JPH11171635A - Production of ceramic for construction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing ceramic for construction, capable of applying unused resource and contributing to saving of resource and energy by sintering a base material composition obtained by compounding refractory granules as a main raw material with a silicic acid alkali-based component, low melting point metal-based component and one or more kinds of materials selected from an alkaline earth metal salt, an aluminum salt and a polyacrylic acid-based polymer at a low temperature. SOLUTION: A base material composition obtained by compounding 100 pts.wt. refractory granules of extrusive rock, plutonic rock, sherd, chamotte, coal ash, volcanic ash, fly ash, etc., used as a main raw material with 5-50 pts.wt. silicic acid alkali-based component, 1.0-25 pts.wt. low melting point metal-based component having <=900 deg.C melting point comprising a low melting point metal powder having <=900 deg.C melting point or a compound thereof and 0.05-40 pts.wt. one or two or more kinds of component selected from an alkaline earth metal salt, an aluminum salt and a polyacrylic acid polymer is formed and sintered at >=350 deg.C and <=1,000 deg.C to provide the objective ceramic for construction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a low-temperature sintering type building ceramic. In particular, use of unused resources and waste materials as the main raw materials
Alternatively, the present invention relates to a method for producing architectural ceramics that can contribute to environmental conservation.

[0002]

2. Description of the Related Art Conventionally, products referred to as architectural ceramics include exterior tiles, interior tiles, floor tiles, mosaic tiles, red bricks, ceramic plates, clay tiles, ceramic blocks, and ceramic tubes according to the purpose of use or shape. There are many types, large and small. These ordinary building ceramics are made from crushed, blended, mixed, molded, and made of clay, ores, including clay, quartzite and feldspars, and ore as main raw materials.
Manufactured through processes such as drying and firing.
In order to produce products with physical properties with good yields, high-quality raw materials with relatively few impurities are required, and as a result of mining for many years, the depletion of high-quality raw materials has become remarkable in recent years. Countermeasures have become a major issue.

[0003] In the firing during the manufacturing process,
Usually, high-temperature sintering of 1100 ° C. or more is required, so that the energy cost of the fuel and the like has been enormous. further,
When a kiln tool such as a pod for accommodating products during firing is required, such as a mosaic tile or an interior tile, the fuel consumption is particularly large because the thermal efficiency is inferior to about 10%. Also,
As a result of consumption of these fuels, there are inherent problems such as generation of a large amount of CO ₂ and NOx gas which are not preferable in terms of environmental conservation.

[0004] In addition to the above problems, most of the above-mentioned ordinary building ceramics are often used by applying a glaze. Among them, a base material is fired at a high temperature like a wall tile and then glazed. For products that are finished at a relatively high firing temperature, frit containing lead and boric acid is used as a glaze raw material, and these harmful substances may elute to the outside, causing occupational health problems or damage to rice cultivation. There were also problems. In addition, glaze tiles fired once at a temperature of 1100 to 1130 ° C. have the same problem.

[0005] In order to solve such problems, the industry is required to maintain or improve the conventional quality and to secure a stable supply at a low price without depending on the conventional raw materials such as clay, feldspar and silica stone. The development of a low-temperature sintering-type ceramic technology that is possible to utilize resources as a new main raw material and that can be fired at a temperature significantly lower than the firing temperature in the past has been greatly expected. The following attempts have been conventionally made for such a purpose.

(1) Utilization of unused resources. As an alternative raw material to clay raw material, it has been intended to utilize wastewater and wastewater collected during mountain gravel and silica sand washing and refining, or sewage sludge obtained at a sewage treatment plant. However, in the above-mentioned wastewater and collected wastewater, a considerable amount of fine sand and fine sand remain, resulting in poor moldability, insufficient molding strength and many handling damages, poor sinterability, and high firing temperature. There are many defects such as rough surface finish after firing, and "shear cracking" failure during the cooling of the firing process. Therefore, the blending ratio is naturally limited. It was difficult.

Further, sewage sludge contains a large amount of lime and sedimentation chemicals such as sodium sulfate added in the treatment process. When firing, there was a problem that the firing temperature range was narrow, so that it was easily deformed. In addition, raw sludge has a large water content, so that drying shrinkage and firing shrinkage are large, so that it is easy to crack. Therefore, calcination or vitrification treatment is required at a temperature of 300 ° C. or more. Since the formability was lost, the amount used did not increase.

