JP2011026170A - Method for producing ceramic product, and base material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a ceramic product by using a vegetable binder, in which the fluidity and plasticity of a base material are controlled by adjusting the moisture content of the base material without depending on clay of a molding component, a drying step is not required and a firing step of the base material is carried out while having the moisture. <P>SOLUTION: The method for producing the ceramic product comprises the steps of: blending 53 and kneading 54 a predetermined amount of waste 52 being a raw material with a predetermined amount of a vegetable raw material 51 being the vegetable binder to form the base material; molding 55 the base material to obtain the compact; and firing 56 the compact having the moisture added by the vegetable binder at the least. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing ceramic products and a base material.

  The basic manufacturing method of conventional ceramics products such as ceramics is as exemplified below. As shown in FIG. 5, main raw materials are silica 1 that forms a skeleton component, clay 2 that forms a molding component, and feldspar 3 that forms a sintering component. The clay 2 controls fluidity and plasticity by adjusting the mixing ratio with water, and ensures mechanical strength by drying.

  An appropriate amount of each of silica 1, clay 2 and feldspar 3 is pulverized 12 and blended 4 and further pulverized 12 and then water is added and kneaded 5 to obtain a clay. The clay is formed into a predetermined shape 6 by a forming method according to the purpose, and then dried 7. Next, the dried molded product is glazed 8, fired 9 in a firing kiln and fired, decorated 10 on the fired surface, and fired 11 later.

  By the way, as a prior art using such a ceramic technique, there is one described in Patent Document 1, for example. This is related to a high-grade method for melting slag resources. When waste such as municipal waste, sewage sludge, fly ash, mine demolition, river deposits, sludge from lakes and the like is melted to form molten slag, Adjusted molten slag is generated by adding an adjusting material to the waste and subjecting it to a melting treatment. Then, the adjusted molten slag is cooled and solidified to form a low-melting glass having a predetermined performance, and the low-melting glass is pulverized to an appropriate particle size to obtain a raw glass as a ceramic raw material.

  Moreover, the manufacturing method of the porous ceramic product described in Patent Document 2 includes a raw material powder that can constitute a ceramic product by sintering at a predetermined temperature in a kneading step, and a disappearing material powder that disappears by heating to a predetermined temperature. Are kneaded together with at least water to form a kneaded product, the molded product is molded with the kneaded product in the molding process, and the molded product is sintered at a predetermined temperature in the sintering process.

  Patent Document 3 describes that a chaff is added to a ceramic raw material containing alumina and / or silica as a main component, mixed, molded, and fired to obtain a wastewater treatment carrier.

Japanese Patent No. 3188326 JP 2000-128657 A JP-A-6-86995

  By the way, in the conventional method for manufacturing ceramic products, the moisture content in the base composition is 7 to 20% by weight in consideration of the plasticity of the clay, and the upper limit of the water that can be added is 20% by weight, and the moisture adjustment Can only be performed on clay as a forming component. If the water content exceeds the upper limit, the fluidity of the clay is increased and the plasticity is lowered, so that it is difficult to keep water and the raw material constituting the skeletal component homogeneous, and the unevenness occurs. Therefore, it becomes difficult to mold into an appropriate shape. In addition, if the moisture content of the molded body is high, the drying time is significantly prolonged.

  When manufacturing a porous body with a light specific gravity in the conventional method for producing ceramic products, the bulk specific gravity is generally limited to about 0.4, and sawdust, rice husk, paper, pearlite are used to reduce the bulk specific gravity. However, since these materials are generally not viscous, a material such as clay is required separately. Foams can be manufactured by adding chemicals, but large ceramics cannot maintain strength, making them difficult to mold, and it is necessary to add cement or the like. Moreover, if it is a large product, defects such as cracks and cracks are likely to occur due to shrinkage and expansion during drying and firing, making it difficult to produce a product.

  In the conventional method for manufacturing ceramic products, it is essential that the molded body is dried after molding, and if not dried, defects such as cracks and cracks occur during firing. Equipment costs, management costs, and fuel costs are incurred in the drying process.

