JP2001302366A - Lightweight porous body and method of producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a porous ceramic which is lightweight, porous and excellent in water absorbing property or transpiratory property, has various pore structures and resistance to decomposition/volume reduction by the action of microorganisms, can be recycled and is harmless even when it is finally abandoned and which is preferably used as a fungus bed material for immobilizing various microorganisms and to provide a method of producing the same. SOLUTION: The porous ceramic is obtained by granulating a mixture containing a binder comprising a foamed fine powder of a natural glass material and a clay mineral as a main material and an organic powder comprising a cereal or a husk as an auxiliary material and firing. The porous ceramic has a bulk density of 0.4 to 1.5 g/cm3 and pores having pore diameters of several micrometers to 100 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lightweight porous body and a method for producing the same.

[0002]

2. Description of the Related Art Attention has been paid to the diverse abilities of microorganisms, and their use and research have become active and diversified. Conservation of the global environment is an internationally important and urgent issue, including the use of organic industrial and domestic waste and sewage sludge for decomposition and volume reduction, and for the purification of contaminated groundwater and contaminated soil by the action of microorganisms. It is expected to be useful for activating the soil by useful soil bacteria and increasing production of agricultural products. The microorganism-immobilized carrier is called a bacterial bed material. Bacterial beds for decomposing and reducing the volume of organic matter include plant-based beds, inorganic bacterial beds, and polymer-based beds. Further, there is a bacterial bed material using these in combination.

[0003] As a plant-based fungal bed material, cedar chip material generally has excellent characteristics. Lignin is present in the cell walls of plants with conduits, etc., and mature plant cells form a double cell wall, blocking extracellular enzymes from microorganisms. Lignin is a hardly decomposable substance for microorganisms, and it is said that white wood decay fungi and other mushrooms act on it. The bed of cedar chips uses this property of lignin. These plant-based bacterial bed materials have a characteristic that they have a bulk specific gravity of about 0.7, are lightweight and have excellent water absorbability, and are easy to handle. However, the cedar chip material bed is inconvenient because it needs to be replenished or replaced at regular intervals because the porosity of the bed is destroyed and the organic matter in the bed material is decomposed and reduced in volume by the action of microorganisms. It is.

[0004] Porous ceramics mainly composed of zeolite for water treatment, activated carbon or the like have been used as the inorganic bacterial bed material. However, these inorganic bacterial bed materials have a bulk specific gravity 3 to 4 times that of the plant bacterial bed material. For this reason, there is a problem that a strong power source is required for the stirring device for mixing the garbage and the cells. Also, 70-80% of the constituents of the garbage is water, but the inorganic bacterial floor material has insufficient water absorption / water retention ability and is inferior in the function of water control. Due to this, there is a problem that it is easy to induce bad smells and sanitary pests. As a countermeasure, a dehydration / deodorization device is required, and control for allowing microorganisms to survive becomes complicated. Furthermore, since the inorganic bacterial bed material is an extremely fine porous material compared to the plant bacterial bed material, the type and quantity of microorganisms to be immobilized are small, and the ability to decompose organic substances by microorganisms is low, which is inconvenient. .

[0005] A high molecular weight bacterial bed material is used for liquid treatment as a fluidized bed by immobilizing microorganisms. Techniques for purifying groundwater contamination by immobilizing biodegradable plastics such as PVA (polyvinyl alcohol) as nutrient sources for microorganisms have also been developed. However, since the microorganism to be immobilized uses a carrier as a nutrient source, the type of microorganism is limited depending on the material.
In some cases, microorganisms are immobilized on PP (polypropylene) and used as a fluidized bed. However, when this is finally disposed of, it must be incinerated. Incineration of plastics can cause environmental pollution and should be avoided as much as possible.

[0006]

The chemical substance conversion of reducing or eliminating the volume of organic matter by microorganisms involves the secretion of various types of extracellular enzymes by metabolism by various types of microorganisms, and the conversion of high-molecular-weight organic substances into appropriate low-molecular-weight substances. It is due to the action of decomposing into organic matter, dissolving in water and absorbing. In order for microorganisms to be activated, appropriate physical, chemical, and biological survival environmental factors such as temperature, osmotic pressure, food, water, and symbiosis are important.

