JP5689676B2 - Refractory and refractory manufacturing method - Google Patents

Description

  The present invention includes linings of molten metal containers such as blast furnaces, kneading cars, converters, ladles, smelting reduction furnaces, nozzles provided in continuous casting equipment, immersion nozzles, long nozzles, sliding nozzles, stoppers, etc. The present invention relates to a refractory suitable for use in a melting furnace crucible for non-ferrous metals and a method for producing the refractory.

  Generally, the refractory used in the above application is manufactured as follows. First, a refractory composition is prepared by blending a binder with a refractory aggregate and kneading the mixture with a kneader. Next, this refractory composition is press-molded to obtain a molded product shaped using an uncured binder as a binder. After that, by heating the molded product, the binder in the molded product is dried and solidified, the binder is cured, or the binder is changed from curing to carbonization. A refractory can be obtained by bonding materials with a binder (see, for example, Patent Document 1).

  Here, when the molded product is heated as described above to produce a refractory by solidifying, curing, or carbonizing the binder, as a heating method, the molded product is dried at a high temperature. Put in a vessel and heat in batch mode for a long time, put the molded product in a shuttle furnace etc. and heat it in batch mode, heat the molded product in a tunnel type heating furnace in a continuous mode Depending on the ambient temperature, the binder is dried and solidified, hardened, or further carbonized.

  When the molded product is heat-treated as described above, there is no particular problem if the heating atmosphere temperature is a low temperature range of 150 ° C. or lower. There is a problem that the binder is oxidized and thermally decomposed, and the strength of the refractory is greatly deteriorated.

  In any of the above heat treatment methods, a gas such as air is heated, and this heat is transmitted to the surface of the molded product by convection and radiation so that the heat is conducted inside the molded product. Since a gas such as air has a small heat capacity, the heat transfer rate from the gas to the surface of the molded product is small, and the surface temperature of the molded product increases slowly. For this reason, it takes a long time to heat the inside of the molded product, and there is a problem that it takes a long time to produce a refractory. In addition, it takes a long time to heat the interior of the molded product, and as a result, the binder near the surface of the molded product hardens to form a film through which gas does not easily pass. The components are contained inside and the gas pressure becomes high, and there is a risk that the explosion will eventually occur and the molded product may be destroyed or the surface may be cracked.

  Furthermore, in order to facilitate the preparation of the refractory composition or to enhance the curability, a solvent or a curing agent may be blended. In this case, the solvent is volatilized in the atmosphere during the heat treatment, and the curing agent, for example, hexamethylenetetramine used for the novolac type phenol resin, is thermally decomposed into formaldehyde and ammonia, and most of the ammonia. Will be released into the atmosphere. Furthermore, also in the process of carbonizing the binder, pyrolytic components generated in large quantities are released to the atmosphere. And if these volatiles are released, not only will the work environment worsen, it will also pollute the atmosphere, which will have a negative impact on the environment, and there is a risk of flammable explosions due to volatiles. is there.

  Therefore, the present applicant can easily heat the molded product to the inside in a short time, and can be heated in a state where the influence of oxygen is eliminated, and has excellent physical properties such as strength in a short time. A refractory manufacturing method has been proposed (see Patent Document 2) that can manufacture a refractory and also prevent emission of volatiles.

  That is, a refractory composition prepared containing a refractory aggregate and a binder is molded, the molded product is set in a heat treatment device, steam is blown into the heat treatment device, and the molded product is formed with water vapor. By heating, the binder is subjected to a treatment selected from solidification, curing, and carbonization to produce a refractory.

  Here, since the water vapor has a high latent heat, when the water vapor contacts the surface of the molded product, the latent heat is transmitted to the molded product, and the temperature of the surface of the molded product is rapidly increased. The refractory can be produced with high productivity by solidifying, curing, and carbonizing the binder in a short time. In addition, the temperature difference between the surface and the center of the molded product is reduced, and volatile components generated from the molded product are evenly released from the interior of the molded product, preventing cracks and explosions caused by trapping the volatile components inside. Is something that can be done. In addition, by blowing water vapor into the heat treatment device, the air inside the heat treatment device can be expelled with water vapor to make the atmosphere lean in oxygen, and the influence of oxygen is eliminated to prevent the binder from being oxidatively decomposed. Meanwhile, a refractory having excellent physical properties such as strength can be obtained by solidifying, curing, and carbonizing the binder. Furthermore, volatiles such as ammonia generated during the heat treatment are taken into the water vapor, and can be prevented from being released into the atmosphere.

JP 2003-89571 A JP 2009-29041 A

  As mentioned above, it is possible to manufacture a refractory while solving various conventional problems by heating a molded product obtained by molding a refractory composition containing a refractory aggregate and a binder with steam. It will be. However, when heat treatment is performed using water vapor in this way, the strength of the refractory may be reduced depending on the type of refractory aggregate.

That is, this is a case where the refractory aggregate easily reacts with water. For example, some refractory aggregates contain not only high-purity components but also components that easily react with water such as CaO as impurities. In many cases, it contains a component that easily reacts with water. For example, when CaO is contained, CaO reacts with water contained in water vapor by the following reaction formula, for example. This reaction takes place quickly when the temperature is high, such as water vapor. CaO contained in the surface of the molded product, as well as water condensed in the molded product, is contained in the molded product. CaO also reacts.
CaO + H ₂ O → Ca (OH) ₂

And when CaO reacts with water in this way, the volume increases, and the molded product expands. When this molded product is heated to a high temperature, it is dehydrated and returned to the original CaO, for example, as in the following reaction. Since the volume also returns to the original state, the volume of the molded product shrinks.
Ca (OH) ₂ → CaO + H ₂ O

  Thus, if the refractory aggregate is easy to react with water, the volume will change when heated with water vapor, and the molded product will expand or contract, resulting in a binder. As a result, the bonding strength of the refractory aggregate is reduced, and there is a problem that cracks or the like may occur in the refractory or the strength of the refractory may be reduced.

Al, Mg, Ca, Si and alloys thereof may be blended as the refractory aggregate, but these also react when contacted with water, so that the same problem as described above may occur. In addition, carbon materials such as graphite are often used as refractory aggregates for the purpose of improving the thermal conductivity and erosion resistance of refractories. It is known that carbon materials are chemically stable at low temperatures, but their reactivity with gases such as H ₂ O increases when the ambient temperature rises. , “Carbon Dictionary”, Agne Jofusha). Therefore, the carbon material also reacts with moisture when exposed to water vapor, which may cause the same problem as described above.

  The present invention has been made in view of the above points, and in producing a refractory by heating with water vapor, the action of water content of the water vapor on the refractory aggregate is reduced, and the refractory does not generate cracks. It aims at providing the manufacturing method of the refractory which can manufacture.

  In the method for producing a refractory according to claim 1 of the present invention, a refractory composition prepared by containing a refractory aggregate and a binder is molded, and the molded product is placed in a heat treatment device having a gas supply means. The steam is blown into the heat treatment device with the gas supply means and the molded product is heated with the latent heat of condensation of the water vapor, and then the heated gas is blown into the heat treatment device with the gas supply means to heat the formed product. The binder is characterized by being subjected to a treatment selected from solidification, curing and carbonization.

  Since water vapor has a high latent heat of condensation, when the water vapor blown into the heat treatment device comes into contact with the surface of the molded product, this latent heat is transferred to the molded product, and the molded product can be quickly heated from the surface to the inside. It is possible to raise the temperature of the molded product efficiently in a short time, and the volatile components generated from the molded product are released evenly from the inside of the molded product, so that the volatile components are confined inside. It can prevent cracks and explosions. In addition, the steam blown into the heat treatment device can expel the air in the heat treatment device to make the atmosphere lean in oxygen, and can eliminate the influence of oxygen and prevent the binder from being oxidatively decomposed. In addition, volatiles such as ammonia generated during the heat treatment are taken into the water vapor and can be prevented from being released into the atmosphere.

  Then, after quickly raising the temperature of the molded product with water vapor blown into the heat treatment device in this way, the molded product is heated by blowing the heated gas into the heat treatment device with a gas supply means. The binder can be solidified, cured, and carbonized by raising the temperature of the molded product to a higher temperature. Since it is possible to suppress the action, it is possible to prevent the refractory aggregate from reacting with moisture of water vapor to expand and contract, and to obtain a refractory with high strength without causing cracks.

  According to a second aspect of the present invention, there is provided a method for producing a refractory comprising molding a refractory composition prepared by containing a refractory aggregate and a binder, and placing the molded product in a heat treatment device having a gas supply means. The steam is heated and gas is blown into the heat treatment device by the gas supply means, and the molded product is heated with the condensation latent heat of steam and the heated gas, so that the binder is solidified, cured, and carbonized. It is characterized in that the processing is performed.

  As described above, since water vapor has a high latent heat of condensation, when the water vapor blown into the heat treatment device contacts the surface of the molded product, the latent heat is transmitted to the molded product until the molded product reaches from the surface to the inside. The molded product can be heated quickly, the temperature of the molded product can be increased efficiently in a short time, and the volatile components generated from the molded product are evenly released from the interior of the molded product, It can prevent cracks and explosions due to being trapped inside. In addition, the oxygen concentration in the heat treatment device can be lowered by the steam blown into the heat treatment device to reduce the oxidative decomposition of the binder due to the influence of oxygen, and the volatilization of ammonia and the like generated during the heat treatment. A thing is taken in by water vapor | steam, Comprising: It can prevent that a volatile matter is discharge | released to air | atmosphere.

  And since steam and heated gas are blown into the heat treatment device, the proportion of the heated gas can reduce the amount of water vapor blown into the heat treatment device, and the action of water vapor on the refractory aggregate It is possible to reduce the expansion and contraction of the refractory aggregate by reacting with the moisture of the water vapor, and to obtain a refractory with high strength without causing cracks. .

  In the first or second aspect of the present invention, the heated gas may be selected from air, nitrogen, and argon.

  In the first aspect of the invention, as the heated gas, a mixed gas of water vapor selected from air, nitrogen and argon can be used.

  In the method for producing a refractory according to claim 5 of the present invention, a refractory composition prepared by containing a refractory aggregate and a binder is molded, and the molded product is placed in a heat treatment device having a gas supply means. The steam is blown into the heat treatment device by the gas supply means and the molded product is heated by the latent heat of condensation of the water vapor, and then the molded product is transferred into a heating furnace having a heat generating means and the molded product is heated by the heat generating means. Thus, the binder is subjected to a treatment selected from solidification, curing and carbonization.

  As described above, since water vapor has a high latent heat of condensation, when the water vapor blown into the heat treatment device contacts the surface of the molded product, the latent heat is transmitted to the molded product until the molded product reaches from the surface to the inside. The molded product can be heated quickly, the temperature of the molded product can be increased efficiently in a short time, and the volatile components generated from the molded product are evenly released from the interior of the molded product, It can prevent cracks and explosions due to being trapped inside. In addition, the steam blown into the heat treatment device can expel the air in the heat treatment device to make the atmosphere lean in oxygen, and can eliminate the influence of oxygen and prevent the binder from being oxidatively decomposed. In addition, volatiles such as ammonia generated during the heat treatment are taken into the water vapor and can be prevented from being released into the atmosphere.

  Then, after quickly raising the temperature of the molded product with water vapor in this way, the molded product is heated to a heating furnace and heated with a heating means, whereby the temperature of the molded product is further increased to a high temperature, and the viscosity is increased. The binder can be solidified, cured, and carbonized. Thus, when the molded product is heated to solidification, curing, and carbonization, it is possible to eliminate the action of water vapor. It is possible to prevent the material from expanding and contracting by reacting with moisture of water vapor, and to obtain a high-strength refractory without causing cracks.

  According to a sixth aspect of the present invention, there is provided a method for producing a refractory, comprising forming a refractory composition prepared by containing a refractory aggregate and a binder, in a heat treatment apparatus having a gas supply means and a heat generation means. By setting this molded product, steam is blown into the heat treatment device with a gas supply means, the molded product is heated with the latent heat of condensation of the water vapor, and then the molded product in the heat treatment device is heated with the heat generating device, thereby forming a binder. It is characterized by performing a treatment selected from solidification, curing and carbonization.

