JP4716196B2 - Aqueous / oxidation-resistant coating material aqueous solution and coating method - Google Patents

Description

  The present invention prevents spalling of refractories such as refractory bricks and castables used in a high temperature atmosphere, delay and reduction of clinker adhesion, prevention of cracks, cracks, collapse, thinning, etc., and refractory castings, stainless steel, iron, The present invention relates to an aqueous solution for heat- and oxidation-resistant coating materials that can prevent high-temperature oxidation of metals such as refractory metals and a coating treatment method.

  Incinerators, incinerators, heating furnaces, reformers, boilers, melting furnaces, internal combustion engines, heat exchangers, etc. Stainless steel, refractory metals, etc. are used, but in particular in incinerators, it is necessary to burn at higher temperatures due to recent dioxin problems, and spalling and melting of the furnace wall due to high temperature corrosive gas generated during combustion The risk of fly ash as a clinker that attaches to the furnace wall in large quantities, or cracks, cracks, collapse, and thinning of the furnace wall increases, leading to an increase in the number of maintenance operations and a reduction in operating days. In addition, the refractory cast grate of the incinerator and the metal used in the heat furnace are depleted due to high-temperature oxidation, leading to an increase in cost due to replacement.

  In addition, heating furnaces used for oil refining and the like, other incinerators such as heating furnaces, boilers, and the like have led to an increase in cost due to soaring oil prices. In addition, there are ceramic spraying and metal spraying to prevent oxidation of refractory metals used in high temperature atmospheres, but ceramic spraying cannot follow the expansion coefficient of metal and cracks occur, and metal spraying can only prevent short-term oxidation. There is no effective method for preventing high-temperature oxidation of metals.

Conventionally, refractories used in high-temperature atmospheres are refractory bricks made by molding fine powders such as zirconia, alumina, silica, etc., which are high melting point materials, and firing at high temperatures, and appropriate amounts of water in the powder like castables. Mainly refractories that are mixed and constructed on site. Even if these refractories have a porous surface and have a heat resistance effect, the penetration of high-temperature corrosive gas into the refractory and the adhesion of fly ash melted at high temperatures are inevitable. When the clinker collapses due to the sprinkling of high temperature corrosive gas or the attachment of fly ash due to the clinker depositing on the surface of the refractory, part of the refractory also collapses, leading to thinning. If these refractories can be used for a longer period of time, the maintenance cost can be reduced and the number of working days can be increased. At present, a method of preventing clinker adhesion by using a silicon carbide refractory or by applying air cooling or water cooling to the inner surface of the refractory has been used, but there is a problem that the cost of the refractory is extremely expensive. In order to verify the effect of high-temperature incineration by countermeasures against dioxins, we applied the method to the industrial waste incinerator of the actual machine using our patent 3399650 heat- and oxidation-resistant coating method. As a result, some material blends have been improved to prevent spalling of refractory bricks and castables that are furnace wall refractories of incinerators and melting furnaces, delay in clinker adhesion and reduction of adhesion amount, cracks and cracks in furnace walls, An object is to find an effective method for preventing collapse, thinning, and the like, and to provide a heat-resistant / oxidation-resistant coating material aqueous solution and a coating method for reducing cost and shortening the maintenance period by simplifying furnace wall maintenance and management. .
Similarly, it provides prevention of spalling of furnace walls such as incinerators, heating furnaces, reformers and boilers, and prevention of cracks, cracks, collapse, and thinning of furnace walls.
Patent No. 3399650 Method for coating heat and oxidation resistant coating material