The present invention is light-weight, porous, has a variety of pore structures, is easy for many kinds of microorganisms to settle, is not decomposed by the action of microorganisms, has excellent durability, and has excellent water absorption and transpiration. Excellent, recyclable and harmless when disposed of. Further, it can be used for garbage treatment and sludge treatment, and can also be used as a fluidized bed for water treatment. Provided is a lightweight porous body suitable as a microbial bed material for immobilizing microorganisms and a method for producing the same.

[0008]

The lightweight porous body of the present invention has the following structure as a carrier having various uses. The lightweight porous body according to the present invention is mainly composed of a foamed fine powder of a natural glass material and a binder made of a clay mineral, and an organic fine powder made of a grain or a cereal hull is used as an auxiliary material, and an additive for pH adjustment is added. The wet product obtained by kneading with water is used as a raw material. A porous binder obtained by extruding and drying the material. And porous ceramics obtained by sizing and firing after extrusion molding, having a bulk specific gravity of 0.4 to 1.5 g / cm ³ , a pore diameter of several μm to 100 μm, a water absorption of 20% or more, and a shaft. It is a lightweight porous body having a diameter or diameter of 1.0 to 30 mm, a main material blend of 40% by weight or more of natural glass fine powder, a firing temperature of 1000 ° C. or less, and pores including open pores and closed cells.

As the natural glass material, use is made of pearlite fine powder composed of obsidian, perlite or pine stone or volcanic glass fine powder of shirasu balloon composed of shirasu / volcanic ash. Rhyolite natural glass pumice fine powder may be used. The common feature is that of the naturally occurring glass material in which the crystal water contained is rapidly heated and foamed. It is preferable to use fine powder having a bulk specific gravity of 0.7 g / cm ³ or less and a size of 1 mm or less in which air bubbles are not crushed.

As the clay mineral of the binder, bentonite, frog-eye clay or the like is preferably used. As the organic fine powder of the auxiliary material, cereals such as corn starch, rice bran, bran, buckwheat and the like, and cereal husks such as buckwheat husk and rice husk may be used. The additive is used as a pH adjuster depending on the type of microorganism used. In general, bacteria prefer weak alkalinity and mycelia prefer weak acidity.

The method for producing a lightweight porous body according to the present invention is characterized in that a foamed fine powder of a natural glass material and a binder made of a clay mineral are used as main materials, and an organic fine powder made of grains or cereal hulls is used as an auxiliary material to adjust pH. Add the material, add water, knead and use the wet product as the raw material. A porous composite obtained by extruding and drying the material. Further, after extrusion molding, a porous ceramic obtained by spheroidizing the particles by a rolling method using a predetermined sizing machine and sintering, having a bulk specific gravity of 0.4 to 1.5 g / cm ³ and a pore diameter of several μm １００100 μm, water absorption of 20% or more, shaft diameter or diameter of 1.0 to 30 mm, main material blend of natural glass fine powder of 40% by weight or more, firing temperature of 1000 ° C. or less, pores including open pores and closed cells It is characterized by obtaining a lightweight porous body.

The lightweight porous body is provided as a carrier for immobilizing microorganisms for the decomposition treatment of organic industrial and domestic waste and sewage sludge. It may be impregnated with a neutralizing agent for contaminated groundwater / soil and provided as an environmental purification material. Alternatively, useful soil bacteria may be immobilized and mixed with fertilizers or seeds to provide soil improving materials or greening materials. Furthermore, it can be used as a biomaterial for bioremediation of contaminated groundwater and soil at contaminated sites, and is harmless even if disposable. Since the porous ceramic of the present invention can be reused, it can be provided as a main component of artificial soil. Also, after immobilizing microorganisms,
It can be dried and stored in an endospore state. Since it is a natural glass material, it is harmless and chemically stable, and can be provided as a bed material for bacteria in the food industry and the environment industry that uses microorganisms.

