JP2007269515A - Porous fire resistant heat insulating board and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a porous fire resistant heat insulating board having fire resistance (heat resistance) not to be burnt or softened and melted at 1,200°C at least for 3 hrs and simultaneously having excellent heat insulating property and suitable as a building materials or the like. <P>SOLUTION: A raw material containing 45-75% coal ash, 5-20% waste glass and 15-40% magnesia and/or alumina by weight is pulverized granular and mixed to be homogeneous, and the mixed raw material is heated and melted at 1,100-1,300°C for 30-240 min and is quenched or naturally cooled. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is a waste of coal ash (fly ash) discharged from a thermal power plant, glass cullet discharged as general waste or industrial waste, and refractory materials (refractory bricks, etc.) such as a smelting furnace. The present invention relates to a porous refractory heat insulation board made of magnesia and a method for producing the same.

  From the long-term perspective of fuel resources, coal-fired power generation is being emphasized in power supply, and the amount of coal ash generated has increased by about 10% per year from 7.6 million tons in 1999. Coal ash is consumed in large quantities in the cement field, civil engineering field, construction field, and the like, but development of new applications is desired in view of the increasing trend of coal ash generation.

  On the other hand, glass has a production volume of 1 million tons or more per year, and most of discarded glass is disposed of in landfills. The glass cullet has zero vitrification reaction heat required for vitrification again, and can greatly reduce the energy required for melting the glass raw material. Considering these advantages, research and development as a raw material for new materials are desired.

A porous lightweight ceramic product having a large porosity using coal ash (fly ash) discharged from a thermal power plant or the like as a raw material and a method for producing the same are known (for example, see Patent Document 1). This prior art is based on heating foam spherical coarse particles such as obsidian and shirasu produced in large quantities as volcanic ejecta, that is, volcanic ejector foam coarse particles such as perlite, or artificial foamed glassy spherical coarse particles such as slag. The heat-expanded spherical coarse particles are used as a main raw material, and a binder composed of a considerable amount of coal ash (fly ash) discharged from a thermal power plant, etc., and organic resin fragments such as synthetic resin and animals and plants is added and mixed. Later, it is characterized by the molding and firing process as well as the porous ceramics obtained by this process. According to this prior art, it is said that a porous lightweight ceramic product having light weight and excellent gas-liquid permeability and high temperature heat resistance (1000 ° C. or higher) can be obtained.
JP-A-11-049585

  Although the above prior art has the characteristics of low bulk specific gravity and excellent gas-liquid permeability, the heat resistance is still at a level of 1000 ° C. or slightly higher, and it has not been achieved from the viewpoint of fire resistance and heat insulation. The present invention is a waste of coal ash (fly ash) discharged from a thermal power plant, glass cullet discharged as general waste or industrial waste, and refractory materials (refractory bricks, etc.) such as a smelting furnace. To provide a porous fire-resistant and heat-insulating board suitable for use as a building material, etc., having magnesia as a raw material and having fire resistance (heat resistance) that does not burn at 1200 ° C. for at least 3 hours or does not soften or melt. With the goal.

  The invention according to claim 1 for solving the above-mentioned problems is composed of coal ash: 45% to 75%, waste glass: 5% to 20%, magnesia and / or alumina: 15% to 40% by weight. It is a porous refractory heat insulation board obtained by melting and cooling from a granular powder blend raw material.

  According to the second aspect of the present invention, the raw materials within the ranges of coal ash: 45% to 75%, waste glass: 5% to 20%, magnesia and / or alumina: 15% to 40% by weight are granulated. It is a method for producing a porous refractory heat insulation board that is made into a shape, mixed and homogenized, and heated and melted at a temperature range of 1100 ° C. to 1300 ° C. for 30 minutes to 240 minutes, and then rapidly cooled or allowed to cool.

  According to the present invention, fireproof (heat resistant) that does not burn or soften / melt at 1200 ° C. for at least 3 hours using coal ash (fly ash), glass cullet, and magnesia, which are industrial waste or general waste, as raw materials. It is possible to provide a porous fireproof and heat insulating board suitable for building materials and the like. Further, since it is porous, it is also useful as a water purification element, microbial carrier, biotope material and the like.

Hereinafter, the present invention will be described according to preferred embodiments thereof.
Porous glass or ceramics is a kind of inorganic porous material and has the following characteristics. 1) heat resistance, 2) microbial fouling resistance, 3) high mechanical strength, 4) chemical durability, 5) presence of rigid micropores, 6) good formability, 7) wide pore structure Selectivity, 8) translucency, gas-liquid permeability, 9) wide composition selectivity, and the like. Characteristics 6) to 9) are characteristics inherent to porous glass or ceramics. Especially, characteristics 6) and 7) are significant characteristics not found in other inorganic materials.

  Coal ash (fly ash) discharged from a thermal power plant or the like has a composition shown in Table 1, for example. On the other hand, the glass cullet has a composition shown in Table 2 in many cases.