  In the conventional method for producing a ceramic product, it is necessary to sinter the firing process generally at 1100 to 1300 ° C. Since conventional ceramics have a large proportion of clay in the raw material, the fire resistance is high, and firing at 1000 ° C. or less is insufficient in strength and it is difficult to ensure proper quality for the product. For this reason, the fuel cost of a baking process occupies most in all the manufacturing costs, and a fuel cost increases, so that unglazed baking, glazed baking, main baking, and baking are repeated.

  Further, since the foam is expanded at the time of firing, it is generally necessary to cut out and prepare the foam with a cutting process after firing, and the cost is also added. Larger products generally require higher strength than the molding, so generally the clay content increases. For this reason, drying shrinkage at the time of drying becomes large, and cracks and cracks are likely to occur. Also, in the firing process, the more clay there is, the greater the shrinkage of firing, and cracks and cracks occur due to their own weight.

  The present invention solves the above-described problems, can control the fluidity and plasticity by adjusting the moisture content of the base material regardless of the clay of the molding component, and eliminates the need for a drying step. It is an object of the present invention to provide a ceramic product manufacturing method and a base material that can be fired while containing moisture during molding.

  In order to solve the above-mentioned problems, a method for producing a ceramic product according to the present invention uses at least one of a ceramic raw material and a mineral waste as a raw material, and a predetermined amount of the raw material and a predetermined amount of plant-derived molding. A material is mixed and kneaded to form a base material, and the base material is formed into a molded body, and at least a molded body containing moisture contained in a plant-derived molding material is fired.

  In the method for producing a ceramic product according to the present invention, the plant-derived molding material is at least a raw plant or a dried plant, and the plant material containing moisture is contained in the molding material. .

In the method for producing a ceramic product of the present invention, the plant-derived molding material is a plant raw material containing at least plant fiber and polysaccharide.
Further, in the method for producing a ceramic product of the present invention, the mineral waste is at least one of a crystalline material, an amorphous material, a glassy material, a gelled material, a metal, and a mixture thereof. And

  In the method for producing a ceramic product of the present invention, the molded body is fired in a state having a predetermined moisture content to become a porous body having a bulk specific gravity of 0.1 to 0.4.

In the method for producing a ceramic product according to the present invention, the moisture of the base material is adjusted by the amount of the plant-derived molding material added.
In the method for manufacturing a ceramic product according to the present invention, the base material has a moisture content of 20 to 70% by weight.

  In the method for producing a ceramic product of the present invention, the plant-derived molding material contains a predetermined amount of potassium element, sodium element and a compound thereof, and the molded article is fired at 600 to 1000 ° C.

  The base material of the present invention is a base material for forming a molded body for ceramic products, comprising at least one base material of ceramic raw materials and mineral waste, and plant cells containing moisture. It is characterized by blending a molding material containing.

  In the present invention described above, by using a plant-derived molding material, a base material having predetermined fluidity, viscosity, and plasticity can be prepared regardless of clay, which is a general molding component.

Process drawing which shows the manufacturing method of the ceramics product in embodiment of this invention Schematic showing the binding structure of plant raw materials and waste in the same embodiment (A) is a schematic diagram showing the binding structure of the plant raw material and waste at the time of molding, (b) is an enlarged view showing the plant cells contained in part A in (a) (A) is a schematic diagram showing the combined structure of plant raw materials and waste during firing, (b) is an enlarged view showing part B in (a), and (c) shows part C in (a). Enlarged view Process diagram showing a conventional method for manufacturing ceramic products Relationship between firing temperature and bulk specific gravity Relationship diagram between firing temperature and degree of shrinkage

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In FIG. 1, a plant-derived molding material is a plant raw material such as a raw plant or a dried plant, and has plant cells containing moisture, and the plant raw material includes at least plant fiber and polysaccharide. Is included.

