JP2003335571A - Method for manufacturing clay tile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To recycle more waste clay tile. <P>SOLUTION: A compounded composition is prepared by compounding an alumina-feeding raw material of 100 μm or less in an average particle size and chamotte, each of 30 wt.% or less into a clay composition, thereby resulting in degraded refractoriness, and shaped, and baked in the range of 1,150 to 1,300°C, thereby baking and compacting tightly the shaped body, and avoiding the strength degradation of the product. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a clay roof tile, which is intended to reduce the weight of the roof tile and to effectively use the waste roof tile.

[0002]

2. Description of the Related Art Conventionally, a defective product (waste roof tile) that has been burned during roof tile production has been used as a raw material for production by crushing and mixing it with clay for the raw material. In addition, when excessively mixed crushed waste roof tiles (chamotte), which has a higher degree of fire resistance than unfired raw materials, are mixed, the baking tightness deteriorates and the product strength decreases, so the chamotte content is 5% by weight. To a limited extent, the surplus waste roof tiles were disposed of by landfilling.

[0003]

However, due to reasons such as environmental protection, it is almost impossible to replenish the landfill site in the future, and it is inevitable that the shortage of the landfill will become serious, and the depletion of high-quality ceramic raw materials. From the standpoint of deregulation, it is earnestly desired that more waste roof tiles be recycled.

[0004]

SUMMARY OF THE INVENTION In view of the problem that more waste roof tiles should be reduced and utilized based on the above-mentioned prior art, the present invention provides an alumina feed material having an average particle size of 100 μm or less and chamotte at 30% by weight. It is compounded in the following proportions in the clay composition to reduce the fire resistance of the composition, and after the composition is molded, it is fired in the range of 1150 to 1300 ° C., so that the molded product is densely baked to reduce the strength. The above problem is solved by avoiding.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. The method for producing a clay roof tile according to the present invention is a method of mixing a clay composition such as Kibushi clay with alumina, a fine powder of an alumina feed material such as aluminum hydroxide, and a fine powder of chamotte, and molding the mixture by an appropriate method. And then 1150-1
This is a method of firing in the range of 300 ° C. Regarding the particle size of the alumina feed material and chamotte, both are preferably 100 μm or less in average particle size, more preferably the average particle size, in order to uniformly disperse both of them in the compound and reduce the fire resistance of the entire molded body without any deviation. The diameter is 50 μm or less. or,
Mixing ratio of alumina feedstock and chamotte is 30% by weight
In the case of excess, it is necessary to set the firing temperature to over 1300 ° C., and there is a possibility that problems such as damage to the firing furnace due to overheating and an increase in fuel cost may occur. Both are preferably 30% by weight or less.

The present invention will be described in more detail based on the following examples. First, the crushed waste roof tile is sieved to collect only fine powder having an average particle size of 100 μm or less, and the obtained chamotte fine powder is used together with alumina having an average particle size of 100 μm or less (commercially available) for roof tile manufacturing. The clay composition was blended at a predetermined ratio and kneaded to uniformly disperse both fine powders in the blend. Next, the above composition was molded into a rectangular flat plate, and then fired in a firing furnace for roof tile production or a small firing furnace for testing, and the bending strength of the obtained test body was measured. The composition of each test piece produced in the firing furnace for roof tile production, firing conditions,
In addition, Table 1 shows the measurement results of the bending strength, and Table 2 shows the composition of each test body prepared in the test firing furnace, the firing conditions, and the measurement results of the bending strength. In addition, the thickness of the prepared test body is about 1
The width was 6 mm and the width was about 32 mm, and the supporting span of the test body in the bending strength test was set to 80 mm. In addition, the temperature of the firing furnace when loading and unloading the test body to the firing furnace is 400 ° C.
And the heating rate was 10 ° C./min.

[0007]

[Table 1]

[0008]

[Table 2]

According to the above-mentioned test results, the bending strength of the test piece was increased by adding the alumina feed material to the clay composition, and the improvement of the bending strength by the alumina feed material was recognized even when chamotte was mixed. However, it was found that this tendency became more remarkable as the temperature was higher. That is, the alumina feedstock reduces the refractory of the blend, and the raw material particles in the blend are fused together,
It is densely sintered to improve the bending strength.

[0010]

In summary, according to the present invention, an alumina feed material and chamotte are mixed in a clay composition, and the composition is molded and then fired. Therefore, it is more difficult to sinter than the clay composition. Even if 5% or more of the chamotte is mixed, the fire resistance of the fired product does not decrease because the melting point of the alumina feedstock lowers the fire resistance of the compounded product. A product having strength can be obtained. Therefore, by using more chamotte (crushed waste tiles), it is possible to reduce the amount of waste tiles disposed, alleviate the shortage of industrial waste treatment plants, and contribute to environmental conservation. It is possible to reduce the amount of materials used and avoid depletion of ceramic raw materials.

Since firing is performed in the range of 1150 to 1300 ° C., the bending strength of the fired product is remarkably improved, and even if it is thin, the bending strength equal to or higher than that of the product made of only the clay composition can be secured. The weight of the product can be reduced.

Since both the alumina feed material and the chamotte have an average particle size of 100 μm or less, the two factors that affect the fire resistance are uniformly dispersed in the mixture, and the firing products are unevenly compacted and shrinked. Since it does not exist, it is possible to stabilize the product quality and obtain good products with good yield.

Since the mixing ratio of the alumina feed material and chamotte is both set to 30% by weight or less, practically sufficient bending strength can be ensured even if firing is performed at a temperature of 1300 ° C. or lower which can be handled by the existing firing furnace. Therefore, the above-mentioned effects can be obtained without making capital investment, which is a great practical effect.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasushi Takasu             2,100, Goshikinen, Nisshin City, Aichi Prefecture

Claims (4)

[Claims] 1. A method for producing a clay roof tile, which is characterized in that an alumina feed material and chamotte are mixed with a clay composition, and the composition is molded and then fired to form the clay roof tile. 2. The method for producing a clay roof tile according to claim 1, wherein the firing is performed in the range of 1150 to 1300 ° C. 3. The method for producing a clay roof tile according to claim 1, wherein both the alumina feed material and the chamotte have an average particle size of 100 μm or less. 4. The method for producing a clay roof tile according to claim 1, wherein the mixing ratio of the alumina feed material and the chamotte is both 30% by weight or less.