[0013]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. The lightweight porous body of the present invention is mainly composed of a foamed fine powder of a natural glass material and a binder made of a clay mineral, an organic fine powder made of grains or cereal hulls is used as an auxiliary material, and an additive for pH adjustment is added. Wet and kneaded wet products are used as raw materials. A porous composite obtained by extruding and drying the material. And a porous ceramic obtained by sizing and firing after extrusion molding, having a bulk specific gravity of 0.4 to 1.5 g / cm ³ and a pore diameter of several μ to 100 μ.
m, water absorption rate is 20% or more, shaft diameter or diameter is 1.0 to 3
0mm, the main material is more than 40% by weight of natural glass powder,
The sintering temperature is 1000 ° C. or less, and the pores are characterized by obtaining a lightweight porous body containing interconnected pores and closed cells.

FIG. 1A shows a fine powder of a natural glass material.
As the natural glass material, pearlite composed of obsidian, perlite and pine stone, rhyolite pumice and shirasu, or volcanic glass of shirasu balloon composed of volcanic ash may be used. The origin and composition are almost the same, and the contained water of crystallization serves as an initiating material and is heated and foamed to form a natural glass material. Microorganisms land on these natural glass materials. A foamed natural glass material containing no titanium oxide in the material composition is suitable. When titanium oxide is contained, a suitable bacterial bed material cannot be obtained due to its antibacterial action. The production method, firing temperature, and foaming rate of pearlite vary depending on the ore. Obsidian has many closed cells, and perlite and pinestone have many open pores. Each of them has an important feature of obtaining a lightweight porous body, and it is important to properly use them according to the application and purpose. As a carrier for immobilizing microorganisms, perlite fine powder of perlite and pine stone, which has the characteristics of interconnected pores, is preferred because its surface structure is important, and pearlite fine powder of pine stone, which has a low foaming rate, breaks during granulation. It is difficult and suitable.

The main components of pearlite are approximately 70 to 75% of silica (Sio ² ) and alumina (Al ² O ³ ) 1
Obsidian (moisture <2%), perlite (moisture 2-5%), pine stone (moisture> 5)
%). Fine powder generated in the pearlite manufacturing process and dust collected by a dust collector are used. Surplus products are waste products that are treated as industrial waste. In the crushing step (1), the particle size of the perlite powder product is adjusted using a crushing rectifier. A screen is disposed inside the crushing and sizing machine, and only the particles that do not pass through the screen are crushed. Set the screen to 1mm (1mm
The following fine powder), the pore size after firing is several μ to 100 μ
m pores are obtained. An airflow classifier may be used. Simply grinding with a hammer mill or a ball mill breaks the pores, increases the bulk specific gravity of the pearlite fine powder, and cannot obtain a suitable lightweight porous body. Further, if only pearlite dust of 0.6 mm or less collected by the dust collector alone, the water retention of the wet product is poor, and the extruding and spherical sizing properties are deteriorated. A crushing and sizing machine is optimal.

(B) is a binder. Bentonite, Frogme clay, or the like is used as the binder. Bentonite is easy to handle due to granulation properties, moldability, sintering strength and the like. From abundant bentonite, select a fine-grained one that does not contain bacteriostatic / antibacterial action or harmful substances as an environment for immobilizing microorganisms. Increasing the mixing ratio of the clay mineral can increase the content, but increases the bulk. (2) uses a dry mixer in the mixing step. When the total amount of the pearlite fine powder and the binder is 100%, the blending ratio of the binder is 15% by weight, which is the lower limit of the granulatable range. 20
The sintering strength and the granulation property are compatible with each other by weight%. About 25% by weight is suitable. It can be increased by 30% by weight.

