JPH11157914A - Modification of ceramics using waste plastic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce practically usable ceramics by effectively utilizing a material containing an organic material (a carbonized material) difficult to use as a ceramic raw material and a waste plastic. SOLUTION: A waste plastic is added to a compounded raw material and an organic material is burned and destroyed by fire at a low temperature together with burning of the waste plastic in a baking process in a method for adding other auxiliary raw materials containing an organic material to a ceramic raw material consisting essentially of a clay or adding an adequate amount of a molding auxiliary to the ceramic raw material which is a clay containing the organic material, kneading the resultant mixture, forming the prepared body into a prescribed shape, drying the formed body and baking the dried formed body. The auxiliary raw material is a coal ash and a waste plastic capable of being pyrolyzed and burnt in a low-temperature region of 170-450 deg.C is further effectively used as the waste plastic.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for modifying ceramics using waste plastic.

[0002]

2. Description of the Related Art Coal ash such as fly ash or fluidized bed ash discharged from a thermal power plant is partially used as a raw material for cement, a raw material for synthetic zeolite, a soil conditioner, etc.
Most of the waste goes to landfills or other costly disposal as industrial waste. In addition, since the chemical composition of fly ash and the like is very similar to the composition of the ceramic raw material, utilization research has been conducted as an alternative raw material for the ceramic raw material, but the unburned carbon contained in the fly ash and the like has been studied. Is burned in the firing process of ceramics, and the CO ₂ and CO gas generated at that time greatly affect the quality and productivity of the product. Therefore, almost all of the non-glazed bricks (eg, Patent No. 1859617) not being used. Similarly, clays and gravel containing carbides (charcoal, coal, etc.) are not used because the combustion gas of the carbides affects the quality of products.

[0003]

The unburned carbon contained in coal ash, such as fly ash, and the carbide contained in clay and gravel generally burn between about 400 ° C. and 900 ° C. On the other hand, a clay raw material, which is a main component of ceramic raw materials such as ceramics, starts to shrink at around 400 ° C. and rapidly shrinks at around 900 ° C. For this reason, sufficient oxygen is not supplied to the inside of the substrate, and it becomes very difficult to burn these materials using unburned carbon or carbide, and the combustion continues to a high temperature region (a furnace temperature of 1000 ° C. or higher). In ceramics that use glaze, if the combustion reaction exceeds 1000 ° C (in-furnace temperature), the combustion gas (CO ₂ , CO) reacts with the glaze that has begun to melt, changing the color of the glaze or causing blistering on the surface. It may cause a foaming phenomenon. In addition, CO gas causes the inside of the substrate to be in a reduced state.
e) occurs. The problem to be solved by the present invention is
The purpose of the present invention is to eliminate such discoloration, blistering, foaming phenomenon, black core phenomenon occurring inside the substrate, and the like on the surface of the ceramic product.

[0004]

According to the method of the present invention for solving the above-mentioned problems, first, a ceramic raw material containing clay as a main component and another auxiliary raw material containing an organic substance added thereto or containing an organic substance are contained. In a method in which an appropriate amount of a molding aid is added to a ceramic raw material that is clay, a kneaded clay is formed into a predetermined shape, and then dried and fired, a waste plastic is added to the compounded raw material, and the firing process is performed at a low temperature. It is characterized in that the organic matter is burned and burned off together with the burning of the waste plastic.

[0005] Second, the auxiliary raw material is coal ash.

Third, waste plastic is 170-450 ° C.
It is characterized in that it can be thermally decomposed and burned in a low temperature range.

Fourthly, the waste plastic to be added is characterized in that it is a powder or a granular material obtained by pulverizing a plastic waste material.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a ceramic (ceramic) raw material and a raw material obtained by mixing a powder or a clay containing organic substances such as unburned carbon and other carbides in the production of ceramic products. The present invention relates to a reforming method for eliminating the drawbacks of ceramic products caused by organic substances by adding waste plastics that can be thermally decomposed and burned at (° C).

The added waste plastic undergoes thermal decomposition and combustion during firing of the green body. At that time, small holes are formed in the green body, and the heat of combustion (6200 to 1100 Kcal / Kg) reduces the temperature inside the green body. To raise. Therefore, organic substances such as unburned carbon and other carbides contained in the raw material can be completely burned in a low-temperature region, and defects (such as defects on the surface of a ceramic product caused by the action of organic combustion gas (CO, CO ₂ )). It is possible to prevent discoloration, pocking) and a black core generated inside the substrate.

The feature of the present invention is that it contains a large amount of organic substances,
An object of the present invention is to make it possible to use powders, clays, and the like containing organic substances that are difficult to use as ceramic raw materials and that cannot be used as ceramic raw materials. Next, specific examples of the present invention will be described in detail. In the following examples, examples in which fly ash, carbide, and fir coal are added to a ceramic raw material made of clay are shown as Examples 1 to 4, respectively. The plastics added to the raw materials were all powdered or finely pulverized.

