JP2005179726A - Heat-resistant material and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a furnace wall material which has superior heat resistance though containing no hazardous material. <P>SOLUTION: This method for manufacturing a heat-resistant material comprises mixing ferrosilica and aluminum into a mixture, compressing the mixture, and expelling oxygen in the mixture. The method for manufacturing the furnace wall material includes baking a mixture at a high temperature in a reducing atmosphere. The thus-manufactured furnace wall material has superior heat resistance and adequate thermophysical properties such as thermal-diffusion wearing resistance and a fireproof temperature, though containing no hazardous material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat-resistant material using metal silicon and aluminum as raw materials and a method for producing the same.

Conventionally, this type of heat-resistant material is manufactured by molding a mixture containing 5% by mass to 70% by mass of chromite, and the balance of a magnesia material as a main material, followed by high-temperature firing in a non-oxidizing atmosphere. A magnesia-chromium fired brick in which fine metal particles are mixed in a refractory structure is known (for example, see Patent Document 1).
JP-A-7-165461 (2nd page)

  However, the heat-resistant material described above contains chromium (Cr), which is a harmful substance, in order to improve heat resistance. For this reason, the chromium in this heat-resistant material is discharged into the natural world due to wear due to the use of the heat-resistant material, and the natural world is contaminated with chromium.

  Thus, it is conceivable to reduce the chromium content in the heat-resistant material, but if the chromium content in the heat-resistant material is reduced, the heat resistance of the heat-resistant material itself is lowered.

  This invention is made | formed in view of such a point, and it aims at providing the heat resistant material excellent in heat resistance, without containing chromium, and its manufacturing method.

  The heat-resistant material according to claim 1 contains metallic silicon and aluminum.

And by containing metallic silicon and aluminum, it becomes a heat resistant material excellent in heat resistance without containing chromium. In addition, since ceramic particles are mixed in the heat-resistant material, the difference in expansion between metals generated during high-temperature firing can be absorbed, and the strength, heat resistance, and thermal diffusion wear resistance are excellent. Furthermore, presumably, hydrogen chloride (HCl), nitrogen oxide (NO _X ) or sulfur oxide (SO _X ) is decomposed due to the unique property of emitting a large amount of far infrared rays inherent to metallic silicon during use. Can be reduced.

  The heat-resistant material according to claim 2 is the heat-resistant material according to claim 1, which contains ferric oxide, silicon dioxide and aluminum oxide.

  And by containing ferric oxide, silicon dioxide, and aluminum oxide, it becomes a heat-resistant material with more excellent heat resistance without containing chromium.

  According to a third aspect of the present invention, there is provided a heat-resistant material manufacturing method in which at least silicon iron and aluminum are mixed to form a mixture, and the mixture is compressed and then fired in a reducing atmosphere.

Then, at least silicon iron and aluminum are mixed to form a mixture, and the mixture is compressed and then fired in a reducing atmosphere, whereby a heat-resistant material having excellent heat resistance can be produced without containing chromium. In addition, since ceramic particles are mixed in the heat-resistant material, the difference in expansion between metals generated during high-temperature firing can be absorbed, and the strength, heat resistance, and thermal diffusion wear resistance are excellent. Furthermore, it is estimated that hydrogen chloride (HCl), nitrogen oxide (NO _X ) or sulfur oxide (SO _X ) is decomposed due to the unique property of emitting a large amount of far infrared rays inherent to metallic silicon during use. Can be reduced.

  The method for producing a heat-resistant material according to claim 4 is the method for producing a heat-resistant material according to claim 3, wherein the ceramic is mixed into the mixture.

  And by mixing a ceramic with a mixture, since this ceramic can function as an extender and the quality can be stabilized, a heat-resistant material excellent in heat resistance without containing chromium can be produced more efficiently.

  The method for producing a heat-resistant material according to claim 5 is the method for producing a heat-resistant material according to claim 4, wherein the ceramic whose surface is covered with water glass is mixed into the mixture.

  And, by mixing the ceramic whose surface is covered with water glass into a mixture to produce a heat resistant material, the water glass covering the ceramic surface absorbs the difference in expansion that occurs when this heat resistant material is heated. Since the stress generated when the heat resistant material is heated can be dispersed, the heat resistance of the heat resistant material can be further improved.

  The method for producing a heat-resistant material according to claim 6 is the method for producing a heat-resistant material according to any one of claims 3 to 5, wherein the heat-resistant material is fired in a reducing atmosphere and then cooled and then fired in an oxygen atmosphere.

  Then, after firing in a reducing atmosphere, cooling and then firing in an oxygen atmosphere to produce a heat-resistant material, the metal in the heat-resistant material is oxidized and the heat-resistant material becomes stronger. Abrasion resistance at high temperature of the material can be improved.

