JP2883636B2 - Manufacturing method of lightweight ceramic building materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a ceramic industry by adopting a dry molding method of a raw material mainly composed of dam sedimentary soil having a large amount of organic matter and Fe ₂ O ₃ and having no plasticity. The present invention relates to a method of manufacturing a building material, particularly a lightweight roof tile.

[Prior art] Ceramic products are still indispensable and useful in our daily lives, even if plastic alternative products are appearing in large numbers today. It is extremely difficult to reduce the weight or less due to the relationship between the raw material used and the strength, which also limits the use and the like, and is a drawback.

For example, in the case of building materials products, especially earthenware tiles for roofing, recently Purihabu method in detached house weight is desired as a result of is incorporated many 25-30 kg / m ^2-position have been appropriate, conventional 40-45 kg / m ² is too heavy, but new cement-based roofing material has emerged and has been partially replaced.

However, this roofing material also has the drawback that it deteriorates in about 10 years due to the material, and that the surface color fades in 4 to 5 years, and the weathering resistance is impaired. A lightweight and weather-resistant ceramic roof tile as described in Japanese Patent Application Laid-Open No. 61-191553 has already been developed and provided. not be lighter only from the constraints of the top to the most weight of 32kg / m ^2.

On the other hand, in the field of ceramic building materials of this type, recently, measures to cope with the depletion of raw material clay and measures for waste soil after dredging of the dam have been engaged, and the use of dam sediment as a part of raw material resources has been attempted. However, although this soil can be expected to give high strength ceramic products due to the contained inorganic components, wet extrusion molding is impossible at first because it contains a lot of organic substances and it is difficult to control heat during firing However, only a usual molding method and a baking method are being studied by mixing with a conventional clay, but a specific product has not yet been produced. Thus, its use has not always been successful, but merely serves as a bulking agent for clay, and has not yet fully exploited the original properties of dam sediment. is there.

[Problems to be Solved by the Invention] Under such a background, the present invention improves the above-mentioned disadvantages of ceramic building materials, especially ceramic tiles, and reduces the weight or the quality while maintaining the high strength of the product. It is intended to make it more difficult.

[Means for Solving the Problems] Accordingly, the present inventor has completely changed the idea, and if ceramic products can be manufactured mainly using the dam sedimentary soil, in that case, high strength Since the product can be expected, thinning of the product, that is, lightening of the product, should be achieved, and as a result of intensive studies aimed at developing a unique forming method suitable for the dam sedimentary soil, the present invention was reached. For the first time, a method for producing lightweight ceramic building materials from this dam sediment was established.

That is, the present invention produces a lightweight ceramic building material by dry-forming a raw material mainly composed of dam sedimentary soil having a large amount of organic matter and Fe ₂ O ₃ and having no plasticity as a thin-walled form, and then firing at 1000 to 1250 ° C. How to

First, where the dam sediment used, generally by soil particles comprising clay fraction which is deposited on the bottom of the lake dam, many chemical composition range silt _{is, SiO 2; 53.1~72.0%, Ai} 2 O _{3; 14.0~20.3%, CaO + MgO} + Fe 2 O 3 + Na 2 O + K 2 O; was 10.6 to 20.8%, the chemical composition range of clay foam of RILEY (SiO _2; 50
_{~75%, Al 2 O 3;} 15~30%, CaO + MgO + Fe 2 O 3 + Na 2 O + K
₂ O; 10-20%), and it is said to foam when over-baked.

The content of Fe ₂ O ₃ is 3.27 to 11.5% (average 5.64%), which is higher than that of Mikawa clay 3.58%, and the color after firing shows a deep red or brown color.

The amount of C acting as a flux is lower than that of SiO ₂ and Al ₂ O _{3.
aO, MgO, Fe 2 O 3} , refractoriness because it contains a large amount of Na ₂ O and K ₂ O content is lower and SK4a～9.

The mineral composition is rich in feldspar, quartz, kaolinite mineral, and mica mineral, and is particularly characterized by a large amount of Fe ₂ O ₃ component and organic matter. Another characteristic is that hematite is observed in the green body after firing.

Further, unlike the conventional base soil, the plasticity is poor as described above, so that it is difficult to perform wet kneading and extrusion molding. In some cases, firing shrinkage is large and foaming occurs particularly at a certain temperature or higher.

In Japan, dams are provided in various places, and all dam sediments have the above properties in common, and are effectively used in the present invention.

In the present invention, this dam sedimentary soil is used as a main raw material, as required, from the conventional natural raw materials such as Mikawa clay, feldspar, pottery stone, and silica stone. , Etc.) and use them in a mixed manner.
Do not use as much as 8% water
Press molding.

In the present invention, this molding method is referred to as dry molding method, and it is difficult to obtain the strength and homogeneity of the product, and it is a method that has not been used in the case of ceramic building materials so far. In such cases, surprisingly, the conventional wet molding method cannot be applied at all, and instead, it has been found that a high-strength product can be easily obtained by the dry molding method.