  As described above, since water vapor has a high latent heat of condensation, when the water vapor blown into the heat treatment device contacts the surface of the molded product, the latent heat is transmitted to the molded product until the molded product reaches from the surface to the inside. The molded product can be heated quickly, the temperature of the molded product can be increased efficiently in a short time, and the volatile components generated from the molded product are evenly released from the interior of the molded product, It can prevent cracks and explosions due to being trapped inside. In addition, the steam blown into the heat treatment device can expel the air in the heat treatment device to make the atmosphere lean in oxygen, and can eliminate the influence of oxygen and prevent the binder from being oxidatively decomposed. In addition, volatiles such as ammonia generated during the heat treatment are taken into the water vapor and can be prevented from being released into the atmosphere.

  And after rapidly raising the temperature of the molded product with water vapor in this way, by heating the molded product with a heating means, the temperature of the molded product is further increased to a higher temperature to solidify the binder, It can be cured and carbonized, and when the temperature of the molded product is increased to solidification, curing and carbonization, it is possible to eliminate the action of water vapor. It is possible to prevent expansion and contraction by reacting with the refractory, and to obtain a high-strength refractory without cracking.

  The refractory manufacturing method according to claim 7 of the present invention is a refractory composition prepared by containing a refractory aggregate and a binder, and is formed in a heat treatment apparatus having a gas supply means and a heat generation means. By setting the molded product, steam is blown into the heat treatment device with a gas supply means, and the molded product is heated with the latent heat of condensation of the water vapor. It is characterized by performing a treatment selected from solidification, curing and carbonization.

  As described above, since water vapor has a high latent heat of condensation, when the water vapor blown into the heat treatment device contacts the surface of the molded product, the latent heat is transmitted to the molded product until the molded product reaches from the surface to the inside. The molded product can be heated quickly, the temperature of the molded product can be increased efficiently in a short time, and the volatile components generated from the molded product are evenly released from the interior of the molded product, It can prevent cracks and explosions due to being trapped inside. In addition, the steam blown into the heat treatment device can expel the air in the heat treatment device to make the atmosphere lean in oxygen, and can eliminate the influence of oxygen and prevent the binder from being oxidatively decomposed. In addition, volatiles such as ammonia generated during the heat treatment are taken into the water vapor and can be prevented from being released into the atmosphere.

  And since heating of the molded product in the heat treatment device is performed by heat generation means in addition to this water vapor, the amount of water vapor blown into the heat treatment device can be reduced by heating with the heat generation means. It is possible to reduce the action of water vapor on the refractory, and to reduce the expansion and contraction of the refractory aggregate by reacting with the moisture of the water vapor, to obtain a high-strength refractory without cracks Is something that can be done.

  Moreover, the manufacturing method of the refractory which concerns on Claim 8 of this invention shape | molds the refractory composition prepared containing a refractory aggregate and a binder, and it has in the heat processing apparatus which has a gas supply means and a heat_generation | fever means. After setting this molded product, steam is blown into the heat treatment device with a gas supply means and the molded product is heated by the latent heat of condensation of the water vapor, and the molded product in the heat treatment device is simultaneously heated by the heat generation device while continuing the heating with water vapor. By heating, the binder is subjected to a treatment selected from solidification, curing, and carbonization.

  As described above, since water vapor has a high latent heat of condensation, when the water vapor blown into the heat treatment device contacts the surface of the molded product, the latent heat is transmitted to the molded product until the molded product reaches from the surface to the inside. The molded product can be heated quickly, the temperature of the molded product can be increased efficiently in a short time, and the volatile components generated from the molded product are evenly released from the interior of the molded product, It can prevent cracks and explosions due to being trapped inside. In addition, the steam blown into the heat treatment device can expel the air in the heat treatment device to make the atmosphere lean in oxygen, and can eliminate the influence of oxygen and prevent the binder from being oxidatively decomposed. In addition, volatiles such as ammonia generated during the heat treatment are taken into the water vapor and can be prevented from being released into the atmosphere.

  Then, water vapor is supplied into the heat treatment device to rapidly heat the molded product, and then the molded product in the heat treatment device is heated with a heating means while continuing the heating with the steam, thereby further increasing the temperature of the molded product. The binder can be solidified, cured, and carbonized by raising the temperature to a solidified, cured, and carbonized state. The amount of water vapor blown into the heat treatment device can be reduced, the action of water vapor on the refractory aggregate can be reduced, and the refractory aggregate reacts with the moisture of the water vapor to expand and contract. Thus, a high-strength refractory can be obtained without causing cracks.

  In each of the above inventions, superheated steam can be used as the steam. Superheated steam is high-temperature dry steam, and by using such superheated steam as steam, condensed water is less generated from the steam, and the refractory aggregate reacts more with the moisture of the steam. Is something that can be done.

  According to the present invention, a refractory composition prepared by containing a refractory aggregate and a binder is molded, and when the molded product is heated with steam to produce a refractory, the water vapor of the refractory aggregate is reduced. The action of moisture can be reduced, and a refractory with high strength can be obtained without causing cracks.

1 shows an example of an embodiment of the present invention, and (a) and (b) are schematic views. 1 shows an example of an embodiment of the present invention, and (a) and (b) are schematic views.

  Embodiments of the present invention will be described below.

In the present invention, any refractory aggregate can be used without any particular limitation. For example, a fused product such as fused alumina or fused magnesia, a fired product such as fired magnesia, or natural magnesia. In addition to natural raw materials such as bauxite, andalusite and sillimanite, any refractory raw material from coarse to fine powders such as ultra fine powder raw materials such as calcined alumina and silica flour can be mixed and used. Moreover, in order to improve corrosion resistance, it is preferable to mix | blend the powder of the carbonaceous material with bad wettability with molten slag as a fireproof aggregate. As the carbonaceous material, any carbonaceous material such as natural graphite, artificial graphite, coke, carbon black, quiche graphite, mesophase carbon, and charcoal can be used, but it is preferable to use a material having as high purity as possible. As the refractory aggregate, Al, Mg, Ca, Si, or one or more of these alloys can be blended and used. Further, various carbides, borides, nitrides such as SiC, B ₄ C, BN, Si ₃ N _{4 and the} like can be used as an antioxidant for the carbon material.

  A refractory composition can be obtained by blending a binder with these refractory aggregates, and further blending and kneading other components such as a coupling agent as necessary. As the binder, a thermoplastic resin, a thermosetting resin, or the like can be used, but as the thermosetting resin, any of a phenol resin, a furan resin, an epoxy resin, a melamine resin, and the like can be used. These may be used singly or in combination of two or more, and tar / pitch may be used in combination. Among these, it is preferable to use a thermosetting phenol resin as the binder.

  Here, what was prepared by making phenols and aldehydes react in presence of a reaction catalyst can be used for a phenol resin. Phenols mean phenol and derivatives of phenol. For example, in addition to phenol, trifunctional compounds such as m-cresol, resorcinol and 3,5-xylenol, and tetrafunctional compounds such as bisphenol A and dihydroxydiphenylmethane. Bifunctional o- or p such as o-cresol, p-cresol, p-ter-butylphenol, p-phenylphenol, p-cumylphenol, p-nonylphenol, 2,4 or 2,6-xylenol -Substituted phenols can be mentioned, and also halogenated phenols substituted with chlorine or bromine can be used. Of course, in addition to selecting and using one of these, a plurality of types can be mixed and used.

  As the aldehyde, formalin in the form of an aqueous solution is optimal, but forms such as paraformaldehyde, acetaldehyde, benzaldehyde, trioxane, and tetraoxane can also be used. It can be used by replacing with aldehyde or furfuryl alcohol.

  The blending ratio of the above phenols and aldehydes is preferably set so that the molar ratio is in the range of 1: 0.5 to 1: 3.5. As a reaction catalyst, when preparing a novolac-type phenol resin, inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid, organic acids such as oxalic acid, paratoluenesulfonic acid, benzenesulfonic acid and xylenesulfonic acid, and acetic acid Zinc or the like can be used. When preparing a resol-type phenolic resin, an alkaline earth metal oxide or hydroxide can be used, and an aliphatic group such as dimethylamine, triethylamine, butylamine, dibutylamine, tributylamine, diethylenetriamine, or dicyandiamide. Primary, secondary, tertiary amine, aliphatic amines having aromatic rings such as N, N-dimethylbenzylamine, aromatic amines such as aniline and 1,5-naphthalenediamine, ammonia, hexamethylenetetramine, etc. Other divalent metal naphthenic acids and divalent metal hydroxides can also be used.

  The novolac-type phenol resin and the resol-type phenol resin may be used singly or may be used by mixing both in an arbitrary ratio. Various modified phenolic resins such as silicon modified, rubber modified, and boron modified can also be used. As a curing agent for the novolac type phenol resin, a resol type phenol resin, an epoxy resin, an isocyanate compound, hexamethylenetetramine, trioxane, tetraoxane or the like can be used. In addition, the resol type phenol resin is cured by heating to 100 ° C. or more, but a curing agent can be used. As the curing agent, novolac type phenol resin, epoxy resin, isocyanate compound, organic ester, alkylene Carbonate or the like can be used. In addition, as a curing catalyst for resol-type phenolic resins, inorganic acids such as hydrochloric acid and sulfuric acid, inorganic compounds such as aluminum chloride and zinc chloride, and organic acids such as benzenesulfonic acid, phenolsulfonic acid, and xylenesulfonic acid should be used. Can do.

  Moreover, saccharides can also be used as a binder. As saccharides, monosaccharides, oligosaccharides, and polysaccharides can be used. From various monosaccharides, oligosaccharides, and polysaccharides, one type can be selected and used alone, or multiple types can be selected and used in combination. You can also.

  Although it does not specifically limit as monosaccharide, Glucose (glucose), fructose (fructose), galactose, etc. can be mentioned.

  Examples of oligosaccharides include disaccharides such as maltose (malt sugar), sucrose (sucrose), lactose (lactose), and cellobiose.

  Furthermore, as polysaccharides, there are starch sugar, dextrin, xanthan gum, curdlan, pullulan, cycloamylose, chitin, cellulose, starch, etc., and one of these can be selected or used in combination of two or more. it can. Examples of starch include raw starch and processed starch. Specifically, raw starch such as potato starch, corn starch, high amylose, sweet potato starch, tapioca starch, sago starch, rice starch, amaranth starch, and these modified starches (roasted dextrin, enzyme-modified dextrin, acid-treated starch, Oxidized starch), dialdehyde starch, etherified starch (carboxymethyl starch, hydroxyalkyl starch, cationic starch, methylolated starch, etc.), esterified starch (acetic acid starch, phosphate starch, succinate starch, octenyl succinate starch, Acid starch, higher fatty acid esterified starch, etc.), cross-linked starch, kraft starch, and wet heat-treated starch. Of these, low-viscosity starches such as roasted dextrin, enzyme-modified dextrin, acid-treated starch, oxidized starch, and crosslinked starch are preferred. Furthermore, saccharide-containing plants such as wheat, rice, potato, corn, tapioca, sweet potato, sago, amaranth and the like can be used. In addition, sugars that are commercially available for food use, such as white crude, medium crude, granulated sugar, invert sugar, super white sugar, medium white sugar, tri-warm sugar, and the like can also be used. Furthermore, phenol-modified saccharides obtained by reacting saccharides with phenols can also be used.

  Carbohydrates may be added to the saccharides, particularly as a polysaccharide curing agent. The carboxylic acid is not particularly limited, and examples thereof include oxalic acid, maleic acid, succinic acid, citric acid, butanetetradicarboxylic acid, methyl vinyl ether-maleic anhydride copolymer, and the like. The blending amount of the carboxylic acid with respect to the saccharide is preferably within a range of 0.1 to 10 parts by mass of the carboxylic acid with respect to 100 parts by mass of the saccharide. Carboxylic acid is preferably mixed with saccharide in a state of being dissolved in water in advance because the effect as a curing agent is exhibited highly.

  And a refractory composition can be prepared by mix | blending and kneading a binder etc. with a refractory aggregate. The kneading can be performed using any kneading apparatus such as a Simpson mill, Melanger, Eirich, Speed Maller, or Whirlmix. Although the compounding quantity of the binder with respect to a fireproof aggregate is not restrict | limited in particular, Binders, such as a phenol resin and saccharides, become the range of 1-50 mass parts with respect to 100 mass parts of fireproof aggregates. It is preferable to set as follows.