According to the heat-resistant material of claim 1, since it contains metallic silicon and aluminum, it can be made a heat-resistant material having excellent heat resistance without containing chromium. In addition, since ceramic particles are mixed in the heat-resistant material, the difference in expansion between metals generated during high-temperature firing can be absorbed, and the strength, heat resistance, and thermal diffusion wear resistance are excellent. Furthermore, it is estimated that hydrogen chloride (HCl), nitrogen oxide (NO _X ) or sulfur oxide (SO _X ) is decomposed due to the unique property of emitting a large amount of far infrared rays inherent to metallic silicon during use. Can be reduced.

  According to the heat-resistant material of claim 2, since it contains ferric oxide, silicon dioxide, and aluminum oxide, it can be made a heat-resistant material with more excellent heat resistance without containing chromium.

According to the method for producing a heat-resistant material according to claim 3, at least silicon iron and aluminum are mixed to form a mixture, and the mixture is compressed and then fired in a reducing atmosphere, so that it does not contain chromium and is heat-resistant. An excellent heat-resistant material can be manufactured. Further, since ceramic particles are mixed in the heat-resistant material, the difference in expansion between metals generated during high-temperature firing can be absorbed, and the strength, heat resistance, and thermal diffusion wear resistance are excellent. Furthermore, presumably, hydrogen chloride (HCl), nitrogen oxide (NO _X ) or sulfur oxide (SO _X ) is decomposed due to the unique property of emitting a large amount of far infrared rays inherent to metallic silicon during use. Can be reduced.

  According to the method for producing a heat-resistant material according to claim 4, since the ceramic functions as an extender and can stabilize the quality by mixing the ceramic with the mixture, it does not contain chromium and has excellent heat resistance. Can be manufactured more efficiently.

  According to the method for manufacturing a heat-resistant material according to claim 5, since the difference in expansion that occurs when the heat-resistant material is heated can be absorbed by the water glass that covers the surface of the ceramic, the stress generated when the heat-resistant material is heated is dispersed. The heat resistance of this heat-resistant material can be further improved.

  According to the method for producing a heat-resistant material according to claim 6, the metal in the heat-resistant material is oxidized by producing the heat-resistant material by firing in an oxygen atmosphere after being baked in a reducing atmosphere, Since this heat resistant material becomes stronger, it is possible to improve the wear resistance of the heat resistant material at high temperatures.

  Hereinafter, an embodiment of a method for producing a heat-resistant material of the present invention will be described with reference to FIG.

  First, as a raw material for producing a furnace wall material that is a metal composition brick as a heat-resistant material, at least metal silicon that is an intermetallic compound, that is, a ferrosilicon powder called ferrosilica (Fe-Si), Aluminum powder is used as a deoxidizer. Here, the ferrosilica is a molded body containing 40% by mass or more and 45% by mass or less of silicon (Si), with the balance containing a composition mainly composed of iron. .

  Furthermore, as a raw material, a lump obtained by pulverizing ceramics such as porcelain, which is industrial waste, is used as an extender. And the water glass has adhered to the surface of this lump, The surface which is the surrounding surface of a lump is covered with this water glass, and it is coated and solid-dissolved. This lump is produced by attaching water glass to the surface and then firing the lump together with water glass at a temperature of 800 ° C.

  And it is set as the mixture which is the raw material which mixed the powdery body of these ferrosilica, the aluminum powder, and the lump which the surface was coated with water glass, and mixed (step 1). In this case, the mixture contains ferrosilica in an amount of 30% to 70% by mass, aluminum in an amount of 5% to 30% by mass, and a mass of 20% to 40% by mass.

  Thereafter, the mixture is put into a mold (not shown) and then compressed at a predetermined pressure by a hydraulic press (not shown) to condense the aluminum in the mixture (step 2). At this time, by compressing the mixture, air, particularly oxygen, in the mixture is expelled from the mixture.

  Next, the compressed mixture is fired at a high temperature in a reducing atmosphere at a temperature of 1300 ° C. or higher and welded to obtain a massive first fired body in which metal fine particles are mixed in the refractory structure (step 3). At this time, the reducing atmosphere is an atmosphere containing less oxygen, and more preferably an oxygen-free state containing no oxygen, that is, a pseudo oxygen-free state. The reducing atmosphere is an atmosphere in which a closed space filled with a compressed mixture is filled with an inert gas, and the oxygen in the closed space is chemically changed to carbon dioxide or the like. By forming.

  Thereafter, the first fired body is cooled to a temperature of 200 ° C. or lower (step 4). Next, the cooled first fired body is fired in an oxygen atmosphere at a temperature of 1000 ° C. or higher and 1500 ° C. or lower, preferably 1400 ° C. to obtain a massive second fired body (step 5).

Further, the second fired body is cooled (step 6). Thereafter, the surface of the cooled second fired body is finished, and a furnace wall material having a predetermined shape is manufactured from the second fired body (step 7). At this time, the furnace wall material is not a harmful substance having any toxicity, ferric oxide (Fe ₂ O ₃ ), which is iron oxide, silicon dioxide (SiO ₂ ), and alumina, which is non-toxic aluminum oxide. Each of (Al ₂ O ₃ ) is contained.