The porous refractory heat insulation board of the present invention uses magnesia (MgO) or alumina (Al ₂ O ₃ ) obtained from the above coal ash (fly ash), glass cullet, and waste refractory (refractory brick waste, etc.) as a starting material. , By mixing the powder granules obtained by pulverizing them, coal ash: 45% -75%, waste glass: 5% -20%, magnesia or alumina: 15% -40% It is obtained by heating or melting in a temperature range of 1100 ° C. to 1300 ° C. for 30 minutes to 240 minutes and then rapidly cooling or allowing to cool.

  Coal ash (fly ash), which is one of the raw materials, functions to form fine pores by combustion gasification of a carbonaceous material present in a minute amount. If the blending ratio (weight ratio) of coal ash (fly ash) is less than 45%, it becomes difficult to obtain porosity, and it is not possible to obtain a ceramic that is lightweight and excellent in heat insulation. On the other hand, if it exceeds 75%, the relative amount of magnesia or alumina becomes too small, and the fire resistance (heat resistance) of the resulting porous ceramic is lowered.

Glass cullet functions as a binder for obtaining porous ceramics, and if the weight is less than 5%, it is difficult to form ceramics. On the other hand, if the glass content exceeds 20%, the content of coal ash (fly ash), magnesia (MgO) or alumina (Al ₂ O ₃ ) will decrease, making foaming difficult in the production process, or fire resistance (heat resistance). Decreases.

Magnesia (MgO) or alumina (Al ₂ O ₃ ) contributes to the fire resistance (heat resistance) of the porous fireproof heat insulation board of the present invention. If it is less than 15%, it is not possible to obtain a porous refractory insulation board that does not burn at 1200 ° C. for at least 3 hours or does not soften or melt. On the other hand, when the content of magnesia or alumina is increased, the fire resistance (heat resistance) of the porous fireproof thermal insulation board obtained is improved, but the relative amount of coal ash (fly ash) is decreased, and the foamability is poor in the manufacturing process. Thus, it becomes difficult to obtain a fire-resistant and heat-insulating board that is porous and has excellent heat insulation and gas-liquid permeability.

  Next, manufacturing process conditions will be described. In the present invention, coal ash is in the range of 45% to 75%, waste glass: 5% to 20%, magnesia or alumina: 15% to 40%. The raw material is granulated, and the blended raw material mixed and homogenized is heated and melted in a temperature range of 1100 ° C. to 1300 ° C. for 30 minutes to 240 minutes, and then rapidly cooled or allowed to cool to be porous, heat insulating, and gas-liquid permeable Get a fireproof insulation board with excellent properties.

  If the heating temperature is less than 1100 ° C., ceramics cannot be formed, and a heating temperature exceeding 1300 ° C. causes an increase in cost. On the other hand, if the heating time is less than 30 minutes, a sufficient molten state cannot be obtained, and ceramics cannot be formed. Moreover, heating time exceeding 240 minutes causes a decrease in productivity and an increase in cost. Preferably, it is 60 minutes to 180 minutes.

  Porous refractory heat insulation boards were manufactured under various raw material blending ratios and heating / melting conditions. It is shown in Table 3. The blended raw material was pulverized by a ball mill. Heating was performed in an electric furnace, and the blended raw material was heated and melted and then gradually cooled in the electric furnace.

  The heat resistance test of the obtained porous fireproof insulation board was performed at 1200 ° C. for 60 minutes to 180 minutes. The results are also shown in Table 3. In Table 3, the result * 1 indicates the porosity of the obtained product (the amount of foaming during the production process or the presence or absence), and * 2 indicates the heat resistance test at 1200 ° C. for 60 minutes to 180 minutes. Shows the results of.

  As is apparent from the results shown in Table 3, those satisfying the blended raw material composition and production conditions limited in the present invention are excellent in both porosity and fire resistance (heat resistance).

  Raw materials were prepared at the blending ratios shown in Table 4. Sample 1 was heated and melted at 1200 ° C. for 180 minutes in an electric furnace and then allowed to cool in the electric furnace. Samples 2 and 3 were heated and melted at 1250 ° C. for 180 minutes in an electric furnace, and then allowed to cool in the electric furnace.

The heat resistance test of the obtained porous fireproof insulation board was performed at 1200 ° C. for 60 minutes to 180 minutes. All samples were excellent in porosity and heat resistance.

Claims (2)

  Obtained by melting and cooling from powdered blended raw materials in the ranges of coal ash: 45% to 75%, waste glass: 5% to 20%, magnesia and / or alumina: 15% to 40% by weight. Porous fireproof insulation board. Coal ash: 45% -75%, waste glass: 5% -20%, magnesia and / or alumina: 15% -40% A method for producing a porous refractory heat insulating board, characterized in that a raw material is heated and melted in a temperature range of 1100 ° C to 1300 ° C for 30 minutes to 240 minutes, and then rapidly cooled or allowed to cool.