  Next, by molding the refractory composition prepared as described above, it is possible to obtain a molded product shaped using a liquid binder as a binder. Molding can be performed using an arbitrary press device such as an oil press, a friction press, a vacuum press, or an isostatic press.

  A refractory can be obtained by heat-treating a molded product prepared by molding a refractory composition as described above, and drying, solidifying, curing, or carbonizing the binder in the molded product. It is. And in this invention, water vapor | steam is mainly used as a heating means which heat-processes a molded object.

  Fig.1 (a) shows an example of the heat processing apparatus 1 which heat-processes a molded object. The heat treatment device 1 is formed with a gas supply means 2, and the introduction port 3 through which gas is blown into the heat treatment device 1 is at the bottom, and the exhaust port 4 through which the gas within the heat treatment device 1 is discharged is at the top. It is provided. By closing the front opening 5 of the heat treatment device 1 with a door 6, the inside of the heat treatment device 1 is sealed except for the introduction port 3 and the exhaust port 4. The gas supply means 2 is connected to the inlet 3.

  The gas supply means 2 is formed by including a steam generating device 10 and a heated gas generating device 11, and the steam generating device 10 and the heated gas generating device 11 are connected to the inlet 3 through a switching valve 12. is there. The steam generation device 10 is formed with a boiler, and can generate water vapor (saturated water vapor) by heating water in the boiler and send it out. By connecting a superheater to this boiler, the steam generated by the boiler can be further heated by the superheater and sent out from the steam generator 10 as superheated steam. Moreover, the heated gas production | generation apparatus 11 is provided with heaters, such as a heater, and an air blower, and sends out the gas heated with the heater with an air blower. When air is used as the gas, the outside air is directly taken into the heated gas generator 11 and heated by the heater and then sent out by the blower. When nitrogen or argon is used as the gas, a cylinder is connected. Then, these gases are taken from the cylinder into the heated gas generator 11 and heated by a heater, and then sent out by a blower.

  Then, after the molded product is set in the heat treatment device 1 and the door 6 is closed, first, steam generated by the steam generation device 10 is blown into the heat treatment device 1 through the switching valve 12. When steam is blown into the heat treatment device 1 in this way, the steam contacts the surface of the molded product, so that the steam is deprived of latent heat by the molded product, but the steam has high latent heat. The temperature of the surface of the molded product rises rapidly. The condensed condensed water is evaporated by the sensible heat of the water vapor, and the temperature of the molded product is further increased by this sensible heat of the water vapor. Here, when the molded product is heated with a gas such as heated air, since the heat capacity of the gas is small, it takes time to raise the surface temperature of the molded product, but when heated with water vapor, the water vapor has Since the molded product can be heated with a large latent heat, the surface temperature of the molded product can be increased in a short time. When the surface temperature of the molded product rises rapidly in this way, heat transfer to the inside of the molded product is also performed quickly, and the entire molded product can be heated at a uniform temperature in a short time.

  Since the entire molded product can be heated uniformly in a short time by heating with water vapor in this way, the binder near the surface of the molded product and the binder inside the molded product can be solidified and cured. It is possible to prevent the time difference of progress from becoming smaller and prevent volatile components inside the molded product from being trapped inside due to the solidification of the binder near the surface of the molded product and the formation of a film by the progress of curing. It is possible to prevent cracks and explosions from occurring in the molded product.

  In addition, when the steam is blown into the heat treatment device 1 in which the molded product is set as described above and heated, the air containing the oxygen in the heat treatment device 1 is pushed out from the exhaust port 4 by blowing the water vapor. It is excluded. Since only a few ppm of oxygen is present in the water vapor generated from water, the atmosphere in the heat treatment apparatus 1 becomes almost oxygen-free when the water vapor is blown in and the air is eliminated. Therefore, when heat-treating the binder in the molded product, it is possible to prevent the binder from thermally decomposing due to the influence of oxygen, and to prevent physical properties such as strength of the molded product from being lowered. Further, it is possible to prevent the occurrence of corner chipping in the refractory and the deterioration of the structure of the surface of the refractory. At this time, it is desirable that the oxygen concentration of the atmosphere in the heat treatment apparatus 1 is 3% or less in terms of volume percentage. When the oxygen concentration is 3% or less by volume percentage, the binder can be heat-treated while substantially preventing the binder from thermally decomposing. It is easy to keep the oxygen concentration at 3% or less by volume percentage by blowing water vapor and discharging the air in the heat treatment device 1.

  Further, when the molded product is heat-treated with water vapor as described above, even if volatile gas or decomposition gas is generated from the binder or the like, this gas component is absorbed by the condensed water of the water vapor whose temperature has dropped, It is possible to prevent the odor from being released into the working atmosphere. Therefore, it is possible to prevent the working environment from being deteriorated by these gases, to prevent adverse effects on the environment such as air pollution, and further, there is no risk of flammable explosion due to gas. Is. These volatile gases and cracked gases can be drained in a state where the toxicity of the gas is confined in the condensed water. In particular, the water vapor condenses to become a liquid from a gas and the volume is significantly reduced. Therefore, compared with the case where volatile gas and decomposition gas generated by heat treatment are discharged as they are, they can be discharged in a very small volume by being absorbed in condensed water, and the processing becomes easy. .

  Here, when heat treatment is performed using high-temperature steam, the temperature rise of the molded product may be abrupt, and blistering may occur in the obtained refractory. At this time, after the heat treatment of the molded product using low-temperature steam, the heat treatment is then performed on the molded product using high-temperature steam, such a blister or the like is generated by performing the heat treatment in two stages. Can be prevented. Of course, the molded product may be heat-treated not only in two stages but also in a plurality of stages in which the temperature of the water vapor is increased in each stage, such as three stages or four stages.

  As described above, when steam is blown into the heat treatment apparatus 1 to heat-treat the molded product with water vapor, it is not necessary to perform heating with water vapor until the binder of the molded product is dried, solidified, cured, and carbonized. The temperature of the entire molded product may be raised uniformly until the temperature at which curing and carbonization are facilitated. The time for heat treatment by blowing water vapor into the heat treatment device 1 varies depending on the temperature of the water vapor, the supply amount of water vapor, and the like, and also requires time for heating the inside of the heat treatment device 1. However, if the molded product is simply raised to around 100 ° C., about 30 to 300 seconds is sufficient.

  Although the temperature of water vapor | steam is not specifically limited here, It is desirable that it is 110 degreeC or more, and it can set arbitrarily in the range below the temperature which decomposes | disassembles a binder. As the water vapor, not only saturated water vapor but also superheated water vapor can be used. Superheated steam is water vapor in a complete gas state that is further heated to saturated boiling water to a temperature equal to or higher than the boiling point, and is dry steam at 100 ° C. or higher. The superheated steam can raise the temperature to about 900 ° C., so that the binder can be heat-treated at a high temperature, and the heat treatment time can be further shortened.

  Next, the switching valve 12 is switched to stop the blowing of water vapor from the steam generator 10 into the heat treatment device 1, and at the same time, the heated gas from the heated gas generation device 11 is blown into the heat treatment device 1. This heated gas is a gas heated to a temperature higher than the temperature of the water vapor, and is a dry gas containing less water than the water vapor. Although the temperature of heating gas is not specifically limited, It is preferable that it is 20 degreeC or more temperature higher than the temperature of said water vapor | steam. The upper limit of the temperature of heated gas should just be below the temperature which decomposes | disassembles a binder. The moisture content of the heated gas is not particularly limited, but is preferably 1/3 or less of the saturated vapor amount.

  After steam is blown into the heat treatment device 1 as described above to raise the temperature of the molded product in a short time, a heating gas higher in temperature than water vapor is blown into the heat treatment device 1 in this way, and the molded product is heated with the heating gas. Thus, the binder of the molded product can be dried, solidified, cured, or further carbonized, and the refractory aggregate is bonded with the solidified, cured, and carbonized binder. A refractory can be obtained.

  Here, in order to solidify, harden, and carbonize the binder by heating the molded product with the heated gas in this way, even if the fireproof aggregate of the molded product contains a component that easily reacts with water, it is heated with water vapor. Thus, water vapor can be prevented from acting on the refractory aggregate as in the case of solidifying, curing, and carbonizing the binder. Therefore, it is possible to reduce the occurrence of expansion / contraction of the molded product by suppressing the reaction of the refractory aggregate with the moisture of the water vapor, and the refractory aggregate by the binder due to the expansion / contraction of the molded product. It is possible to prevent the strength of the refractory from being lowered and cracks from being generated by suppressing the reduction of the bonding strength of the refractory.

  And since the heating gas has a smaller heat capacity than water vapor, it takes time to raise the temperature of the molded product, but the binder of the molded product is a thermosetting resin such as a thermosetting resin such as a phenol resin. In this case, since the temperature can be raised slowly with heated gas, the binder can be cured while controlling the reaction rate so that the binder does not cure rapidly, and a refractory with less distortion can be obtained. Is. In addition, when using a binder with a large amount of volatile components, there is a possibility that gas blistering, cracking, peeling off, etc. may occur if the molded product is heated rapidly, but the heated gas will heat the molded product without increasing the temperature rapidly. Therefore, rapid volatilization can be prevented, and the occurrence of gas blistering, cracking, peeling, etc. can be reduced. Even when using a refractory aggregate with a high coefficient of thermal expansion, there is a risk that cracks and the like may occur due to a sudden rise in temperature of the molded product. Similarly, the occurrence of cracks and the like can be suppressed.

  Although it does not specifically limit as gas of heating gas, The air in air | atmosphere can be used as it is. When air is used as the heating gas in this way, it is possible to burn off the binder and prevent the binder from remaining in the molded product, and produce sintered products (ceramics) that are heat-treated to a high temperature. When an inert gas such as nitrogen or argon is used as the heating gas, the binder is heated without being denatured by oxidative decomposition, and solidified, cured, or carbonized. It is possible to obtain a refractory having a high bond strength of the refractory aggregate by the binder. Of course, a mixed gas in which two or more of these air, nitrogen, and argon are mixed at an arbitrary ratio can also be used.

  Moreover, as the gas of the heated gas, a mixed gas of the above-described gas such as air, nitrogen, and argon and water vapor can be used. In this way, by using a mixed gas of gas such as air, nitrogen and argon and water vapor, the temperature rise rate of the molded product can be increased by the action of water vapor, and the productivity of the heat treatment can be improved. . Even in the case of a mixed gas of air and water vapor, the oxygen concentration in the heat treatment device 1 can be lowered, the influence of oxygen can be kept low, and further the volatile matter and decomposition gas in the binder. Can be absorbed into water vapor to suppress odor generation and gas explosion. And since the mixed gas has a lower water content than when water vapor is used alone, the reaction between the refractory aggregate and moisture of the molded product can be kept low, and the molded product may expand and contract. This can be reduced. The mixing ratio of water vapor and other air, nitrogen, and argon is not particularly limited, but the volume ratio is preferably in the range of 2: 8 to 8: 2.

  As described above, when the heating gas is blown into the heat treatment apparatus 1 to solidify, cure, and carbonize the binder of the molded product, the time required for blowing the heating gas depends on the temperature of the heating gas and the binder. It varies depending on the type, the size of the molded product, and the degree of solidification, curing, and carbonization, and is arbitrarily set as necessary.

  FIG.1 (b) shows an example of the heat processing apparatus 1 which heat-processes a molded object. The heat treatment device 1 is formed with a gas supply means 2, and the introduction port 3 through which gas is blown into the heat treatment device 1 is at the bottom, and the exhaust port 4 through which the gas within the heat treatment device 1 is discharged is at the top. It is provided. By closing the front opening 5 of the heat treatment device 1 with a door 6, the inside of the heat treatment device 1 is sealed except for the introduction port 3 and the exhaust port 4. The gas supply means 2 is connected to the inlet 3.