Means to solve the problem

The first invention is an alkali metal silicate in order to achieve the above object 50~80 w%, 0.02~0.4w% boric acid compound, 0.02～0.4W% zinc compounds, mica the 0.015～8W%, with including inorganic refractory aggregate, Fellow silicon 6～20W%, manganese compound 5～0.14W%, one or more elements of a cobalt compound 5～0.14W% It is a heat-resistant and oxidation-resistant coating material aqueous solution for metals.
The alkali metal silicate refers to an aqueous potassium silicate solution, an aqueous sodium silicate solution, an aqueous lithium silicate solution, or a mixture prepared by adding colloidal silica to these and adjusting the molar ratio. Alternatively, the alkali metal silicate includes one or more elements of a potassium silicate aqueous solution, a sodium silicate aqueous solution, and a lithium silicate aqueous solution alone. Alternatively, the alkali metal silicate includes one or more elements of a potassium silicate aqueous solution, a sodium silicate aqueous solution, and a lithium silicate aqueous solution mixed with colloidal silica. Further, the alkali metal silicate includes one or two or more elements in a mixture of colloidal silica blended with each simple substance.
The boric acid compound means sodium borate, metaborate, ratolaborate, pyroborate, borate, tetraborate, boron trioxide, sodium pentaborate, ammonium borate, and one of them Or two or more elements are included. A zinc compound refers to zinc oxide, zinc hydroxide, zinc carbonate, zinc sesquioxide, zinc borate, zinc silicate, and includes one or more elements among them. Ferrosilicon is a degassed surface oxidized coating. Manganese compounds refer to natural manganese dioxide and electrolytic manganese having a purity of 65% or more, and include one or more elements among them. The cobalt compound refers to cobalt tetraoxide, cobaltous oxide, cobaltous oxide, Raney cobalt, and includes one or more elements among them . The inorganic heat-resistant aggregate refers to an inorganic high-melting point material such as magnesium compound, zirconium oxide, aluminum oxide, anhydrous silicic acid, kaolinite, titanium oxide, etc., and is a powder material containing one or more of these elements. Magnesium compounds are magnesium oxide, magnesium borate, magnesium sulfate, and magnesium fluoride.
A second invention uses the aqueous solution of claims 1 to 2 and is fired at a temperature lower than the melting point of the refractory or metal that is the object to be treated. It is. The refractory material to be treated includes refractory bricks and castables used in thermal furnaces such as incinerators, incinerators, heating furnaces, reformers, boilers and melting furnaces. The surface of these refractories is coated with an aqueous heat / oxidation resistant coating material to prevent spalling, delay and reduction of clinker adhesion, cracks, cracks, collapse, and thinning. Alternatively, it is possible to prevent high-temperature oxidation by applying a heat-resistant and oxidation-resistant coating material aqueous solution to metals such as refractory castings, stainless steel, iron, and refractory metals used in high-temperature atmospheres such as the above-mentioned furnaces, turbines, and heat exchangers. This is a coating treatment method of an aqueous solution of a heat- and oxidation-resistant coating material characterized by the following.

Action

  According to the present invention, a magnesium compound, a cobalt compound, and a high melting point material such as a magnesium compound, zirconium oxide, aluminum oxide, anhydrous silicic acid, kaolinite, and titanium oxide, which are inorganic heat-resistant aggregates, and a metal film on the surface of the object to be treated By adding a boric acid compound or zinc compound that plays a catalytic role to ferro-silicon, etc., the inorganic heat-resistant aggregate, manganese compound, cobalt compound, ferro-silicon, etc. are treated at a temperature lower than the melting point of the refractory or metal of the object to be processed. Can be melted and coated on the workpiece. The aqueous solution of alkali metal silicate compound is made into a paint to make it easy to apply to the object to be processed, and as an adhesive to the surface of the object to be processed up to a certain temperature zone where inorganic heat-resistant aggregate, manganese compound, ferrosilicon, etc. melt. As a glassy film, it plays the role of preventing the entry of hot corrosive gas and preventing oxidation. Mica is used to prevent cracks that are likely to occur during the formation of heat and oxidation resistant coatings in a high temperature atmosphere. Manganese compounds, cobalt compounds, and fellow silicon may contain one or more elements depending on the type and purpose of the object to be treated, and the fellows, cobalt compounds, and manganese compounds in the fellow silicon are alkali metal silicate compounds. Forms a ceramic metal compound film with silicon in aqueous solution or silicon in fellow silicon, and coats the porous surface of the object to be processed with a dense coating, delaying and reducing the adhesion of clinker, and protecting the object from high temperature corrosive gas Demonstrate the effect. Manganese compounds and cobalt compounds in the case where the object to be processed is a metal form a metal coating that is extremely resistant to high-temperature oxidation on the metal surface, and the expansion coefficient of the inorganic heat-resistant aggregate composed of a ceramic compound with a low expansion coefficient and the metal to be processed. Contributes to buffering. The inorganic heat-resistant aggregate made of a ceramic compound exhibits a stone wall shape by using materials with different particles, which absorbs the difference in expansion coefficient and is one of the factors that do not cause cracks and cracks.