(D) is an auxiliary material of the organic fine powder. It is good to use corn starch, flour, buckwheat husk, rice husk, and the like. It contributes to the granulation and moldability of wet products, burns out during firing, and contributes to weight reduction and porous body formation. It is advisable to select one with a low bulk specific gravity. Organic substances also have the effect of increasing the water retention of wet products and expanding the range of moisture control. It is more preferable than a binder such as PVA or Metrose (a water-soluble cellulose ether). (E) is an additive. Use zeolite, calcium carbonate, silica sand, acid clay, etc. Adjust the microbial colonization environment. It is said that the elucidation of the function of useful microorganisms is about 10%. In many cases, fellow microorganisms such as Bacillus subtilis are used to decompose and reduce the volume of organic matter. In general, bacteria prefer weak alkalinity, and the number of living microorganisms is large when the pore diameter is about several μm to 20 μm. On the other hand, mycelia prefer weak acidity,
The above pore size is good. Various microorganisms act in a chain in the process of disappearing and reducing the volume of organic matter. Microbial carriers have various pore structures, and adjustment of the fixing environment is also important.

In (3), a kneading machine (kneader) is used in the kneading step. In order to enhance the abrasion property of the bacterial bed material, waste glass fine powder, diatomaceous earth and the like are effective. When the filler is mixed, the water absorption of the bacterium floor material after firing decreases, and the bulk specific gravity also increases. When the auxiliary material of the organic fine powder and the additive are mixed, water (c) is added and kneaded to produce a wet product. The water content of a wet product depends on empirical rules. (4) is an extrusion molding machine (pelleter) in the extrusion process
use. It is a structure in which when a wet product is put in from an inlet, it is extruded from a die with a screw. Extrusion pressure cannot be obtained if the water content of the wet product is small. If the amount of water is large, it becomes long like a udon. It breaks at a certain length with an appropriate amount of water. (5) is a drying step. After drying with air or by air, pellets of the porous binder (f) are obtained. Further, firing (8) is performed to obtain a porous ceramic (g).

(6) A spherical rectifier (malmerizer) in the spherical sizing process. The pellets extruded and granulated are spherically sized by a high-speed rolling method. Plasticity, residence time, rotation speed,
The length of the pellets is adjusted by the grooves of the turntable, and the pellets are adjusted to spherical particles. If the moisture of the wet product is insufficient, the grains do not harden. If the water content is too high, it will aggregate. An appropriate amount of water forms a uniform spherical shape. The organic fine powder of the auxiliary material has the effect of widening the moisture control width of the wet product. If moisture in the grains comes to a surface during rolling, fine pearlite powder should be used as the powder. Surface structure is important and rolling residence time is 3-5
About a minute is good.

(7) In the drying step, a ventilation drying oven is used. 1
It may be dried at about 00 ° C. (8) is a firing step. Precisely, thermal analysis such as TG-DTA is performed for each material, and the transition temperature, the melting point, and the crystallization temperature are grasped and fired. The temperature rise time is 3 hours, the holding time is 2 hours, and the temperature is lowered by furnace cooling. The firing temperature is 1000 ° C. or less. When pearlite is used and the binder is bentonite, 500 to 950
Good range of ° C. The preferred range of both strength and light weight is 7
50-850 ° C. 70 for Shirasu balloon
0-800 ° C is a suitable temperature range. When using an organic substance as the auxiliary material, supply oxygen and pay attention to lack of oxygen in the firing atmosphere. The particle size of the porous ceramic thus obtained is adjusted as necessary by an electric sieve or the like in the sieving step (9). (G) is a lightweight porous ceramic. The lightweight binder used before firing is well dried after granulation. It is harmless even if it is impregnated with microorganisms and drugs and disposable as biomaterials at the contaminated site. Can be provided as agricultural material by mixing with fertilizer. It can also be provided as a greening material by mixing seeds and the like. Since the fired porous ceramics are effective for recycling, they are suitable as a carrier for immobilizing microorganisms,
It can also be provided as a fluidized bed for waste treatment and sewage treatment.

[0021]

EXAMPLES Examples will be described below in detail with reference to Table 1, but the present invention is not limited to these examples.