Therefore, the present invention ideally uses only dam sedimentary soil, but ordinary clay or the like is also used for the purpose of adjusting shrinkage.
Up to 50% can be blended, but in this case
About 20-40% is desirable.

In addition, pottery stone, feldspar, silica sand, and the like can be further added depending on the use or the like, but in any case, it is necessary to keep the strength or the water absorption rate within a range that does not decrease.

The thickness at the time of molding must be thin for the purpose of the present invention, and about 5 mm to 8 mm is most suitable, but if the composition and process of the base material are devised, about 2 mm to 30 mm or more Is possible.

Therefore, the present invention can be used for the production of thin building materials in this way, and can produce, for example, lightweight interior / exterior materials and floor materials in addition to lightweight tiles.

The firing temperature is from 1000 to 1250 ° C., but around 1130 ° C. is particularly preferred.

[Example A] Hereinafter, the present invention will be described in more detail with reference to examples particularly relating to lightweight roof tiles.

Examples 1 to 6 Porcelain tiles were manufactured by the dry molding method at the firing temperatures shown in Table 2 using only the dam sediment of the Sakuma Dam whose component ratio is shown in Table 1. The properties of the product obtained are summarized in Table 2 below.

Examples 7 to 12 Mikawa clay shown in Table 1 was blended with the dam sediment of Sakuma Dam whose composition ratio is shown in Table 1 by 25% of the whole, and the pottery tiles were dry-molded under the conditions shown in Table 2. Manufactured. The properties of the product obtained are summarized in Table 2.

[Embodiment B] Next, an embodiment relating to use for a ceramic plate will be described.

Examples 13 to 20 Porcelain plates were manufactured by the dry molding method using the dam sedimentary soil shown in Table 1 and feldspar, pottery stone, and clay at the mixing ratio and temperature shown in Table 3. The properties of the product obtained are summarized in Table 3 below.

Comparative Example 1 For comparison, only Mikawa clay was wet-molded, and 1110
A ceramic tile having a thickness of 13 mm was manufactured at a firing temperature of ° C. The properties of the obtained product were as follows.

Water absorption 6.2% Strength 142.0kgf / cm ² Weight 43.4kg / m ² Comparative example 2 90: 10,8 with Mikawa clay and Sakuma dam sediment for comparison
Using a mixture of 0:20, 70:30 and 60:40 (all by weight), kneading with a wet clay kneading machine, the wall thickness (mm) 14, 13,
13 and 14, moisture content (%) 17.6, 17.2, 15.3 and 15.1,
When extruded and fired in a tunnel kiln at 1120 ° C, a black carbonized portion remained in the center and foamed up.

Comparative Example 3 For comparison, 60% of Mikawa clay and 40% of Sakuma dam sedimentary soil were kneaded with a wet vacuum kneading machine, and the dimensions were 220 mm x 100 mm x
When a 60 mm compact was extruded and fired in a tunnel room at 1120 ° C., a black carbonized portion remained in the center and foamed up.

Comparative Example 4 For comparison, only the Mikawa clay was dry molded and
Although ceramic tiles were manufactured at a sintering temperature of ° C., they did not sinter sufficiently, and could not obtain a product with satisfactory water absorption and strength.

[Effects of the Invention] The present invention has the following excellent effects supported by the embodiments by adopting the above-described configuration.

(1) Compared to conventional clay and building materials made by a wet molding method using raw materials mainly composed of clay, as a feature of dam sedimentary soil, sufficient strength is maintained even with thin walls, so considerable weight reduction is achieved. Can be expected.

(2) Especially in the case of lightweight tiles, it is possible to apply a glaze differently from a new lightweight roofing material, and since this glaze is glassy, there is no fading over time and the appearance is not impaired.

(3) Ceramic tiles having good sinterability and low water absorption can be obtained, and therefore, it can be expected to be used especially for cold-resistant tiles.

(4) Since the sinterability is good and the strength is high as described above, it can also be used for ceramic plates, interior and exterior materials, and floor materials.

(5) Further, since the sinterability is good, it is expected that the temperature is reduced, that is, energy is saved.

(6) Since firing conditions can be set for both oxidation firing and reduction firing, building materials having different colors can be manufactured by selecting the conditions.

Since it has the above technical effects and solves the following problems as described above, it can be said that the invention is extremely useful.

(7) Effective use of dam sediment can be achieved. This means
It aims to solve both dam burial measures and waste soil pollution measures at the same time.

(8) The problem of exhaustion of raw materials for ceramic building materials can be solved.

Claims (1)

(57) [Claims] (1) After dry-forming a raw material mainly composed of a dam sedimentary soil containing a large amount of organic matter and Fe ₂ O _{3 and} having low plasticity,
A method for producing lightweight ceramic building materials, characterized by firing at ~ 1250 ° C.