  With respect to claim 3, the powder material specified in the heat-resistant / oxidation-resistant coating material aqueous solution of claims 1 to 2 and an alkali metal silicate compound adjusted to a predetermined concentration are blended according to the object to be treated. (Table 1 to Table 2) A heat-resistant / oxidation-resistant coating material aqueous solution is prepared. At this time, the heat-resistant / oxidation-resistant coating material aqueous solution is formulated by stirring well so that the powder material does not become lumps. A spray gun such as a ricin gun, a brush, and a roller are suitable for application to the heat-resistant and refractory material to be processed. Particularly, application with a lysine gun can be efficiently applied. In the case of a new refractory brick, it is not necessary to treat the surface of the object to be treated. Even if it is exposed to a high temperature atmosphere without waiting for the coating to dry after application, it will not crack, crack or collapse. When the object to be treated is a metal, the surface of the object to be treated can be degreased or blasted to remove oil from the surface, and the adhesion can be improved by making the surface uneven. In particular, the metal edge surface can be prevented from peeling off the edge surface by chamfering. Similarly, a spray gun, brush, roller, etc. can be used for the metal coating method, but spray gun coating is efficient. After application, dry naturally enough or after forced drying at low temperature, after sufficiently drying the moisture contained in the heat-resistant and oxidation-resistant coating film, the alkali metal silicate compound becomes a strong siloxane bond Pre-baking is performed at a temperature of 200 ° C. for 20 to 30 minutes. At this stage, moisture in the air is not adsorbed to cause choking and can be stored for a long time. Further, by pre-baking, even if the temperature is suddenly increased, the formed coating does not peel off, break or crack from the object to be processed.

The invention's effect

  The present invention forms a strong coating against dense hot corrosive gas that eliminates the porous shape of the refractory surface, and the coating material itself is made of a material that does not easily adhere to clinker, thereby at least high temperature corrosion inside the refractory. It is possible to reduce the amount of clinker deposited by suppressing gas intrusion and further delaying the adhesion of molten fly ash. As a result, it is possible to prevent spalling of refractories, reduction of clinker adhesion, cracks, cracks, collapse, and thinning. In addition, as heat-resistant metals used in high-temperature atmospheres, corrosion-resistant materials such as heat-resistant castings, heat-resistant steel pipes, heat-resistant alloys such as nickel, carbon, chromium, tungsten, etc. are used. Even if it exists, the oxidation in a high temperature atmosphere cannot be stopped. Therefore, if a coating material that is a non-oxidizing ceramic compound coating and is an aqueous solution for heat- and oxidation-resistant coating materials of the present invention and that follows the expansion coefficient, oxidation on the metal surface can be prevented. Accordingly, it is possible to extend the useful life of the currently used refractory metal, and to use metals such as iron and stainless steel that could not be used until now.

Best method for carrying out the invention

Examples of the present invention will be described below for understanding of the present invention. It should be noted that the following example is an example embodying the present invention, and does not limit the technical scope of the present invention. Moreover, it is the usage method of prescription or a part improvement based on the coating processing method of the patent 3399650 heat-resistant / oxidation-resistant coating material of patent document 1 of our own.
Table 1 shows the blending ratio of the materials constituting the heat-resistant / oxidation-resistant coating material aqueous solution according to Examples 1 to 3, which is applied to the castable surface, which is a refractory material of an industrial waste incinerator, and adheres to the clinker. This test verifies the simplicity of wall cracking, cracking, collapse, thinning, and maintenance. It also specifies how to use it. The blending range of the refractory is specified in Table 3.

As shown in Table 1, the inorganic heat-resistant aggregate and other powder materials were weighed at a predetermined blending ratio and stirred with a powder mixer so that the whole was well mixed. The potassium silicate solution, which is an alkali metal silicate compound, is diluted to a predetermined concentration. The powder material mixture was stirred well so as not to become lumps in the potassium silicate solution adjusted to a predetermined concentration.
Mixing and stirring before construction will cause a hardening phenomenon if the powder material mixture and potassium silicate liquid are mixed and allowed to stand.

Coating method of heat-resistant / oxidation-resistant coating material A heat-resistant / oxidation-resistant coating material aqueous solution prepared using the materials shown in Table 1 is applied to an object to be treated with a ricin gun (spray gun), a brush, a roller, or the like. At this time, it is effective to apply about 2 m ² per kg, and it is required to apply about 1 m ² per kg to a part exposed to extremely high temperature. In particular, it is more effective to increase the coating thickness at high load parts exposed to high temperatures.

