JP2000154073A - Production of porous fired body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a porous fired body utilizable as an adsorbent, a soil conditioner, hen feed, livestock feed, a vermin repellent, a magnetic field adjuster, etc. SOLUTION: A process is proposed by which porous carbon fired body coated with ceramics is produced. A combustible organic material (a) prepared so as to contain 70% water, a clay mineral (b) as a binder and a powdery additive (c) selected from a zeolite, calcium carbonate, inorganic waste containing a zeolite or calcium carbonate, copper carbonate, iron oxide, copper oxide and a ferrite are mixed so that the contents of the components (b) and (c) are adjusted to 2-20 pts.wt. and 0.3-8 pts.wt., respectively, based on 100 pts.wt. component (a). The surface of the component (a) is uniformly coated with the components (b) and (c) by the mixing and the mixture is heated to 600-700 deg.C using a rotary kiln to cause self-combustion. Firing is carried out by the self- combustion and a ceramic layer is formed on the surface of carbon produced by the carbonization of the combustible organic material to obtain the objective porous fired body.

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 fired body which can be used as an adsorbent, a soil conditioner, chicken feed, livestock feed, insect repellent, magnetic field regulator and the like. .

[0002]

2. Description of the Related Art Conventionally, in the production of activated carbon, some combustible materials such as wood (thinned wood) and sawdust have been used, but agricultural residues such as wood, sawdust and fir husks have been used. Most of the residue such as coffee has been disposed of or disposed of by incineration, and it is desired to reuse such organic waste from the viewpoint of environmental problems. At present, waste chips generated in large quantities at construction sites, punched paper chips, waste paper pulp, bamboo chips, and the like generated from semiconductor-related factories are also disposed of or incinerated.
On the other hand, conventionally known activated carbon is generally in the form of powder or granules, its main constituent is amorphous carbon, contains only a trace amount of inorganic components, and generally has many pores. Has a large adsorption surface area of about 600 to 1400 m ² / g and has been widely used as a gas phase or liquid phase adsorbent.
Almost no adsorptivity to harmful organic gases such as formaldehyde.

[0003] Japanese Patent Laid-Open Publication No. Hei 10-194865 discloses a charcoal having improved adsorbability for harmful organic gases, such as SiO ₂ and flammable organic substances such as wood and fir husk.
And a porous fired body produced by adding bentonite containing Al ₂ O ₃ as a main component and performing firing, and discloses a fired body having a structure in which a carbon surface is coated with ceramics. However, it is described that it can be used not only as a gas adsorbent but also as a humidity control material, a soundproof material, and the like. However, there has not been proposed a fired product that has been modified (improved in functionality) by further adding components other than clay minerals such as bentonite, and the types of substances for imparting functionality, The functionality provided by the company is not disclosed.

[0004] Similarly to the above-mentioned organic wastes, inorganic wastes such as dust generated from a crushed stone plant and shells generated from a food processing plant can be procured at a low cost. The law has hardly been found, and most of them have been disposed of. Currently, there is a demand for the reuse of these inorganic wastes from the viewpoint of environmental problems.

[0005]

SUMMARY OF THE INVENTION The present invention aims at recycling organic wastes such as wood and sawdust, and at the same time, inorganic wastes such as quarry sludge and crushed shells which have hardly been used so far. It is an object of the present invention to provide a method for producing a fired body having excellent functionality other than the gas adsorption function by reusing the same. In addition, special functions (soil improvement effect, plant growth promotion effect, electric conduction effect) have been imparted by adding metal oxides and carbonates, which have not been noticed at all, together with clay minerals such as bentonite. It is also an object of the present invention to provide a method for producing a fired body. As a result of various studies, the present inventor has found that when carbonizing and burning a combustible organic substance in a rotary open furnace, together with a clay mineral (kaolinite, halloysite, bentonite, etc.) used as a binder for coating the organic substance. , Zeolite, calcium carbonate, zeolite or calcium carbonate-containing inorganic waste, by mixing powdered additives selected from the group consisting of copper carbonate, iron oxide, copper oxide and ferrite, after firing, on the surface of carbon The inventors have found that a porous fired body having a structure coated with ceramics and having various special functions can be manufactured depending on the type of the powdery additive, and the present invention has been completed.

