JP2003165783A - Lightweight porous sintered compact and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method where a lightweight, porous sintered compact is produced by using chaff ash, which is disposed as unused wastes, as a raw material. <P>SOLUTION: A raw material composition, which comprises chaff ash, inorganic aggregate, cement and water, is molded. Next, after being subjected to an aging process where hydration reaction of the cement proceeds, the molded body is burned at a high temperature so that the porous sintered compact is obtained. Silica rock or silicate is preferably used as the inorganic aggregate, and the burning temperature is preferably set at 800-1,500°C. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a rice husk ash as a raw material, which has hardly been used effectively in the past, and is used as a filter material, an adsorption filter, a lightweight porous material used as a carrier in the field of biotechnology, etc. The present invention relates to a sintered body and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, tableware, sanitary equipment, or electricity,
Ceramics used as industrial products such as electronic materials,
Clay, sericite, a raw material such as wax stone is manufactured by sintering or melting it by high temperature firing, but these plastic raw materials tend to be depleted in recent years,
There is an urgent need to develop new alternative raw materials in this field. In addition, conventional ceramics are generally heavy,
With the spread of new applications, there are increasing demands for weight reduction.

On the other hand, the rice husks produced during threshing of rice are discharged as agricultural wastes in large amounts every year, and some of them are used as fuels, but most of them have no way to be effectively used and remain as they are. At present, it is the waste ash that is discarded or incinerated and then disposed of.
In recent years, with the growing interest in effective use of resources and recycling, it has been strongly desired to devise a concrete measure for effective use of rice husks and rice husk ash.

[0004]

The present inventors have noticed that the rice husk ash contains a large amount of silicic acid (SiO ₂ ), and the rice husk ash has a low bulk density of about 0.25. We thought that such rice husk ash could be used as a raw material component for ceramics, and that the resulting sintered body would be lightweight.

The present invention has been made based on the above-mentioned idea in view of the above technical background, and is made of rice husk ash, which has been discarded as an unused material, as a raw material, and is lightweight and porous. It is an object to provide a method for producing a conjugate.

[0006]

[Means for Solving the Problems] The above object is to obtain a compact by molding a raw material composition obtained by adding water to a solid raw material containing rice husk ash, inorganic aggregate and cement,
Light-weight porous material including a curing step of curing the molded body by a hydration reaction of cement, and a sintering step of firing the cured molded body at a high temperature to obtain a porous sintered body. This is achieved by the method for producing a sintered body.

According to this manufacturing method, a lightweight and porous sintered body can be obtained. The porous structure of this sintered body is, as shown in the electron micrograph of FIG. 1, a continuous porous structure that communicates with the outside, and is, for example, a filter material, an adsorption filter, or a support in the biotechnology field. It can be used as a body or the like. In addition, it is considered that the use of rice husk ash as one of the raw materials and the porous structure greatly contribute to the lightness.

Further, in the production of conventional ceramics, the degree of shrinkage due to sintering was large (for example, the shrinkage rate was 10 to 3).
On the other hand, according to the present manufacturing method, by using rice husk ash as a raw material, shrinkage due to sintering can be suppressed (for example, a shrinkage rate of about 2%), and thus a desired shape can be accurately obtained. It is considered that the continuous porous structure can be formed because the shrinkage during sintering is small as described above.

Further, in this manufacturing method, since rice husk ash, which has been conventionally discarded as unused, is used as one of the main raw materials, effective use of resources can be achieved and waste of rice husk ash can be avoided. As a result, it is possible to contribute to environmental protection and to manufacture a lightweight porous sintered body at low cost.

In the production method of the present invention, the content of rice husk ash in the solid raw material is 20 to 60% by weight, the content of inorganic aggregate is 20 to 60% by weight, and the content of cement is 10%.
It is preferably set in the range of ˜50% by weight. By setting in the above-mentioned specific range, it becomes possible to perform sintering at a temperature of 1500 ° C. or lower (that is, high firing temperature is not required), and the molded body after the curing step (before sintering) can be obtained. Sufficient strength can be obtained, the handleability of the molded body is excellent, and the strength of the obtained sintered body can be sufficiently improved.

The above raw material composition is preferably composed of 100 parts by weight of the solid raw material and 10 to 50 parts by weight of water mixed therein. By setting the blending amount of water in such a range, the hydration reaction of the cement can be sufficiently promoted and the molding becomes easy.

