JP3094226B2 - Crystallized glass composite ceramics and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to crystallized glass and composite ceramics used as building and construction materials.

[0002]

2. Description of the Related Art Conventionally, ceramics used in the above-mentioned fields include porcelain, stoneware, pottery, crystallized glass and the like. Sintered or melt-crystallized.

[0003] The structure of ceramics produced by sintering is
The vitreous material produced by melting feldspar has a structure in which insoluble particles such as quartz are welded or clay particles are sintered.

[0004] A crystallized glass building material, which is a kind of ceramics, does not use clay, but is mainly made of feldspar, silica sand, limestone, sodium carbonate, etc. at a high temperature of about 1400 ° C, and then rapidly cooled. Pulverized and granulated to obtain 110
A method of generating crystals such as nepheline, anorthite, wollastonite or diopsite in glass by sintering while maintaining a high temperature state of 0 ° C. to 1200 ° C. (both crystallization sintering and integration methods) Or a method in which a molten glass is formed into a plate at a high temperature and then crystallized at a temperature of 1100 to 1200 ° C. (roll-out method) to produce a structure in which crystals are dispersed in a vitreous base. Has become.

[0005]

The conventional ceramic building materials are:
The raw materials are blended and adjusted to obtain a compact having as few structural defects as possible using high quality raw materials. To obtain a dense sintered body, a high temperature of 1100 ° C or more is required, and rapid thermal stress during firing is required. Since the baking conditions such as heating and cooling are adjusted so as not to be added to the substrate, much heat energy is consumed in the production.

[0006] In addition, a crystallized glass building material having the texture of artificial stone material is melted at a high temperature of 1400 ° C. or more, and further melted.
This also requires a large amount of heat energy to be crystallized by a heat treatment at a temperature of from 00 ° C. to 1200 ° C., and its use is limited to wall materials because it is expensive.

In recent years, while high-quality natural raw materials have been depleted, companies have been required to properly dispose of waste generated during production and recycle defective products and collected product waste. When recycled as a part of the raw material due to variations or contamination of foreign substances, there has been a problem that the yield and quality are reduced.

[0008] As a method of reducing the thermal energy required for the production of a ceramic building material by shortening the firing time, natural β-wollastonite having a linear and low expansion coefficient (the coefficient of thermal expansion is 65 × 10 -7) and a method of blending synthetic α-wollastonite into the base material have been studied.
It has not been put into practical use due to problems such as requiring a high temperature of 0 ° C. or more, difficulty in densification due to its difficulty in sintering, and an increase in the price of raw materials.

In particular, wollastonite-based crystallized glass building materials require a large amount of energy since they are produced by a method in which the raw material mixture is once melted and vitrified and crystallized at a high temperature, so that price competition is severe. In addition to the situation, there has been a problem that a large amount of CO2 is generated in the production and the environmental load is large.

In recent years, the situation surrounding the ceramic building materials manufacturing industry has become even more severe. The situation is in need of reinforcement.

[0011] As a conventional technique to cope with the above-mentioned problem, glass waste generated as industrial waste or general waste is mixed with a conventional ceramic raw material as a medium melting material for feldspar, and is used as a raw material.
Some are baked at a temperature of ℃ or more to form tiles or bricks.
(For example, JP-A-08-165163, JP-A-09-77
530)

However, in those cases, the glass has a low thermal conductivity and a high expansion coefficient (a soda-lime glass used for ordinary housing windows and bottles has an expansion coefficient of 90-10).
0 × 10-7), the difference in thermal expansion coefficient between the vitreous part and the crystalline part or the aggregate-like particles causes a tensile stress to act on the vitreous part where the aggregate and the clay mineral are fused, causing cracking. However, it was not possible to increase the size of the aggregate particles or reduce the firing temperature to 900 ° C. or less.

Further, since glass has a lower viscosity at the time of melting than natural minerals such as feldspar, deformation such as bending is large, and a glassy floor material has a smooth surface and is slippery when wet. The stress caused by the temperature difference between the surface and the inside is large because of the drawbacks and the low thermal conductivity as compared with the crystal, so that a longer slow cooling operation is required than with a normal ceramic.

Further, waste glass is used as a raw material in the range of 760 to 96.
There is a method of producing nepheline-based crystallized glass at 0 ° C. (Japanese Patent Laid-Open No. 5-97473). However, since nepheline is produced in a high alkali composition, a large amount of an alkali component must be added as a raw material, and the raw material cost is reduced. In addition to the increase in the crystallinity, the crystal is not acicular, and the physical properties are lower than those of the β-wollastonite type.

If the crystallized glass portion of the grain boundary is colored with a coloring material such as a metal oxide in order to further enhance the design, the color tone will inevitably become dark. Had been.