[0006]

The method for producing a porous fired body according to the present invention is a method for producing a porous fired body in which a ceramic is coated on the surface of carbon. An organic material; b) a clay mineral as a binder; c) a granular additive selected from the group consisting of zeolite, calcium carbonate, zeolite or inorganic waste containing calcium carbonate, copper carbonate, iron oxide, copper oxide and ferrite. And the clay mineral 2 to 20 parts by weight with respect to 100 parts by weight of the flammable organic substance which has been adjusted so that the water content becomes 70% in advance.
Parts by weight and the powdery additive are mixed at a ratio of 0.3 to 8 parts by weight, and the surface of the flammable organic material is uniformly coated with the clay mineral and the powdery additive. The method is characterized in that self-combustion is caused by heating to 600 to 700 ° C., and thereafter, firing is performed by self-combustion to form a ceramic layer on the surface of carbon generated by carbonization of the combustible organic substance.

[0007] In the present invention, in the above-mentioned production method, the flammable organic substance is selected from the group consisting of thinned wood chips, construction waste chips, coffee residue, fir hulls, punched paper pieces, waste paper pulp and bamboo chips. It is also characterized by being. Furthermore, the present invention is characterized in that, in the above-mentioned production method, the clay mineral is selected from the group consisting of kaolinite, halloysite and bentonite.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, each component used in the production method of the present invention will be described. In the manufacturing method of the present invention, the flammable organic substance used as the component a contains a carbon component, has a solid flammability, and may be a substance which changes to a carbide when fired, Those which are granular in the state are preferable, and particularly preferable ones include thinned wood chips, construction waste chips, coffee residue, fir hulls, punched paper pieces, waste paper pulp, bamboo chips, and the like. The advantages and disadvantages are as follows. (1) Thinned wood chips Although procurement costs are relatively high, unused wood resources can be used effectively. (2) Construction waste chips Stable procurement is possible, and procurement costs are almost negligible. (3) Coffee residue The particle size is small and uniform, the procurement cost is low, and the phosphorus content is high. (4) Fir husk Although stable procurement is difficult, it is inexpensive and contains a large amount of SiO ₂ components. (5) Punched paper pieces Uniform particle size, low procurement cost, and contain inorganic components. (6) Waste paper pulp The procurement cost is low, it is fibrous, and it can be pelletized. (7) Bamboo chip It is conductive and has high adsorption performance in the liquid phase.

Next, in the production method of the present invention, the component b
The clay mineral used as a clay mineral acts as a binder, and various materials mainly composed of SiO ₂ and Al ₂ O ₃ can be used. Examples thereof include bentonite, halloysite, and kaolinite. But
Among them, bentonite is preferable in that it has an excellent effect of suppressing the oxidation of the combustible organic substance, and the main component mineral of this bentonite is montmorillonite.

Further, in the production method of the present invention, the component c
The powdery additive used as is added to impart various properties to the porous fired body obtained by firing, zeolite, calcium carbonate, zeolite or calcium carbonate-containing inorganic waste, The characteristics and functions of the fired body obtained by the selection from the group consisting of copper carbonate, iron oxide, copper oxide and ferrite, and the physical properties and addition of each are as follows.

(I) Zeolite A zeolite is a natural porous mineral mainly composed of hydrated alumina silicate, and its particle size is suitably 25 to 300 μm, and particularly preferably 50 to 150 μm. The specific surface area is 5000 cm ² / g or more, and 8000 cm ² / g
The above is preferred. The fired body obtained by adding zeolite is particularly excellent in terms of porosity, and has a high adsorption performance due to its porous structure, and can be activated in a microbial system. Optimal. Further, the obtained fired body can be used as chicken feed, and since it absorbs the odor of the poultry house, it is also effective in odor control. Furthermore, when added to soil and used, it has the effect of promoting plant growth. The zeolite used in the present invention is particularly preferably a high-temperature vitrification type.

(Ii) Calcium carbonate A powder having a purity of 90% or more, preferably 99% or more. The fired body obtained by adding calcium carbonate generally exhibits a strong alkalinity of pH 11 or more, and is most suitable as a pest repellent, particularly for countermeasures against slug damage at a tangerine farm. Further, it is most suitable as a neutralizing agent for acidic soil, and has the advantage that the soil is not hardened by the action of charcoal.

