to in the present invention is
Glass powder such as clay, natural stone, or waste glass product such as plate glass or glass container, which is used to obtain a porous ceramic having a predetermined porosity and mechanical strength by melting and binding aggregate during firing. However, it is also possible to use a powdery crushed product obtained by crushing a glass-based waste material of an enamel product. In order to minimize the strain generated in the aggregate and the binder during firing, it is preferable that the thermal expansion coefficient of the secondary binder be the same as that of the aggregate. The secondary binder melts at the time of firing to bond the aggregates together.However, in order to ensure that this binding is performed uniformly and that the melting time at firing does not take a long time to increase the energy cost, The diameter is preferably 1.0 mm or less.

It is preferable to mix the aggregate 100 with 3 to 30%.

A method of manufacturing a molded product for manufacturing a ceramic product of the present invention will be described with reference to FIG. 1 which schematically shows the manufacturing process.

First, as shown in FIGS. 1 (a) and 1 (b), a secondary binder 3 is added to the mixture of the porous inorganic aggregate 2 and the primary binder 4 little by little. Alternatively, as shown in FIG. 1 (b), a liquid primary binder (water glass) 4 is added to a mixture of a porous inorganic aggregate 2 and a secondary binder 3 in a shower and mixed little by little. .

Aggregate 2, primary binder 4 and secondary binder 3
When these three are mixed at the same time, especially since the secondary binder of fine powder does not aggregate and cannot be uniformly dispersed, it adheres to the mold at the time of molding or foams at the time of firing to yield. Becomes worse.

When manufacturing a colored porous ceramic, a predetermined amount of an inorganic pigment is appropriately added during this mixing process.

Explaining with reference to FIGS. 1 (c) to 1 (d), first, the mold is a fixed frame 5 having a space for molding a mixture in which the above three are uniformly mixed into a predetermined shape dimension.
And a pallet 7 which is provided with a large number of fine through holes 6 and which is detachably provided on the lower surface of the fixed frame 6. The space is filled with a predetermined amount of the mixture.

When the mixture is filled in the mold, it is preferable to use a vibrator to fill the mixture while vibrating it, because the density can be kept uniform.

As shown in FIG. 1 (e), the press-molded body 1 is released from the mold while being placed on the pallet 7, and prior to firing, as shown in FIG. ), The entire body including the inside of the molded body and the floor surface is uniformly cured to facilitate handling and prevent uneven curing of the molded body.

FIG. 2 schematically shows an example of a curing device 10 for curing the whole of the molded product 1 including the inside and the floor surface. The molded product 1 is mixed with water glass as a binder. Detailed description will be given with reference to FIG. 2 by taking an example of a molded product which is dry-press molded into a predetermined shape and dimension.

First, the curing apparatus 10 includes a pallet 12 having a large number of small through holes 11 formed therein, and the pallet 12
And a carbon dioxide injection capsule 15 having an injection port 14 for injecting pressurized carbon dioxide gas provided on the upper surface of the pallet 12 and a carbon dioxide gas suctioned on the lower surface of the pallet 12 via the seal material 13. Outlet 16 for discharging
And a suction capsule 17 having
The dry press-molded product 1 is placed so as to cover all the many through holes 11 formed in the pallet 12.

Therefore, when pressurized carbon dioxide gas is injected into the carbon dioxide gas injection capsule 15 and the vacuum suction means 19 is operated to reduce the pressure in the suction capsule 17, the carbon dioxide gas is molded as shown by the arrow. It is possible to move from the surface of No. 1 toward the through hole 11 through the inside thereof. At this time, the water glass and carbon dioxide gas mixed in the molded product are
It reacts as shown in the following chemical formula to change into a substance called silica gel, and adjacent aggregates bond with each other through silica gel, so that the entire molding including the inside and bottom of the molded body can be cured without unevenness. It can be cured almost evenly and can be handled.

