JP2003335572A - Magnesia - titania - alumina based clinker and refractory obtained by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a basic material for a refractory containing magnesia as a main component having good corrosion-resistance, slaking-resistance, slag- resistance, and spalling-resistance, or a magnesia-titania-alumina based clinker, and the refractory obtained by using the clinker. <P>SOLUTION: A mixture, in which one or at least two of glass components selected from phosphoric acid or phosphate, and basic aluminium lactate are mixed to 100 weight part of a composition having a chemical composition of magnesia of 25 to 95 weight percent, titania of 2 to 50 weight percent, and alumina of 3 to 73 weight percent, is baked, thereby an objective clinker is obtained. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a magnesia-titania-alumina clinker and a refractory material obtained by using the clinker, and particularly to a molten steel container, a smelting furnace container or a kiln for burning cement or lime in the steel industry. The present invention relates to a raw material for a refractory for lining, a non-standard refractory such as castable or spraying material, and a basic refractory used as a repair material.

[0002]

BACKGROUND ART Conventionally, in the field of steelmaking and non-ironmaking,
Metal oxides such as alumina, spinel, magnesia, zirconia, and silica have been widely used as refractory materials. Among them, magnesia is used as a main raw material for basic refractory materials because of its excellent corrosion resistance. Has been done.

However, although such a magnesia-based refractory material has excellent corrosion resistance, it has the disadvantages of large thermal expansion, poor spalling resistance, remarkable slag infiltration, and easy digestion. Since it is inherent, magnesia refractory materials have the problem of life shortening due to spalling due to thermal stress and structural spalling due to slag infiltration. However, there is a drawback that it is difficult to use in places where

However, the combination of magnesia and carbon has been used to solve the spalling due to such thermal stress and the structural spalling due to slag infiltration. As magnesia-carbon bricks, it is used in converters, molten steel pots, etc. It is used. However, this magnesia-carbon brick emits carbon dioxide, which is a source of global warming, during its use, and therefore, as a refractory in the future considering the environment, the brick contains a big problem. I have to say that.

Further, in order to improve the digestion resistance of magnesia, it is possible to add silica such as silica flour, which is widely adopted. However, the addition of such silica forms a low melting point compound. However, since the corrosion resistance is deteriorated, the amount added is limited, and there is a problem that the improvement of digestion resistance is also limited.

In addition to the above, a basic refractory in which titania or the like is added to magnesia has been reported. For example, in JP-A-9-2055, a magnesia-calcia-titania basic refractory is clarified. In addition, Japanese Patent Laid-Open No. 58-1593 discloses a sintered body in which aluminum titanate is added to spinel. Further, Japanese Patent Laid-Open No. 49-6008 discloses magnesia-titania-
Alumina-zirconia refractories have been proposed.

However, the method of adding titania or alumina to magnesia is considered to be an effective means because it has the function of improving the spalling property due to thermal stress by forming a solid solution of magnesia-alumina spinel and magnesium titanate. However, when used as a refractory, there is a drawback that titania reacts with iron oxide or silica on the working surface, which is the surface that comes into contact with the molten metal or slag, to lower the corrosion resistance.

Further, in particular, calcia contained as an impurity in magnesia reacts with the added titania,
Although it is expected to generate perovskite and thereby improve digestion resistance, since the content of calcia as an impurity is low, less perovskite is produced, and therefore improvement in digestion resistance can be sufficiently satisfied. It wasn't something.

[0009] In addition, although the calcia in the slag reacts with the added titania to form the above-mentioned perovskite, forming a dense layer on the working surface, and improving the slag resistance, As described above, since titania reacts with silica and iron oxide with time, there is an inherent problem of causing deterioration of corrosion resistance.

[0010]

The present invention has been made in view of such circumstances, and the problem to be solved is to have excellent corrosion resistance, excellent digestion resistance, and slag infiltration resistance. It is intended to provide a basic refractory raw material containing magnesia as a main component, that is, a magnesia-titania-alumina clinker excellent in excellent heat resistance and spalling resistance, and a refractory obtained by using the clinker.

[0011]

The present invention, in order to solve the above problems, magnesia: 25 to 95% by weight, titania: 2 to
50% by weight, and alumina: 3 to 73% by weight, based on 100 parts by weight of the composition giving a chemical composition, one or more of glass component, phosphoric acid or phosphate, and basic aluminum lactate. Magnesia-titania-, which comprises a calcined product obtained by calcining a compounded product of 0.2 to 10 parts by weight.
Alumina-based clinker is the main point.

As described above, the basic refractory raw material clinker according to the present invention contains magnesia, which is excellent in corrosion resistance, as a main component, and is mixed with titania and alumina, and further, a glass component, phosphoric acid or phosphate. And one or more of basic aluminum lactate are mixed, and such a glass component forms a phase in a fired product (clinker), magnesia, etc. By forming various compounds between and, it is possible to greatly contribute to the improvement of digestion resistance.

