JP5255836B2 - Method for producing ceramic porous body - Google Patents

Description

  The present invention relates to a method for producing a ceramic porous body.

Table 1 shows the composition and firing temperature of the base material in the ceramic (see Non-Patent Document 1). As is apparent here, the main firing is usually performed at 1000 ° C. or higher. The purpose is to place importance on the strength of the fired body. As a result, the structure of the fired body becomes dense and tends to be composed of many glass phases and crystal phases.
However, unglazed firing at 1000 ° C. or less is often made into a porous sintered body. Its main purpose is water absorption and filterability. That is, the glass-forming component particles and solute in the cocoon (slurry) are attracted mainly to the pores of μm by the capillary water absorption force of the unglazed porous fired body in the glazing process to ensure adhesion with the main body and the thickness of the cocoon. Because. Many industrial products utilizing the properties of this unglazed fired body were proposed after the prewar period, but examples of those that remain in the market to date include gelling cake dehydration base plates that contain many filters, colloids, etc. Besides, there are ceramic porous bodies for heaters. In particular, heaters have been used industrially since 1975 due to the far-infrared effect.

In addition, a conventional ceramic is composed of a base material composed of three components obtained by adding feldspar and quartz (silica) to plastic clay of kaolinite, bauxite, and porcelain clay. Since this substrate has good plasticity, various molding methods can be freely used, and a complex molded body can be created (see Non-Patent Document 2).
On the other hand, porous white ceramics (dolomite standing pottery) and lime-feldsparous pottery (limestone standing pottery) developed in Japan are well known as ceramic porous bodies. As shown in Table 2, the base composition is composed of limestone, dolomite, kaolinite clay (kibushi clay), porcelain clay, quartz, feldspars, and the constituent minerals in the constituent materials are , Dolomite, limestone, quartz, kaolinite mineral, sericite, pyrophyllite, and feldspar minerals, and the constituent materials of these industrial raw materials often contain quartz.

Ceramic Engineering Handbook Volume 5 Ceramics (1989) Ikuo Shibasaki “From Ceramic Manufacturing to Establishment of Hydroplastic Molding Technology” Ceramics, 40 (2) 106-110 (2005)

For this reason, the reaction of CaO (MgO) -SiO ₂ -feldspar proceeds rapidly around 1100 ° C. in dolomite (white dolomite) and limestone standing pottery, resulting in the formation of a large amount of melt, resulting in softening distortion of the fired body It was connected. In order to prevent this, an attempt has been made to add an Al ₂ O ₃ component, but this is insufficient to obtain a porous body.
In addition, a conventional ceramic porous body uses a base material in which a combustible organic substance and an inorganic substance are homogeneously mixed, and a fired body in which voids between particles of the inorganic substance on the base are pores is generally used. However, it is difficult to design a pore diameter freely and produce a uniform porous body. Also, since the plasticity of the substrate is low, there are restrictions on the molding method, and at present, plate-shaped and tile-shaped molding is the mainstream.

  Accordingly, the present invention has an object to provide a method for producing a ceramic porous body that can arbitrarily design a pore diameter and a pore volume in a nano to sub-micrometer range while maintaining heat resistance, and is excellent in formability. It is what.

First, in order to suppress the softening during firing on ceramic production as much as possible, avoid the presence of feldspar and quartz with many alkali components that easily form a glass phase (melt) in the constituent material of the base as much as possible. It is necessary to use a constituent material that generates a monomolecular gas that is a source of pores of the body at a low temperature.
In other words, the heat resistance improvement measure to reduce the deformation of the molded body exposed to the high temperature gas during firing is the addition of Al ₂ O ₃ component, and gas is generated in the ceramic porous body production due to thermal decomposition of the constituent materials. Easy preparation of Al (OH) _{3 and} other Al-containing salts as main constituent materials, and other constituent materials avoiding the incorporation of quartz as much as possible, and base preparation using various hydroxides and salts that generate gas by thermal decomposition Is to do.