Na ₂ O.mSiO _2. (Mn + x) H ₂ O
+ CO ₂ → Na ₂ CO ₃ · xH ₂ O + m (SiO
₂・ nH ₂ O)

It should be noted that a mixed gas containing carbon dioxide gas may be used instead of the carbon dioxide gas, and examples of the mixed gas containing carbon dioxide gas include combustion exhaust gas.

According to this apparatus, even if the molded body is large, it can be cured quickly, simply and reliably to the extent that it can be handled.

It is preferable to inject carbon dioxide gas that has been heated in advance, because consumption of carbon dioxide gas can be reduced and curing time can be shortened.

Then, as shown in FIG. 1 (g), the hardened molded body (green) is fired to obtain a porous ceramic. The green may be fired using a tunnel kiln or a roller hearth kiln.

The firing temperature is determined in consideration of the heat resistance of the aggregate and the like, but is usually in the range of 700 to 1300 ° C. The firing time is about 30 minutes to 72 hours, although it varies depending on the type of aggregate and the size of the molded body. When using a calcined product that has been calcined as the aggregate, a holding time of the calcining temperature of 10 minutes to 180 minutes is sufficient.

Although the basic steps of the present invention have been described above, various other modes can be adopted. For example, when producing a colored porous ceramic, a glaze may be applied at the green stage, and when manufacturing multilayer products having different densities, the density is preferably at the green stage before firing. Aggregate particles of different types may be applied to the surface of, for example, those suspended in water or an organic solvent, sprayed, or immersed in the suspension. This is because the green itself has a self-water supply property, so that the suspension solvent penetrates and the base particles are captured on the surface. Therefore, a multilayer structure can be easily achieved.

The porous ceramics produced by the method for producing a porous ceramics according to the present invention can be used for water-permeable tiles, water-permeable blocks, water-permeable cylinders, water-permeable casings, aquaculture ponds, etc. It can be widely used as a diffuser plate, a diffuser cylinder, a filter material, an adsorbent material, a sound absorbing material, a fungal bed material, a planting block, etc., in a closed water area.

[0051]

EXAMPLE According to the present invention, 400 mm × 400 mm × 6
A 2 mm water permeable block of 0 mm was made.

First, the composition for forming the lower layer is 80% tile cerben having a particle size of 5.0 to 1.0 mm and 10% tile selben having a particle size of 1.0 to 0.5 mm as an aggregate. , Tile cerven 10 with a particle size of 0.5 mm or less
% Cerben mixture was used as a secondary binder, and crushed glass waste material was used as a secondary binder, and 12 g per 100 g of the cerven mixture (aggregate) was added and mixed to prepare a dry sample, and water glass 3 was used as a primary binder. No. 7 was added to 100 g of aggregate and mixed. The composition for forming the upper layer uses tile cerben having a particle size of 1.0 to 0.5 mm as an aggregate, and a crushed glass waste material as a secondary binder. A dry sample was prepared by adding and mixing 11 g per 100 g, and 11 g of water glass No. 3 as a primary binder was added to and mixed with 100 g of the aggregate.

Next, a mold comprising a mold having a space for molding into a predetermined shape and a pallet provided with a large number of fine through holes and detachably provided on the lower surface of the mold The composition for preparing the lower layer is filled in the inside and 0.5 kgf /
After applying a pressure of cm ² for primary molding, the space formed above the mold is filled with the composition for preparing the upper layer, and 0.5 kgf is applied in the same manner as above while vibrating.
/ M ² pressure is applied for secondary molding, and the two-layer molded product is demolded downward together with the pallet, and the pallet with the molded product placed on the upper surface is transferred to the curing device by the conveyor. Will be transported to.

Then, as shown in the curing apparatus of FIG.
Between the gas injection capsule and the drain capsule, the pallet on which the molded body is placed is attached in a hermetically sealed state, 2 kg.
After passing a pressure of carbon dioxide gas through the inside of the molded body for 2 to 30 seconds to primarily cure the whole including the inside and the bottom,
It was baked at 1100 to 1150 ° C for 2 hours in a roller hearth kiln.