[Table 1]

[0022]

Example 1 Pearlite fine powder (Chikuma pearlite powder-1)
No.) 80% by weight of bentonite (Kanto bentonite
Tone) Add 20% by weight to make the total amount. 1% by weight of Metrolze (Shin-Etsu Chemical, SM4000) was added to the total amount, and the mixture was kneaded with water. A wet product having a bulk specific gravity of 0.47 g / cm ³ was obtained. It was subjected to spherical sizing for 1 minute and 15 seconds with a marmellaizer, and then fired at 750 ° C. after drying. As a result, a lightweight porous ceramic having a bulk density of 0.85 g / cm ³ was obtained. The natural water absorption rate of 35.2% when left in water for 2 hours,
A vacuum absorption rate of 53% when left in water for 3 hours under a reduced pressure of 0.5 kg / cm ² , FE-SEM (scanning electron microscope)
The pore size read from the photograph is 10 to 40 μm, and B is a biopharmaceutical for environmental purification (Meiji Seika and BN Clean Granule)
An N-cell suspension was prepared, immersed for 30 minutes, and cultured to obtain 440000 cells / g in viable cell count. As the immersion time of the water absorption, a time required to stabilize by measuring a change with time of water absorption was adopted. The viable cell count is a method performed in food inspection or the like. For the BN bacteria suspension, 1 g of the granules of the biopharmaceutical are placed in a test tube and sterilized with an autoclave to prepare a suspension. The lightweight porous body is put therein, immersed for 30 minutes with occasional stirring, taken out and washed twice with sterile water. After draining with filter paper, the ceramic is put into 10 ml of sterilized water, and the mixture is vortexed for 30 seconds. This is repeated twice. After dilution, culture in a chalet. The culture method was measured after 24 hours at 37 ° C. as in the general viable cell count test.

[0023]

Example 2 20% by weight of bentonite was added to 80% by weight of Shirasu balloon (Sanki Kako Sankilite Y02) to make the total amount. 1% by weight of Metrolze was added to the total amount, and the mixture was kneaded with water. A wet product having a bulk specific gravity of 0.31 g / cm ³ was obtained. It was subjected to spherical sizing for 3 minutes and 20 seconds using a marmellaizer, and then fired at 750 ° C after drying. As a result, the bulk density was 0.73 g / cm ³ , the natural water absorption was 43.1%, the water absorption under reduced pressure was 55.8%, the pore diameter was 10 to 50 μm, and the number of viable BN bacteria was 340000 / g. Obtained.

[0024]

Example 3 25% by weight of bentonite was added to 65% by weight of pearlite fine powder, and 10% by weight of pulverized blue glass fine powder was added as an enhancer, and the mixture was kneaded. Bulk specific gravity is 0.3
A wet product of ³ g / cm ³ was obtained. It was subjected to spherical sizing for 5 minutes and 15 seconds with a marmellaizer, dried and baked at 800 ° C. As a result, the bulk density was 1.11 g / cm ³ , the natural water absorption was 24.4%, the reduced water absorption was 33.1%, and the pore diameter was 1
0-100 μm, the number of viable BN bacteria is 160,000 / g
Was obtained. The BN bacteria were immobilized, left in a thermostat at 25 ° C., and the number of viable bacteria was 70,000 cells / g after 10 days and 46,000 cells / g after one month. In addition, the growth of BN bacteria is cultivated in about 30 minutes if the environment is in place. Therefore, the function of immobilizing and storing the microorganism was confirmed.

[0025]

Embodiment 4 Pearlite fine powder (Asano perlite / p-
1) 25% by weight of bentonite was added to 65% by weight, and 10% by weight of corn starch (Nippon Constarch, unmodified) was added, followed by kneading. As a result, the bulk specific gravity was 0.36
g / cm ³ was obtained. Use it with a marmalizer 1
The particles were spherically sized for 30 minutes, dried, and fired at 800 ° C.
As a result, the bulk density was 0.75 g / cm ³ , the natural water absorption was 49%, the reduced water absorption was 66.1%, and the pore diameter was 20 to 80.
μm, the number of viable BN bacteria was 59000 / g. 32,000 pieces / g after 10 days, 2500 after 1 month
0 / g BN bacteria were immobilized. It is presumed that the reason why the number of viable bacteria is smaller than that of others is that the pore diameter has increased, the pore diameter density suitable for BN bacteria has decreased, and the number of implantations of BN bacteria has decreased.