As the inorganic aggregate, it is preferable to use one kind or two or more kinds of aggregates selected from the group consisting of silica stone and silicate from the viewpoint that the strength of the sintered body can be further improved.

The firing temperature in the sintering process is 800-1500.
It is preferable to set it at ℃. By setting such a range, it is possible to improve the production efficiency of the sintered body and to reliably produce the sintered body having a continuous porous structure.

The raw material composition may contain one or more kinds of fibers selected from the group consisting of pulp fibers, synthetic fibers, glass fibers, carbon fibers and mineral fibers. Total amount of aggregate and cement 1
It is preferable to set the blending amount of the fibers to 2 to 5 parts by weight with respect to 00 parts by weight. By containing a specific amount of such a specific fiber, it is possible to improve the shape retention of the molded body,
The strength of the molded body (before sintering) after the curing step, and further the strength of the sintered body can be further improved, and the dimensional stability of the sintered body can also be improved.

Furthermore, the raw material composition may contain one or more kinds of a viscosity-imparting agent selected from the group consisting of water-soluble fibrin and water-soluble polymer, and the rice husk ash, inorganic aggregate and It is preferable to set the compounding amount of the viscosity imparting agent to 0.5 to 4 parts by weight based on 100 parts by weight of the total amount of cement. This makes it possible to sufficiently impart viscosity and lubricity to the raw material composition, obtain a molded product with good moldability even when extrusion molding is performed, and eventually manufacture a high quality sintered product.

The lightweight porous sintered body of the present invention is characterized by being manufactured by any one of the above manufacturing methods.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing a lightweight porous sintered body according to the present invention comprises molding a raw material composition obtained by adding water to a solid raw material containing rice husk ash, inorganic aggregate and cement. And a curing step of curing the molded body by hydration of cement, and a sintering step of firing the cured molded body at a high temperature to obtain a porous sintered body. And

An electron micrograph of the sintered body obtained by this manufacturing method is shown in FIG. As is clear from FIG. 1,
The obtained sintered body has a continuous porous structure communicating with the outside. The present manufacturing method uses rice husk ash as one of the raw materials, and the obtained sintered body has the above-mentioned porous structure, so that it is extremely lightweight.

Furthermore, since rice husk ash is used as a raw material,
There is an advantage that shrinkage due to sintering is very small, and therefore a desired shape can be accurately formed.

In addition, since the rice husk ash, which has been conventionally discarded, is effectively used, a porous sintered body can be manufactured at a low cost, and the rice husk ash can be avoided, which contributes to environmental protection. it can.

In the present invention, as the rice husk ash used as a raw material for manufacturing, any ash obtained by burning rice husk obtained by milling rice can be used, and the rice husk can be used as a fuel. Includes ash (usually black) after use. Generally, when the combustion temperature is low, the ash color is black,
At a combustion temperature of about 500 ° C, the ash is amorphous silica,
When the combustion temperature is about 1000 ° C, crystallization progresses to give a white color, and the color tone of the rice husk ash and the type of crystals differ depending on the atmosphere during firing, firing temperature, and firing time. Any of these can be used. The color tone of rice husk ash and the type of crystals are not particularly limited.

Table 1 shows typical examples of the composition of rice husk ash.

[0023]

[Table 1]

In the present manufacturing method, by using such rice husk ash as one of the raw materials, it is possible to secure the lightness and
It is considered that the shrinkage during sintering can be sufficiently suppressed and the continuous porous structure can be formed.

The content rate of rice husk ash in the solid raw material is 20.
It is preferably in the range of ˜60% by weight. If it is less than 20% by weight, the fire resistance of the molded body after curing becomes high and a remarkably high firing temperature is required for sintering, and it becomes impossible to sufficiently reduce the weight. Is insufficiently controlled, and the formation rate of the continuous porous structure is reduced, which is not preferable. On the other hand, if it exceeds 60% by weight, it is difficult to secure sufficient strength and it is difficult to maintain the shape of the sintered body, and for example, the surface may be shattered even if it is touched by hand, which is not preferable.

The inorganic aggregate is an essential raw material component for forming a skeleton in the sintered body, that is, for improving the strength.
The inorganic aggregate is not particularly limited, but for example, silica stone containing silicon dioxide as a main component (quartz or the like),
Examples include river sand, mountain sand, sea sand, and silicates. Examples of the silicate include clay, feldspar, blast furnace slag, fly ash, and the like. Among these, it is preferable to use silica stone or silicate from the viewpoint that the strength of the sintered body can be further improved. Particularly preferable is a structure in which silica stone is used as the inorganic aggregate, which has an advantage that the strength of the sintered body can be further improved.