Accordingly, a first aspect of the present invention, the plastic clay to remove feldspar and quartz containing alkali components was classified, and limestone or dolomite, alumina component, or a Ranaru green body composition, each component By blending so as to contain at least 10% by weight or more with respect to 100% of the total weight, forming the base composition into a predetermined shape, and selecting the firing temperature in the range of 500 ° C to 1400 ° C and firing. Any pore diameter and pore volume can be selected in the range of nano to submicrometer.
The invention described in Claim 2, and plasticity clay to remove feldspar and quartz containing alkali components was classified, and limestone or dolomite, alumina component, and hydrotalcite, or Ranaru green body composition Is prepared such that the total plastic weight , limestone or dolomite, and the alumina component are each at least 10% by weight and hydrotalcite is contained in an amount of 5 to 40% by weight with respect to the total weight of 100%. That the desired pore size and pore volume can be selected in the nano to sub-micrometer range by selecting the firing temperature in the range of 500 ° C to 1400 ° C and firing. It is a feature.
In addition to the object of claim 1 or 2, the invention described in claim 3 adds an alkaline slurry adjusting agent of 3% by weight or less to 1000% by weight to the substrate composition in order to obtain a porous material of better quality. To do.

According to the inventions described in claims 1 and 2, by arbitrarily firing the compact with a firing width of 500 to 1400 ° C. and firing, the pore size and the pore diameter can be arbitrarily set within a range of about nano to submicrometer. The pore volume can be designed. In addition, deformation and distortion of the fired body can be suitably suppressed by adding the alumina component. Furthermore, since the microstructure is a homogeneous porous body, it has excellent thermal shock resistance and is useful in a wide range of industrial fields. In particular, in the invention according to claim 2, since the specific surface area changes linearly with respect to the change in the firing temperature due to the inclusion of hydrotalcite, the control of the pore diameter and the pore volume is possible compared to the dolomite system and the like. It becomes easy.
According to the invention described in claim 3, in addition to the effect of claim 1 or 2, by addition of alkaline mud modifiers of _{trace, CaO (MgO) -Al 2 O} 3 -SiO 2 composition system solid phase A better quality porous body can be obtained by lowering the reaction start temperature.

The plastic clay used in the present invention is selected from at least one selected from Kibushi clay, Sasame clay, Kaolinite clay, bauxite clay, porcelain clay, and various artificial clays. The feldspar and quartz containing the alkali component of the plastic clay and, if necessary, mica are removed using a water tank or an industrial centrifuge.
On the other hand, lime and a bitter earth component may be those hydroxides, carbonates, and double salts.
The alumina component is preferably at least one selected from porous Al ₂ O ₃ , hydroxides, carbonates / ammonium groups / hydroxyl salts and double salts.

A base composition is prepared by containing 10% by weight or more of each of these components. Preferably, the plastic clay is 15 to 70% by weight with respect to the base composition, the limestone or dolomite is 15 to 70% by weight with respect to the base composition, and the alumina component is 15 to 70% by weight with respect to the base composition. Select and formulate each.
Further, when preparing a substrate composition by adding hydrotalcite to the above components , if the hydrotalcite is contained in the range of 5 to 40% by weight relative to the total weight of 100%, the pore diameter and pore volume It is suitable for the control. In addition, water glass or the like can be used as the alkaline slurry adjusting agent.
A ceramic having an arbitrary pore size and pore volume from nano size to sub-micron size and micrometer size is obtained by firing the prepared base composition by selecting a firing temperature in the range of 500 ° C. to 1400 ° C. A porous body can be obtained.

  Examples of the present invention will be described below.

<Baking of limestone compound base>
Mixing the substrate with 16% by weight of limestone, 47% by weight of Al (OH) ₃ , 37% by weight of kaolinite clay, and adjusting the water glass to 3.0% by weight with respect to the substrate weight of 1000 Five crucibles (height 70 mm × diameter 81.5 mm) and rod-shaped specimens (10 cm × diameter 2 cm) were prepared by the method. This was air-dried, installed in an electric furnace, heated to 300 ° C. as shown in the firing curve shown in FIG. 1, held for 1 hour, further heated to reach the set temperature and held for 1 hour, Firing was carried out at 50 ° C. every temperature from 600 ° C. to 1400 ° C. in the form of natural cooling. As a result, the crucible shape of the fired body was sufficiently maintained up to 1400 ° C.

<Sintering of dolomite-based compound base>
A slurry casting with 16% by weight of dolomite, 47% by weight of Al (OH) ₃ , 37% by weight of kaolinite clay, and water glass adjusted to 3.0% by weight with respect to the base weight of 1000. The same rod-shaped test body as in Example 1 was molded by the molding method. This was air-dried, placed in an electric furnace, and fired at 50 ° C. every 600 ° C. to 1400 ° C. in the same manner as in Example 1.