When the mixing ratio of the materials is constant, the firing temperature determines the basic characteristics of the porous ceramic. The feature of the porous ceramic of the present invention is that it is lighter as it floats on water. FIG. 2 shows the surface structure. Another characteristic is that various microorganisms are implanted. FIG. 3 shows a photograph observed by FE-SEM. The relationship between the firing temperature, the bulk density, and the water absorption will be specifically described based on Table 2. Note that the present invention is not limited by these examples. As mentioned above, it is important to obtain the desired porous ceramics by conducting thermal analysis etc. for each material, grasping the transition temperature, melting point, and crystal temperature of the material, conducting microscopic observation of the surface structure of the sintered body, etc. . In the embodiment, the binding material bentonite is 2
It is fixed at 5% by weight.

[Table 2]

[0027]

Embodiment 5 The natural glass material contains pearlite fine powder and shirasu balloon in equal amounts. The preferred range of firing temperature is 80
0-900 ° C. The internal structure has a mixture of independent pores of the balloon and interconnected pores of perlite. The difference between natural water absorption and reduced water absorption is small. The water absorption of ceramics used for conventional garbage disposal is 10% or less. Further, the bulk specific gravity is about 2.5 g / cm ³ or more.

[0028]

Embodiment 6 In the case of blending 75% by weight of pearlite fine powder, a preferable range of the firing temperature is around 900 ° C. Baking can be performed at a temperature as high as about 50 ° C. compared to the fifth embodiment. The bulk specific gravity is not much different.
Compared with Example 5, the difference between the natural water absorption and the reduced water absorption is widened. Due to the large number of interconnected pores. It is suitable as a material for bioremediation in which a microorganism or a neutralizing agent is impregnated. It can also be provided as a fluidized bed in which microorganisms are fixed.

[0029]

Example 7 10% by weight of glass fine powder was blended. The firing temperature is between 800 and 900C. Filled with glass fine powder to improve abrasion due to agitated friction in garbage treatment and sludge treatment. Bulk specific gravity of cedar chip material is 0.7g / cm in the initial state
It is about ³ . However, when worn and powdered, the bulk density becomes 1.
It is about 5 to 2.0 g / cm ³ . The water absorption specific gravity of the porous ceramics in this case is 1.5 g / cm ^3, which is lighter than the worn cedar chip fungus flooring material. This case is suitable as a bacterial bed material for organic matter treatment.

[0030]

Example 8 10% by weight of corn starch was blended. The preferred range of the firing temperature is the same as that of Example 6. Addition of the organic fine powder improves the production quality such as granulation and moldability as described above. At the same time, it is possible to improve functions such as weight reduction, control of water absorption and pore diameter, and improvement of strength. Suitable results were obtained with flour or buckwheat husks. The reason why the number of viable BN bacteria is smaller than others suggests that the pore size distribution and the pore size can be controlled by the organic fine powder. Based on future research.

[0031]

According to the porous ceramics of the present invention, when microorganisms are immobilized and used as a fungal bed material,
As there is no decomposition or disappearance of the organic matter in the bacterial bed itself due to the action of microorganisms like a plant-based bacterial bed material, there is no need to replace or replace the bacterial bed material unless the bacterial bed is worn or damaged. . Further, even if the microorganisms are killed due to a change in environmental conditions or the like, if the ceramics are sterilized and washed with hot water or the like and the commercially available useful bacteria are readjusted, they can be reused at low cost.