  The gas supply means 2 is formed by including a steam generator 10 and a heated gas generator 11, and the steam generator 10 and the heated gas generator 11 are connected to the inlet 3 via a mixer 14. is there. The steam generation device 10 is formed with a boiler, and can generate water vapor (saturated water vapor) by heating water in the boiler and send it out. By connecting a superheater to this boiler, the steam generated by the boiler can be further heated by the superheater and sent out from the steam generator 10 as superheated steam. Moreover, the heated gas production | generation apparatus 11 is provided with heaters, such as a heater, and an air blower, and sends out the gas heated with the heater with an air blower. When air is used as the gas, the outside air is directly taken into the heated gas generator 11 and heated by the heater and then sent out by the blower. When nitrogen or argon is used as the gas, a cylinder is connected. Then, these gases are taken from the cylinder into the heated gas generator 11 and heated by a heater, and then sent out by a blower.

  Then, the molded product is put in the heat treatment device 1 and set, and the door 6 is closed, and then the water vapor generated by the steam generation device 10 and the heating gas generated by the heating gas generation device 11 are respectively mixed in the mixer 14. Then, the water vapor and the heated gas are mixed in the mixer 14, and the mixed gas of the water vapor and the heated gas is blown into the heat treatment device 1. When a mixed gas of water vapor and heated gas is blown into the heat treatment apparatus 1 in this way, the water vapor is condensed by the contact of the water vapor with the surface of the molded product. Therefore, the surface temperature of the molded article rapidly rises due to this latent heat. The condensed condensed water is evaporated by the sensible heat of the water vapor, and the temperature of the molded product is further increased by this sensible heat of the water vapor. Here, when the molded product is heated only with a heated gas such as heated air, it takes time to raise the surface temperature of the molded product because the heat capacity of the gas is small, but the mixed gas contains water vapor. In this case, since the molded product can be heated with the large latent heat of water vapor, the surface temperature of the molded product can be increased in a short time. When the surface temperature of the molded product rises rapidly in this way, heat transfer to the inside of the molded product is also performed quickly, and the entire molded product can be heated at a uniform temperature in a short time.

  When a mixed gas of water vapor and heated gas is used in this way, the entire molded product can be heated uniformly in a short time mainly by heating with water vapor. The time difference between the solidification and curing progress is reduced with the internal binder, and the volatile components inside the molded product are contained inside by forming a film due to the solidification and curing of the binder near the surface of the molded product. It is possible to prevent the occurrence of cracks and explosions in the molded product.

  In addition, when a mixed gas of water vapor and heated gas is blown from the inlet 3 into the heat treatment apparatus 1 in which the molded product is set as described above and heated, the water vapor is squeezed even if it is a mixed gas of water vapor and heated air. The oxygen concentration in the mixed gas is low by volume, and the atmosphere in the heat treatment apparatus 1 is in a low oxygen state. Therefore, when heat-treating the binder in the molded product, it is possible to prevent the binder from thermally decomposing due to the influence of oxygen, and to prevent physical properties such as strength of the molded product from being lowered. Further, it is possible to prevent the occurrence of corner chipping in the refractory and the deterioration of the structure of the surface of the refractory.

  In addition, when heat-treating the molded product with water vapor as described above, even if volatile gas or decomposition gas is generated from the binder, the gas component is absorbed by the water vapor condensate in the gas mixture. Thus, the gas odor can be prevented from being released into the working atmosphere. Therefore, it is possible to prevent the working environment from being deteriorated by these gases, to prevent adverse effects on the environment such as air pollution, and further, there is no risk of flammable explosion due to gas. Is. These volatile gases and cracked gases can be drained in a state where the toxicity of the gas is confined in condensed water. In particular, the volume of water vapor is significantly reduced by condensation, so it is generated by heat treatment. Compared to the case where the volatile gas or the decomposition gas is discharged as it is, it can be discharged in a very small volume by being absorbed in the condensed water, and the processing becomes easy.

  Then, as described above, by blowing a mixed gas of water vapor and heated gas into the heat treatment device 1 and heat-treating the molded product, the binder of the molded product is dried, solidified, cured, or further carbonized. The refractory material can be obtained by bonding the refractory aggregate with the binder that has been solidified, hardened, and carbonized in this manner.

  Here, the molded product is heat-treated using water vapor as described above, but since water vapor is used as a mixed gas with the heated gas, the amount of water vapor is reduced by heating the molded product with the heated gas. It is something that can be done. Therefore, it is possible to reduce the action of moisture in the steam on the refractory aggregate than when the binder is solidified, cured, and carbonized by heating with steam alone, and the refractory aggregate reacts with the moisture in the steam. It is possible to suppress the occurrence of expansion / contraction of the molded product, and the bonding strength of the refractory aggregate by the binder due to the expansion / contraction of the molded product. It is possible to prevent the strength of the refractory from decreasing or cracking from occurring.

  Moreover, since the mixed gas of water vapor and heated gas has lower heating efficiency than the case of water vapor alone, the rate at which the molded article is heated can be made slower than that of water vapor alone. Therefore, when the binder of the molded product is thermosetting like a thermosetting resin such as phenol resin, it can be cured while controlling the reaction rate so that the binder does not cure rapidly, A refractory with less strain can be obtained. In addition, when using a binder with a large amount of volatile components, there is a risk of gas blistering, cracking, or peeling if the molded product is heated rapidly, but this prevents sudden volatilization and prevents gas blistering, cracking, peeling, etc. The generation can be reduced. Even when a fireproof aggregate with a high coefficient of thermal expansion is used, there is a risk that cracks and the like may occur due to a sudden rise in temperature of the molded product, but the sudden rise in temperature is suppressed, and the occurrence of cracks and the like is similarly suppressed. It is something that can be done.

  Although the temperature of water vapor | steam is not specifically limited here, It is desirable that it is 110 degreeC or more, and it can set arbitrarily in the range below the temperature which decomposes | disassembles a binder. As the water vapor, not only saturated water vapor but also superheated water vapor can be used. Superheated steam is water vapor in a complete gas state that is further heated to saturated boiling water to a temperature equal to or higher than the boiling point, and is dry steam at 100 ° C. or higher. The superheated steam can raise the temperature up to about 900 ° C., so that the binder can be heat-treated at a high temperature and the binder can be easily carbonized.

  Moreover, it does not specifically limit as gas of heating gas, However, The air in air | atmosphere can be heated and used as it is. When air is used as the heating gas in this way, the binder can be burned off so that the binder does not remain in the molded product, and a sintered product (ceramics) that is heat-treated to a high temperature is produced. When an inert gas such as nitrogen or argon is used as the gas of the heating gas, it can be heated, solidified, cured, and carbonized without degrading the binder by oxidative decomposition or the like. It is possible to obtain a refractory having a high bond strength of the refractory aggregate by the binder. Of course, a mixed gas in which two or more of these air, nitrogen, and argon are mixed at an arbitrary ratio can also be used. Although the temperature of heating gas is not specifically limited, It is preferable that it is 20 degreeC or more temperature higher than the temperature of said water vapor | steam. The upper limit of the temperature of heated gas should just be below the temperature which decomposes | disassembles a binder. The moisture content of the heated gas is not particularly limited, but is preferably 1/3 or less of the saturated vapor amount.

  The mixing ratio of the water vapor and the heated gas is not particularly limited, but is set in a range of 8: 2 to 2: 8 in terms of volume ratio in order to effectively exhibit each action of the water vapor and the heated gas. Is preferred.

  In the embodiment of FIG. 1B, the heat treatment device 1 is prepared by mixing the water vapor generated by the water vapor generation device 10 and the heating gas generated by the heating gas generation device 11 with the mixer 14. However, there is no need to use the mixer 14 in particular, and the steam generated by the steam generator 10 and the heated gas generated by the heated gas generator 11 are sent through the same pipe to heat as a mixed gas. It can be blown into the processor 1. Further, the steam generated by the steam generator 10 and the heated gas generated by the heated gas generator 11 may be separately blown into the heat treatment device 1 so that the steam and the heated gas are mixed in the heat treatment device 1. . In short, it is only necessary to be able to act on the molded product in the heat treatment apparatus 1 in a gas state in which water vapor and heated gas are mixed.

  FIG. 2 (a) shows another embodiment of the present invention, in which a heat treatment device 1 and a heating furnace 7 are used as an apparatus for heat treating a molded product. The heat treatment device 1 is formed with a gas supply means 2, and the introduction port 3 through which gas is blown into the heat treatment device 1 is at the bottom, and the exhaust port 4 through which the gas within the heat treatment device 1 is discharged is at the top. It is provided. By closing the front opening 5 of the heat treatment device 1 with a door 6, the inside of the heat treatment device 1 is sealed except for the introduction port 3 and the exhaust port 4. The gas supply means 2 is connected to the inlet 3. The gas supply means 2 is formed with the vapor generating device 10. The steam generation device 10 is formed with a boiler, and can generate water vapor (saturated water vapor) by heating water in the boiler and send it out. By connecting a superheater to this boiler, the steam generated by the boiler can be further heated by the superheater and sent out from the steam generator 10 as superheated steam.

  The heating furnace 7 is formed with a heating means 8, and an opening 17 with a door 16 is provided on the front surface of the heating furnace 7. The heating means 8 is provided on the side wall of the heating furnace 7. The heating means 8 may be anything as long as it can heat the inside of the heating furnace 7 by self-heating by combustion or electric resistance. For example, a gas burner or an electric heater can be used. The inside of the heating furnace 7 can be heated by causing the heat generating means 8 to generate heat.

  First, the molded product is set in the heat treatment device 1, the door 6 is closed, and then water vapor generated by the steam generation device 10 is blown into the heat treatment device 1. When steam is blown into the heat treatment device 1 in this way, the steam contacts the surface of the molded product, so that the steam is deprived of latent heat by the molded product, but the steam has high latent heat. The temperature of the surface of the molded product rises rapidly. The condensed condensed water is evaporated by the sensible heat of the water vapor, and the temperature of the molded product is further increased by this sensible heat of the water vapor. Here, when the molded product is heated with a gas such as heated air, since the heat capacity of the gas is small, it takes time to raise the surface temperature of the molded product, but when heated with water vapor, the water vapor has Since the molded product can be heated with a large latent heat, the surface temperature of the molded product can be increased in a short time. When the surface temperature of the molded product rises rapidly in this way, heat transfer to the inside of the molded product is also performed quickly, and the entire molded product can be heated at a uniform temperature in a short time.

  Since the entire molded product can be heated uniformly in a short time by heating with water vapor in this way, the binder near the surface of the molded product and the binder inside the molded product can be solidified and cured. It is possible to prevent the time difference of progress from becoming smaller and prevent volatile components inside the molded product from being trapped inside due to the solidification of the binder near the surface of the molded product and the formation of a film by the progress of curing. It is possible to prevent cracks and explosions from occurring in the molded product.

  In addition, when the steam is blown into the heat treatment device 1 in which the molded product is set as described above and heated, the air containing the oxygen in the heat treatment device 1 is pushed out from the exhaust port 4 by blowing the water vapor. It is excluded. Since only a few ppm of oxygen is present in the water vapor generated from water, the atmosphere in the heat treatment apparatus 1 becomes almost oxygen-free when the water vapor is blown in and the air is eliminated. Therefore, when heat-treating the binder in the molded product, it is possible to prevent the binder from thermally decomposing due to the influence of oxygen, and to prevent physical properties such as strength of the molded product from being lowered. Further, it is possible to prevent the occurrence of corner chipping in the refractory and the deterioration of the structure of the surface of the refractory. At this time, it is desirable that the oxygen concentration of the atmosphere in the heat treatment apparatus 1 is 3% or less in terms of volume percentage. When the oxygen concentration is 3% or less by volume percentage, the binder can be heat-treated while substantially preventing the binder from thermally decomposing. It is easy to keep the oxygen concentration at 3% or less by volume percentage by blowing water vapor and discharging the air in the heat treatment device 1.