"Example 1"
Apply the product of the present invention created in Table 1 to a castable furnace wall of a rotary kiln / stoker combined furnace manufactured by Mitsubishi Heavy Industries, Ltd., owned by Mie Kosha Co., Ltd. Verified.
Current problems:
* The refractory in the re-combustion chamber was severely damaged everywhere during 60 days of operation. The thickness of the refractory 150 mm is reduced to 20 mm, and the dropout has occurred three times.
Causes 1) Due to high-temperature combustion, fly ash melts, clinker adheres to the furnace wall, and the refractory is damaged when it grows larger and falls off.
2) The refractory wall is eroded by thermal spalling due to continued high-temperature combustion.
Verification period and content;
Verification period: 60 days span x 2 verification contents;
1) Erosion of refractory furnace walls due to spalling 2) Influence of acid and alkali 3) First improvement of clinker adhesion and furnace cleaning time (maintenance) (60 days); Two reactors, furnace No. 1 and No. 2 were held, and verification was carried out in No. 1 furnace, which has a particularly heavy load. The coating was applied to the No. 1 furnace, and the No. 1 and No. 2 furnaces were shut down and the internal inspection was performed in about 20 days. The door of Unit 1 could be opened easily, but the door of Unit 2 was very hard due to clinker adhesion. Normally, the 1st furnace is in the same state as the 2nd furnace due to adhesion of the clinker. At this point, it was verified that the clinker had not yet adhered to the No. 1 furnace. Further, the furnace wall of the first furnace was completely coated with the coating material, and a black coating was formed. Furthermore, the clinker adhesion state after continuous operation was observed for up to 60 days, but in the first verification, there was almost no clinker adhesion, and no spalling, cracking, cracking, furnace wall collapse, or thinning was observed.
Second verification (60 days): In order to verify the reproducibility of the first effect, repeated coating was performed again and verification was further performed for 60 days. At this time, the low-quality castable, which is normally missing, is applied to a part of the furnace wall, and the coating material is applied on top of this to verify whether the low-quality refractory material can be used. The same reproducibility as the first time was verified, and it was verified that even low-quality castable furnace materials could be used without missing. After the opening of the second furnace, the inside of the furnace was cleaned, but the work normally required for 2 days was completed in 4 hours, and the maintenance management was greatly improved.

"Example 2"
The product of the present invention prepared in Table 1 was applied to a castable furnace wall of a rotary kiln furnace flue section manufactured by Kureha Environment Co., Ltd. of Otsusha, Fukushima Prefecture, and the effect was verified.
Current problems:
Normally, when the clinker with a thickness of about 30 cm adheres to the continuation of the operation for 2 weeks, the clinker is baked and squeezed and it is difficult to crush, so the furnace is stopped once every 2 weeks and the clinker is removed.
As a cause;
Industrial waste and medical waste are combusted at 1,100 ° C in a rotary kiln, and the flow velocity of drawing combustion gas into the secondary combustion furnace is high, so not only fly ash but also part of the bottom ash goes to the secondary combustion furnace. The clinker deposits on the flue wall in a short period of time.
Verification period and content;
Verification period: 80 days (3 verifications)
Contents of verification: Verification of clinker adhesion The first time after normal clinker removal work, about 20 m ² was applied to the flue entrance with a ricin gun and the furnace was opened after 13 days to verify the clinker adhesion amount. did. Usually, when the clinker of 30 cm adhered in 2 weeks, only about 10 mm was adhered this time, and when pressed by hand, the plate-shaped clinker peeled off easily. The second coating was applied in the same manner and verified after 28 days. At this time, the amount of clinker deposited was 20 to 50 mm, and the amount of clinker deposited was different depending on the part of the furnace wall. The third time, verified in 39 days, the clinker adhesion amount is about 100 mm and is very effective.
Further, no spalling, cracking, cracking, thinning, or collapse was observed.

"Example 3"
The product of the present invention prepared in Table 1 was applied to a castable furnace wall of a rotary kiln / stalker combined use furnace manufactured by Takuma Co., Ltd., Fukuoka Prefecture, and its effect was verified.
In the first round, about 5 m ² (5 kg) was applied to the flue site from the first combustion section to the first gas cold chamber, and the amount of clinker adhering to the flue section after 75 days of continuous operation was verified. Normally, the clinker adhered to the flue site in a tunnel shape, but there was no deposit on the top and bottom of the flue, although only 100 to 200 mm adhered to the walls on both sides. The wall clinker could also be removed simply by pressing. In the second round, 100 m ² (50 kg) was applied to the flue, the bottom of the rotary kiln, and the side wall of the stalker with a ricin gun in order to conduct a reproduction test, and the operation was continued for 86 days for verification. 200-300 mm adhered to the side wall of the flue site. This time, it was applied at a rate of ² m 2/1 kg, and the film thickness was half the first time. The side wall at the bottom of the rotary kiln was the site where the ash melted from the kiln flowed down, and the effect could not be confirmed. In addition, although a clinker was deposited on a part of the stalker side wall, it was considerably smaller than the usual amount of adhesion. Thus, it was verified that the amount of clinker attached can be reduced by increasing the thickness of the coating film in a portion where the amount of attached is usually large. Further, no spalling, cracking, cracking, thinning, or collapse was observed.