In order to solve such problems, the present invention utilizes β-wollastonite-based waste materials that can be manufactured quickly at low temperatures and reduce the burden on the environment by utilizing wastes such as glass and cement. It is an object of the present invention to provide a crystallized glass composite ceramic and a method for producing the same.

[0017]

In order to solve such problems, waste glass, Portland cement or waste mainly composed of Portland cement is finely pulverized as an inexpensive and highly reactive multicomponent material. Using silica sand or siliceous plant waste, ceramics that produce wollastonite crystals at low temperatures are obtained.

In order to achieve the above object, a soda-lime waste glass and a calcium raw material, which is a component of wollastonite, are used as a medium melting raw material for vitrifying at a low temperature and promoting fusion of aggregate particles and crystal formation. Use high-hardness and self-hardening Portland cement or waste containing it as the main component, and use high-reactivity silicic acid raw materials such as finely ground silica sand or plants with a high amorphous silica content to maintain high temperatures for a long time. Instead of the method, the raw materials are blended and adjusted so as to have a composition in which crystals are precipitated by ordinary firing.

In this case, when obtaining a dense sintered body at a low temperature, ash of a rice plant having no organic substance is used as a raw material of silicic acid, and when obtaining a porous body or a foam, the organic substance remains. Use rice plants and those in which the components of cement are carbonated.

Further, in the case of producing crystallized glass composite ceramics using glass waste or ceramic waste as aggregate-like particles, crystallization in which wollastonite crystals according to claim 2 are precipitated around the aggregate particles. It is surrounded by glass and has a tissue structure in which a compressive stress is applied around the particles as shown in FIG.

In order to obtain ceramics with further improved design, titanium oxide or zircon crystals and inorganic colorants are used to increase the whiteness of the crystallized glass portion on which wollastonite crystals are precipitated. Although the structure is dispersed, the overall color tone can also be changed by selecting the aggregate particles.

BEST MODE FOR CARRYING OUT THE INVENTION

In the above-mentioned raw material mixture adjusted product, the hydrated cement and the slaked lime produced thereby exhibit self-hardening due to the hydration reaction and the carbonation reaction, and the molded product hardens.

When this is calcined, the adsorbed water of the gelled calcium silicate hydrate formed by hydration of the cement component is dehydrated at about 60 ° C. to 70 ° C., and crystallized at a temperature of 100 ° C. to 200 ° C. And become closer to the chemical composition of wollastonite.

Calcium hydroxide produced simultaneously with calcium silicate hydrate decomposes at around 460 ° C. to release water, and calcium carbonate produced by reaction with carbon dioxide gas is 200 times less than natural mineral limestone. 700 lower than ℃
Decomposes at ℃ to produce active calcium oxide.

When organic matter remains, the siliceous plant carbonizes at around 300 ° C. and generates amorphous silicic acid by burning carbon from around 450 ° C.

The waste glass softens from around 600 ° C. and undergoes a solid-phase reaction with active calcium oxide, silicic acid, etc., and precipitates β-wollastonite crystals in the glass at a temperature of 750 ° C. to 800 ° C. Therefore, crystallized glass in which crystals and glass are mixed at a low temperature of about 800 ° C. to 900 ° C. is obtained.

Since organic matter is burned to generate carbon dioxide, by adjusting the composition and firing conditions, a foamed or porous body of crystallized glass having independent pores or continuous pores can be obtained and is not affected. In this case, a dense body is obtained.

It is known that the presence of wollastonite crystal in glass results in a smaller thermal expansion coefficient than in the case of only a glass composition. You can do it.

As shown in FIG. 1, the surroundings of ceramic waste and glass particles serving as aggregates are made of the crystallized glass according to claim 2 (crystallized glass in which wollastonite crystals are dispersed in glass). Due to the difference in thermal expansion coefficient, the surrounding ceramic has a compressive stress applied around the high expansion particles, and becomes a crystallized glass composite ceramic having high mechanical strength.

The needle-like β-wollastonite crystals dispersed in the ceramic not only function to inhibit the propagation of cracks, but also play a role in increasing the slip resistance when used for flooring.

Since titanium oxide and zircon are insoluble, they remain in glass containing β-wollastonite crystals as crystals and enhance the coloring effect of the colorant.

[0032]

EXAMPLE 1 Soda-lime glass pulverized waste from a glass processing plant, waste cement slurry discharged from a concrete pile manufacturing plant (80% of component is Boltland cement), rice husk discharged from agricultural cooperative facilities Ash (charcoal) and the like were mixed in various ratios, and molding experiments were performed.

The waste glass is finely pulverized in a dry system, the waste cement slurry is in a state of not yet solidified, the one hardened once in a room and then finely pulverized in a dry state. After being wet-mixed, the mixture was cast into a mold and molded, and hardened by the self-hardening property of the cement component.