  Further, when the molded product is heat-treated with water vapor as described above, even if volatile gas or decomposition gas is generated from the binder or the like, this gas component is absorbed by the condensed water of the water vapor whose temperature has dropped, It is possible to prevent the odor from being released into the working atmosphere. Therefore, it is possible to prevent the working environment from being deteriorated by these gases, to prevent adverse effects on the environment such as air pollution, and further, there is no risk of flammable explosion due to gas. Is. These volatile gases and cracked gases can be drained in a state where the toxicity of the gas is confined in condensed water. In particular, the volume of water vapor is significantly reduced by condensation, so it is generated by heat treatment. Compared to the case where the volatile gas or the decomposition gas is discharged as it is, it can be discharged in a very small volume by being absorbed in the condensed water, and the processing becomes easy.

  As described above, when steam is blown into the heat treatment apparatus 1 to heat-treat the molded product with water vapor, it is not necessary to perform heating with water vapor until the binder of the molded product is dried, solidified, cured, and carbonized. The temperature of the entire molded product may be raised uniformly until the temperature at which curing and carbonization are facilitated. The time for heat treatment by blowing water vapor into the heat treatment device 1 varies depending on the temperature of the water vapor, the supply amount of water vapor, and the like, and also requires time for heating the inside of the heat treatment device 1. However, if the molded product is simply raised to around 100 ° C., about 30 to 300 seconds is sufficient.

  Although the temperature of water vapor | steam is not specifically limited here, It is desirable that it is 110 degreeC or more, and it can set arbitrarily in the range below the temperature which decomposes | disassembles a binder. As the water vapor, not only saturated water vapor but also superheated water vapor can be used. Superheated steam is water vapor in a complete gas state that is further heated to saturated boiling water to a temperature equal to or higher than the boiling point, and is dry steam at 100 ° C. or higher. The superheated steam can raise the temperature to about 900 ° C., so that the binder can be heat-treated at a high temperature, and the heat treatment time can be further shortened.

  Next, the blowing of water vapor into the heat treatment device 1 is stopped, the door 6 is opened, the molded product in the heat treatment device 1 is taken out, this molded product is put into the heating furnace 7 and the door 16 is closed. It is desirable to quickly transfer the molded product from the heat treatment device 1 to the heating furnace 7 so that the temperature of the molded product does not decrease. The inside of the heating furnace 7 has a high temperature atmosphere due to the heat generated by the heat generating means 8, and the molded product set in the heating furnace 7 is heated by the heat generating means 8. The heating temperature by the heating means 8 is not particularly limited as long as it is higher than the temperature of the water vapor, but is preferably 20 ° C. higher than the temperature of the water vapor. The upper limit of the heating temperature by the heat generating means 8 may be equal to or lower than the temperature at which the binder is decomposed.

  After the steam is blown into the heat treatment device 1 as described above to raise the temperature of the molded product in a short time, the molded product is heated by the heating means 8 in this manner, thereby drying and solidifying the binder of the molded product, Alternatively, it can be hardened or further carbonized, and the refractory can be obtained by bonding the refractory aggregate with the binder thus solidified, cured and carbonized.

  Here, since the molded product is heated by the heat generated by the heat generating means 8 to solidify, harden, and carbonize the binder, the fireproof aggregate of the molded product contains a component that easily reacts with water. It is possible to prevent the moisture of water vapor from acting on the refractory aggregate as in the case where the binder is solidified, cured, and carbonized by heating. Therefore, it is possible to reduce the occurrence of expansion / contraction of the molded product by suppressing the reaction of the refractory aggregate with the moisture of the water vapor, and the refractory aggregate by the binder due to the expansion / contraction of the molded product. It is possible to prevent the strength of the refractory from being lowered and cracks from being generated by suppressing the reduction of the bonding strength.

  Further, when a gas burner is used as the heat generating means 8, since the combustible gas is burned with oxygen in the air, the oxygen concentration in the heating furnace 7 becomes low. For this reason, it is possible to suppress the thermal decomposition of the binder due to the influence of oxygen when the binder in the molded article is heated, solidified, cured, and carbonized by the heating means 8, and the strength of the molded article, etc. It is possible to prevent the physical properties from deteriorating.

  The time required to heat the molded product in the heating furnace 7 when the molded product is heated by the heating means 8 in the heating furnace 7 as described above and the binder is solidified, cured, and carbonized is as follows. The heating temperature of the heating means 8, the type of binder, the size of the molded product, and the degree of solidification, curing and carbonization of the binder, etc., can be arbitrarily set as required. is there.

  FIG.2 (b) shows an example of the heat processing apparatus 1 which heat-processes a molded object. The heat treatment device 1 is formed by including a gas supply means 2 and a heat generation means 8, an introduction port 3 through which gas is blown into the heat treatment device 1 is formed at the lower portion, and an exhaust port through which the gas within the heat treatment device 1 is discharged. 4 is provided at the top. By closing the front opening 5 of the heat treatment device 1 with a door 6, the inside of the heat treatment device 1 is sealed except for the introduction port 3 and the exhaust port 4.

  The gas supply means 2 is connected to the inlet 3. The gas supply means 2 is formed with the vapor generating device 10. The steam generation device 10 is formed with a boiler, and can generate water vapor (saturated water vapor) by heating water in the boiler and send it out. By connecting a superheater to this boiler, the steam generated by the boiler can be further heated by the superheater and sent out from the steam generator 10 as superheated steam.

  The heating means 8 is provided on the side wall of the heat treatment device 1. Any heat generating means 8 may be used as long as it can heat the inside of the heat treatment device 1 by self-heating by combustion or electric resistance. For example, a gas burner, an electric heater or the like can be used. By making the heat generating means 8 generate heat, the inside of the heat treatment device 1 can be heated.

  Then, the molded product is set in the heat treatment device 1 and the door 6 is closed. After that, steam generated by the steam generation device 10 is first blown into the heat treatment device 1. At this time, the operation of the heat generating means 8 is stopped. When steam is blown into the heat treatment device 1 in this way, the steam contacts the surface of the molded product, so that the steam is deprived of latent heat by the molded product, but the steam has high latent heat. The temperature of the surface of the molded product rises rapidly. The condensed condensed water is evaporated by the sensible heat of the water vapor, and the temperature of the molded product is further increased by this sensible heat of the water vapor. Here, when the molded product is heated with a gas such as heated air, since the heat capacity of the gas is small, it takes time to raise the surface temperature of the molded product, but when heated with water vapor, the water vapor has Since the molded product can be heated with a large latent heat, the surface temperature of the molded product can be increased in a short time. When the surface temperature of the molded product rises rapidly in this way, heat transfer to the inside of the molded product is also performed quickly, and the entire molded product can be heated at a uniform temperature in a short time.

  Since the entire molded product can be heated uniformly in a short time by heating with water vapor in this way, the binder near the surface of the molded product and the binder inside the molded product can be solidified and cured. It is possible to prevent the time difference of progress from becoming smaller and prevent volatile components inside the molded product from being trapped inside due to the solidification of the binder near the surface of the molded product and the formation of a film by the progress of curing. It is possible to prevent cracks and explosions from occurring in the molded product.

  In addition, when the steam is blown into the heat treatment device 1 in which the molded product is set as described above and heated, the air containing the oxygen in the heat treatment device 1 is pushed out from the exhaust port 4 by blowing the water vapor. It is excluded. Since only a few ppm of oxygen is present in the water vapor generated from water, the atmosphere in the heat treatment apparatus 1 becomes almost oxygen-free when the water vapor is blown in and the air is eliminated. Therefore, when heat-treating the binder in the molded product, it is possible to prevent the binder from thermally decomposing due to the influence of oxygen, and to prevent physical properties such as strength of the molded product from being lowered. Further, it is possible to prevent the occurrence of corner chipping in the refractory and the deterioration of the structure of the surface of the refractory. At this time, it is desirable that the oxygen concentration of the atmosphere in the heat treatment apparatus 1 is 3% or less in terms of volume percentage. When the oxygen concentration is 3% or less by volume percentage, the binder can be heat-treated while substantially preventing the binder from thermally decomposing. It is easy to keep the oxygen concentration at 3% or less by volume percentage by blowing water vapor and discharging the air in the heat treatment device 1.

  Further, when the molded product is heat-treated with water vapor as described above, even if volatile gas or decomposition gas is generated from the binder or the like, this gas component is absorbed by the condensed water of the water vapor whose temperature has dropped, It is possible to prevent the odor from being released into the working atmosphere. Therefore, it is possible to prevent the working environment from being deteriorated by these gases, to prevent adverse effects on the environment such as air pollution, and further, there is no risk of flammable explosion due to gas. Is. These volatile gases and cracked gases can be drained in a state where the toxicity of the gas is confined in condensed water. In particular, the volume of water vapor is significantly reduced by condensation, so it is generated by heat treatment. Compared to the case where the volatile gas or the decomposition gas is discharged as it is, it can be discharged in a very small volume by being absorbed in the condensed water, and the processing becomes easy.

  As described above, when steam is blown into the heat treatment apparatus 1 to heat-treat the molded product with water vapor, it is not necessary to perform heating with water vapor until the binder of the molded product is dried, solidified, cured, and carbonized. The temperature of the entire molded product may be raised uniformly until the temperature at which curing and carbonization are facilitated. The time for heat treatment by blowing water vapor into the heat treatment device 1 varies depending on the temperature of the water vapor, the supply amount of water vapor, and the like, and also requires time for heating the inside of the heat treatment device 1. However, if the molded product is simply raised to around 100 ° C., about 30 to 300 seconds is sufficient.

  Although the temperature of water vapor | steam is not specifically limited here, It is desirable that it is 110 degreeC or more, and it can set arbitrarily in the range below the temperature which decomposes | disassembles a binder. As the water vapor, not only saturated water vapor but also superheated water vapor can be used. Superheated steam is water vapor in a complete gas state that is further heated to saturated boiling water to a temperature equal to or higher than the boiling point, and is dry steam at 100 ° C. or higher. The superheated steam can raise the temperature to about 900 ° C., so that the binder can be heat-treated at a high temperature, and the heat treatment time can be further shortened.

  Next, simultaneously with stopping the blowing of water vapor into the heat treatment device 1, the heat generating means 8 is operated, the heat treatment device 1 is heated to a high temperature atmosphere by the heat generation by the heat generation means 8, and the molded product is heated by the heat generation means 8. The heating temperature by the heating means 8 may be any temperature that is higher than the temperature of the water vapor and is not particularly limited because it varies depending on the heating target temperature of the molded product, but is 20 ° C. higher than the temperature of the water vapor. It is preferable that the temperature is higher. The upper limit of the heating temperature by the heat generating means 8 may be equal to or lower than the temperature at which the binder is decomposed.

  After the steam is blown into the heat treatment device 1 as described above to raise the temperature of the molded product in a short time, the molded product is heated by the heating means 8 in this manner, thereby drying and solidifying the binder of the molded product, Alternatively, it can be hardened or further carbonized, and the refractory can be obtained by bonding the refractory aggregate with the binder thus solidified, cured and carbonized.

  Here, since the molded product is heated by the heat generated by the heat generating means 8 to solidify, harden, and carbonize the binder, the fireproof aggregate of the molded product contains a component that easily reacts with water. It is possible to prevent the moisture of water vapor from acting on the refractory aggregate as in the case where the binder is solidified, cured, and carbonized by heating. Therefore, it is possible to reduce the occurrence of expansion / contraction of the molded product by suppressing the reaction of the refractory aggregate with the moisture of the water vapor, and the refractory aggregate by the binder due to the expansion / contraction of the molded product. It is possible to prevent the strength of the refractory from decreasing by suppressing the decrease in the bonding strength of the refractory.

  When a gas burner is used as the heat generating means 8, the combustible gas is burned with oxygen in the air, so that the oxygen concentration in the heat treatment device 1 becomes low. For this reason, it is possible to suppress the thermal decomposition of the binder due to the influence of oxygen when the binder in the molded article is heated, solidified, cured, and carbonized by the heating means 8, and the strength of the molded article, etc. It is possible to prevent the physical properties from deteriorating.

  When the molded product is heated by the heating means 8 as described above to solidify, cure and carbonize the binder, the time required for heating the molded product by the heating means 8 is the heating of the heating means 8. It varies depending on the temperature, the type of binder, the size of the molded article, the degree of solidification, curing, and carbonization of the binder, and is arbitrarily set as necessary.