金属用耐熱・耐酸化被覆材水溶液
表２のごとく、無機耐熱骨材他の粉末材料を所定の配合比率にて夫々計量し粉体混合機にて全体が良く混ざるように攪拌した。アルカリ金属ケイ酸塩化合物であるケイ酸カリウム液は所定の濃度に希釈調整する。粉末材料混合物が所定の濃度に調整したケイ酸カリウム液内でダマにならないように良く攪拌した。特に金属に使用する場合は水溶液中の粉末粒子同士をできるだけ分散するようにプラスチック容器に耐熱・耐酸化被覆材水溶液とアルミナビーズを入れシェーカーにて良く分散する方がよりきめ細かな被膜の形成を可能にする事が判明した。
粉末材料混合物とケイ酸カリウム液を混合して放置すると硬化現象を起こす為、施工前に混合攪拌する。Table 2 shows the compounding ratios of the materials constituting the heat-resistant / oxidation-resistant coating material aqueous solutions according to Examples 4 to 5, and the metal test was verified. It also specifies how to use it. The range of the metal is specified in Table 4.

As shown in Table 2, the inorganic heat-resistant aggregate and other powder materials were weighed at a predetermined blending ratio and stirred by a powder mixer so that the whole was well mixed. The potassium silicate solution, which is an alkali metal silicate compound, is diluted to a predetermined concentration. The powder material mixture was stirred well so as not to become lumps in the potassium silicate solution adjusted to a predetermined concentration. In particular, when used for metals, it is possible to form a finer film by placing an aqueous solution of heat- and oxidation-resistant coating material and alumina beads in a plastic container and dispersing well with a shaker so that the powder particles in the aqueous solution are dispersed as much as possible. It turned out to be.
Mixing and stirring before construction will cause a hardening phenomenon if the powder material mixture and potassium silicate liquid are mixed and allowed to stand.

Coating method of heat and oxidation resistant coating material Use a spray gun (use a nozzle that can sufficiently coat 100 μm particles), brush, roller, etc. using an aqueous solution of heat and oxidation resistance coating material prepared using the materials in Table 2 Apply to the workpiece. The thickness of the coating is suitably 50 μm to 200 μm. If it is 50 μm or less, it is not sufficient for preventing oxidation and oxidation, and if it is 200 μm or more, there is a possibility of cracking and cracking due to expansion and contraction of the metal during cooling. As a result of the test, it was found that 100 μm to 150 μm is the most effective film thickness for following the metal expansion coefficient and preventing oxidation with the most stable coating thickness. In the application, it is applied evenly with a spray gun, and after the surface is dried, the application is repeated 4 to 5 times or until a predetermined coating thickness is obtained. After coating, it is naturally dried, or it is stabilized by temporarily baking at a temperature of 200 ° C for about 20 to 30 minutes while allowing the moisture in the coating to sufficiently evaporate with low-temperature forced drying or cold air, and then gradually raising the temperature in a baking furnace. To process.
By performing the stabilization treatment, it can be stored for a long time without causing choking.
Furthermore, when the temperature is raised at 900 to 1100 ° C., which is lower than the melting point of the object to be treated after calcination, and baked for about 40 to 60 minutes, the coating material is completely ceramicized and firmly adhered to the metal.

"Example 4"
Sumitomo Metal Technology Co., Ltd. prepared in Table 2 and applied to the iron piece (SS400) and stainless steel piece (SUS304) with a brush based on the heat-resistant / oxidation-resistant coating material coating method of claim 3 and pre-baked. The heat resistance / oxidation resistance test was performed on the test specimens and the test specimens that had not been subjected to anything.
The following are the results.
(Test data table 1)