<< Baking of hydrotalcite preparation (HT-1) >>
Mix the substrate with 15% by weight of limestone, 37% by weight of Al (OH) ₃ , 10% by weight of hydrotalcite, 18% by weight of clay, and 20% by weight of Kibushi clay. A rod-like test body similar to that of Example 1 was molded by a mud casting method adjusted to 3.0% by weight with respect to 1000. This was air-dried, then placed in an electric furnace and fired at 100 ° C. every 500 ° C. to 1400 ° C. in the same manner as in Example 1.

<< Firing of hydrotalcite preparation (HT-2) >>
Mix the substrate with 15% by weight of limestone, 27% by weight of Al (OH) ₃ , 20% by weight of hydrotalcite, 18% by weight of clay, and 20% by weight of Kibushi clay. A rod-like test body similar to that of Example 1 was molded by a mud casting method adjusted to 3.0% by weight with respect to 1000. This was air-dried, then placed in an electric furnace and fired at 100 ° C. every 500 ° C. to 1400 ° C. in the same manner as in Example 1.

Comparative Example 1
A rod-shaped specimen was molded using 100% by weight of Kibushi clay, dried, and then fired in an electric furnace at 400 ° C., 600 ° C., 900 ° C., and 1000 ° C., respectively.
Comparative Example 2
The prepared white cloud ceramic body (kaolinite clay content 30%, dolomite 30%, feldspar / quartz 40%) was molded, dried, and baked at 700 ° C. The obtained porous body becomes a porous body on the order of μm in order to utilize the interparticle voids of the raw material base material.
Comparative Example 3
Alumina catalyst supports (KHA-24, NKH3-24) in which Al (OH) ₃ is blended at 90% by weight or more and kaolinitic clay at 10% by weight or less are commercially available. This was fired at 900 ° C. and 1000 ° C., respectively.

Hereinafter, the fired bodies obtained in the above examples were evaluated.
<< Shrinkage and 3-point bending strength >>
The calcining shrinkage of the limestone-based fired body of Example 1 above, the dolomite-based fired body of Example 2, and the HT-1 green fired body of Example 3 was analyzed and evaluated.
The three-point bending strength of the limestone-based fired body of Example 1 and the HT-1 fired body of Example 3 was measured and evaluated.
Limestone-based green fired rod-shaped test body (600-1400 ° C.) of Example 1, dolomite-based green fired rod-shaped test body (600-1400 ° C.) of Example 2, and HT-1 green fired body of Example 3 FIG. 2 shows a firing shrinkage curve of the rod-shaped specimen (500 to 1100 ° C.).
3 shows the three-point bending strength curves of the limestone-based green fired body (600-1400 ° C.) of Example 1 and the HT-1 green fired body (500-1100 ° C.) of Example 3. The bending strength is at least 5 MPa or more, and is characterized in that 10 MPa or more can be obtained at a firing temperature of 800 ° C. or more. Moreover, it can be estimated from FIG. 2 and FIG.

《Water absorption rate》
The water absorption rate of the limestone-based fired body of Example 1 and the HT-1 fired body of Example 3 was measured and evaluated. The water absorption was measured using LIBBROR ED-2000 manufactured by Shimadzu Corporation. The measurement was performed according to the following procedure.
Each specimen was boiled for 2 hours and then wiped with a towel to measure the moisture content, and then each specimen was dried at 110 ° C. for 3 hours to measure the dry weight. The dry weight was subtracted from the water content, divided by the dry weight, and a value obtained by multiplying by 100 was taken as the water absorption rate. FIG. 4 shows water absorption curves of the limestone-based fired body of Example 1 (600 to 1400 ° C.) and the HT-1 fired body of Example 3 (500 to 1100 ° C.) thus obtained.
FIG. 4 also shows a three-step change in pore volume. In the range of 500 to 800 ° C., the constituent basic materials sequentially undergo a decomposition reaction. Therefore, it can be estimated that the number and volume of pores are increased due to the increase of the starting point of the generated gas and the expansion of the generated gas.

  In addition, the decreasing tendency of the water absorption rate and the firing shrinkage rate at 800 to 900 ° C. is a decrease in the interparticle void accompanying the start of the sintering reaction, and the increase in the contact point between the particles increases the bending strength. In the range of 900-1200 ° C, as the sintering reaction progresses, the growth of the crystal grains and the growth of the nanopores progress, so that it appears that there is no decrease in the firing shrinkage and water absorption. Yes. However, since the three-point bending strength decreases at around 1200 ° C. and increases in the water absorption rate and the firing shrinkage rate, one aspect of the pore coalescence phenomenon can be detected by the progress of the sintering reaction. The phenomenon in the range of 1300-1400 ° C. is due to the progress of melting and softening of some of the many crystals.