On the other hand, instead of feldspar raw materials, obsidian, pine stone, shirasu natural glass, crushed artificial glass, and the like have been studied. These vitreous raw materials are inferior in adhesion to clay raw materials, have low strength of molded products, and are melted in a very narrow temperature range during firing. The problem that a predetermined shape and dimensional accuracy cannot be maintained due to deformation such as large warpage of the fired product has not been solved yet. For this reason, even when baked on a plate-like sheath like a mosaic tile, it can be blended at a maximum of about 15%, but it is difficult to put it to practical use.

(2) Energy saving measures. Conventionally, energy-saving measures studied in kiln furnace construction and furnace operation technology do not attempt to lower the firing temperature itself.For example, methods to reduce the heat dissipation loss by increasing the efficiency of the heat insulation structure, or to reduce the furnace ceiling A method of improving the thermal efficiency by reducing the temperature difference between the top and bottom inside the kiln by devising a flat shape and a suction port for sensible heat gas has been tried,
It is not decisive because there are problems such as a fall in the ceiling member of the kiln, an increase in rag dropping, or a decrease in the cooling effect of the single furnace.

The application of the residual heat of the combustion exhaust gas to the preheating of the primary or secondary air for combustion has been in practical use for a long time, but in this case, the concentration of nitrogen oxides in the final exhaust gas is limited to the protection of the atmospheric environment. Strict management has become necessary since the above regulatory values may be exceeded. Therefore, at present, there is no new progress in utilizing the residual heat of the combustion exhaust gas from the conventional method of using it as a heat source in a drying process.

[0011] In addition, high-efficiency burning by a high-speed combustion burner has been promoted, but the burner itself is expensive.
Unless the combustion chamber is modified, it is difficult to apply it to existing kilns. As described above, even as an energy-saving measure, the operating condition has been improved, and the fuel consumption has been reduced at most by several percent to several tens percent.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. First, 1) keeping the quality of a product at a conventional level, for example, the quality of JIS standard, 2). It is a method of manufacturing ceramics for building which can utilize unused resources as main raw materials without using high-grade raw materials such as clay and feldspars as indispensable raw materials, and 4). Shortening the drying process, 5) providing a method for manufacturing architectural ceramics that can significantly reduce fuel consumption in the drying process and the firing process, and consequently contribute to 6) resource saving, energy saving and environmental conservation. I do.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a method for producing a building ceramic according to the present invention comprises a refractory powder as a main raw material, an alkali silicate component and a low melting point. A base composition comprising a metal component and one or more components selected from alkaline earth metal salts, aluminum salts and polyacrylic polymers is molded and sintered at a low temperature of 350 ° C. or higher. It is characterized by doing.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment according to the method for producing a building ceramic of the present invention will be described. First of the present invention
Is characterized in that the following refractory powders are used as main raw materials. The main raw material of the ceramics of the present invention is not necessarily clayey, pottery, quartz,
Or refractory, eg, at least 35 mm, without the need for grounds of high grade ceramic raw materials such as feldspar.
0 ° C., preferably a fire-resistant material containing silica and / or alumina having a certain degree of durability at a temperature at the time of fire, for example, 600 ° C. or more, or changes into the fire-resistant material by heating to produce fire resistance Material is available. As such a material, an unused resource, which has been rarely used in the past, or a waste which has been difficult to reuse can also be applied, and typical examples thereof are shown below.

1) Erupted rocks such as rhyolite, andesite, and basalt. 2) Plutonites such as granite, diorite and gabbro. 3) weathered rocks and mountain sands of the erupted rocks and plutonic rocks. 4) Natural glass such as pumice, black stone, and pine stone. 5) Sediments such as lapilli and volcanic ash, for example, shirasu. 6) Selven powder obtained by crushing defective tiles, brick waste, and waste tiles. 7) Chamottes obtained by sintering and crushing refractory clay. 8) Collected glass such as plate glass and bottle glass. 9) Incineration ash such as garbage, sludge generated from sewage treatment plants and its incineration ash. 10) Coal ash generated from boilers such as power plants. 11) Fly ash generated from a cement plant. 12) Silts, which are also called fine sand, are fine-grained sediments (particle size: from micron order to several tens of microns) in which many impurities are mixed in silica sand and feldspar. 13) Separated minerals at the time of concentrate, for example, silica sand and mica-containing by-products including mica separated from the ore in the refining process of refined clay, such as Frogme clay.