所見
＜ＳＵＳ材＞
＊ステンレス材については酸化劣化による変化がほとんど見られなかった。
＊変化の少なさは、もともとのステンレスの耐熱範囲にあるためと考えられる。
＊厚さ及び重量の変化については、塗布されたコーティング材の加熱焼き絞め及び、部分剥離によるものと考えられる。
＜ＳＳ材＞
＊厚さおよび重量とも若干の変化が見られるが、ほとんどないと言える値である。
＊試験片Ｈの重量減はＳＵＳ材と同様のものと思われる。
＊通常の鉄片を同条件で加熱したものに比較すれば、変形・変質ともにあきらかに酸化が抑制されているといえる。
＜結論＞
１．塗布条件が適えば１０００℃の３時間条件でＳＳ材においてはほとんど酸化が認められないといえる。ただし、塗布条件（下地処理・均一性）が重要である。
２．ＳＵＳ材用についてはさらに高温化での使用に耐えるものに向け、改良の余地があるといえる。
３．結果、前項１，２、の条件範囲内であれば焼却炉など高温の雰囲気にさらされる金属部材（鉄・ステンレス材）での保護コーティング材への利用が可能と思われる。"Example 5"
Prepared in Table 2 at Kyushu Kyoritsu University Research Institute and applied to the iron piece (SS400) and stainless steel piece (SUS304) with a brush based on the coating method of the heat- and oxidation-resistant coating material of claim 3 and pre-baked The heat-resistant / oxidation-resistant test was performed on the test piece subjected to the above and the test piece not subjected to any treatment.
The following are the results and findings of the Kyushu Kyoritsu University Sogo Research Institute.
<Test piece> SUS350 4 pieces (overall application) SS400 4 pieces (overall application)
<Testing method> Each test piece is charged at room temperature, the temperature in the furnace is raised between 1000 ° C. (2 hours 40 minutes), and after reaching 1000 ° C., one piece is taken out every 1 hour while keeping 1000 ° C. at room temperature. It was cooled rapidly.
<Measurement> In each test piece, changes in weight and thickness before and after heating were measured, and the deterioration of the member due to oxidation was tested.
Measurement results (test data table. 2)

Findings <SUS material>
* For stainless steel, there was almost no change due to oxidative degradation.
* Small changes are considered to be within the heat resistance range of the original stainless steel.
* Changes in thickness and weight are thought to be due to heat baking and partial peeling of the applied coating material.
<SS material>
* Slight changes in both thickness and weight are observed, but it can be said that there is almost no change.
* The weight loss of the specimen H seems to be the same as that of the SUS material.
* Compared to a normal iron piece heated under the same conditions, it can be said that oxidation is clearly suppressed in both deformation and alteration.
<Conclusion>
1. If the coating conditions are suitable, it can be said that almost no oxidation is observed in the SS material under the condition of 1000 ° C. for 3 hours. However, the application conditions (base treatment / uniformity) are important.
2. It can be said that there is room for improvement for the SUS material, which can withstand use at higher temperatures.
3. As a result, if it is within the conditions of the preceding paragraphs 1 and 2, it can be used as a protective coating material in a metal member (iron / stainless steel material) exposed to a high temperature atmosphere such as an incinerator.

In the blending ratio of each constituent material used for the refractory shown in Table 1, use is made of irreplaceable materials such as ferrosilicon, boric acid compound, zinc borate zinc borate, mica, and alkali silicate compound. Powder materials such as aluminum oxide, zirconium oxide, anhydrous silicic acid, kaolinite, titanium oxide and manganese dioxide, which are inorganic heat-resistant aggregates, according to the purpose of countermeasures such as heat resistance, anti-spalling, cracking, cracking, thinning, collapse, etc. Any element of one or two or more materials in this formulation or any other heat-resistant inorganic material can be used. It is also possible to add one or more elements of magnesium compounds or magnesium oxide, magnesium borate, magnesium sulfate, magnesium fluoride. Manganese dioxide can be replaced with one or more elements of electrolytic manganese and cobalt compounds such as cobalt tetroxide, cobaltous oxide, cobaltous oxide, and Raney cobalt. In particular, the fellow portion of the fellow silicon melts at a relatively low temperature and forms a metal film on the surface of the refractory to form a metal silicon compound, which seals the porous portion of the surface of the refractory. Zinc borate is a high-temperature melting material that is useful as a catalyst to lower the melting point of inorganic heat-resistant aggregates such as aluminum oxide, zirconium oxide, anhydrous silicic acid, kaolinite, and titanium oxide, and is an alkali metal silicate compound, potassium silicate Aqueous solution exhibits an adhesive effect until the high melting point material is bonded to the refractory material to be processed, and the vitrification is performed at 200 ° C. by virtue of siloxane bonding to prevent high temperature corrosive gas from entering. Forms a metal film with the fellow, greatly contributing to the reduction and prevention of clinker adhesion and contributing to cross-linking with inorganic heat-resistant aggregates. Mica serves to prevent cracks that tend to occur during the formation of the coating. Moreover, the potassium silicate aqueous solution which is an alkali metal silicate compound can be used not only as a simple substance but also as a mixture with a sodium silicate aqueous solution, a lithium silicate aqueous solution, or colloidal silica.