<< Identification by X-ray powder diffraction >>
The limestone-based fired body of Example 1 and the HT-1 fired body of Example 3 were identified by X-ray powder diffraction.
The limestone-based fired body of Example 1 and the HT-1 fired body of Example 3 were pulverized to obtain a test powder for powder X-ray diffraction. Tables 3 and 4 show the crystal phase transitions of the limestone-based fired body (600 to 1400 ° C.) and the HT-1 fired body (500 to 1400 ° C.) determined from the powder X-ray diffraction pattern, respectively.

The constituent material CaCO ₃ was decomposed at around 750 ° C., and (Mg, Ca) CO ₃ was decomposed at around 700 ° C., and a small amount of SiO ₂ mixed in kaolinitic clay remained up to 850 ° C. Other components were pyrolyzed to 500 ° C. It is presumed that a porous structural skeleton is formed by metakaolinite, which is a decomposition product of active porous Al ₂ O ₃ and kaolinite produced by decomposition at 500 ° C. or lower. Among them, Hydrotalcite is progressing to spinel formation. It is likely that MgO and CaO react with the porous skeleton to form Gehlenite and Anorthite by skeletal surface reaction. Furthermore, it is considered that the surplus Al ₂ O ₃ component undergoes a phase transition to α-Al ₂ O ₃ at 1100 ° C. or higher. As a result of this reaction process, the sintering reaction was suppressed and the porous skeleton was maintained even at a high temperature of 1000 ° C. or higher.

<< Measurement of BET specific surface area >>
After pulverizing the limestone-based fired body of Example 1, the dolomite-based fired body of Example 2, the HT-1 green fired body of Example 3, and the HT-2 green fired body of Example 4, the nitrogen adsorption method The BET specific surface area was measured by
Kibushi clay fired body of Comparative Example 1, alumina catalyst carrier of Comparative Example 3, limestone-based fired body of Example 1, dolomite-based fired body of Example 2, HT-1 green fired body of Example 3, The results of measuring the BET specific surface area of the HT-2 green body of Example 4 are shown in FIG.
From this graph, it was shown that the specific surface area of 30 m < ² > / g or more was obtained about the 900 degreeC sintered body of Examples 1-4. Accordingly, it can be said that each example has a sufficient pore specific surface area as a ceramic filter.
Further, HT-1 and HT-2 prepared by blending hydrotalcite linearly develop a specific surface area graph from a low temperature to a high temperature as compared with a dolomite system containing magnesium. This is because dolomite, a dolomite component material, starts to decompose at around 700 ° C, whereas hydrotalcite, the component material of HT-1, HT-2, starts to decompose before 500 ° C. caused by. As a result, the graphs of HT-1 and HT-2 change linearly even when spinel is generated around 1000 ° C. From this, it can be said that the addition of hydrotalcite makes it easier to control the specific surface area compared to the dolomite system.

<Relationship between pore volume and pore diameter>
Furthermore, based on the data, the limestone-based fired body of Example 1, the dolomite-based fired body of Example 2, the HT-1 green fired body of Example 3, and the HT-2 green fired body of Example 4 A distribution curve showing the relationship between pore volume and pore diameter at each firing temperature was obtained.
For the limestone-based fired body of Example 1, the dolomite-based fired body of Example 2, the HT-1 green fired body of Example 3, and the HT-2 green fired body of Example 4, the fineness at each firing temperature. The pore volume and pore diameter distribution curves are shown in FIG. 6, FIG. 7, FIG. 8, and FIG.
The pore diameter and pore volume were measured using Tristar 300 manufactured by Shimadzu Corporation. In the measurement, 0.2 g of powder was vacuum degassed for 12 hours. The pore volume and pore diameter were calculated from the separation side based on the BJH model.