(Iii) Mineral waste containing zeolite or calcium carbonate (quarry sludge, shell crushed material, etc.) Examples of the quarry sludge (crushed dust generated in a quarry plant) include hard sandstone, rhyolite, and quartz porphyry, preferably. Is suitable to contain a porous mineral such as zeolite or vermiculite as a main component, and has a specific gravity of 2.0 to 3.0.
0, preferably 2.5 to 2.7, and the particle size is 25 to 3
00 μm is suitable, and 50 to 150 μm is particularly preferred. The specific surface area is at 1100 cm ² / g or more, preferably at least 5000 cm ² / g, excellent adsorption performance by the above-mentioned porous mineral is shown. In addition, the fired body obtained by adding quarry sludge shows excellent soil improvement effect and plant growth promotion effect when used by adding to soil, and is bentonite (market price of about 30 to 50 yen / kg).
It can be procured at an extremely low price (about 3 to 5 yen / kg) as compared with the case of using the bentonite alone, and the cost can be reduced by 70% or more. Also, crushed shells are
It contains a large amount of calcium and mineral components, and the fired body obtained by adding it exhibits a fertilizer effect of mineral supplementation together with the soil improvement effect of the carbide, resulting in the promotion of plant growth . In addition, it can be used as chicken feed and livestock feed, and can be procured at a low cost (about 10 to 20 yen / kg), similar to quarry sludge, with a cost reduction of 40% or more compared to the case where only bentonite is used. be able to. The specific gravity and particle size of the preferable ground shell are the same as those of the above-mentioned quarry sludge.

(Iv) Copper carbonate Powder having a purity of 90% or more, preferably 99% or more, is used. The calcined product obtained by adding copper carbonate is obtained by reducing copper carbonate to copper during carbonization. To become pure copper, which acts as a catalyst to increase the adsorption capacity and decompose the adsorbed substances. In addition, the antibacterial action of copper can suppress the growth of various bacteria such as mold.

(V) Iron oxide (magnetite), copper oxide These metal oxides are all powders having a purity of 90% or more, preferably those having a purity of 99% or more. Has low electric conductivity, but the fired body obtained by adding iron oxide and copper oxide has charge conductivity. This is because iron oxide is reduced during carbonization to become pure iron, and copper oxide is reduced during carbonization to become pure copper.

(Vi) Ferrite A powder having a purity of 90% or more, preferably 99% or more. MO-Fe ₂ O ₃ (M is a divalent metal ion)
The fired body obtained by adding is not conductive, but has magnetism, for example, it can be buried in a site such as a farm to adjust the magnetic field, and enhance the function of promoting the growth of agricultural products. It can be used as a carbon resource when practicing “carbon burial”. In addition, the sintered body obtained by adding cobalt ferrite among the ferrites can control the magnetism, has the function of stabilizing the current direction (rectification function), and can be applied to batteries. It is. For example, when a powdered carbide is solidified with a binder and formed into a rod shape, one end of the rod is irradiated with sunlight, and the other end is light-shielded, a heat battery capable of converting heat energy into electricity. Available as

In the production method of the present invention, the mixing ratio of the component b (clay mineral) and the component c (powder additive) with respect to the component a (flammable organic substance) is as follows. With respect to (iii), with respect to 100 parts by weight of the flammable organic matter previously adjusted to have a water content of 70%,
The clay mineral is 2 to 10 parts by weight, preferably 3 to 5 parts by weight, the powdery additive is 1 to 8 parts by weight, preferably 5 to 7 parts by weight. The powdery additives (iv) to (vi) are composed of a flammable organic substance 1 previously adjusted to have a water content of 70%.
The amount is 2 to 20 parts by weight, preferably 8 to 10 parts by weight, and 0.3 to 2.0 parts by weight, preferably 0.5 to 1.5 parts by weight of a powdery additive, based on 00 parts by weight.

Next, a process for producing a fired body having a ceramic layer formed on a carbon surface generated by carbonization of a flammable organic substance using the above-described components a to c will be described. First, flammable organic substances such as thinned wood chips and construction waste chips (the water content of the chips is about 70% by weight, preferably 6% by weight.
The clay mineral is adjusted in a ratio of 2 to 20 parts by weight and the powdery additive is added in a ratio of 0.3 to 8 parts by weight with respect to 100 parts by weight of 100 parts by weight. And the surface of the combustible organic material is uniformly coated with the clay mineral and the powdery additive. In the present invention, the coating of the clay mineral and the powdery additive on the surface of the flammable organic substance is performed by:
It is performed in the presence of water, and when adjusting the water content, when the original flammable organic matter has a small amount of water, for example, in the case of thinned wood chips or fir husks, the addition of water is necessary. In the case of highly raw materials, for example coffee residues, the addition of water is not necessary.