  The plant raw material 51 used as a plant-derived molding material in the present embodiment has a moisture content of 50 to 97% by weight, and includes cellulose, semicellulose, lignin, inorganic potassium elements, sodium elements, and compounds thereof Etc. The plant raw material 51 may be either a terrestrial plant or a marine plant. The terrestrial plant is, for example, grass, wood, bamboo, aquatic plants, etc., and contains a lot of minerals such as moisture, potassium element, sodium element, and magnesium element. Among marine plants, seaweeds and seaweeds such as kelp and tengu, which are rich in plant fiber and polysaccharides are useful as plant-derived molding materials. Compared to terrestrial plants, marine plants are weak in cellulose and have flexibility, and are suitable for the plant-derived molding material of the present invention.

Further, plant materials suitable for plant-derived molding materials include the following.
1. Various wood waste Thinned wood, pruned wood, large sawdust 2. 2. Waste of various grasses Mowing materials, Susukino, bamboo grass, bamboo, weeds Processed waste Paper, building waste, cloth, okara 4. Agricultural waste Agricultural crops, rice, straw, corn, straw, soybeans, tea chaff, bran Food waste Vegetables, fruits, and their juices and pomace Various seaweeds and aquatic plants Seaweeds such as blue seaweed, tengu, seaweed, and kelp, seaweeds, seaweeds, and their juices and pomace. Mineral waste 52, the main component of the raw material, is a vitreous material and is a glassy material. The material consists of glass cullet such as waste bins and molten slag derived from waste (industrial waste from municipal waste, sewage sludge, factories, etc.), and mineral waste 52 as metal (for example, iron scrap, aluminum scrap, It is also possible to use copper scrap), and the mineral waste 52 may be at least one of a crystalline material, an amorphous material, a glassy material, a gelled material, and a mixture thereof.

  However, conventional raw materials for ceramics such as silica can be used as the main material, and the base material can also contain clay. Furthermore, the structure which substitutes a part of clay with the binder function in the clay in the conventional manufacturing method with the vegetable raw material 51 is also possible.

  The plant raw material 51 and the mineral waste 52 are pretreated by pulverizing 58 into a shape that can be put into a kneader or the like that constitutes a kneading means in a kneading step described later, and the shape and particle size are arbitrarily set. The plant raw material 51 can be input in a state close to the original form.

  This plant material 51 and mineral waste 52 are blended 53. The moisture of the base material is mainly adjusted by the addition amount of the plant raw material 51 having a moisture content of 50 to 97% by weight, and contains at least the water added by the plant raw material 51 as a plant-derived molding material. In the present embodiment, moisture is further adjusted by adding moisture separately, and moisture adjustment is performed so that the moisture content of the base material is 20 to 70% by weight.

  A plant material 51, a mineral waste 52, and water are mixed and adjusted in a kneader serving as a kneading means and kneaded 54 to prepare a base material having a predetermined moisture content of 20 to 70% by weight. By using a plant-derived raw material 51 containing plant fiber and polysaccharide as a plant-derived molding material, a substrate having a predetermined fluidity, viscosity and plasticity regardless of clay as a general molding component The material can be prepared.

Plants are carbohydrates, made of water-soluble and insoluble sugars, raw plants contain more than 50% water, and many insoluble fibers are gel-like and sticky.
That is, as shown in FIG. 2, the plant-derived molding material 151 made of the plant raw material 51 contains a predetermined amount of cellulose, semicellulose, lignin, inorganic potassium element, sodium element, and a compound thereof. The base material 152 made of the mineral waste 52 is collected. The plant-derived molding material 151 is formed by joining polysaccharides or lignin as an adhesive between the base material 152 and the base material 152 between the plant fiber consisting of cellulose and semicellulose in the plant material and the base material 152. Gives the base material predetermined fluidity, viscosity and plasticity.

  This base material is molded 55 by molding, press molding, hand-bending, or the like to obtain a molded body having a predetermined shape. At the time of molding, the base material is in a state in which most of the moisture is contained in the plant cells and the movement of moisture is suppressed, and the plant cells are evenly diffused in the base material so that The moisture distribution is averaged without any unevenness of the moisture, and the molded product does not lose its shape due to the unevenness of the moisture. Therefore, the ceramic product 57 obtained by firing the molded body in the firing step described later has a uniform quality. Moreover, since strength is expressed in the molded body by the vegetable fiber, a large-sized molded body having a thickness of about 10 cm and a length and width of about 1 m × 1 m can be formed.