In the magnesia-titania-alumina clinker according to the present invention, the basic aluminum lactate preferably contains polyethylene glycol and / or monoethanolamine. By compounding basic aluminum lactate containing such a compound, it is possible to advantageously contribute to the improvement of digestion resistance.

According to another preferred embodiment of the present invention, the basic aluminum lactate is used together with the polyethylene glycol and / or monoethanolamine, or in place of polyethylene glycol or the like.
Since it contains silica, it is possible to further improve the digestion resistance.

Further, the magnesia-titania of the present invention
In the alumina-based clinker, preferably, one or more of iron oxide, chromium oxide and zirconium oxide is 0.2 or more with respect to 100 parts by weight of the composition.
In the proportion of 10 to 10 parts by weight, further blended,
A composite spinel will be generated. By further blending such a specific compound to form a composite spinel, it is possible to advantageously contribute not only to the digestion resistance but also to the corrosion resistance, the slag infiltration resistance, and the spalling resistance. .

In addition, the present invention also provides a refractory material characterized by using the clinker according to the present invention as a refractory material. Even in such a refractory material according to the present invention, the characteristics of the clinker according to the present invention described above, that is, the excellent corrosion resistance, digestion resistance, spalling resistance, and slag infiltration resistance can be exhibited as they are.

[0017]

By the way, in the magnesia-titania-alumina clinker according to the present invention,
Magnesia should be contained in a proportion of 25 to 95% by weight, preferably in a proportion of 50 to 70% by weight. When the content of magnesia is less than 25% by weight, a solid solution composed of magnesia-alumina spinel and magnesium titanate is not sufficiently formed, and the effect of giving high melting point and corrosion resistance by magnesia cannot be sufficiently exerted. If it exceeds 95% by weight, the content ratio of other components (titania, alumina) decreases, and it becomes difficult to obtain a clinker having the desired characteristics.

The titania and alumina to be combined with such magnesia have a chemical composition of 2 to 50% by weight and 3 to 73% by weight, respectively, preferably 10 to 3%.
It is necessary to have a chemical composition of 0% by weight and 20-40% by weight, but in order to fully exert the effect of adding these components, titania is 2% by weight or more and alumina is 3% by weight.
It is necessary to set the above content. In addition, a part of titania reacts with magnesia to form magnesium titanate, while alumina reacts with magnesia, resulting in magnesia.
Alumina spinel will be produced. Then, the generated spinel forms a solid solution with magnesium titanate, but in this case, when the titania is too much, magnesium titanate which is a low melting point increases, and the solid solution with spinel is also biased to magnesium titanate. Therefore, the upper limit of the titania content is 50 because the corrosion resistance decreases.
It is desirable to set it as the weight%. If the content of alumina exceeds 73% by weight, the amount of solid solution of magnesia-alumina spinel and magnesium titanate is not sufficient, so the upper limit of the content of alumina is 73% by weight.
Is desirable.

In the clinker according to the present invention, magnesia, titania, and alumina are mixed with one or more of a glass component, phosphoric acid or phosphate, and basic aluminum lactate, Where it is constructed, it has a great feature.
That is, when at least one kind or two or more kinds of glass components and the like are mixed in a composition composed of magnesia, titania, and alumina, and the resulting composition is fired, a fired product (clinker) is formed. Since various phases such as glass component and various compounds are formed, contact between magnesia and water molecules can be effectively avoided by such compounds, and thus digestion resistance can be advantageously improved. Can be done.

Specifically, when the above-mentioned components are blended with a composition consisting of magnesia, titania, and alumina, when a glass component is used with magnesia, the magnesia is mixed in the magnesia. A glass phase is formed, the surface of periclase is coated, and when phosphoric acid or a phosphate is used, it reacts with periclase to form magnesium phosphate. Furthermore,
In the case of basic aluminum lactate, since it disperses well in a composition composed of magnesia or the like, when a mixture containing such basic aluminum lactate is baked,
The MgO—Al ₂ O ₃ -based compound is more effectively produced as compared with the case where only alumina alone is used. Therefore,
Since such various compounds are produced and the contact between magnesia and water molecules can be effectively prevented, the digestion resistance of the clinker can be advantageously improved.

Here, 100 parts of a composition comprising magnesia, titania and alumina is used as the glass component.
If the amount is more than 10 parts by weight, the corrosion resistance of the fired product (clinker) may be deteriorated. On the other hand, if the amount is less than 0.2 parts by weight, the corrosion resistance of the composition may be reduced. Since the digestibility cannot be sufficiently improved, the glass component, phosphoric acid or phosphate and basic aluminum lactate in the present invention may be mixed in the above composition depending on the characteristics of the clinker of interest. It will be appropriately selected within the range of 0.2 to 10 parts by weight with respect to 100 parts by weight of the product.

The glass component and the like to be added to the composition of magnesia or the like as described above,
Various known materials can be used, and examples of the glass component include silicate glass, borate glass, and phosphate glass, and the phosphate includes monoammonium phosphate. Etc. will be used appropriately. On the other hand, when adding phosphoric acid,
It goes without saying that commercially available phosphoric acid can be used as it is, and one that is appropriately diluted with water can also be used.