The resulting water-permeable block has a compressive strength of 238.
It has a good strength of kg / cm ² and a porosity of 49.
It exhibited a performance of 5% and a water permeability of 0.38 cm / sec, and no abnormality was found in the frost damage test.

[0056]

As described above, according to the method for firing a porous ceramic of the present invention, cerven or the like can be used as an aggregate and a crushed material of a glass-based waste material can be used as a secondary binder. A porous fired body with excellent strength and with freely adjusted porosity and pore diameter can be easily produced without the need for a dehydration / drying process, and the firing time is short, so mass production is possible at low cost. It has an excellent effect of being able to.

In particular, unlike the conventional case in which a gas (mainly carbon dioxide gas) is blown onto the surface of the molded product and only the surface layer of the molded product is primarily cured (the inside and the bottom surface are not cured), the molded product is The interior and bottom can be cured.
In addition, even if the carbon dioxide gas treatment time is shortened, it can be cured to such an extent that it can be handled sufficiently, uneven curing of the molded product can occur, the mold can collapse or be deformed, the dimensional accuracy of the molded product can deteriorate, and cracks ( Since no scratches are generated, the yield of products and the production efficiency can be improved, and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory view schematically showing the steps of the method for producing a porous ceramic of the present invention.

FIG. 2 is a front view showing one curing device used for curing the entire molded article including the inside and the floor surface in the present invention. The broken line with an arrow schematically shows the movement of carbon dioxide gas.

FIG. 3 is a front view showing a conventional curing device. A broken line with an arrow schematically shows movement of carbon dioxide gas.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Molded body 2 ... Porous inorganic aggregate 3 ... Primary binder 4 ... Secondary binder 5 ... Fixed frame 6 ... Through hole 7 ... Pallet 10 ... Curing device 11 ... Through hole 12 ... Pallet 13 ... Sealing material 14 ... Note Inlet 15 ... Carbon dioxide injection capsule 16 ... Ejection port 17 ... Suction capsule 18 ... Air cylinder 19 ... Decompression suction means 20 ... Conventional curing device

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[Procedure amendment]

[Submission date] October 21, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] Claim 2

[Correction method] Change

[Correction contents]

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0001

[Correction method] Change

[Correction contents]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a porous ceramic, and more particularly , to a mixture of an aggregate and a binder containing water glass, which is formed into a desired shape and size. The present invention relates to a method for producing a porous ceramic in which a gas is allowed to pass through the inside, the entire mixture including the inside is cured by the action of the gas, and then the mixture is fired.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

[0014]

[Means for Solving the Problems] The means adopted by the present invention to solve the above-mentioned problems are as follows: "The aggregate is made of an inorganic material typified by water glass or silica sol. In the method for producing a porous ceramic, a binder containing at least one selected mixture or a mixture of two or more types is mixed, and then a molded body formed into a desired shape and dimension is fired to produce a porous ceramic. A gas is passed through the inside of the molded body before firing, and a curing step is included to cure the entire body including the inside of the molded body.
This is the summary.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

Next, the invention of claim 2 is that "the aggregate contains at least one kind or a mixture of two or more kinds selected from organic substances typified by ethyl silicate, phenol isocyanate, carboxymethyl cellulose, and starch. In a method for producing a porous ceramic, in which a binder is mixed and then a molded body that is molded into a desired shape and dimension is fired, a gas is passed through the inside of the molded body before firing the molded body. Let
The gist is a method for producing a porous ceramic, which has a feature of "a curing step of curing the entire molded body including the inside thereof".