Then, the ground material coated in this manner is transferred to a rotary kiln (rotary carbonization furnace) through a charging hopper and uniformly heated by the rotary kiln. Upon reaching the surface, the surface of the crushed raw material (internal material) is sealed, and for example, in the case of fir husks, when the temperature reaches 600 ° C., raw gas is generated from the internal material. When the temperature is further increased to 650 ° C., the raw gas ignites and the material itself starts self-combustion. In the present invention, the heating temperature is slightly different depending on the kind of the flammable organic substance, but the temperature required to cause self-combustion is 600 to 7
00 ° C. It is up to this point that the energy supply for combustion is required.
When the temperature rises to about the same level and the residue is burned together, the product is transferred from the furnace to the cooling device when the gas has burned out, and cooled by the cooling device to obtain a porous fired body.

In the present invention, all the space occupied by ultra-fine bubbles and residues generated in the material at the stage of self-combustion becomes hollow, forming pores on the surface of the carbide, A ceramic component is coated on the surface of carbon generated by carbonization of the volatile organic material to form a ceramic layer, and a fired body having a porous structure is produced. The content ratio of carbon in the fired body is generally 30 to
It is 60% by weight, preferably 30 to 50% by weight, and the content ratio of ceramics in the fired body is 70 to 40% by weight, preferably 70 to 50% by weight. This is because when the content of carbon is extremely less than 30% by weight and the content of ceramics extremely exceeds 70% by weight, the specific surface area (pore volume) of the fired body becomes small, and the porous structure collapses. On the contrary, the content of carbon extremely exceeds 60% by weight, and the content of ceramics is 4%.
If the content is extremely lower than 0% by weight, a porous structure is obtained, but the soil neutralization effect, fertilizer effect, plant growth promotion effect, electric conduction effect, and the like provided by the ceramic layer are unpreferably reduced.

The porous fired body obtained by the production method of the present invention has an advantage that the fired carbon particles have a structure in which they are strongly bonded to each other, so that they are hardly pulverized and are very easy to handle. It is water-insoluble and easy to regenerate, and exhibits a water-retaining effect due to water absorption. Moreover, the fired body is excellent in safety because its constituents are carbon and ceramic components harmless to the human body and exhibit super-flammability. Incidentally, as the particle size of the fired body obtained in the present invention, the powdery additive of the component c is (i) to (iii), namely, zeolite, calcium carbonate, zeolite or calcium carbonate-containing inorganic waste. In the case of either one, the diameter is generally about 0.1 to 10 mm, but in the present invention, the particle size of the fired body is not limited to this range, and can be appropriately selected depending on the application. Further, when the additive of the component c is the above (iv) to (vi), that is, a metal carbonate or a metal oxide, the additive can be used in the above-mentioned particle size range, but the electric conductivity of the fired body is utilized. In applications where the average particle size is 30 to 100,
It is preferable to use the product after pulverizing it to about μm.

In the present invention, any of the above-mentioned (i) to (iii), that is, zeolite, calcium carbonate, zeolite or calcium carbonate-containing inorganic waste is added as a powdery additive of the component c. The obtained fired body (carbide)
Generally, the average pore diameter according to the Langmuir method is 22 to 32.
Å. Dioxins, which are problematic during waste incineration, have a large molecular weight and are difficult to adsorb with conventional activated carbon with a small pore size.However, this calcined product has a relatively large pore size and a high molecular weight. It is suitable for adsorption of large objects, and its ignition point temperature is as high as 370 ° C.
It has features such as being easily crushed into fine powder. Therefore, using such a fired body, activated carbon can be blown into exhaust gas in front of an electric dust collector or a bag filter of an incinerator to adsorb and remove dioxins.

Further, according to the present invention, the lipophilicity can be increased by spraying a small amount of vegetable oil (eg, waste oil of tempura oil) on the surface of the carbonized material obtained by calcination. Can be effectively used as an oil adsorbent as a countermeasure for tanker wastewater purification and crude oil spill accidents. In this case, 5 to 10 parts by weight of vegetable oil, preferably 7 to 9 parts by weight, per 100 parts by weight of carbides.
It is preferred to spray parts by weight.