[0034]

Embodiment 2 The compact was heated from 800 ° C. to 110 in an oxidizing atmosphere.
As a result of calcination in the range of 0 ° C, measurement of physical properties and composition analysis,
A dense body, a foamed body, a porous body, etc. containing β-wollastonite crystals are 40 to 80 parts of soda lime waste glass, 10 to 40 parts of waste cement slurry, and 0 to 40 parts of rice husk charcoal.
Parts obtained.

As an alternative raw material for rice husk charcoal, completely incinerated rice husk or silica sand finely pulverized to 10 microns or less is used.
As a result of conducting a comparative experiment with charcoal on a composition having the same chemical composition, the physical properties of the fired body at 900 ° C. were almost the same as those using charcoal.

[0036]

Example 3 In Example 2, a composition confirmed to produce β-wollastonite by firing at 900 ° C. (40 parts of waste glass having a soda-lime glass composition, 20 parts of waste cement slurry, 20 parts of rice husk charcoal) Part of the mixture), water and a binder are added, and the mixture is pulverized, and the waste glass cullet having a particle size adjusted from 5 mm to 1 mm is reduced to 1/10 by dry weight ratio.
And the mixture was mixed with a mixer so that the additive covered the waste glass cullet.

In order to compare this with a refractory mold having a thickness of 10 mm and a length and width of 50 mm filled with the mixture and similarly filled only with glass cullet, it was placed in the same firing furnace at 900 ° C. Fired.

The fired product of Example 3 was in the form of a translucent plate in which the grain boundaries of the glass particles used as the aggregate were crystallized, and no cracks were observed. In the form of a transparent plate, with some cracks.

In order to measure their mechanical strength, the surface was polished in the same manner, a test piece having a thickness and width of 5 mm and a length of 50 mm was prepared, and the physical properties such as bending strength were compared. As shown in Table 1, the glass-ceramics according to the present invention showed a small coefficient of thermal expansion and a high bending strength.

[0040]

[Table 1]

[0041]

Embodiment 4 In order to improve whiteness and lightness, Embodiment 2
Of the raw material composition according to the invention by weight percentage of zircon 5
%, Titanium oxide 2% added or not added,
Cobalt oxide pigments are used as inorganic colorants in an amount of 0.
In the method used in Example 3 by adding in the range of 1 to 3%,
The periphery of the waste glass particles was coated, filled in a mold, and fired at 900 ° C.

As a result, a crystallized glass composite ceramics having a slightly opaque and unique texture in which the periphery of the glass particles was colored blue was obtained, and had a brighter color tone than those without zircon or titanium oxide added. It was confirmed that it became.

[0043]

Since the present invention is configured as described above, it has the following effects.

Unlike conventional natural mineral raw materials, multi-component synthetic material waste such as glass waste and cement waste and waste decomposition products such as plant ash are used as raw materials, so that raw material costs can be greatly reduced.

Since active raw materials such as multi-component synthetic raw material waste and vegetable ash are used and the sintering method is used instead of the melting method,
The crystallization temperature can be lowered, and the heat energy required for the production is about one-third of the conventional one (compared with an electric furnace), so that the firing cost can be greatly reduced.

Since the crystallized glass composite ceramics of the present invention can utilize the self-hardening property for molding, it is possible to produce an irregular complex shape by a casting method using a mold.

The composite ceramics in which the aggregate particles are made of glass are highly viscous and less slippery than glass, even though they are glassy. Can be

The crystallized glass composite ceramics of the present invention can be manufactured at a lower cost than conventional wollastonite crystallized glass building materials, which promotes recycling and reduces the environmental burden.

In addition to ceramic waste such as tiles, it can be used as a binder for particles made of refuse melting sludge or the like, and large aggregate particles can be fused, so that it has excellent physical properties such as sound absorption and water permeability. It can be applied to recycled high-performance building materials.

[Brief description of the drawings]

FIG. 1 shows a comparison between a conventional glass ceramic structure and the glass ceramic structure of the present invention.

FIG. 2 is a comparison diagram of the conventional method and the method of the present invention.

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Claims (2)

(57) [Claims] 1. The method according to claim 1, further comprising at least aggregate particles obtained from waste such as glass waste and ceramic waste, and crystallized glass in which β-wollastonite (low-temperature wollastonite) crystals are precipitated and dispersed. Characterized in that the aggregate particles are covered with the crystallized glass having a smaller coefficient of thermal expansion than the crystallized glass composite ceramics. 2. A plant comprising 40 to 80 parts of pulverized soda lime glass or waste material containing the same as a main component, 10 to 40 parts of Portland cement or waste material containing the same as a main component, and a siliceous inorganic component. Ash or finely ground silica sand is mixed and finely ground with 0 to 40 parts and then mixed with aggregate particles obtained from waste such as glass chips and ceramics chips. A method for producing ceramics, wherein the aggregate particles are covered with crystallized glass in a state in which β-wollastonite (low-temperature wollastonite) crystals are precipitated and dispersed by sintering at the above temperature.