Example 1) A raw material was prepared by adding 42% by weight of fly ash containing 6% of unburned carbon to a pulverized ceramic raw material (clay mineral, quartz, feldspar, mica mineral) having a passing rate of 74% through a 74μ sieve. , glazed and test piece _{a 1 (150mm × 40mm × 20mm} ) and allogeneic the same raw material, prepared by adding the same amount of fly ash and pulverized methacrylic resin weight ratio 16%, glazed and test piece B _{1 (150} mm (× 40 mm × 20 mm) was placed in a tunnel furnace for firing tiles and fired at a rate of temperature rise of 300 ° C./h. As a result, the black core was observed over the entire inner matrix is in the test piece A _1, also pinhole occurs in釉面. On the other hand, test piece B ₁ represents, but weight compared to A ₁ is decreased slightly, abnormality due to the unburned carbon is not observed at all, the matrix also exhibited white.

Example 2) A crushed ceramic raw material (clay mineral, quartz, feldspar, mica mineral) having a passing rate of 74% through a 74μ sieve was prepared by adding 40% by weight of fly ash having an unburned carbon content of 6%. A test piece B ₂ made by adding the same material, the same amount of carbide and crushed polystyrene to the same raw material as the glazed test piece A ₂ (150 mm × 40 mm × 20 mm) by 16% by weight,
(150 mm × 40 mm × 20 mm) was placed in an electric furnace and fired at a heating rate of 300 ° C./h. As a result, test piece A
_In No. ₂ , a black core having a thickness of 10 mm was recognized inside the substrate, and a pinhole was generated on the glaze surface. On the other hand, test piece B ₂
Although weight compared to the A ₂ is decreased slightly, abnormality due to the unburned carbon is not observed at all, foundation colors also white in color.

Example 3) Rice husk charcoal was used as a raw material for pulverized ceramics with a passing rate of 74% through a 74μ sieve.
The added 5% by weight test piece A ₃ was wet-molded
(40 mm × 20 mm × 150 mm) and a test piece B ₃ (40 mm × 20 mm) which was wet-formed by adding 5% by weight of “rice husk charcoal” and 5% by weight of acrylic resin to the ground material.
X150 mm), and then baked at 1200 ° C at a rate of 300 ° C / h using an electric furnace. When observing the inside by cutting the central portion of the fired test pieces, test piece A ₃ is the entire surface of a black color, the test piece B ₃ was completely observed black core almost white.

Considering the above results, when an appropriate amount of waste plastic material is added to a carbide-containing raw material and fired, the waste plastics (particularly, thermoplastic resin and the like) are decomposed at a decomposition temperature (170 to 450 ° C.) during the firing process. ) Melts (endothermic reaction) at relatively low temperature below and is adsorbed by clay, then volatilizes and burns (combustion heat 6200-11000 Kcal /
Kg). For this reason, the trace of the presence of the melt becomes a porous state in which small holes are opened, the diffusion of the air and the decomposition gas inside the base material is promoted, and the temperature inside the base material increases due to the combustion of the decomposition gas. As a result, the subsequent combustion of carbides, unburned carbon and the like contained in the base material becomes very easy, and the combustion reaction of the organic matter such as carbides and unburned carbon is almost completed by 1000 ° C. Has no effect on the quality of ceramic products.

On the other hand, in the case where no waste plastic is added, the burning of carbides and the like becomes insufficient due to the shrinkage of the material during the firing, the generation of a black core inside, and the discoloration due to the continued burning after the start of melting the glaze. It has been found that a problem that the foaming phenomenon cannot be avoided is caused. Further, the combustibles contained in the material are not limited to unburned carbon of fly ash, and can be widely applied to general organic substances in addition to the various carbides shown in the examples.

Other materials for the waste plastic include methacryl (acrylic) resin (PMMA) and polystyrene resin (PS), as well as polypropylene (P) which thermally decomposes or burns at a low temperature of about 170 to 450 ° C.
P), polyethylene (PE), ABS resin, unsaturated polyester resin (UP), etc. can be used, and the use of these waste plastics is a double cost merit in terms of waste disposal cost and raw material unit cost by using waste. There are advantages that can be achieved.

[0017]

According to the present invention constructed as described above, fly ash and fluidized bed ash which are wastes such as industrial wastes discharged in large quantities, and other organic substances which are of poor quality as ceramic materials Contained ceramic materials can be effectively used as raw materials for practical ceramic products,
These improvements can be realized by the effective use of waste plastics, which is also a waste, which has the effect of providing excellent economics in both processing costs and material costs.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yutaka Murata 1268, Tsunozu-cho, Gotsu-shi, Shimane Prefecture Inside Yoken Co., Ltd. Person Kunihiko Hiraiwa 1268 Tsunozu-cho, Gotsu City, Shimane Prefecture Inside Yoken Co., Ltd. (72) Inventor Yoshihiko Maeda 1-16-8-301 Kamimiya, Tsurumi-ku, Yokohama

Claims (4)

[Claims] 1. A kneaded clay obtained by adding an appropriate amount of a molding aid to a ceramic raw material containing clay as a main component and adding an auxiliary material containing an organic substance to a ceramic raw material containing the clay or an auxiliary material containing an organic substance. In the method of firing the formed and dried product in the shape of, a waste plastic is added to the compounding raw material, and the waste plastic is burned and burned down by burning the organic matter together with the waste plastic at a low temperature in a firing process. Reforming method. 2. The method according to claim 1, wherein the auxiliary raw material is coal ash. 3. The method for modifying ceramics using waste plastic according to claim 1, wherein the waste plastic can be thermally decomposed and burned in a low temperature range of 170 to 450 ° C. 4. The waste plastic to be added is a powder or granules obtained by pulverizing plastic waste.
Or a method for modifying ceramics using waste plastics of 3.