[0024]

EXAMPLES Example 1 Specific Example of the Manufacturing Method of the Present Invention A waste chip 10 whose water content was adjusted to about 70% by weight.
To 0 parts by weight, 3 parts by weight of bentonite and 7 parts by weight of a powdery additive described below were added, and the mixture was kneaded for about 15 minutes with a kneader, so that bentonite and the powdery additive were added to the surface of the waste chip. After uniform coating, the mixture is heated to 650 ° C. using a rotary kiln, and then fired by self-combustion. After the combustion is completed, the fired product is transferred to a cooling device, cooled, and the final product is taken out. A porous fired body (particle size: about 0.5 to 5 mm) having a ceramic layer formed on the surface of carbon generated by carbonization of a combustible organic substance was obtained. Kinds of powdered additives Example 1a: zeolite Example 1b: calcium carbonate Example 1c: quarry sludge (trade name: Microstone, manufactured by Kinki Crushed Stone Cooperative Association) Example 1d: shell sludge In addition, in the above-mentioned production method, except that 9 parts by weight of bentonite and 1 part by weight of a powdery additive described below are added to 100 parts by weight of building waste chips whose water content is adjusted to about 70% by weight. Similarly, a porous fired body was obtained. Example 1e: Copper carbonate Example 1f: Iron oxide Example 1g: Ferrite

COMPARATIVE EXAMPLE: Production Example of a Porous Fired Body Containing No Component c in the Present Invention Waste chip 10 whose water content was adjusted to about 70% by weight.
After adding 10 parts by weight of bentonite to 0 parts by weight and kneading with a kneading machine for about 15 minutes, the surface of the waste chip is uniformly coated with bentonite, and then 65 kg using a rotary kiln.
After heating to 0 ° C, firing is performed by self-combustion. After the combustion is completed, the fired product is transferred to a cooling device to be cooled, and the final product is taken out. Thus, a porous fired body having a ceramic layer formed thereon was obtained.

A test for confirming the effect of the fired body obtained by adding zeolite powder as the component c on the growth of agricultural crops [Kaiwa radish cultivation experiment] Three glass dishes with a diameter of 10 cm were prepared, and a commercially available sponge was placed in each of them. On this sponge, 25 cc of the fired body of Example 1a (carbide with zeolite added), 25 cc of the fired body of the comparative example (carbide with single addition of bentonite), and one without any (blank) ) Were prepared, and about 20 seeds of radish were sown in each. On the fourth, sixth, and ninth days from the start of the experiment, the length of the grown shoots was measured, and the average value (unit) : Mm). [Experimental Result] Type of fired body 4th day 6th day 9th day Example 1a 11 24 37 Comparative example 11 22 31 Blank 10 17 22 From this experimental result, firing of Example 1a obtained by adding zeolite The body showed a growth effect (a growth effect of about 20% with respect to the comparative example on the ninth day) in a cultivation experiment of radish.

Test for confirming pest repellent effect and soil improvement effect of calcined product obtained by adding calcium carbonate powder as component c [Pest repellent experiment]
When 5 liters of the fired body of Example 1b were sown on soil having a radius of 1 m around the tree, slugs could be effectively repelled as compared with trees not sown with the fired body. [Soil improvement experiment] As a neutralizing agent for acidic soil, pH 4.
It was confirmed that when the fired body of Example 1b was mixed with the soil of Example 5 so as to have a volume of 1% of the soil volume, the soil was effective in neutralizing acidic soil. Moreover, when only normal calcium carbonate is used as a neutralizing agent, the soil hardens and becomes unsuitable for plant cultivation. However, the fired body of Example 1b does not harden the soil but I was able to sum up.

A test for confirming the effect of the fired body obtained by adding quarry sludge or shell sludge as component c on the effect of promoting the growth of agricultural crops [Kaiwa radish cultivation experiment] In the same manner as in A, the fired body of Example 1c (quarry sludge) ) And the fired body of Example 1d (carbonized material obtained by adding shell sludge) were subjected to a radish cultivation experiment. On the fourth and sixth days from the start of the experiment, On the ninth day, the lengths of the grown shoots were 11 mm and 24 m on average.
m, 37 mm, which is about 20% less at the time of the ninth day than in the case of the bentonite single addition carbide not containing the component c.
% Growth effect was observed. In addition, the fired body of Example 1d had a soil improving effect by a calcium component and a mineral component contained in shell sludge, in addition to a growth effect on plants.