  Next, another embodiment in which the molded product is heat-treated using the heat treatment device 1 of FIG. First, the molded product is put in the heat treatment device 1 and set, and after the door 6 is closed, the steam generated by the steam generating device 10 is blown into the heat treatment device 1 and at the same time, the heating means 8 is operated to generate heat. The inside of the heat treatment device 1 is heated by means 8. Therefore, the molded product in the heat treatment device 1 is heated by the water vapor and the heating means 8.

  At this time, when the water vapor contacts the surface of the molded product, the water vapor is condensed by the latent heat being taken away by the molded product, but since the water vapor has a high latent heat, the surface of the molded product is rapidly heated by this latent heat. To rise. The condensed condensed water is evaporated by the sensible heat of the water vapor, and the temperature of the molded product is further increased by this sensible heat of the water vapor. Here, when the molded product is heated with a gas such as heated air, since the heat capacity of the gas is small, it takes time to raise the surface temperature of the molded product, but when heated with water vapor, the water vapor has Since the molded product can be heated with a large latent heat, the surface temperature of the molded product can be increased in a short time. When the surface temperature of the molded product rises rapidly in this way, heat transfer to the inside of the molded product is also performed quickly, and the entire molded product can be heated at a uniform temperature in a short time. At the same time, heat generation by the heat generating means 8 is also applied, so that it is easier to raise the temperature of the entire molded product uniformly.

  Since the entire molded product can be heated uniformly in a short time by heating with water vapor in this way, the binder near the surface of the molded product and the binder inside the molded product can be solidified and cured. It is possible to prevent the time difference of progress from becoming smaller and prevent volatile components inside the molded product from being trapped inside due to the solidification of the binder near the surface of the molded product and the formation of a film by the progress of curing. It is possible to prevent cracks and explosions from occurring in the molded product.

  In addition, when the steam is blown into the heat treatment device 1 in which the molded product is set as described above and heated, the air containing the oxygen in the heat treatment device 1 is pushed out from the exhaust port 4 by blowing the water vapor. It is excluded. Since only a few ppm of oxygen is present in the water vapor generated from water, the atmosphere in the heat treatment apparatus 1 becomes almost oxygen-free when the water vapor is blown in and the air is eliminated. Therefore, when heat-treating the binder in the molded product, it is possible to prevent the binder from thermally decomposing due to the influence of oxygen, and to prevent physical properties such as strength of the molded product from being lowered. Further, it is possible to prevent the occurrence of corner chipping in the refractory and the deterioration of the structure of the surface of the refractory. At this time, it is desirable that the oxygen concentration of the atmosphere in the heat treatment apparatus 1 is 3% or less in terms of volume percentage. When the oxygen concentration is 3% or less by volume percentage, the binder can be heat-treated while substantially preventing the binder from thermally decomposing. It is easy to keep the oxygen concentration at 3% or less by volume percentage by blowing water vapor and discharging the air in the heat treatment device 1.

  Further, when the molded product is heat-treated with water vapor as described above, even if volatile gas or decomposition gas is generated from the binder or the like, this gas component is absorbed by the condensed water of the water vapor whose temperature has dropped, It is possible to prevent the odor from being released into the working atmosphere. Therefore, it is possible to prevent the working environment from being deteriorated by these gases, to prevent adverse effects on the environment such as air pollution, and further, there is no risk of flammable explosion due to gas. Is. These volatile gases and cracked gases can be drained in a state where the toxicity of the gas is confined in condensed water. In particular, the volume of water vapor is significantly reduced by condensation, so it is generated by heat treatment. Compared to the case where the volatile gas or the decomposition gas is discharged as it is, it can be discharged in a very small volume by being absorbed in the condensed water, and the processing becomes easy.

  Here, the temperature of the water vapor blown into the heat treatment apparatus 1 is not particularly limited, but is desirably 110 ° C. or higher, and can be arbitrarily set within a range equal to or lower than the temperature at which the binder is decomposed. As the water vapor, not only saturated water vapor but also superheated water vapor can be used. Superheated steam is water vapor in a complete gas state that is further heated to saturated boiling water to a temperature equal to or higher than the boiling point, and is dry steam at 100 ° C. or higher. The superheated steam can raise the temperature to about 900 ° C., so that the binder can be heat-treated at a high temperature, and the heat treatment time can be further shortened.

  The heating temperature by the heating means 8 is not particularly limited, but is preferably higher than the temperature of the water vapor, and preferably 20 ° C. or more higher than the temperature of the water vapor. The upper limit of the heating temperature by the heat generating means 8 is not particularly set as long as it is equal to or lower than the temperature at which the binder is decomposed.

  By heating the molded product in the heat treatment apparatus 1 with water vapor and the heating means 8 as described above, the binder of the molded product can be dried, solidified, cured, or further carbonized. Thus, a refractory material can be obtained by bonding the refractory aggregate with a solidified, hardened and carbonized binder.

  Here, since the molded product is heated by using the steam and the heat generating means 8 together, the amount of water vapor blown into the heat treatment apparatus 1 can be reduced by heating the molded product with the heat generating means 8. Is. For this reason, even if the fire-resistant aggregate of the molded product contains a component that easily reacts with water, the water content of water vapor is the same as when the binder is solidified, cured, and carbonized by heating with water vapor alone. It is possible to reduce the action on the water. Therefore, it is possible to reduce the occurrence of expansion / contraction of the molded product by suppressing the reaction of the refractory aggregate with the moisture of the water vapor, and the refractory aggregate by the binder due to the expansion / contraction of the molded product. It is possible to prevent the strength of the refractory from being lowered and cracks from being generated by suppressing the reduction of the bonding strength.

  When the molded product is heated using the steam and the heat generating means 8 together as described above to solidify, cure, and carbonize the binder, the time required to heat-treat the molded product is as follows. The size of the molded product, the size of the molded product, and the degree of solidification, curing, and carbonization of the binder are arbitrarily set according to need.

  Next, another embodiment in which the molded product is heat-treated using the heat treatment device 1 of FIG. After the molded product is set in the heat treatment apparatus 1 and the door 6 is closed, first, steam generated by the steam generation apparatus 10 is blown into the heat treatment apparatus 1. At this time, the operation of the heat generating means 8 is stopped. When steam is blown into the heat treatment device 1 in this way, the steam contacts the surface of the molded product, so that the steam is deprived of latent heat by the molded product, but the steam has high latent heat. The temperature of the surface of the molded product rises rapidly. The condensed condensed water is evaporated by the sensible heat of the water vapor, and the temperature of the molded product is further increased by this sensible heat of the water vapor. Here, when the molded product is heated with a gas such as heated air, since the heat capacity of the gas is small, it takes time to raise the surface temperature of the molded product, but when heated with water vapor, the water vapor has Since the molded product can be heated with a large latent heat, the surface temperature of the molded product can be increased in a short time. When the surface temperature of the molded product rises rapidly in this way, heat transfer to the inside of the molded product is also performed quickly, and the entire molded product can be heated at a uniform temperature in a short time.

  Since the entire molded product can be heated uniformly in a short time by heating with water vapor in this way, the binder near the surface of the molded product and the binder inside the molded product can be solidified and cured. It is possible to prevent the time difference of progress from becoming smaller and prevent volatile components inside the molded product from being trapped inside due to the solidification of the binder near the surface of the molded product and the formation of a film by the progress of curing. It is possible to prevent cracks and explosions from occurring in the molded product.

  In addition, when the steam is blown into the heat treatment device 1 in which the molded product is set as described above and heated, the air containing the oxygen in the heat treatment device 1 is pushed out from the exhaust port 4 by blowing the water vapor. It is excluded. Since only a few ppm of oxygen is present in the water vapor generated from water, the atmosphere in the heat treatment apparatus 1 becomes almost oxygen-free when the water vapor is blown in and the air is eliminated. Therefore, when heat-treating the binder in the molded product, it is possible to prevent the binder from thermally decomposing due to the influence of oxygen, and to prevent physical properties such as strength of the molded product from being lowered. Further, it is possible to prevent the occurrence of corner chipping in the refractory and the deterioration of the structure of the surface of the refractory. At this time, it is desirable that the oxygen concentration of the atmosphere in the heat treatment apparatus 1 is 3% or less in terms of volume percentage. When the oxygen concentration is 3% or less by volume percentage, the binder can be heat-treated while substantially preventing the binder from thermally decomposing. It is easy to keep the oxygen concentration at 3% or less by volume percentage by blowing water vapor and discharging the air in the heat treatment device 1.

  Further, when the molded product is heat-treated with water vapor as described above, even if volatile gas or decomposition gas is generated from the binder or the like, this gas component is absorbed by the condensed water of the water vapor whose temperature has dropped, It is possible to prevent the odor from being released into the working atmosphere. Therefore, it is possible to prevent the working environment from being deteriorated by these gases, to prevent adverse effects on the environment such as air pollution, and further, there is no risk of flammable explosion due to gas. Is. These volatile gases and cracked gases can be drained in a state where the toxicity of the gas is confined in condensed water. In particular, the volume of water vapor is significantly reduced by condensation, so it is generated by heat treatment. Compared to the case where the volatile gas or the decomposition gas is discharged as it is, it can be discharged in a very small volume by being absorbed in the condensed water, and the processing becomes easy.

  As described above, when steam is blown into the heat treatment apparatus 1 to heat-treat the molded product with water vapor, it is not necessary to perform heating with water vapor until the binder of the molded product is dried, solidified, cured, and carbonized. The temperature of the entire molded product may be raised uniformly until the temperature at which curing and carbonization are facilitated. The time for heat treatment by blowing water vapor into the heat treatment device 1 varies depending on the temperature of the water vapor, the supply amount of water vapor, and the like, and also requires time for heating the inside of the heat treatment device 1. However, if the molded product is simply raised to around 100 ° C., about 30 to 300 seconds is sufficient.

  Although the temperature of water vapor | steam is not specifically limited here, It is desirable that it is 110 degreeC or more, and it can set arbitrarily in the range below the temperature which decomposes | disassembles a binder. As the water vapor, not only saturated water vapor but also superheated water vapor can be used. Superheated steam is water vapor in a complete gas state that is further heated to saturated boiling water to a temperature equal to or higher than the boiling point, and is dry steam at 100 ° C. or higher. The superheated steam can raise the temperature to about 900 ° C., so that the binder can be heat-treated at a high temperature, and the heat treatment time can be further shortened.

  Next, while continuing to blow water vapor into the heat treatment device 1, the heat generating means 8 is operated, and the molded product in the heat treatment device 1 is also heated by the heat generated by the heat generation means 8. The heating temperature by the heating means 8 is not particularly limited as long as it is higher than the temperature of the water vapor, but is preferably 20 ° C. higher than the temperature of the water vapor. The upper limit of the heating temperature by the heat generating means 8 may be equal to or lower than the temperature at which the binder is decomposed.

  Thus, by heating the molded product in combination with the steam blown into the heat treatment device 1 and the heat generated by the heat generating means 8, the binder of the molded product is dried, solidified, cured, or further carbonized. The refractory material can be obtained by bonding the refractory aggregate with the binder that has been solidified, hardened, and carbonized in this manner.

  Here, since the heating of the molded product is performed by using the steam and the heating means 8 together, the amount of water vapor blown into the heat treatment apparatus 1 can be reduced by heating the molded product with the heating means 8. is there. For this reason, even if the fire-resistant aggregate of the molded product contains a component that easily reacts with water, the water content of water vapor is the same as when the binder is solidified, cured, and carbonized by heating with water vapor alone. It is possible to reduce the action on the water. Therefore, it is possible to reduce the occurrence of expansion / contraction of the molded product by suppressing the reaction of the refractory aggregate with the moisture of the water vapor, and the refractory aggregate by the binder due to the expansion / contraction of the molded product. It is possible to prevent the strength of the refractory from decreasing by suppressing the decrease in the bonding strength of the refractory.

  When the molded product is heated using the steam and the heat generating means 8 together as described above to solidify, cure, and carbonize the binder, the time required to heat-treat the molded product is as follows. Depending on the type of the binder and the degree of solidification, curing, and carbonization of the binder, and can be arbitrarily set as necessary.

  Next, the present invention will be specifically described with reference to examples.