  In the present embodiment, for example, a base material having a moisture content of 40% by weight is molded 55 by press molding or hand-bending. The base material has predetermined fluidity, viscosity, and plasticity even under a moisture content of 20 to 70% by weight, and the base material constituting the skeleton component can be kept homogeneous. In this way, a plant-derived molding material 151 is added to prepare a base material having a predetermined fluidity, viscosity, and plasticity with a moisture content of 20 to 70% by weight, and the base material is molded 55 to form a molded body. This is referred to as water forming in the present embodiment. This water forming is one of the features of the present invention.

Conventionally, it is essential to dry the molded body under certain conditions, and when the drying conditions are not satisfied, the molded body is cracked or cracked.
This is because the moisture contained in the clay does not escape evenly from the clay and a part of the molded body dries early, and if it is not sufficiently dried, the moisture remaining in the clay of the molded body Rapid evaporation during firing causes the product to expand and crack the product.

  Conventionally, when a large product is required, the strength of the molded product is required even at the time of molding, so generally the blending ratio of clay increases, drying shrinkage during drying increases, and cracks are likely to occur due to the weight of the molded product. In the firing process, the more clay, the greater the shrinkage of firing and the occurrence of cracks due to its own weight.

  However, in this embodiment, the plant-derived molding material 151 can prevent the deformation of the base material 152 by holding the base material 152 due to its adhesiveness, and most of the moisture in the base material is contained in the plant cells, and its movement is prevented. It is in a suppressed state, and the moisture distribution in the molded body is not biased by the plant cells evenly diffusing into the base material, so that the moisture distribution is averaged as a whole, and the molded body has high water retention. It becomes difficult for water to evaporate, and it becomes possible to maintain the moisture content of the molded body under the control of humidity at room temperature, thereby eliminating the occurrence of defective products due to cracks and cracks in the conventional drying process.

  In the low temperature region where the firing temperature is 600 ° C. to 850 ° C., the plant-derived molding material functions as a molding component in the molded body and retains the base material that forms the skeletal component, but the cells disappear during firing. Thus, moisture can easily escape from between the particles of the vitreous material as the raw material, so that a firing method without firing shrinkage or firing expansion is possible.

  Therefore, the dimensional accuracy can be maintained between the molded body before firing and the ceramic product after firing, cracks due to firing shrinkage and firing expansion are difficult to appear, and it becomes possible to produce a large product, It is not necessary to cut out the fired product and commercialize it, and the fired product can be directly used as a porous ceramic product.

  In addition, since a firing method having a smaller shrinkage rate than the conventional method can be performed even in a region of a higher firing temperature, as shown in FIG. 7, relative to the size that can be produced by the conventional method. Large fired products can be manufactured.

  For this reason, in this Embodiment, without passing through a drying process, the molded object containing the water | moisture content added at least by the plant-derived molding material 151 is baked 56 at 600-1000 degreeC, and bulk specific gravity 0.1-0.4. It becomes the ceramic product 57 of the porous body.

  In addition, as shown in FIG. 3, moisture exists in the cell membrane 202 of the plant cell 201 as a vacuole 203 in the molded body, and a strong cell wall 204 surrounds the outside of the cell membrane 202, so that heating during firing is performed. Although the water 153 evaporates due to this, since it is not free water, it evaporates slowly, so that no cracks or the like occur. At the time of firing, the plant itself self-combusts with a certain amount of oxygen contained in its own organic matter, so it can be heated not only from the outside but also from the inside of the molded body. For example, a thick product having a thickness of 10 cm is also fired it can.

  Carbon reacts with oxygen by heating and generates heat. However, carbon does not generate heat by reacting with oxygen in silicon oxide, which is an inorganic substance in rocks. On the other hand, the carbon compound in the plant is decomposed by heating and burns to generate water and carbon dioxide to generate heat. This is one of the major factors that show energy-saving effects, promote the sintering reaction, and enable low-temperature sintering. Therefore, the more it is used, the better the sintering stability and energy saving due to internal heat generation.