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction contents]

First, as shown in FIGS. 1 (a) and 1 (b),
To a mixture of quinic machine protein aggregate 2 and the primary binder 4, or mixed with addition of secondary binders 3 gradually or, as in FIG. 1 (b), no aircraft quality aggregate 2 and the secondary A liquid primary binder (water glass) 4 is mixed with the mixture of the next binder 3 while being added little by little in a shower.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] Explanation of sign

[Correction method] Change

[Correction contents]

[Description of Reference Numerals] 1 ... molded body 2 ... No aircraft quality aggregate 3 ... primary binder 4 ... secondary binder 5 ... fixed frame 6 ... through hole 7 ... pallet 10 ... curing device 11 ... through hole 12 ... pallet 13 ... seal Material 14 ... Injecting port 15 ... Carbon dioxide injecting capsule 16 ... Discharging port 17 ... Suction capsule 18 ... Air cylinder 19 ... Decompression suction means 20 ... Conventional curing device

Claims (11)

[Claims] 1. A porous aggregate is mixed with a binder containing at least one kind or a mixture of two or more kinds selected from inorganic substances typified by water glass or silica sol, and then molded into a desired shape and size. In a method for producing a porous ceramic, in which a molded body is fired to manufacture a porous ceramic, a gas is passed through the inside of the molded body before the molded body is fired to cure the entire body including the inside of the molded body. A method for producing a porous ceramic, which comprises the steps of: 2. A porous aggregate is mixed with a binder containing at least one kind or a mixture of two or more kinds selected from organic substances typified by ethyl silicate, phenol isocyanate, carboxymethyl cellulose, and starch. In a method for producing a porous ceramic, which comprises manufacturing a porous ceramic by firing a molded body that is molded into a shape and shape, a gas is passed through the molded body before firing the molded body, A method for producing a porous ceramic, comprising a curing step of curing the whole including 3. The binder is selected from the group of powdery crushed material of sinter waste material represented by powdery crushed material of crushed glass product waste and crushed powdery material of enamel product. 3. The method for producing a porous ceramic according to claim 1, wherein any one of them or a mixture of two or more thereof is blended. 4. The gas is either carbon dioxide gas or a mixed gas containing carbon dioxide gas.
4. The method for producing a porous ceramic according to any one of 3 to 3. 5. The natural material such as pearlite, obsidian, hirucite, and porous pearlite or vermiculite, foamed shirasu, glass, alumina, fly ash, silica sand, shale, etc. 5. A raw material is any one kind selected from inorganic bubble-containing particles such as glass balloons made of fine hollow bodies and Silasvaloo, or a mixture of two or more kinds thereof, according to any one of claims 1 to 4. Method for producing porous ceramics. 6. The aggregate is any one selected from a crushed material of a burned material waste material, or a mixture containing at least one selected from these. The method for producing a porous ceramic according to claim 1. 7. The aggregate is any one selected from a slag, a waste casting sand, a waste cement, a sand form, a powdery and granular waste represented by kira, or at least one selected from these. It is a mixture containing the above, The manufacturing method of the porous ceramics in any one of Claims 1-4. 8. The aggregate according to claim 1, wherein the aggregate is a mixture of selben and a powdery or granular waste such as a slag, a waste foundry sand, a waste cement, a sand form, and kira. The method for producing a porous ceramic according to any one of 1. 9. The porous ceramic is a diffusing plate, a diffusing cylinder, a filter material, an adsorbent material, a sound absorbing material, or a fungus in a closed water area such as a water permeable tile, a water permeable block, a water permeable cylinder, a water permeable casing, or a culture pond. A floor material and a planting block, The manufacturing method of the porous ceramics in any one of Claims 1-8 characterized by the above-mentioned. 10. The method for producing a porous ceramic according to claim 1, wherein the porous ceramic has at least two layers having different contents of the aggregate. 11. Carbon dioxide gas is passed through the inside of the molded body before firing the molded body which is mixed with at least water glass as a binder in the aggregate and is molded into a desired shape and dimension, to obtain water glass and carbon dioxide gas. A method for manufacturing a ceramic product, which comprises a step of binding aggregates adjacent to each other by silica gel produced by the reaction of 1. to cure the entire body including the inside of the molded body.