In the present invention, one or more of these materials can be appropriately selected and applied. When these are mixed, they can be selected according to the desired appearance, such as the desired color tone, pattern, and roughness of the obtained product, and are almost unrelated to the mechanical properties such as the strength of the product. It is selectable without. It does not preclude the use of high-grade raw materials such as conventionally used clay.

A second feature of the present invention is that the essential components added to the main raw material are one or two selected from an alkali silicate component, an alkaline earth metal salt, an aluminum salt and a polyacrylic polymer. The point is that more than one kind of additional components and a low melting point metal-based component are used.

The alkali silicate-based component, which is the first essential component, is alkali silicate such as water glass, a mixture of alkali silicate and silica sol, or a hydroxide or carbonate of silica sol and alkali metal. And mixtures of these, or a plurality of mixtures thereof. As the alkali silicate, sodium, potassium or lithium silicate can be applied, respectively, and the ratio between the silicate content and the alkali content is determined according to JIS standard (K140
There is no limitation to what is specified in 8). Rather, in the present invention, Na ₂ O / SiO ₂ (molar ratio) is 1/5 to
About 1/6 is preferably used.

The role of the alkali silicate-based component is as follows. First, it functions as a molding aid when the obtained base composition is formed by press molding or extrusion, and imparts sufficient plasticity to the base. It is in. The second is to improve the adhesiveness between the base constituent particles after molding to increase the strength and to withstand handling. Since the plasticity and the green base strength are improved in this way, the dimensional accuracy and the finish of the molding surface are improved, and no handling loss occurs.

The second role of the alkali silicate-based component is as follows, although the mechanism is not necessarily clear.
It is considered that the interaction with the alkaline earth metal salt, aluminum salt, and the like, which are essential components, contributes to the natural hardening of the molded article regardless of the drying operation. For example, even when sewage sludge with a high water content is applied as it is as a main raw material, it can be naturally hardened at room temperature, and can be collected from several minutes by adjusting the amount of the blended components. Since a free curing time within the time range can be set, a drying operation and a step of substantially applying ordinary heating and ventilation can be omitted.

Further, the third role of the alkali silicate-based component is that although the molded product is heated to 350 ° C. or higher, it does not exist conventionally, due to the interaction with a low-melting-point metal-based component which is a third essential component described later. The point is that sintering can be performed at a particularly low temperature. It is considered that such a metal-based component reacts with these alkali silicate-based components at a temperature of 300 ° C. or more to form a complex polycondensate and strongly binds the constituent particles of the blended composition. . In terms of sintering in such a low temperature range, the result is similar to a situation in which conventional ceramics mainly composed of clay, feldspar and the like form a sintered body in a high temperature range of approximately 1200 ° C. or higher.

As a result, according to the present invention, there is no difference in the mechanical strength, abrasion resistance, waterproofness, weather resistance, fire resistance, etc., compared with conventional products, even though the sintering is performed in a low temperature range. Ceramics can be obtained. In addition, the porosity or water absorption of the product can be controlled quite freely from the state of water absorption of 0 to about 50% by adjusting the kind and the amount of the essential components including the alkali silicate component. Do you get it. In this way, it is possible to produce a sound absorbing wall material or a road or floor pavement material having good sound absorbing properties or water permeability.

Conventional sintering of porcelain is based on a melting reaction of feldspar or the like. However, in the present invention, the melting reaction is not recognized, and the above-mentioned compounds are melted in a low temperature range, and the main raw material is melted. Since sintering is performed by sticking, the dimensional accuracy is high, the effect of reducing deformation and the like is significantly improved, and the fuel required for firing is reduced, which greatly contributes to the energy saving effect. Advantages are also obtained in terms of environmental conservation, such as suppression of generation of carbon dioxide and nitrogen oxides in the combustion exhaust gas. Furthermore, since the firing temperature is low, many effects can be expected, such as an advantage that the fire resistance of the firing furnace and the heat insulation structure can be simplified.