  For example, in firing at about 800 ° C., the water contained in the molded body is not evaporated, the area occupied by the water becomes voids, the plant cells of the plant-derived molding material 151 disappear, and the plant-derived molding is performed. The area occupied by the material 151 is a void. In this state, the bulk specific gravity is about 0.2, for example, and a large product can be manufactured.

  On the other hand, when the firing temperature is about 900 ° C., the raw material 152, the inorganic potassium element, the sodium element, and the compound move to the void region, the molded body shrinks, and the bulk specific gravity becomes about 1.0, for example. Manufacturable.

  Further, when the firing temperature is about 1000 ° C., the raw material 152, the inorganic potassium element, the sodium element, and the compound move so as to fill the voids, and the voids become small. Thus, a low-boiling substance is surrounded as a sintering component, and a fired product having a higher specific gravity can be produced.

  Thus, at the time of baking, low-boiling substances such as potassium element and sodium element contained in the plant raw material 51 forming the plant-derived molding material 151 function as a sintering component, so that baking is performed at 600 to 1000 ° C. Therefore, it can be fired in a shorter time than conventional equipment for firing ceramic products, and can be fired using a metal setter, thereby saving energy and reducing costs.

  Further, as shown in FIG. 4 (a), during firing, the moisture 153 in the molded body is transferred to the outer surface at a low temperature, and the combustion exhaust gas 154 in which the organic matter is burned is generated on the basis of the evaporation of moisture. Since it passes through the fine voids in the inside, defects such as cracks are unlikely to occur in the fired body due to the ejection of the combustion exhaust gas 154. Further, the surface strength of the ceramic product 57 is increased by the salt 155 of low boiling point substances such as potassium element and sodium element moving to the surface of the molded body together with the combustion exhaust gas 154 at a low temperature and consolidating and solidifying like a glaze on the surface. . At the time of firing, decoration can be performed at the same time, laser spraying processing to the ceramic product 57 can be performed, and processing for strengthening various functions by composite and reinforcement is possible.

  Further, as shown in FIG. 4B, when the firing temperature is in a low temperature range, the plant raw material 51 of the molding material 151 in the molded body functions as a molding component and forms a skeleton component. By holding the vitreous material of the mineral waste 52, cells are lost at the time of firing, and moisture easily escapes from between the particles of the vitreous material, so that a firing method without firing shrinkage and firing expansion becomes possible. More specifically, as shown in FIG. 4 (c), in the low temperature range where the firing temperature does not react with inorganic substances, only the plant raw material 51 forming the molding material 151 burns first, and also from the inside of the molded body. Heat (indicated by arrow A) generated from the inside of the molded body due to combustion of the plant raw material 51 is transferred to the mineral waste 52 of the base raw material 152, and the low-boiling point salts 155 generated by the combustion are the base raw material. Since the behavior which plays the role of the sintering auxiliary material which joins the vitreous materials of the mineral waste 52 of 152 is shown, it does not shrink as a whole. In a high temperature range where the firing temperature reacts with inorganic materials, shrinkage starts due to the reaction between inorganic materials.

  For this reason, the dimensional accuracy does not change between the molded body before firing and the ceramic product 57 after firing, and it is not necessary to cut out a porous fired product to produce a product. It is possible to produce a large-sized product in which cracks due to firing shrinkage and firing expansion are difficult to occur.

  In the present embodiment, the high moisture content of the base material means that the proportion of the mineral waste 52 that is the base material 152 that remains after firing decreases, and the plant material that is the plant-derived molding material 151 that disappears by firing. The ratio of the raw material 51 is increased.