  The concentration of the aqueous solution of potassium silicate that is an alkali metal silicate compound can be higher or lower than a predetermined concentration. The higher the concentration is, the more difficult it is to mix uniformly with the powder material, and the lower the concentration, the thinner the glass coating at the siloxane bond, which is not preferable for coating formation. The mixing ratio of the aqueous solution of potassium silicate, which is an alkali metal silicate compound, and the powder material such as inorganic heat-resistant aggregate and manganese compound varies depending on the properties of the material to be treated, the purpose of use, and the conditions of use. A suitable range is 50 to 70% weight ratio of potassium silicate which is an acid salt compound: 30 to 50% weight ratio of powder material such as inorganic heat-resistant aggregate and manganese compound.

In forming the heat-resistant / oxidation-resistant coating on the surface of the refractory by the respective material configurations according to the combination of claim 1 and claim 2 and the coating treatment method thereof, the refractory which is the object to be treated and the materials of claim 1 and claim 2 There is no significant difference in the expansion coefficient of the coating formed from the aqueous solution of heat-resistant / oxidation-resistant coating material prepared by the above method, and there is a feature that cracks and cracks do not occur even when subjected to a rapid temperature increase after coating. In addition, when the potassium silicate aqueous solution, which is an alkali metal silicate compound, takes 20 minutes at a temperature of 200 ° C., the water in the potassium silicate aqueous solution evaporates, and silicon dioxide forms a strong glass film by siloxane bonding by polymerization. In addition, the porous surface of the refractory surface is hermetically sealed to prevent the high temperature corrosive gas from entering. As the temperature rises, the fellow in the fellow silicon softens and melts to form a dense metal film. The silicon dioxide particles in the fellow silicon and the inorganic heat-resistant aggregates such as aluminum oxide, zirconium oxide, silicic anhydride, kaolinite, titanium oxide and other powder materials and manganese dioxide are incorporated into the metal coating material in the form of particles and further increased. Manganese dioxide forms a new metal compound with the metal film of the fellow and the metal film formed while melting the surface of the inorganic heat-resistant aggregate to form a bluish metal ceramic film by zinc borate, which is a catalyst at a temperature .
Fellow silicon and manganese dioxide form a high-temperature oxidation-resistant metal ceramic film on the surface of the refractory material to be treated, soften at high temperatures, and have the flexibility to harden when the temperature decreases, and the refractories expand and contract. Also follow. Also, this metal film is difficult to adhere to the molten clinker originally, and the clinker adheres to the inorganic heat-resistant aggregate aluminum oxide, zirconium oxide, silicic anhydride, kaolinite, titanium oxide, etc. incorporated in the metal film, but on the metal film. It only adheres to the exposed part, its adhesion is low and the amount of clinker deposited does not increase, and even if deposited, the adhesion strength is low, so even a small amount of deposition falls by its own weight. In particular, titanium oxide is excellent in corrosion resistance, and when high-temperature corrosive gas is generated in large quantities, it is possible to change the composition depending on conditions such as increasing the amount.

  In the compounding ratio of each constituent material used for the metal of the object shown in Table 2, the alkali metal silicate compounds potassium silicate, boric acid compound, zinc oxide, mica and manganese dioxide are materials that cannot be replaced. One boric acid compound, sodium tetraborate, is one of sodium borate, metaborate, ratolaborate, pyroborate, borate, tetraborate, boron trioxide, sodium pentaborate, ammonium borate. Alternatively, manganese dioxide can be replaced with two or more elements, and manganese dioxide can be replaced with one or more elements of electrolytic manganese and cobalt compounds cobalt tetraoxide, cobaltous oxide, cobaltous oxide, and Raney cobalt. Can do. Zinc borate, zinc oxide can be replaced with one or more elements of zinc hydroxide, zinc carbonate, zinc sesquioxide, zinc silicate, aluminum oxide, zirconium oxide, anhydrous silicic acid, inorganic heat-resistant aggregate, Titanium oxide can be used for inorganic heat-resistant aggregates such as aluminum oxide, zirconium oxide, silicic anhydride, and titanium oxide as long as they are elements of one or two or more materials within this composition depending on the purpose of use, including the heat-resistant temperature of the use conditions. It is also possible to add one or two or more elements of magnesium compounds such as magnesium oxide, magnesium borate, magnesium sulfate, and magnesium fluoride. Zinc borate and zinc oxide are useful as catalysts for lowering the melting point of inorganic heat-resistant aggregates such as aluminum oxide, zirconium oxide, anhydrous silicic acid and titanium oxide, and alkali metal silicate compound potassium silicate has a high melting point. By virtue of the adhesive effect until the material is bonded to the object to be treated, it becomes vitrified to prevent the object from being oxidized in a high-temperature oxygen atmosphere, and the alkali metal silicate compound potassium silicate is only a simple substance. It is also possible to use a mixture of sodium silicate, colloidal silica and potassium silicate, or sodium silicate. In particular, in order to strengthen the siloxane bond, silica powder, colloidal silica, or the like can be blended in order to increase the molar ratio of silicic acid (silica) of the alkali metal silicate compound to the alkali metal.