The content of the inorganic aggregate in the solid raw material is 2
It is preferably in the range of 0 to 60% by weight. 20% by weight
If it is less than the above range, it is difficult to secure sufficient strength, and it is difficult to maintain the shape of the sintered body. For example, the surface may be shattered even if it is touched by hand, which is not preferable. on the other hand,
If it exceeds 60% by weight, the fire resistance of the molded body after curing becomes high and a remarkably high firing temperature is required for sintering, which is not preferable.

As the cement used as a raw material for production, any kind of cement can be used, and examples thereof include Portland cement, magnesia cement, alumina cement, mixed cement and natural cement, and one of these can be used. They may be used alone or in combination of two or more. By including such cement as an essential component, the hydration reaction between the cement and the rice husk ash and the inorganic aggregate ensures the strength of the molded body after the curing process (before sintering). And the handling property of the molded article becomes good. Among them, it is preferable to use alumina cement.

The content of cement in the solid raw material is 10
It is preferably in the range of ˜50% by weight. If it is less than 10% by weight, the strength of the molded product after the curing step (before sintering) is lowered and the handling property is deteriorated, which is not preferable. On the other hand, if it exceeds 50% by weight, the fire resistance of the molded body after curing becomes high and a remarkably high firing temperature is required for sintering, which is not preferable.

The raw material composition further includes pulp fiber,
It is preferable to contain one kind or two or more kinds of fibers selected from the group consisting of synthetic fibers, glass fibers, carbon fibers and mineral fibers, and to 100 parts by weight of the total amount of the rice husk ash, the inorganic aggregate and the cement. It is preferable to set the blending amount of the fibers to 2 to 5 parts by weight. By containing a specific amount of such a specific fiber, the shape retention of the molded body before curing can be improved, and the strength of the molded body after the curing step (before sintering), and further the strength of the sintered body, It is possible to improve the lightness and also improve the dimensional stability of the sintered body. If the compounding amount is less than 2 parts by weight, the above-mentioned effects (improvement in strength, etc.) are hardly obtained, and if the compounding amount exceeds 5 parts by weight, the same effect cannot be expected.

Further, the raw material composition may contain one or more kinds of viscosity-imparting agents selected from the group consisting of water-soluble fibrins and water-soluble polymers, the rice husk ash and the inorganic aggregate. And, when the compounding amount of the viscosity imparting agent is set to 0.5 to 4 parts by weight with respect to the total amount of 100 parts by weight of cement, there is an advantage that the formability can be remarkably improved. That is, when the molding is carried out by extrusion molding, if the raw material composition lacks viscosity and lubricity, molding becomes difficult and it is difficult to obtain a good molded body. Even if there is a specific amount of the specific viscosity-imparting agent, a molded product can be obtained with good moldability, and a high quality sintered product can be manufactured. Further, since the viscosity-imparting agent burns and volatilizes during firing, it is possible to produce a sintered body having a higher porosity, and further, it is possible to design the bulk density of the obtained sintered body to be smaller and to burn it. The water absorption rate of the aggregate is also higher. If the blending amount is less than 0.5 parts by weight, the above effect (improvement in moldability) is hardly obtained, and
Even if the blending amount exceeds 4 parts by weight, the above effect cannot be expected in the same manner, which is not preferable.

The water-soluble fibrin is not particularly limited, and examples thereof include carboxymethyl cellulose, hydroxyethyl cellulose, micropulp and the like. Further, the water-soluble polymer is not particularly limited, for example, polyvinyl alcohol,
Examples thereof include saponified products of polyvinyl acetate.

The amount of water blended in the raw material composition is
Solid materials (rice husk ash, inorganic aggregate, cement, etc.) 1
It is preferably set to 10 to 50 parts by weight with respect to 00 parts by weight. If it is less than 10 parts by weight, not only a sufficient molded article cannot be obtained, but also the progress of the hydration reaction of cement is delayed, which is not preferable. On the other hand, if it exceeds 50 parts by weight, excess water increases and the shape retention of the molded product before curing is deteriorated, which is not preferable.

When the extrusion molding method is adopted as the molding method for molding the raw material composition, the amount of water in the raw material composition is 30 to 50 with respect to 100 parts by weight of the solid raw material. It is particularly preferable to set it in parts by weight.