The porous ceramics according to the present invention is light in weight, unlike conventional inorganic bacterial bed materials, can reduce the power of the stirring device, and contributes to energy saving. In addition, it is excellent in water absorption, and can adjust the water content of garbage and the like, and can suppress the generation of offensive odor and sanitary pests. The structure of the porous body is diverse, and various microorganisms are established. Furthermore, the function of the fungal bed material can be easily adjusted even when a new useful microorganism appears, and its ability can be utilized. In addition, the use of a mixture of various types of ceramics contributes to bioreactors that utilize the capabilities of various microorganisms.

The pearlite material used in the present invention is dust or fine powder generated during the manufacturing process, and its use is limited. If there is no demand, the material is treated as industrial waste. Also, since only natural materials are used for mixing, they are harmless even if disposed of in final disposal. Unlike polymer-based bacterial flooring, there is a low possibility that environmental pollution will occur even if incinerated.

The light-weight porous body of the present invention has a high water absorption and is light enough to float on water. It can be provided as a biomaterial for bioremediation of already contaminated soil and groundwater pollution, and also as a carrier for impregnating drugs and neutralizing and detoxifying harmful substances. Also,
It can also be provided as a greening material mixed with seedling raising soil, horticultural soil, and seeds. Further, it can be provided as an element material for artificial soil of agricultural products which is not affected by abnormal weather or environmental pollution.

[0035]

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a manufacturing process.

FIG. 2 is a photograph of the surface structure of a porous ceramic at a magnification of 100.

FIG. 3 is a photograph at 500 × magnification of various microorganisms that settle on porous ceramics.

[Explanation of symbols]

 a Natural glass b Binder c Water d Auxiliary material e Additive f Porous binder g Porous ceramics 1 Crusher and sizing machine 2 Dry mixer (mixer) 3 Kneader (kneader) 4 Extrusion granulator (pelleter) 5, 7 Dryer 6 Spherical sizing machine (malmerizer) 8 Firing furnace 9 Sieving machine

Claims (10)

[Claims] 1. A binder comprising a natural glass material fine powder foamed from a pearlite or shirasu balloon and a clay mineral as a main material, and an organic material powder such as a grain or a grain hull as an auxiliary material,
The adjusted additive is added, and the wet product kneaded with water is used as a raw material. The material is obtained by extrusion molding and drying, and has a bulk specific gravity of 0.4 to 1.5 g / cm ³ and a pore diameter of several μ to 100 μ.
It is a porous binder having m pores. 2. A porous ceramic obtained by subjecting claim 1 to spherical sizing after molding and firing. 3. The lightweight porous body according to claim 1, wherein the shaft diameter or the diameter is 1.0 to 30 mm. 4. The method according to claim 1, wherein closed cells and continuous pores are mixed, and the water absorption is 15 wt% or more.
Or the lightweight porous body according to 3. 5. The light weight according to claim 1, wherein the natural glass material fine powder is at least 40% by weight based on the total amount of the binder of the foamed natural glass material and the clay mineral. Porous body. 6. The lightweight porous body according to claim 1, wherein the binder is at least one clay mineral selected from bentonite and frog-eye clay. 7. The lightweight porous body according to claim 1, further comprising a pH adjuster as an additive. 8. The method according to claim 1, wherein an organic fine powder of a grain or a grain hull is used as an auxiliary material to assist granulation and formability, and adjust pore size distribution and density during sintering. 4,
The lightweight porous body according to 5, 6 or 7. 9. The method according to claim 1, wherein the material comprises a mineral powder containing no titanium oxide.
A carrier (bacterial bed material) for immobilizing microorganisms using the lightweight porous body according to 5, 6, 7, or 8. 10. A binder comprising a natural glass material fine powder foamed from a pearlite or shirasu balloon and a clay mineral as a main material, and an organic powder such as a grain or a grain hull as an auxiliary material.
The adjusted additive is added, and the wet product kneaded with water is used as a raw material. The material is extruded and dried to obtain a bulk specific gravity of 0.4 to 1.5 g / cm ³ and a pore diameter of several μm to 100 μm.
The porous conjugate that obtains the characteristics of And a method for producing a porous ceramic obtained by spheroidizing the particles by a rolling method after extrusion molding and firing at 500 to 1000 ° C.