Example 1
The reaction vessel was charged with 940 parts by weight of phenol, 1216 parts by weight of 37% by weight formalin, and 50 parts by weight of 28% by weight animonia water. The temperature was raised to 70 ° C. in about 60 minutes, and the reaction was continued for 240 minutes. Then, after dehydrating under reduced pressure up to 80 ° C. at 133 hPa, it was dissolved in 300 parts by mass of ethylene glycol to obtain a resol type phenol resin solution. This resol type phenol resin solution had a viscosity at 25 ° C. of 9 Pa · s and a nonvolatile content at 135 ° C. of 77% by mass.

  Next, 70 parts by mass of fused alumina having a particle size of 3.0 to 0.0 mm and 30 parts by mass of natural graphite having a fixed carbon content of 98% are used as a refractory aggregate, and these are put into a mixer and further a binder. As above, 8.0 parts by mass of the above-mentioned resol type phenolic resin solution was added and kneaded for 10 minutes to obtain a wet refractory composition.

  Next, 250 g of this refractory composition was put into a molding die having a cylindrical cavity having an inner diameter of 45 mm, and press molded to a height of 60 mm using a hydraulic press to obtain a cylindrical molded product.

  Further, as the heat treatment device 1, a superheated steam small batch tester (“Model GE-10B” manufactured by Nomura Engineering Co., Ltd.) having an effective dimension in the warehouse of width 390 mm, depth 370 mm, and height 390 mm was used. The heat treatment apparatus 1 is provided with an introduction port 3 for introducing water vapor at the bottom and an exhaust port 4 at the ceiling, which can be sealed by closing the door 6 of the front opening 5. As shown in FIG. 1A, a steam generator 10 and a heated gas generator 11 are connected to the inlet 3 of the heat treatment apparatus 1 of this embodiment.

  Then, the above molded product was placed on a stainless steel wire mesh provided in the heat treatment device 1, and the molded product was set in the heat treatment device 1. At this time, as a molded product, a hole from the center of the side surface to the inner center of the molded product was inserted and a temperature sensor was inserted so that the temperature of the central part of the molded product could be measured over time. Each of the molded products without holes was set in the heat treatment device 1 (the same applies to the following examples and comparative examples).

  After the molded product is set in the heat treatment apparatus 1 in this way, saturated steam having a gauge pressure of 0.3 MPa and a temperature of 143 ° C. generated by the boiler of the steam generation apparatus 10 is heated by a superheater (“Model GE-” manufactured by Nomura Engineering Co., Ltd.). 10B "), superheated steam having a temperature of 350 ° C and a gauge pressure of 0.35 MPa was blown into the heat treatment apparatus 1 from the inlet 3 at a flow rate of 60 kg / h. Then, 63 seconds after the start of the heat treatment, the temperature of the center of the molded product reaches 100 ° C. near the condensation temperature of the steam, and at this time, the steam generator 10 is quickly switched to the heated gas generator 11 to supply superheated steam. And 450 ° C. heated air was blown into the heat treatment apparatus 1 at a gauge pressure of 0.10 MPa as a heated gas. 47 minutes after the start of the heat treatment, the temperature at the center of the molded product reached 300 ° C, and the blowing of heated air was continued for 3 hours. By performing the heat treatment in this way, the phenolic resin of the molded product was cured to obtain a refractory material.

(Example 2)
After setting the molded product in the heat treatment device 1, the flow rate of 60 kg / h is maintained without heating the saturated water vapor with a gauge pressure of 0.3 MPa and a temperature of 143 ° C. generated by the boiler of the steam generation device 10 without being heated by the superheater. Then, it was blown into the heat treatment device 1 from the inlet 3. Then, the temperature at the center of the molded article reached 100 ° C. 76 seconds after the start of the heat treatment, and at this time, the steam generator 10 was switched to the heated gas generator 11 immediately. Others were the same as in Example 1, and the phenolic resin of the molded product was cured to obtain a refractory.

(Example 3)
In the same manner as in Example 1, superheated steam was blown into the heat treatment device 1, and when the temperature at the center of the molded article reached 100 ° C. near the condensation temperature of the steam, the steam generator 10 to the heated gas generator 11 were promptly used. Switched to. A mixed gas of superheated steam having a temperature of 350 ° C., a gauge pressure of 0.35 MPa, a flow rate of 30 kg / h, and heated air having a temperature of 450 ° C. and a gauge pressure of 0.05 MPa was blown into the heat treatment apparatus 1 as the heated gas. 33 minutes after the start of the heat treatment, the temperature at the center of the molded product reached 300 ° C., and the blowing of the mixed gas was continued for 3 hours. By performing the heat treatment in this way, the phenolic resin of the molded product was cured to obtain a refractory material.

Example 4
A refractory composition was prepared in the same manner as in Example 1 to obtain a molded product. In addition, the same superheated steam small batch tester (“Model GE-10B” manufactured by Nomura Engineering Co., Ltd.) as in Example 1 was used as the heat treatment device 1. A steam generator 10 and a heated gas generator 11 are connected to the inlet 3 of the heat treatment apparatus 1 of this embodiment as shown in FIG.

  Then, after setting the molded product in the heat treatment device 1 as in Example 1, a superheater (manufactured by Nomura Engineering Co., Ltd.) was used to generate saturated steam having a gauge pressure of 0.3 MPa and a temperature of 143 ° C. generated by the boiler of the steam generating device 10. “Model GE-10B”), heated air generated at a temperature of 350 ° C. and a gauge pressure of 0.35 MPa at a flow rate of 30 kg / h, and heated air from the heated gas generator 11 as a heated gas at 450 ° C. Were blown into the heat treatment apparatus 1 through a mixer 14 at a gauge pressure of 0.05 MPa. The temperature at the center of the molded article reached 100 ° C. 85 seconds after the start of the heat treatment, and the temperature at the center of the molded article reached 300 ° C. 32 minutes after the start of the heat treatment. The mixed gas of superheated steam and heated air was blown in for 3 hours. By performing the heat treatment in this way, the phenolic resin of the molded product was cured to obtain a refractory material.

(Example 5)
A refractory composition was prepared in the same manner as in Example 1 to obtain a molded product. In addition, the same superheated steam small batch tester (“Model GE-10B” manufactured by Nomura Engineering Co., Ltd.) as in Example 1 was used as the heat treatment device 1. A steam generator 10 is connected to the inlet 3 of the heat treatment apparatus 1 of this embodiment as shown in FIG. Further, as the heating furnace 7, a high-temperature dryer (“Model DRD360DA” manufactured by Toyo Seisakusho, interior dimensions: width 300 mm, depth 300 mm, height 300 mm) was used. The heating furnace 7 is formed with an electric heater as the heating means 8.

  After setting the molded product in the heat treatment apparatus 1 in the same manner as in Example 1, a saturated steam having a gauge pressure of 0.3 MPa and a temperature of 143 ° C. generated by the boiler of the steam generation apparatus 10 was superheated (manufactured by Nomura Engineering Co., Ltd. “ Superheated steam having a temperature of 350 ° C. and a gauge pressure of 0.35 MPa, which was generated by heating with a model GE-10B ”), was blown into the heat treatment apparatus 1 from the inlet 3 at a flow rate of 60 kg / h. Then, 63 seconds after the start of the heat treatment, the temperature of the center of the molded product reaches 100 ° C. near the condensation temperature of the water vapor, and at this time, the molded product is quickly heated from the heat treatment device 1 to a temperature of 450 ° C. in advance. Was transferred to the heating furnace 7. 53 minutes after the start of the heat treatment, the temperature at the center of the molded product reached 300 ° C., and heating in the heating furnace 7 was continued for 2 hours. By performing the heat treatment in this way, the phenolic resin of the molded product was cured to obtain a refractory material.

(Example 6)
A refractory composition was prepared in the same manner as in Example 1 to obtain a molded product. Further, as the heat treatment device 1, an introduction port 3 for introducing water vapor into the bottom portion, an exhaust port 4 at the ceiling portion, and a door 6 of the opening portion 5 on the front surface that can be sealed are used. As shown in FIG. 2B, the steam generating apparatus 10 is connected to the inlet 3 of the heat treatment apparatus 1 of this embodiment, and an electric heater is provided as a heating means 8 on the side wall.

  After setting the molded product in the heat treatment apparatus 1 in the same manner as in Example 1, a saturated steam having a gauge pressure of 0.3 MPa and a temperature of 143 ° C. generated by the boiler of the steam generation apparatus 10 was superheated (manufactured by Nomura Engineering Co., Ltd. “ Superheated steam having a temperature of 350 ° C. and a gauge pressure of 0.35 MPa, which was generated by heating with a model GE-10B ”), was blown into the heat treatment apparatus 1 from the inlet 3 at a flow rate of 60 kg / h. Then, 64 seconds after the start of the heat treatment, the temperature of the center of the molded article reaches 100 ° C. near the condensation temperature of the water vapor. At this time, the blowing of the superheated water vapor is stopped at the same time, and the electric heater is turned on. The internal temperature was raised to 450 ° C. by heat generation. 55 minutes after the start of the heat treatment, the temperature at the center of the molded product reached 300 ° C, and the electric heater continued to generate heat for 2 hours. By performing the heat treatment in this way, the phenolic resin of the molded product was cured to obtain a refractory material.

(Example 7)
A refractory composition was prepared in the same manner as in Example 1 to obtain a molded product. Further, as the heat treatment device 1, the same one as shown in FIG.

  After setting the molded product in the heat treatment apparatus 1 in the same manner as in Example 1, a saturated steam having a gauge pressure of 0.3 MPa and a temperature of 143 ° C. generated by the boiler of the steam generation apparatus 10 was superheated (manufactured by Nomura Engineering Co., Ltd. “ Superheated steam having a temperature of 350 ° C. and a gauge pressure of 0.35 MPa, which was generated by heating with a model GE-10B ”), was blown into the heat treatment apparatus 1 from the inlet 3 at a flow rate of 30 kg / h. At the same time, the electric heater was operated to heat the inside of the heat treatment device 1 with the electric heater. At this time, the electric heater was operated under heat generation conditions in which the internal temperature rose to 450 ° C. when heated alone. The temperature at the center of the molded product reached 100 ° C. 78 seconds after the start of the heat treatment. After 49 minutes, the temperature of the center of the molded product reached 300 ° C., and this heating was continued for 2 hours. By performing the heat treatment in this way, the phenolic resin of the molded product was cured to obtain a refractory material.

(Example 8)
A refractory composition was prepared in the same manner as in Example 1 to obtain a molded product. Further, as the heat treatment device 1, the same one as shown in FIG.

  After setting the molded product in the heat treatment apparatus 1 in the same manner as in Example 1, a saturated steam having a gauge pressure of 0.3 MPa and a temperature of 143 ° C. generated by the boiler of the steam generation apparatus 10 was superheated (manufactured by Nomura Engineering Co., Ltd. “ Superheated steam having a temperature of 350 ° C. and a gauge pressure of 0.35 MPa, which was generated by heating with a model GE-10B ”), was blown into the heat treatment apparatus 1 from the inlet 3 at a flow rate of 60 kg / h. Then, 68 seconds after the start of the heat treatment, the temperature of the center of the molded article reaches 100 ° C. near the condensation temperature of the water vapor. At this time, the flow rate of the superheated water vapor is lowered to 30 kg / h, and at the same time, the electric heater is operated. I let you. At this time, the electric heater was operated under an exothermic condition in which the internal temperature rose to 450 ° C. when heated alone. And 47 minutes after the start of the heat treatment, the temperature at the center of the molded product reached 300 ° C., and this heating was continued for 2 hours. By performing the heat treatment in this way, the phenolic resin of the molded product was cured to obtain a refractory material.

(Comparative Example 1)
The molded product produced in the same manner as in Example 1 was placed in a high-temperature dryer (“Toyo Seisakusho“ Model DRD360DA ”: built-in electric heater, internal dimension width 300 mm, depth 300 mm, height 300 mm) in Teflon. It was set on a (registered trademark) sheet. The inside temperature is adjusted to 450 ° C. and heated. When the temperature at the center of the molded article reaches 300 ° C., the inside temperature is adjusted to 300 ° C. and the heat treatment is performed for 3 hours. The phenol resin was cured to obtain a refractory.