  Therefore, the molded body having a high moisture content is in a state swollen by the moisture of the plant raw material 51. By firing the molded body having a high moisture content, a ceramic product 57 having a low bulk specific gravity is obtained. By adjusting the content ratio, the specific gravity of the fired ceramic product 57 is arbitrarily adjusted, and a porous ceramic product 57 having a bulk specific gravity of 0.1 to 0.4 (used for a composite material of a roof and a wall material). Can be manufactured. Conversely, by setting the moisture content of the base material to be low, it is also possible to produce a porous ceramic product 57 having a bulk specific gravity of 0.4 to 1.5 (used for roofs and wall materials). A ceramic product 57 having a bulk specific gravity of 1.5 to 3.0 (used for a flooring material) can be manufactured by setting the moisture content of.

The cell size of the porous ceramic product 57 can be arbitrarily adjusted by pre-processing the plant raw material 51 to be put into the kneader and processing it to an appropriate particle size. This light specific gravity porous ceramics product 57 can be used for a wide range of functional applications, and is suitable for functional building materials (fireproof, soundproof, moisture absorption), for example.
Example 1
Light-weight body with a firing temperature of 800 ° C and a bulk specific gravity of 0.2 Example of pulverized wood 50%
15% seaweed ground
Molten slag 30%
Sintering aid 5%
Example 2
Sintered body with a firing temperature of 900 ° C. and a bulk specific gravity of 1.0 Mixing example Wood pulverized product 30%
10% ground seaweed
Sewage melt slag pulverized product (coarse) 40%
Waste incineration ash molten slag pulverized material (fine granules) 15%
Bentonite 5%
Example 3
Sintered body with a firing temperature of 1000 ° C. and a bulk specific gravity of 2.0 Compounding example 10% crushed material
5% ground seaweed
70% ceramic materials
Gulf sludge 15%
As shown in FIG. 6, conventionally, only a fired product having a firing temperature of 1000 ° C. or more and a bulk specific gravity of 0.4 or more could be produced.

As shown in FIG. 7, the baked product of the method of the present invention produced using a plant as a molding material has a smaller degree of shrinkage than that produced by replacing a part of the molding material with clay. The shrinkage is 0 at the blending and firing temperatures.
In the above embodiment, the ceramic raw materials such as silica, sand, clay, frit, etc. may be used as the raw material, and further, the ceramic raw material and the mineral waste as described above are used as the raw material. May be used.

DESCRIPTION OF SYMBOLS 51 Plant raw material 52 Waste 53 Compounding 54 Kneading 55 Molding 56 Firing 57 Ceramics product 58 Crushing 151 Plant-derived molding material 152 Base material 153 Moisture 154 Combustion exhaust gas 155 Low-boiling point salt 201 Plant cell 202 Cell membrane 203 Vacuole 204 Cell wall

Claims (9)

  At least one of ceramic raw materials and mineral waste is used as a raw material, a predetermined amount of raw material and a predetermined amount of plant-derived molding material are mixed and kneaded to form a raw material, and the raw material is molded A method for producing a ceramic product, comprising firing a molded body containing moisture contained in at least a plant-derived molding material.   The method for producing a ceramic product according to claim 1, wherein the plant-derived molding material is at least a raw plant or a dried plant, and the plant material contains moisture in the molding material.   The method for producing a ceramic product according to claim 1, wherein the plant-derived molding material is a plant raw material containing at least plant fiber and a polysaccharide.   The mineral waste is at least one of a crystalline material, an amorphous material, a glassy material, a gelled material, and a mixture thereof. Manufacturing method for ceramic products.   The method for producing a ceramic product according to claim 1, wherein the formed body is fired in a state having a predetermined moisture content to become a porous body having a bulk specific gravity of 0.1 to 0.4.   The method for producing a ceramic product according to any one of claims 1 to 5, wherein the moisture of the base material is adjusted by the amount of the plant-derived molding material added.   The method for producing a ceramic product according to any one of claims 1 to 6, wherein the base material has a moisture content of 20 to 70% by weight.   The ceramic product according to any one of claims 1 to 7, wherein the plant-derived molding material contains a predetermined amount of potassium element, sodium element and a compound thereof, and the molded body is fired at 600 to 1000 ° C. Manufacturing method.   A base material for forming a molded body for ceramic products, comprising at least one base material of ceramic materials and mineral waste and a molding material containing plant cells containing moisture A base material characterized by

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