The amount of the alkali silicate component having such a role is from 5% by weight of the main raw material (hereinafter the same) to 5%.
0% is appropriate, and when it is out of this range, the above-mentioned effect is not obtained or becomes insufficient,
If it is excessively mixed, the soluble alkali component exceeds the limit, and disadvantages such as reduced weather resistance and water resistance and lack of practicality become noticeable. Further, the compounding amount of these alkali silicate-based components is preferably 8% to 40%. When emphasis is placed on the quality of the product by surrounding the refractory granules of the main raw material or by sufficiently joining them together, 12 % To 37% is the most preferable range.

Next, the alkaline earth metal salts, aluminum salts and polyacrylic polymers which are the second essential components will be described. As the alkaline earth metal salts, one or a combination of two or more chlorides or sulfates of strontium and barium can be applied in addition to magnesium and calcium which are easily available. The chlorides and sulfates of aluminum salts are also suitable. The chlorides of these alkaline earth metals and aluminum may be either synthetic or naturally occurring, and any of anhydrides and hydrates are similarly used. As the polyacrylic polymer, a hydrophilic or water-soluble polyacrylic polymer can be applied, and specifically, polyacrylamide, polyacrylamine, sodium polyacrylate, and the like are suitable. It is easily available as a molecular coagulant.

As described above, these second essential components, together with the alkali silicate component as the first essential component, have a role of naturally hardening the base composition after being compounded. The amount is suitably in the range of 0.05% to 40% in total with respect to 100% of the main raw material.
Further, 3% to 25% is more preferable, but the ratio, the total amount, and the like of the alkaline earth metal and aluminum may be appropriately selected according to the blending amount of the alkali silicate component.

Next, the low melting point metal-based component, which is the third essential component, will be described. As this component, one or more metal powders of magnesium, calcium, aluminum, barium, strontium, zinc, tin, bismuth, and antimony having a melting point of 900 ° C. or less, or a melting point of compounds of these metals Is preferably 900 or less.

Although the mechanism of action of such a low-melting metal component in the substrate has not been fully elucidated, as described above, particularly, the alkali silicate component and the low-melting metal component are calcined. It is believed that they react with one another to form complex polymer-like silicate glasses or glasses containing fine crystals that act as strong fusing agents. The amount of the low-melting point metal-based component may be adjusted according to
1.0% to 25% is appropriate for 00%, more preferably 2% to 20%, and most preferably 5% to 17%.

As described above, in the present invention, the above-mentioned refractory powder is used as a main raw material, and the above-mentioned alkali silicate component, alkaline earth metal salt or aluminum salt or polyacrylic polymer is used as the main material. , And a low-melting metal component are blended to prepare a base composition to be subjected to the molding step, but the order of blending is not particularly limited and can be arbitrarily performed. However, since the alkaline earth metal salts and the like have a function of hardening the compounding base material, it is necessary to complete the molding before setting after the compounding, so that this point will be considered. .

A further feature of the present invention resides in that the thus obtained molded body of a ceramic base composition for construction or construction is made of 3
Although the temperature is 50 ° C. or higher, sintering is performed in a particularly low temperature range as compared with conventional ceramics. In this case, an appropriate molding method can be adopted for molding before firing, for example, molding into a predetermined shape by a mold extrusion molding method, a mold press molding method, and the like, and then, as described above, Has a property of curing naturally, and after a predetermined time elapses, the base material is sufficiently cured, and then the mixture is kiln-filled in an appropriate heating furnace and heated to 350 ° C.
The sintering may be completed by raising the temperature as described above. In addition, this sintering does not hinder sintering at 1000 ° C. or more because the above-described compound strongly fuses the main raw materials to form a building ceramic, but is preferably an upper limit in terms of energy saving and environmental conservation. Temperature to 1000 ° C., more preferably 9 ° C.
It is desirable to control the temperature to 00 ° C.

The strength of building ceramics is
It is often glazed to improve aesthetics and weather resistance.
The method for producing a building ceramic of the present invention can also be embodied in a form in which a glaze is applied to a molded product before firing. Here, as a basic composition of the glaze, an alkali silicate component and a low melting point metal component used in the base composition are essential components, and as an adjusting component, a salt of an alkaline earth metal and aluminum or a polyacrylic polymer is used. Based on the added composition, the base is glazed and then fired simultaneously with the base.