(Comparative Example 2)
The molded product produced in the same manner as in Example 1 was set in a heat treatment device as in Example 1, and superheated steam was blown under the same conditions as in Example 1 so that the temperature at the center of the molded product was 300 ° C. Heated with superheated steam until. When the temperature of the center of the molded product reaches 300 ° C., the molded product is heated for 3 hours while adjusting the amount of superheated steam so that the 300 ° C. temperature of the molded product is maintained. The phenolic resin was cured to obtain a refractory.

  As described above, when the molded product was heat-treated in each of the examples and the comparative examples, the temperature change of the molded product was measured with a temperature sensor. Table 1 shows the time required for the temperature at the center of the molded product to reach 100 ° C., 200 ° C., 250 ° C., and 300 ° C. in each example and each comparative example.

The refractories obtained as described above were measured for bulk specific gravity, volatile content, compressive strength, and appearance, and are shown in Table 1. The measurement was performed on a molded product (refractory) in which no hole for inserting the temperature sensor was provided. Here, the bulk specific gravity was measured according to JIS R2001 for a molded product before heat treatment and a refractory after heat treatment, respectively. The volatile content was determined from the following formula.
Volatile content (%) = 100− (mass after heat treatment (g) / mass before heat treatment (g)) × 100

The compressive strength was measured according to JIS R2206. The appearance was measured by visually observing the surface of the refractory and evaluated as follows.
“◎”: No swelling or cracking.
“○”: There are several blisters but no cracks.
“△”: In addition to blisters, several cracks also occur.
“×”: Innumerable blisters and many cracks.

  As can be seen in Table 1, in each example in which the molded product is heated with water vapor, the temperature inside the molded product rises to 100 ° C. in one minute, but the molded product is heated by an electric heater to be heat-treated. In Comparative Example 1, it took 11 minutes for the internal temperature of the molded product to reach 100 ° C., and the time to reach 300 ° C. was longer. In each example, the heat treatment can be performed without causing blisters or cracks in the refractory. However, in Comparative Example 2 in which the molded article is heated only with water vapor from the beginning to the end, the temperature rises. Although the speed was high, blistering was generated in the obtained refractory.

(Examples 9 to 16, Comparative Example 3)
A reaction vessel was charged with 940 parts by weight of phenol, 568 parts by weight of 37% by weight formalin, and 3.76 parts by weight of oxalic acid, and refluxed for about 1 hour with stirring, and allowed to react at the reflux temperature for 3 hours. Next, it heated until internal temperature became 170 degreeC, spin-dry | dehydrating. Further, the liquid was removed at 40 hPa while reducing the pressure until the internal temperature reached 200 ° C. Thereafter, the solid solution was discharged from the reaction solution and cooled to obtain a solid novolac type phenol resin. The softening point of the obtained novolac type phenol resin was 78 ° C. 30 parts by mass of ethylene glycol was added to 70 parts by mass of this novolac-type phenol resin and mixed well to obtain a novolac-type phenol resin liquid having a viscosity of 8.5 Pa · s (25 ° C.).

Then, as the refractory aggregate, natural magnesia (MgO content 95.55 wt%, SiO ₂ content of 1.32 mass%, CaO content of 2.81 wt%, _Al 2 _{O 3} content of 0.32 wt% ) 30 parts by mass with a particle size of less than 3 mm and 1 mm or more, 20 parts by mass with a particle size of less than 1 mm and 0.5 mm or more, 25 parts by mass with a particle size of less than 0.5 mm and more than 0.21 mm, (Less than 21 mm, 0 mm or more) 10 parts by mass and 15 parts by mass of natural graphite were placed in a Henschel mixer and stirred for 5 minutes. Furthermore, 3.0 parts by mass of the above-mentioned novolac type phenolic resin solution and 0.3 parts by mass of hexamethylenetetramine as a binder are blended and kneaded at a rotational speed of 285 rpm for 15 minutes to form a wet refractory composition. Obtained.

  Next, 285 g of this refractory composition was put into a mold having a cylindrical cavity having an inner diameter of 45 mm, and press-molded to a height of 60 mm using a hydraulic press to obtain a cylindrical molded product.

  By using the molded product thus prepared, the molded product was heated under the same methods and conditions as in Examples 1 to 8 and Comparative Example 2 to cure the phenolic resin of the molded product, thereby obtaining a refractory. . Thus, the temperature change of the center part of the molded object at the time of heat processing was measured similarly to the above, and the obtained refractory was measured similarly to the above and is shown in Table 2.

  As can be seen from Table 2, in each example, the blistering is suppressed, and the heat treatment can be performed without causing cracks, but the molded product is heated only with water vapor from the beginning to the end. In Comparative Example 3, although the rate of temperature increase was fast, blisters and cracks occurred in the obtained refractory. This is because natural magnesia containing CaO that easily reacts with water is used as the refractory aggregate, so that in the comparative example 3 in which the molded product is heated only with water vapor from the beginning to the end, the molded product is expanded by reaction with water. It is considered that expansion and contraction occurred and cracks became prominent.

(Example 17)
Using dextrin (“No4-C” manufactured by Nissho Kagaku Co., Ltd.) as a saccharide, 70 parts by mass of this dextrin is added to 30 parts by mass of ethylene glycol and dispersed to disperse, and the ethylene glycol solution of dextrin is used as a binder. As prepared.

  In the above Example 1, a cylindrical molded product was obtained in the same manner as in Example 1 except that this ethylene glycol solution of dextrin was used instead of the resol type phenol resin. The molded product was heat-treated with superheated steam and heated air in the same manner as in Example 1 to solidify the dextrin of the molded product to obtain a refractory.

(Example 18)
A refractory composition was prepared in the same manner as in Example 1, and a molded product was obtained in the same manner as in Example 1. Then, in the same manner as in Example 1, superheated steam was blown into the heat treatment apparatus 1, and when the temperature at the center of the molded article reached 100 ° C. near the condensation temperature of the steam, the steam generating apparatus 10 quickly turned to the heated gas generating apparatus. Switched to 11.

  At this time, a mixed gas of superheated steam at a temperature of 600 ° C., a gauge pressure of 0.25 MPa, a flow rate of 30 kg / h, and heated air at a temperature of 750 ° C. and a gauge pressure of 0.05 MPa is heat-treated as the heated gas from the heated gas generator 11. Blowed into vessel 1. 58 minutes after the start of the heat treatment, the temperature at the center of the molded product reached 600 ° C., and the blowing of the mixed gas was continued for 3 hours. By performing the heat treatment in this manner, the phenol resin of the molded product was carbonized to obtain a refractory.

(Example 19)
A refractory composition was prepared in the same manner as in Example 1, and a molded product was obtained in the same manner as in Example 1. Further, as the heat treatment device 1, the same one as shown in FIG.

  After setting the molded product in the heat treatment apparatus 1 in the same manner as in Example 1, a saturated steam having a gauge pressure of 0.3 MPa and a temperature of 143 ° C. generated by the boiler of the steam generation apparatus 10 was superheated (manufactured by Nomura Engineering Co., Ltd. “ Superheated steam having a temperature of 600 ° C. and a gauge pressure of 0.35 MPa, which was generated by heating with a model GE-10B ”), was blown into the heat treatment apparatus 1 from the inlet 3 at a flow rate of 30 kg / h. At the same time, the electric heater was operated to heat the inside of the heat treatment device 1 with the electric heater. At this time, the electric heater was operated under heat generation conditions in which the internal temperature rose to 600 ° C. when heated alone. The temperature at the center of the molded product reached 100 ° C. 60 seconds after the start of the heat treatment. Further, after the temperature at the center of the molded article reached 600 ° C., this heating was continued for 3 hours. By performing the heat treatment in this manner, the phenol resin of the molded product was carbonized to obtain a refractory.

(Comparative Example 4)
A refractory composition was prepared in the same manner as in Example 1, and a molded product was obtained in the same manner as in Example 1. This molded product was put in a heat-resistant box, covered with coke, and set in an electric furnace (“Siliconit electric furnace type“ BSH-1530 ”manufactured by Siliconit Co., Ltd.). And it heated up to 600 degreeC with the temperature increase rate of 10 degree-C / min, and also hold | maintained at this temperature for 3 hours, Then, the refractory material which the phenol resin in the molding carbonized was obtained.

  When heat-treating the moldings in Examples and 17 to 19 as described above, the temperature change of the moldings was measured with a temperature sensor in the same manner as described above, and the temperature at the center of the molding was 100 ° C., Table 3 shows the time required to reach 300 ° C. and 600. Further, the refractories obtained in Examples 17 to 19 and Comparative Example 4 were measured in the same manner as described above, and are shown in Table 3.

  In Example 17, saccharides are used as a binder, and the binder is dried and solidified to obtain a refractory. In this case, heat treatment can be performed without causing blisters or cracks. Met.

  In Examples 18 and 19, a refractory was obtained by heating until the binder was carbonized, and in this case, heat treatment could be performed without generating blisters or cracks. In Examples 18 and 19, a result equivalent to or higher than that of Comparative Example 4 of the conventional method in which carbonization was performed by firing using coke could be obtained.

DESCRIPTION OF SYMBOLS 1 Heat processing device 2 Gas supply means 7 Heating furnace 8 Heating means 10 Steam generator 11 Heated gas generator 12 Switching valve 14 Mixer

Claims (10)

  A refractory composition prepared containing a refractory aggregate and a binder is molded, this molded product is set in a heat treatment device having a gas supply means, and steam is blown into the heat treatment device by the gas supply means. In addition to heating the molded product with the latent heat of condensation of water vapor, the heated gas is blown into the heat treatment device with a gas supply means to heat the molded product, whereby the binder is solidified, cured, and carbonized. A method for producing a refractory material.   A refractory composition prepared containing a refractory aggregate and a binder is molded, the molded product is set in a heat treatment device having a gas supply means, and steam and heated gas are gasified in the heat treatment device. A method for producing a refractory material, characterized in that a treatment selected from solidification, curing, and carbonization is performed on a binder by blowing with a supply means and heating a molded product with condensation latent heat of steam and a heated gas.   The method for producing a refractory according to claim 1 or 2, wherein the heated gas is selected from air, nitrogen, and argon.   2. The method for producing a refractory according to claim 1, wherein a gas mixture of water and a gas selected from air, nitrogen, and argon is used as the heated gas.   A refractory composition prepared containing a refractory aggregate and a binder is molded, this molded product is set in a heat treatment device having a gas supply means, and steam is blown into the heat treatment device by the gas supply means. Heating the molded product with the latent heat of condensation of water vapor, then transferring the molded product into a heating furnace having a heat generating means and heating the molded product with the heat generating means, so that the binder is solidified, cured, and carbonized. The manufacturing method of the refractory characterized by doing.   A refractory composition prepared containing a refractory aggregate and a binder is molded, the molded product is set in a heat treatment device having a gas supply means and a heat generation means, and the gas supply means is placed in the heat treatment device. It is characterized in that steam is blown and the molded product is heated with the latent heat of condensation of the steam, and then the molded product in the heat treatment device is heated by a heating means, whereby the binder is solidified, cured, and carbonized. Refractory manufacturing method.   A refractory composition prepared containing a refractory aggregate and a binder is molded, the molded product is set in a heat treatment device having a gas supply means and a heat generation means, and the gas supply means is placed in the heat treatment device. Blowing steam and heating the molded product with the latent heat of condensation of the steam, and simultaneously heating the molded product in the heat treatment device with a heating means, the binder is solidified, cured, and carbonized, and is characterized by Refractory manufacturing method.   A refractory composition prepared containing a refractory aggregate and a binder is molded, the molded product is set in a heat treatment device having a gas supply means and a heat generation means, and the gas supply means is placed in the heat treatment device. After the steam is blown and the molded product is heated with the latent heat of condensation of the steam, the molded product in the heat treatment device is heated by the heating means while continuing the heating with the steam, so that the binder is solidified, cured, and carbonized. The manufacturing method of the refractory characterized by carrying out the process processed.   The method for producing a refractory according to any one of claims 1 to 8, wherein superheated steam is used as the steam.   A refractory material comprising a refractory aggregate bonded with a binder selected from solidification, curing, and carbonization by the production method according to any one of claims 1 to 9.

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