  The concentration of the aqueous solution of potassium silicate that is an alkali metal silicate compound can be higher or lower than a predetermined concentration. The higher the concentration is, the more difficult it is to mix uniformly with the powder material, and the lower the concentration, the thinner the glass coating at the siloxane bond, which is not preferable for coating formation. The mixing ratio of the aqueous solution of potassium silicate, which is an alkali metal silicate compound, and the powder material such as inorganic heat-resistant aggregate and manganese compound varies depending on the properties of the material to be treated, the purpose of use, and the conditions of use. A suitable ratio is 20 to 40% by weight of potassium silicate, which is an acid salt compound, and 60 to 80% by weight of a powder material such as inorganic heat-resistant aggregate or manganese compound.

In forming the heat-resistant / oxidation-resistant coating on the surface of the refractory by the respective material configurations and the coating treatment method according to the combination of claim 1 and claim 2, the refractory which is the object to be treated and the materials of claim 1 and claim 2 There is a large difference in the expansion coefficient of the coating formed from the aqueous solution of the heat-resistant / oxidation-resistant coating material prepared by the above, and it is necessary to pay particular attention to the coating formation. At the time of application, it is necessary to apply thinly by any method of spraying, brush, or roller and drying, then repeatedly applying to a predetermined thickness by the method of applying repeatedly, and applying repeatedly while removing moisture in the coating. Also, after coating, after sufficiently removing moisture remaining in the coating by performing natural drying, low-temperature forced drying, or cold-air drying, the temperature is gradually raised to 200 ° C. in the furnace to reach a predetermined temperature. Pre-sinter for 20-30 minutes to stabilize. After pre-baking, cracks, blisters, and cracks do not occur even when a rapid temperature rise is applied. The point transfer differs depending on the type of metal, and large expansion and contraction occur when the temperature rises or falls. The problem of this expansion coefficient is verified in “Example 5”. Although there is no data that can accurately explain the theory that the expansion coefficient follows, the metal coating with manganese dioxide is metal-bonded to the metal surface, and powder materials such as inorganic heat-resistant aggregates and magnesium compounds are incorporated into the metal coating compound. In addition to realizing an oxidation resistance effect, the manganese-based metal film compound itself is a film resistant to high-temperature oxidation. The metal coating compound also plays a role in buffering the expansion coefficient of ceramics made of a powder material such as an inorganic heat-resistant aggregate or magnesium compound and a metal base material to be processed.
Powdered materials such as aluminum oxide, zirconium oxide, silicic anhydride, and titanium oxide, which are inorganic heat-resistant aggregates, are coated with manganese dioxide by lowering the melting point of these aggregates with zinc oxide and zinc borate as catalysts. It is considered that the metal ceramic compound is formed at the interface of the object to be treated by bonding with the compound. Mica has a role of buffering cracks, cracks, etc. when the temperature rises or falls, and a stone wall-like film is formed by controlling the particle size of the inorganic heat resistant aggregate. It is understood that the expansion coefficient is followed by a synergistic effect.
[Table 3] and [Table 4] show the distribution ratio of the heat-resistant / oxidation-resistant coating material aqueous solution of the present invention.

  Regarding industrial applicability, it is used especially in refractories of all heat furnaces such as industrial waste incinerators, administrative incinerators, incinerators, heating furnaces, reformers, boilers, etc. and in these high-temperature atmosphere environments. For example, incinerator grate, heat exchanger pipe, heating furnace pipe, incinerator furnace, and other metal materials such as turbine cases and internal combustion engines can prevent oxidation and improve durability.

Claims (2)

50-80 w% alkali metal silicate compound , 0.02-0.4 w% boric acid compound , 0.02-0.4 w% zinc compound , 0.015-8 w% mica , inorganic heat resistant aggregate A heat- and oxidation-resistant coating material aqueous solution containing 6 or 20 % by weight of fellow silicon , 5 to 0.14 w% of manganese compound, and 5 to 0.14 w% of cobalt compound. A method for coating a heat and oxidation resistant coating material, comprising using the aqueous solution of claim 1 and firing at a temperature lower than the melting point of the workpiece.