The preferred range of the basic composition of the glaze is exemplified by 5 to 50 parts of an alkali silicate-based component (weight basis, the same applies hereinafter), 1 to 25 parts of a low-melting metal-based component, and salts of an alkaline earth metal and aluminum or Glaze compositions containing one or more polyacrylic polymers in a proportion of 0 to 40 parts are preferred.

The glaze composition is appropriately diluted with water according to the article to be glazed, and glazed by a suitable method such as a spray method, a dipping method, and a pouring method. Then, the glaze composition forms a transparent or translucent glass-like coating at the sintering temperature. In the case where coloring is performed, inorganic pigments for ceramics can be appropriately applied in the same manner as in the related art.

[0034]

Next, the present invention will be described in detail with reference to Examples 1 to 5. (Example 1) The granite crushed product was further pulverized to a particle size of 5 μm.
A powder containing 30% or more of the following is used as a main raw material, and anhydrous magnesium chloride (10%) and metallic zinc powder (6%) are added and mixed, and a No. 3 water glass (sodium silicate) stock solution is added to the mixture.
% And 30%, and two kinds of base compositions were prepared. Water is appropriately added thereto, and the mixture is kneaded, and then, using a wet extruder, a width of 600 x a thickness of 20 x a length of 300 m.
m was produced. This was left to cure at room temperature for 3 hours and then fired at the temperatures shown in Table 1 below. A base composition containing 3% aluminum chloride simultaneously with the anhydrous magnesium chloride was also prepared and fired in the same manner.
In Table 1, the bending strength (kgf / cm ² ) of the quality of each test piece is exemplified, but the test piece at each firing temperature did not show water absorption and was densely sintered.
(Substantially, water absorption = 0).

[0035]

[Table 1] Note: The curing time column shows the elapsed time until the molded product is cured so that it can be handled.

As described above, according to the method for manufacturing a building ceramic of the present invention, wet extrusion molding can be easily applied, firing can be performed only three hours after molding, and shape defects such as cracks and deformation can be obtained. Was not found. In each case, the shrinkage due to firing is extremely small, 0.1% or less, so that a product with high dimensional accuracy can be obtained. In addition, the water absorption is low and the mechanical strength is excellent. It is very suitable for producing the building ceramics. Incidentally, for ceramic tiles of the conventional products, interior tiles, exterior tiles, floor tiles have been classified by the JIS-A5209 into four mosaic tiles, their bending strength is 100 kgf / cm ² or more interior wall tiles ,
400 kgf / cm ^{2 for} exterior tiles exceeding 150 mm
That is all.

On the basis of Example 1, in the case of using No. 2 or No. 1 water glass instead of No. 3 water glass as the alkali silicate-based component, the molding operation was facilitated.
Although the curing time was slightly longer and the bending strength was reduced by about 5%, almost no change was observed overall. Moreover, about the test body obtained in Example 1, minus 4 degreeC-20 degreeC
A cold resistance test and a weather resistance test were repeated 40 times during the cold and heat cycles, and no abnormalities such as breakage and whitening were observed.

Further, instead of 10% sodium chloride, 10% barium sulfate or 10% polyacrylamide
As a result of preparing and performing a quality test under the conditions of the above example, the curing time of the molded body was about 10%.
Approximately the same quality as the result in Table 1 was obtained except that a delay of about a minute was recognized.

Example 2 80% of sewerage sludge having a water content of 17.2% and 20% of a gravel-washed and collected matter previously ground so that a particle size of 10 μm or less becomes 30% or more were used as main raw materials 10
The composition was prepared by adding 25% of No. 3 water glass (sodium silicate) stock solution, 12% of bittern, and 8% of metallic magnesium powder to 0%. 50kgf /
A test specimen having a size of 100 × 100 × 8 mm was molded at a molding pressure of cm ² and fired at each temperature shown in Table 2 after standing for 30 minutes.
Firing shrinkage (%), water absorption (%) of the obtained specimen
The bending strength (kgf / cm ² ) is shown in the table.