When preparing the raw material composition, the order of mixing the respective material components is not particularly limited. For example, water may be added last, or may be added in the middle.

If necessary, the raw material composition may be blended with other additives and the like within a range that does not impair the effects of the present invention.

The molding method for molding the raw material composition is as follows:
It is not particularly limited, and examples thereof include mold molding, pressure molding, extrusion molding and the like. Above all, it is preferable to mold by pressure molding or extrusion molding because a high-quality porous sintered body can be manufactured with high productivity.

The curing method in the curing step is not particularly limited, and examples thereof include natural curing, underwater curing, steam curing and autoclave curing. The strength required for handling is secured by advancing the hydration reaction of the cement through such a curing step, setting and hardening.

The firing temperature in the sintering step is not particularly limited as long as it is high, but it is 800 to 1500 ° C.
The range is preferably If the temperature is lower than 800 ° C., it takes time to complete the sintering and the production efficiency of the sintered body decreases, which is not preferable. On the other hand, if the temperature exceeds 1500 ° C, the raw material is melted and a porous structure cannot be obtained, which is not preferable. Above all, it is more preferable to set the firing temperature in the range of 1000 to 1300 ° C., and it is best to maintain the firing temperature for 1 to 2 hours.

The rate of temperature increase until the firing temperature is reached is preferably set to 5 to 10 ° C./min. Also,
Generally, when firing ceramic raw materials to manufacture ceramics,
The temperature lowering rate at the time of lowering the temperature from the firing temperature to room temperature needs to be as slow as possible in order to prevent cracking and cracking at that time, but in the sintered body of the present invention, the shrinkage rate during sintering is extremely high. Since it is very small, cracks and the like do not occur even when the temperature is lowered at a high temperature lowering rate of, for example, 5 to 10 ° C./min. Therefore, the temperature lowering rate after firing can be set to a large value, and there is also an advantage that a lightweight porous sintered body can be manufactured with high production efficiency.

The lightweight porous sintered body obtained by the production method of the present invention is used as a heat insulating material, a sound insulating material, a humidity control building material, earth and wood, a filter material, an adsorption filter, a carrier in the biotechnology field and the like. be able to. Further, the lightweight porous sintered body may be loaded with an enzyme, a catalyst or the like and used as a water purification material or the like. The application of the lightweight porous sintered body obtained by the production method of the present invention is not particularly limited to the above-mentioned applications.

[0042]

EXAMPLES Next, specific examples of the present invention will be described, but the present invention is not particularly limited to the manufacturing methods shown in these examples.

<Example 1> Rice husk ash (average particle size: 350 μm)
m, black) 40 parts by weight, silica stone (average particle size 4.63 μm)
40 parts by weight, alumina cement (average particle size 14.5μ
m) 20 parts by weight and 15 parts by weight of water were sufficiently mixed to obtain a uniform raw material composition. The rice husk ash, silica stone, and alumina cement used here had the compositions shown in Table 1, respectively.

Next, this raw material composition was placed in a mold and the
A molded body was obtained by pressure molding at a pressure of 0 kg / cm ² . The molded body was kept in a curing tank at 25 ° C. and a humidity of 90% for 24 hours to be cured by a hydration reaction (curing step). Then, after drying at 50 ° C. for 24 hours, the molded body is exposed to 1300 ° C. for 1 hour in the air.
It was fired for a time to obtain a sintered body. The rate of temperature increase until reaching 1300 ° C. was 10 ° C./minute, and the rate of temperature decrease thereafter was 10 ° C./minute.

<Examples 2 and 3> A sintered body was obtained in the same manner as in Example 1 except that the composition ratios of the raw material compositions were set as shown in Table 2.

<Example 4> A sintered body was obtained in the same manner as in Example 1 except that 40 parts by weight of silica stone was added to the raw material composition in an amount of 40 parts by weight.