  As described above, according to the above-described embodiment, the ferrosilica powder, the aluminum powder, and the lump obtained by pulverizing the ceramic are mixed to form a mixture, and the mixture is compressed, After expelling oxygen, the furnace wall material is produced by firing in a reducing atmosphere. As a result, it does not contain harmful substances that are harmful to the natural world, such as chromium, mercury, and cadmium, and has excellent heat resistance and slag penetration resistance, and has thermal properties such as thermal diffusion wear resistance and fire resistance temperature. A good furnace wall material can be manufactured with a simple configuration.

  That is, there are no residues containing hazardous heavy metals such as waste chromium, which are harmful substances, in the incinerators incinerated with the furnace wall material or in the incinerator.

Furthermore, since this furnace wall material contains ceramic particles, which are fine metal particles, in the refractory structure of this furnace wall material, it can absorb the difference in expansion between metals that occurs during high-temperature firing. Excellent in heat resistance and heat diffusion wear. Also, as an estimate, during use of this furnace wall material, hydrogen chloride (HCl), nitrogen oxide (NO) from the unique characteristics of emitting a large amount of far infrared rays inherent to the metal silicon in the furnace wall material. _{X 3} ) or sulfur oxide (SO _X ) can be decomposed. For this reason, by using this furnace wall material, the generation of hydrogen chloride (HCl), nitrogen oxide (NO _X ), or sulfur oxide (SO _X ) can be reduced, thereby suppressing the generation of harmful substances such as dioxins. it can.

  Furthermore, by mixing the ceramic with the furnace wall material, the ceramic functions as an extender in the furnace wall material and stabilizes the quality of the furnace wall material. Therefore, since the manufacturability of the furnace wall material that does not contain harmful substances and has excellent heat resistance can be improved, the furnace wall material can be manufactured more efficiently.

  Further, the surface of the ceramic to be mixed with the furnace wall material was coated with water glass and then mixed with the mixture. For this reason, the water glass which covers the surface of a ceramic absorbs the expansion difference which arises when the furnace wall material manufactured by mixing the ceramic with which this surface was coated with water glass is heated. That is, water glass acts as a cushioning agent for different expansion coefficients between metals generated when firing at a constant temperature. Therefore, since the stress generated when the heat-resistant material is heated can be dispersed, the furnace wall material is not easily damaged, and the heat resistance of the furnace wall material can be further improved.

  Further, the mixture of ferrosilica, aluminum and ceramic is compressed and fired in a reducing atmosphere to form a first fired body, and then the first fired body is cooled and fired in an oxygen atmosphere to obtain a second fired body. As a furnace wall material. As a result, by firing the first fired body in an oxygen atmosphere, the metal in the first fired body, in particular, aluminum and iron on the surface of the first fired body are oxidized, and alumina and oxidized The first fired body becomes stronger by using iron instead of oxygen as a binder. Therefore, the wear resistance of the furnace wall material when the furnace wall material is heated to a high temperature can be improved.

In the above embodiment, the furnace wall material is manufactured from a mixture of ferrosilica, aluminum, and ceramic. Instead of aluminum as the raw material of the furnace wall material, glycerin that functions as a deoxidizer and forms a shape. Even if (C ₃ H ₅ (OH) ₃ ) and boric acid (H ₃ BO ₃ ), which is compatible with glycerin, are mixed into a ferrosilica powder, it does not contain harmful substances such as chromium and is gentle to nature. A furnace wall material excellent in heat resistance can be manufactured.

  Moreover, after forming a compound mainly composed of 10% by mass to 70% of metal silicon and the balance of aluminum and ceramic as the main materials, and firing at a high temperature in a reducing atmosphere, if ceramic particles are mixed in the refractory structure Any other substance can be used correspondingly.

  Furthermore, although the furnace wall material used for the furnace wall of the incinerator has been described, if it is necessary to attach a heat-resistant material, it can be used as a furnace wall material for a blast furnace other than an incinerator, It can also be used as a heat-resistant material.

It is explanatory drawing which shows the manufacturing method of the heat resistant material of one embodiment of this invention.

Claims (6)

A heat-resistant material characterized by containing metallic silicon and aluminum. The heat-resistant material according to claim 1, comprising ferric oxide, silicon dioxide and aluminum oxide. Mix at least metallic silicon and aluminum to make a mixture,
A method for producing a heat-resistant material, characterized in that the mixture is compressed and then fired in a reducing atmosphere. The method for producing a heat-resistant material according to claim 3, wherein ceramic is mixed into the mixture. The method for producing a heat-resistant material according to claim 4, wherein a ceramic whose surface is covered with water glass is mixed into the mixture. The method for producing a heat-resistant material according to any one of claims 3 to 5, wherein after firing in a reducing atmosphere, the material is cooled and then fired in an oxygen atmosphere.

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