Formation of pores and maintenance measures up to high temperature (see FIGS. 6, 7, 8, and 9)
In the present invention, the mixture is made porous by a pyrolysis method of a mixture of kaolinite and Al (OH) ₃ at a low temperature, and suppresses generation of a SiO ₂ —Na ₂ O-based glass phase that causes liquid phase sintering as much as possible. The porous body can be maintained up to a high temperature by precipitating an alkali-containing earth-based crystal that can impart heat resistance from a low temperature to suppress the progress of sintering.
The generation of nanopores is a low-temperature pyrolyzate, and after decomposition, it is added to the Al-Si-O system centered on kaolinite and alumina to precipitate a crystalline phase containing alkaline earth that contributes to improving heat resistance. I made it. From the results of X-ray diffraction, it was inferred that the sharpness of the pore size distribution could be maintained up to 900 ° C. because various crystals containing calcium aluminosilicate were formed near the Al—Si—O porous skeleton at 1000 ° C. or less. Is done. Furthermore, since Hydrotalcite to which MgO component and Al ₂ O ₃ component are added is decomposed and spinel having good heat resistance at low temperature is generated on the surface side of the skeleton pores, the porous skeleton is maintained. It can be inferred that the sharpness of the pore size distribution could be maintained up to 1100 ° C. Furthermore, from the specific surface area measurement result of FIG. 5, it was estimated that the porous skeleton could be maintained while the pores forming the porous skeleton were enlarged up to about 1300 ° C.

For reference, FIGS. 10 to 12 show the relationship between the pore procedure and the pore diameter of the fired bodies in Comparative Examples 1 to 3, respectively.
In each fired body obtained in Comparative Example 1, the pore size distribution curve on the order of nm is as shown in FIG. 10, but the sharpness of the pore volume and pore distribution curve is also insufficient for use as a filter. Body strength (5 MPa or less) is also insufficient for use as a filter.
As in Comparative Example 2, the base fired body using dolomite as a base material containing a large amount of pyrolyzate can obtain pores in the order of nm as shown in FIG. 11, but the pore capacity is still insufficient. It is.
The catalyst carrier of Comparative Example 3 has insufficient strength, low compressive strength, is easily crushed, and the sharpness of the pore distribution curve is lost as shown in FIG. Porosity is also lost by sintering accompanying the phase transition to α-Al ₂ O ₃ at 1000 ° C.

《Thermal shock test》
A thermal shock test was performed on the HT-1 green body of Example 3 and the HT-2 green body of Example 4.
The HT-1 substrate and HT-2 substrate were each fired at 1200 ° C., and the prepared crucible was heated with a gas burner and then dropped into water, but there was no damage.

<Ink Test>
Each temperature-fired crucible (color tone: white) obtained in Example 1 was put into a transparent red ink (Pilot product number: ink-350-R) up to the sixth minute and observed for 15 minutes. The findings at each temperature are shown below.
(1) The baking at 700 ° C. only moistens the surface, and moisture is not transferred under the hill. Moisture reached the top of the crucible. After the ink was removed, the inner wall had a dark, reddish gel-like substance that could be wiped off with paper. The color of the inner wall was white.
(2) In the baking at 800 ° C., after the ink is introduced, the moisture gradually expands upward as the moisture appears. About 10 minutes later, the portion below the inner liquid surface was apparently light yellow. The hills were partially wet. After the ink was removed, the inner wall of the crucible had the same result as at 700 ° C., but after removing the dark reddish gel-like dye, a light yellow color was felt on the white pigment background.
(3) After firing at 900 ° C., the wetness appears on the surface, gradually rises and changes from a portion below the water surface to light yellow, and this also rises upward. Furthermore, it became a little pinkish from about 14 minutes. The hills were completely wet and lightly pink. After ink removal, the inner surface of the crucible was able to remove the dark red dye, but the subsequent white pigment background became light yellow.
(4) At 1200 ° C., it becomes pinkish in about one minute after the ink is added and rises above the water surface. In about 10 minutes, pink reaches the top, but the rise stops at about 5 mm from the top. The remaining upper part became pale yellow. The plateau was ink-colored. After the ink was removed, the inner surface of the crucible and the firing base were pink with the same color. These ink test results are schematically shown in FIG.

As a result of these observations, it can be seen from these experiments that, as a dynamic movement, moisture permeates and diffuses first, followed by a fine pale yellow dye dispersed in water, and a red dye of μm order moves through the pores. Is estimated.
On the other hand, since the hills do not get wet up to about 900 ° C., water permeation does not occur up to about 900 ° C. The movement of water molecules or several water molecules (clusters) was a capillary condensation phenomenon, and then the capillary phenomenon in which fine particles of sub-μm dye dispersed in water moved up with the water to the μm pore diameter was confirmed.