Example 5 Rice husk ash (average particle size 350 μ
m, black) 40 parts by weight, silica stone (average particle size 4.63 μm)
40 parts by weight, alumina cement (average particle size 14.5μ
m) 20 parts by weight, pulp fibers 2 parts by weight, carboxymethyl cellulose (manufactured by Shin-Etsu Chemical, trade name "Metrose 90S"
H15000 ") 2.5 parts by weight and 50 parts by weight of water are sufficiently mixed to obtain a uniform raw material composition, and the raw material composition is kneaded and extrusion molded at an extrusion pressure of 20 to 21 kg / cm ² to obtain a molded article. Got The molded body was kept in a curing tank at 25 ° C. and a humidity of 90% for 24 hours to be cured by a hydration reaction (curing step). Then, after drying at 50 ° C. for 24 hours, the molded body is exposed to 1300 ° C. for 1 hour in the air.
It was fired for a time to obtain a sintered body. The rate of temperature increase until reaching 1300 ° C. was 10 ° C./minute, and the rate of temperature decrease thereafter was 10 ° C./minute.

<Examples 6 and 7> Sintered bodies were obtained in the same manner as in Example 5 except that the composition ratio of the raw material composition was set to the ratio shown in Table 2.

[0049]

[Table 2]

Comparative Example 1 Example 1 was repeated except that 40 parts by weight of shirasu balloon obtained by heating and foaming volcanic shirasu shirasu was added to the raw material composition instead of 40 parts by weight of rice husk ash. A sintered body was obtained in the same manner as in.

The sintered bodies of Examples 1 to 7 all exhibited a continuous porous structure as shown in FIG. 1 when observed with an electron microscope. On the other hand, in the sintered body of Comparative Example 1, no continuous porous structure was observed as shown in FIG.

The respective sintered bodies obtained as described above were evaluated by the following measuring methods. The results are shown in Table 3.

<Measurement Method of Green Strength and Bending Strength> The green strength (after curing) of the molded body and the bending strength of the sintered body were measured in accordance with the three-point bending method of the bending strength test method of JIS R1601. .

<Bulk Density Measuring Method> The value obtained by dividing the weight of the sintered body by its outer volume was taken as the bulk density.

<Specific Strength Measurement Method> The value obtained by dividing the strength of the sintered body by the specific gravity of the sintered body was taken as the specific strength.

<Shrinkage> The linear shrinkage was adopted and calculated by the following formula.

{(Length before sintering)-(length after sintering)}
÷ (length before sintering) × 100

<Water Absorption Rate Measuring Method> The sintered body was boiled in water, cooled and wiped to remove water from the surface, and the dry weight of the sintered body was subtracted from the weight to determine the water absorption. The value obtained by dividing by the dry weight of was taken as the water absorption rate.

[0059]

[Table 3]

As is apparent from the table, the sintered bodies of Examples 1 to 7 produced by the production method of the present invention are all lightweight, have a continuous porous structure, and shrink due to sintering. The rate was very small. In addition, the sintered bodies of Examples 5 to 7 in which the amount of water mixed in the raw material composition was large and carboxymethyl cellulose was mixed, have bulk densities in comparison with those of Examples 1 to 4. It is small, has a high water absorption rate, and has a feature that the cavity volume due to the porous structure is larger than those of Examples 1 to 4.

On the other hand, the shirasu balloon-based sintered body of Comparative Example 1 has an insufficient lightweight property, does not have a continuous porous structure, and has a shrinkage rate due to sintering. It was great.

[0062]

The method for producing a sintered body according to the present invention comprises the steps of molding a raw material composition obtained by adding water to a solid raw material containing rice husk ash, inorganic aggregate and cement to obtain a molded body. A curing step of hardening the molded body by a hydration reaction of cement, and a sintering step of firing the cured molded body at a high temperature to obtain a porous sintered body. Therefore, a lightweight and porous sintered body can be manufactured. In addition, since rice husk ash is used as a raw material in the present manufacturing method, there is an advantage that shrinkage due to sintering is extremely small and therefore a desired shape can be faithfully formed. Furthermore,
Since rice husk ash, which has been conventionally discarded, is used as a raw material, resources can be effectively used and a lightweight porous sintered body can be manufactured at low cost. In addition, since shrinkage during sintering is extremely small, cracks and the like do not occur even if the temperature lowering rate after firing is increased.Therefore, there is an advantage that a sintered body can be manufactured with high production efficiency by setting a high temperature lowering rate. is there.

The content rate of rice husk ash in the solid raw material is 2
When the content of the inorganic aggregate is 0 to 60% by weight, the content of the inorganic aggregate is 20 to 60% by weight, and the content of the cement is 10 to 50% by weight, the handleability of the molded body and the strength of the sintered body are sufficient. Can be improved.