[0040]

[Table 2]

The values in parentheses in Table 2 are data for glaze products in which glaze has been applied to the surface of the molded product. In this case, the glaze used was a mixture of 25 parts of No. 3 water glass stock solution, 12 parts of bittern, and 8 parts of metal magnesium powder, which had been diluted with about three times the amount of water. Further, in Example 2, a test was also conducted on a composition in which both barium sulfate 8% and polyacrylamide 4% were added instead of bitter 12%, and in this case also, results equivalent to the quality shown in Table 2 were obtained. Was.

In this embodiment, sludge which is relatively difficult to dewater is used as the main raw material. However, wet to semi-dry molding by a press molding machine is possible, and a glaze product has excellent smooth appearance. The product was obtained. In addition, both unglazed and glazed products had sufficient mechanical strength as ceramics for construction and construction.

Example 3 60% of aluminum refining sludge having a moisture content of 19%, incineration ash of 30%, raw clay for wet exterior tiles of 10% were used as main raw materials, and silica sol and sodium carbonate were added in a weight ratio of 4%. : 10% of alkali silicate component, 10% of anhydrous magnesium chloride, and 5% of metallic zinc powder were added and kneaded with a molding composition. An extruder was used to form a 300 × 300 × 20 mm plate specimen using an extruder. , 1
After natural curing for a time, firing was performed at each temperature shown in Table 3. The quality of the test specimen is shown in the table. The figures in parentheses show the same glaze specimens as in Example 2.

[0044]

[Table 3]

In this example, the shrinkage rate of the 1000 ° C. baked product was lower than that of the 800 ° C. baked product, but the shrinkage rate was lower, the water absorption rate was higher, and the strength was lower. Was seen. This is because the firing temperature is 1
It is considered that the temperature of 000 ° C. was a little too high, and the overheating phenomenon such as partial foaming occurred, and a maximum firing temperature of 800 ° C. was recognized as an appropriate firing temperature.

The glaze used here was a basic composition in which the above components were mixed in the same ratio, that is, an alkali silicate component 1 in which silica sol and sodium carbonate were mixed at a weight ratio of 4: 1.
0 parts, 10 parts of anhydrous magnesium chloride, and 5 parts of metallic zinc powder as a basic composition, and 10% of kaolin fine powder,
7% ferric oxide was added, finely polished, and adjusted to a water content of 35%. This glazed product exhibited a baked appearance of a glossy red-brown milky opaque glaze. Such opaque glazes are much cheaper than conventionally used zircon emulsion glazes, and do not contain lead and boron contained in conventional low-temperature glaze frit. It is particularly preferable for environmental protection such as no adverse effect.

Example 4 Next, a crushed material obtained by crushing waste (commonly called Kira) obtained from silica sand and a fireclay mine to 60 mesh or less was used as a main raw material 100%, and Na ₂ O: SiO _{2 was used.}
40% of No. 4 water glass ( ₂ : 1: 4 (molar ratio), 20% of bittern, and 20% of metal zinc powder were blended and kneaded to obtain a molding composition. This was formed into a JIS53A type tile tile shape, glazed, and fired at each temperature shown in Table 4 three hours after the formation. The table shows the average quality of the obtained test pieces based on the JIS standard of 20 sheets. In addition, the number of defective products
Indicates the number of sheets deformed due to dimensional defects.

The glaze used here was composed of a composition obtained by mixing the No. 4 water glass, bittern, and zinc metal powder in the same ratio, and consisting of 8% of red earth fine powder, iron oxide and manganese dioxide, etc. It is prepared by adding 8% of a color pigment and pulverizing it finely, and then adjusting the water content to about 50%. Further, Table 5 shows the results in the case where a crushed material obtained by crushing the collected used waste glass bottle to 60 mesh or less instead of the waste was used as a main raw material.

[0049]

[Table 4]

[0050]

[Table 5]

According to this example, the quality of the obtained roof tile exceeds the water absorption rate and bending fracture load specified in JIS standard (JIS-A5208). There is an advantage that the product has excellent heat resistance and does not cause frost damage, and since the main raw material is a non-plastic material, the firing shrinkage is extremely small, so that the product has excellent dimensional accuracy.
In addition, while maintaining the above-mentioned quality, one such as a traditional roof tile
Since high-temperature firing at around 200 ° C is not required, it is possible to significantly reduce fuel consumption in conjunction with shortening the firing time. As a result, the amount of exhaust gas is also reduced, leading to a reduction in carbon dioxide gas and nitrogen oxides. It has great industrial effects, such as contributing to environmental protection.