  Cleaning after a 1200 ° C firing crucible after the ink test took a long time when immersed in water, but when the pink crucible was floated on the surface of the water, it floated for about 12 hours and became pink only on the inner surface side. It was washed in the same procedure about 3 times. This found a water-saving cleaning method. While the inner and outer surface levels were the same, there seemed to be no dye particles on the outer surface side. If this is used as a filter, the possibility of backwashing is shown.

Al (OH) ₃ , Sakaime clay, and limestone were mixed at a ratio of 6 patterns 001 to 006 shown in Table 5 and molded into a rod-like test body similar to that of Example 1 by a mud casting method. This was air-dried, placed in an electric furnace, and fired at temperatures of 700 ° C., 900 ° C., and 1100 ° C. Table 6 shows the measurement results of the shrinkage rate and water absorption rate of each fired body and the results of the thermal shock test.

From Table 6, 001, 002, 005, 006 are all less than 10% at each temperature (especially, 001, 005 is 8% or less at each temperature), and the water absorption is 001, 002, 005, 006. Is over 20% at each temperature, and it is clear that it can be suitably used as a porous body. With regard to 001,003,004,006, the performance may be lower than others depending on the firing temperature, but the formulation itself can be said to be a practical range.
As described above, according to the production method of the present invention, it is understood that desired performance can be obtained as a porous body even when a part of the three components is blended at 10% by weight.

The porous body for a ceramic filter according to the present invention includes a ceramic filter, a heat-resistant reaction vessel, a heat-resistant impact ceramic, a lightweight ceramic building material, a moisture-conditioning building material, a lightweight ceramic, a large lightweight ceramic (such as sanitary ware, a combustion appliance), a lightweight bone In industrial fields such as materials, catalyst carriers for gas reactions, gas diffusion separation membranes, gas separation membranes, ceramic filters that can be back-washed, ceramic membranes for ion exchange, microbial filters, medical filters, and various filters for food processing On the other hand, it is possible to use inexpensive manufacturing methods and various shapes, high strength, heat resistance, and chemical resistance.

It is a graph which shows the baking curve of a compounding body. It is a graph which shows the baking shrinkage rate curve of each base material. It is a graph which shows the 3 point | piece bending strength curve of each base sintered body. It is a graph which shows the water absorption rate curve of each base sintered body. It is a graph which shows the BET specific surface area according to each base sintered body. It is a graph which shows the relationship between the pore capacity | capacitance and pore diameter in each calcination temperature of a limestone type body. It is a graph which shows the relationship between the pore capacity | capacitance and pore diameter in each calcination temperature of a dolomite type body. It is a graph which shows the relationship between the pore capacity | capacitance in each calcination temperature of a HT-1 base | substrate, and a pore diameter. It is a graph which shows the relationship between the pore volume and pore diameter in each calcination temperature of HT-2 base. It is a graph which shows the relationship between the pore capacity | capacitance and the pore diameter of the porous body of the fired Kibushi clay. It is a graph which shows the relationship between the pore capacity | capacitance and pore diameter of Mizuno pottery clay cloud ware (700 degreeC baking). It is a graph which shows the relationship between the pore capacity | capacitance and the pore diameter of the catalyst support | carrier (NKH3-24) which mixed and baked Al (OH) ₃ and kaolinitic clay. It is explanatory drawing which shows the transparent red ink injection | throwing-in test to the baking body (crucible) of a limestone type compounding body.

Claims (3)

And plasticity clay to remove feldspar and quartz containing alkali components was classified, and limestone or dolomite, each at least 10 wt alumina component, or a Ranaru green body composition, each component relative to the total weight of 100% % Of the composition, the base composition is molded into a predetermined shape, and the firing temperature is selected in the range of 500 ° C. to 1400 ° C. A method for producing a ceramic porous body, wherein the pore diameter and pore volume can be selected. And plasticity clay to remove feldspar and quartz containing alkali components was classified, and limestone or dolomite, alumina component, and hydrotalcite, or a Ranaru green body composition, previous to the entire weight of 100% A plastic clay, limestone or dolomite, and an alumina component are each blended so as to contain at least 10% by weight and hydrotalcite is contained in an amount of 5 to 40% by weight, and the base composition is molded into a predetermined shape. A method for producing a ceramic porous body, wherein an arbitrary pore diameter and pore volume can be selected in a range of nano to submicrometer by firing at a firing temperature of 1400 ° C.   The method for producing a porous ceramic body according to claim 1 or 2, wherein an alkaline sludge adjusting agent having a weight of 3/1000 or less is added to the substrate composition.

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