When the raw material composition is composed of 100 parts by weight of the solid raw material and 10 to 50 parts by weight of water mixed, the hydration reaction of the cement can be sufficiently promoted, and
The shape retention of the molded product before curing can also be improved.

When one kind or two or more kinds of aggregates selected from the group consisting of silica stone and silicate are used as the inorganic aggregate, the strength of the sintered body can be further improved.

The firing temperature in the sintering process is 800 to 1500.
When the temperature is 0 ° C, the productivity can be improved and a continuous porous structure can be sufficiently formed.

The raw material composition should contain one or more fibers selected from the group consisting of pulp fibers, synthetic fibers, glass fibers, carbon fibers and mineral fibers,
When the compounding amount of the fibers is set to 2 to 5 parts by weight with respect to the total amount of the rice hull ash, the inorganic aggregate and the cement of 100 parts by weight, the shape retention of the molded body before curing can be improved,
The strength of the molded body after curing and the strength and lightness of the sintered body can be improved, and the dimensional stability of the sintered body can also be improved.

The raw material composition may contain one or more viscosity-imparting agents selected from the group consisting of water-soluble fibrins and water-soluble polymers, and the rice husk ash, the inorganic aggregate and the cement may be added. When the blending amount of the viscosity-imparting agent is set to 0.5 to 4 parts by weight with respect to 100 parts by weight as a total amount, it is possible to sufficiently impart viscosity and lubricity to the raw material composition and to perform extrusion molding. It can be molded with good moldability, and thus a higher quality sintered body can be manufactured. Furthermore, since these viscosity imparting agents burn and volatilize during firing, it is possible to produce a sintered body having a higher porosity, which results in a porous sintered body having a lower bulk density and a higher water absorption rate. You can get the body.

[Brief description of drawings]

FIG. 1 is an electron micrograph of a sintered body obtained by the manufacturing method of the present invention.

FIG. 2 is an electron micrograph of a shirasu balloon-based sintered body of a comparative example.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Nori Kamio             1011-23 Kokura, Kiyama-cho, Sanyo-gun, Saga Prefecture (72) Inventor Koichi Kawamura             88 Uguisudai, Nagaokakyo, Kyoto Prefecture (72) Inventor Eiichi Koyama             2-19-79 Mami Nishi, Kashiba City, Nara Prefecture (72) Inventor Yoshiharu Nishino             231-16 Ko, Minami-Nagai-cho, Nara

Claims (8)

[Claims] 1. A step of molding a raw material composition obtained by adding water to a solid raw material containing rice husk ash, an inorganic aggregate and cement to obtain a molded body, and hardening the molded body by a hydration reaction of cement. A method of manufacturing a lightweight porous sintered body, comprising: a curing step of: and a sintering step of firing the cured molded body at a high temperature to obtain a porous sintered body. 2. The content of rice husk ash in the solid raw material is 20 to 60% by weight, and the content of inorganic aggregate is 20 to 6%.
The method for producing a lightweight porous sintered body according to claim 1, wherein the content of 0% by weight and the content of cement are in the range of 10 to 50% by weight. 3. The solid raw material 100 is the raw material composition.
The method for producing a lightweight porous sintered body according to claim 1 or 2, comprising 10 to 50 parts by weight of water mixed with parts by weight. 4. The lightweight porous sintered body according to claim 1, wherein one or more kinds of aggregates selected from the group consisting of silica stones and silicates are used as the inorganic aggregates. Body manufacturing method. 5. The firing temperature in the sintering step is 800-1.
It is 500 degreeC, The manufacturing method of the lightweight porous sintered compact of any one of Claims 1-4. 6. The raw material composition contains one kind or two or more kinds of fibers selected from the group consisting of pulp fibers, synthetic fibers, glass fibers, carbon fibers and mineral fibers, and the rice husk ash, Total amount of inorganic aggregate and cement 1
The method for producing a lightweight porous sintered body according to any one of claims 1 to 5, wherein the blending amount of the fibers is set to 2 to 5 parts by weight with respect to 00 parts by weight. 7. The rice husk ash, the inorganic aggregate, wherein the raw material composition contains one or more viscosity-imparting agents selected from the group consisting of water-soluble fibrins and water-soluble polymers. 7. The method for producing a lightweight porous sintered body according to any one of claims 1 to 6, wherein the compounding amount of the viscosity imparting agent is set to 0.5 to 4 parts by weight with respect to 100 parts by weight of the total amount of cement. . 8. A lightweight porous sintered body produced by the production method according to claim 1.