In Example 4, when potassium silicate (K ₂ O / SiO ₂ molar ratio = 1/4) was used instead of sodium silicate, there was almost no difference except that the bending fracture load was reduced by several percent. Was not recognized, and there was no problem in practical use.

(Example 5) Mikawa clay which has been conventionally used as a raw material for roof tiles, clay which is a by-product at the time of collecting mountain soil or gravel or the like is used as a main raw material.
Water glass stock solution 10%, bitterness 2%, aluminum chloride 1
%, 1: 1 mixed powder of metallic aluminum and metallic zinc
% And kneaded to prepare a molding composition. This one
It was extruded into a 00 × 100 × 10 mm flat plate, and the obtained molded body was left for 3 hours to be naturally cured, and then baked at a maximum temperature of 850 ° C. while smoking using a mixed gas of LPG and nitrogen gas. Table 6 shows the results of the five test pieces.

[0054]

[Table 6]

According to Example 5, the appearance of each of the obtained test pieces was glossy silver, and the color unevenness was very small. The embodiment of this embodiment can be effectively applied not only to the refractory roof tiles but also to interior and exterior building materials such as bricks and tiles.

[0056]

As described above, the method for producing a building ceramic according to the present invention is constructed as described above, so that the quality of the product is maintained at a conventional level, for example, JIS standard quality, and the method is conventionally used. Unused resources and the like can be applied as main raw materials without using high-grade raw materials such as clay and feldspar as essential raw materials. In addition, it is possible to shorten the drying process and greatly reduce the amount of fuel used in the drying and firing processes. As a result, it is possible to significantly reduce costs and contribute to resource saving, energy saving, and environmental conservation. There is. Therefore, the present invention has a very large industrial value as a method for producing a building ceramic which has solved the conventional problems.

Claims (7)

[Claims] 1. A refractory powder as a main raw material, which comprises one or more selected from an alkali silicate component, a low-melting metal component, an alkaline earth metal salt, an aluminum salt and a polyacrylic polymer. A method for producing a building ceramic, comprising: molding a base composition containing two or more components and sintering at 350 ° C. or higher. 2. The method according to claim 1, wherein the refractory granules are eruptive rocks, plutonic rocks and weathered products thereof, selvens, chamotte, wastes, and their incinerated ash, coal ash, volcanic ash, fly ash, silt, and concentrates. Refractory materials containing one or more of silicic acid and / or alumina, such as minerals,
The method for producing a building ceramic according to claim 1, wherein the material is a material that changes into the refractory material by heating to generate fire resistance. 3. The method according to claim 1, wherein the alkali silicate component comprises an alkali silicate, a mixture of an alkali silicate and a silica sol, a mixture of a silica sol and a hydroxide or carbonate of an alkali metal, or a mixture of a plurality of them. The method for producing a building ceramic as described in the above. 4. The low melting point metal component has a melting point of 900.
Magnesium, calcium, aluminum, barium, strontium, zinc, tin, bismuth,
One or more metal powders of antimony, or
The method for producing a building ceramic according to claim 1, comprising one or more compounds having a melting point of 900 ° C. or less among the compounds of these metals. 5. The method according to claim 1, wherein the alkaline earth metal is magnesium,
Calcium, strontium, selected from barium, the salts are chlorides or sulfates, the polyacrylic polymer is polyacrylamide, polyacrylamine,
2. The method according to claim 1, wherein said material is selected from sodium polyacrylate.
3. The method for producing a building ceramic according to claim 1. 6. The compounding amount of the alkali silicate-based component is 5% to 50% by weight (hereinafter the same) with respect to the main raw material, and the total compounding amount of the salt of the alkaline earth metal and aluminum or the polyacrylic polymer is Also 0.05% -40%,
And the compounding amount of the low melting point metal component is also 1.0%
The method for producing a building ceramic according to any one of claims 1 to 5, wherein the amount of the ceramic is from 25% to 25%. 7. The method for producing a building ceramic according to claim 1, wherein the sintering temperature is in the range of 350 ° C. to 1000 ° C.