Evaluation of Characteristics of Fired Body Obtained by Adding Copper Carbonate as Component c The fired body of Example 1e has a carbon surface formed by carbonization,
It has a porous structure in which copper generated by reduction of copper carbonate is dispersed in the ceramic layer, and has a growth inhibitory effect more than the fired body of the comparative example in a mold growth experiment.

Evaluation of Characteristics of Fired Body Obtained by Adding Iron Oxide as Component c The fired body of Example 1f has a surface on carbon generated by carbonization.
It has a porous structure in which iron generated by reduction of iron oxide is present in a state of being dispersed in the ceramic layer, which is pulverized so that the average particle size becomes about 70 microns. When the electrical conductivity of the fired body of the comparative example was compared with the pulverized product obtained by similarly pulverizing, the latter showed low electrical conductivity, whereas the former was dispersed in the ceramic layer. Due to the action of iron, it exhibited high electrical conductivity.

Evaluation of Characteristics of Fired Body Obtained by Adding Ferrite as Component c The fired body of Example 1e and the fired body of the comparative example were subjected to a magnetic field using a permanent magnet. Although it was magnetized, the latter was not magnetized and the former was found to be more strongly magnetized.

Example of application of the fired body obtained by the production method of the present invention as an oil adsorbent [Oil adsorption experiment] 8 parts by weight of tempura oil (waste oil) was added to 100 parts by weight of the fired body obtained in Example 1a. By spraying, oil was attached to the surface of the fired body, and 120 cc of the fired body surface-treated in this manner was prepared. On the other hand, as a comparative example, 120 cc of the fired body (untreated product) obtained in the comparative example was prepared. Then, the above-mentioned surface-treated fired body was formed into a bag-shaped product (length 10 cm × width 10 cm) using a commercially available nonwoven fabric having a water permeability (Coffee Milacron (trade name) manufactured by Yamanaka Sangyo Co., Ltd.). And the untreated calcined body are separately put and sealed, and a circular hollow is formed in the center of the bag, and 10 cc of commercially available salad oil is dropped therein, until the oil is visually absorbed into the bag. Was measured. The measurement was performed five times for each sample, and the average value was calculated. Oil absorption time of the fired body of Example 1 after surface treatment:
3.2 seconds Oil absorption time of the fired body of the comparative example (burned body with only bentonite added): 7.0 seconds From the above experimental results, the fired body obtained by the production method of the present invention is subjected to surface treatment with oil to obtain an oil. It turned out that it can be used as an adsorbent.

[0033]

As described above, by appropriately selecting the type of the component c as the third component and carrying out the production method of the present invention, an adsorbent, a soil conditioner, chicken feed, livestock feed, pest repellent Materials having various functionalities can be produced depending on the use, such as agents, magnetic field regulators, and growth promoters for agricultural crops. Further, the production method of the present invention, as a flammable organic substance,
Thinned wood chips, construction waste chips, coffee residue, fir shells, etc. can be used, and quarry sludge and shell crushed materials can be used as inorganic waste, so resource saving,
It also contributes to environmental protection and has the advantage that it can be implemented relatively easily without using special equipment.

Continued on front page F-term (reference) 4G019 KA02 4G066 AA04B AA27B AA43B AA61B AA64B AA66B AA75B AC39A CA05 DA08 FA18 FA21 FA34 FA37

Claims (3)

[Claims] 1. A method for producing a porous fired body having a surface of carbon coated with ceramics, comprising: a) a combustible organic substance; b) a clay mineral as a binder; c) A zeolite, calcium carbonate, a zeolite or calcium carbonate-containing inorganic waste, a powdery additive selected from the group consisting of copper carbonate, iron oxide, copper oxide and ferrite are adjusted in advance to a water content of 70%. 100 parts by weight of the above combustible organic matter,
Parts by weight and the powdery additive are mixed at a ratio of 0.3 to 8 parts by weight, and the surface of the flammable organic material is uniformly coated with the clay mineral and the powdery additive. A porous fired body characterized in that self-combustion is caused by heating to 600 to 700 ° C., followed by firing by self-combustion to form a ceramic layer on the surface of carbon generated by carbonization of the combustible organic substance. Manufacturing method. 2. The method according to claim 1, wherein the combustible organic matter is selected from the group consisting of thinned wood chips, construction waste chips, coffee residue, fir hulls, punched paper chips, waste paper pulp and bamboo chips. 2. The method for producing a porous fired body according to 1. 3. The method for producing a porous fired body according to claim 1, wherein the clay mineral is selected from the group consisting of kaolinite, halloysite, and bentonite.