The basic aluminum lactate used in the present invention generally has a chemical composition such that the ratio (molar ratio) of Al ₂ O ₃ / lactic acid is 0.2 to 2.0. Precipitates formed by reacting water-soluble aluminum salts such as aluminum, aluminum sulfate, aluminum nitrate and basic ammonium chloride with alkali metal or ammonia carbonates or bicarbonates (bicarbonates) (alumina hydration It is produced by various known methods such as a method of dissolving the product) in lactic acid.

Further, as the basic aluminum lactate in the present invention, especially polyethylene glycol and / or
Alternatively, those containing monoethanolamine will be advantageously used. By blending basic aluminum lactate containing such a substance,
The digestion resistance of the clinker can be effectively improved.

As described above, as the polyethylene glycol to be contained in the basic aluminum lactate, those having an average molecular weight of about 200 to 20,000 are preferably used, and the polyethylene glycol and monoethanolamine are contained. The amount is appropriately determined depending on the Al ₂ O ₃ / lactic acid molar ratio in the basic aluminum lactate, the digestion resistance required for the clinker, and the like. Specifically, Al in basic aluminum lactate
_With respect to 100 parts by weight of the ₂ O ₃ component, in the ratio of 30 to 350 parts by weight for polyethylene glycol, and in the ratio of 10 to 200 parts by weight for monoethanolamine, polyethylene glycol and / or Basic aluminum lactate containing monoethanolamine is used.

Furthermore, in the basic aluminum lactate of the present invention, more advantageously, together with the polyethylene glycol and / or monoethanolamine,
Alternatively, instead of the polyethylene glycol or the like, silica is mixed. Here, it is preferable that such silica has a particle diameter of 10 μm or less. And, by using such a basic aluminum lactate, between the fine particles of silica contained therein, magnesia and alumina,
Since various compounds such as MgO—SiO ₂ —Al ₂ O ₃ system are produced, the digestion resistance of the clinker can be further improved, and the physical strength of the clinker is also improved.
In addition, it can be advantageously improved.

When the basic aluminum lactate as described above is blended with a composition giving a chemical composition of magnesia, titania, and alumina, it is in the form of dried powder or dried. It is possible to use any of the solution forms which are not used.

By the way, in the clinker according to the present invention, first, the composition is prepared by mixing the raw materials of the respective components so that magnesia, titania, and alumina are provided in the chemical composition as described above. However, various known materials can be used as the raw materials of the respective components for preparing such a composition. For example, as a magnesia source material, natural magnesia, seawater magnesia, magnesia produced by various known manufacturing methods,
Clinker, magnesium hydroxide, electro-fused magnesia, etc. can be used, and as the titania source material, rutile type or anatase type titania can be used, and as the alumina source material, calcined alumina or sintered. Alumina or the like can be used.

Further, one or two or more of the glass component, phosphoric acid or phosphate and basic aluminum lactate is mixed with such a composition in a predetermined ratio. However, more advantageously, one or more of iron oxide, chromium oxide and zirconium oxide is 0.2 to 100 parts by weight of the composition.
In the proportion of 10 parts by weight, it will be further compounded. The blending of such iron oxide is to form various composite spinels by firing, and to improve not only digestion resistance but also corrosion resistance, slag infiltration resistance, and spalling resistance.

Specifically, when iron oxide is used, the Mg (Fe, Al) ₂ O ₄ composite spinel is used, and when chromium oxide is used, Mg (Cr, Al) _{2 is used.} O ₄ composite spinel was produced respectively, and when both of them were used, (Mg, Fe) (Cr, Al)
₂ O ₄ composite spinel is formed and forms a solid solution between such composite spinel and magnesium titanate. On the other hand, when zirconium oxide is used, it reacts with periclase to stabilize zirconia. Therefore, it contributes to the improvement of digestion resistance, corrosion resistance and the like. Here, in the present invention, FeO, Fe ₂ O ₃ , Fe ₃ O ₄
Any of the above iron oxides can be used, and also as chromium oxide, CrO, Cr ₂ O ₃ , CrO ₂ , Cr ₂ O ₅ ,
Any material such as CrO ₃ can be used.

The blending amount of iron oxide, etc. as described above is
If the amount is less than 0.2 parts by weight based on 100 parts by weight of the composition, the effect is not recognized, and even if the amount exceeds 10 parts by weight, it is not practical from the viewpoint of cost effectiveness. Therefore, the blending amount of the iron oxide or the like is appropriately determined within the range of 0.2 to 10 parts by weight with respect to 100 parts by weight of the composition, depending on the properties of the target clinker and the like. It will be.

In producing the magnesia-titania-alumina clinker according to the present invention, first, a glass component is added to the composition giving the above chemical composition,
Prepare one or more of phosphorus or phosphate and basic aluminum lactate, or one or more of iron oxide, chromium oxide and zirconium oxide. Then, add water to it to make a slurry, and then dehydrate and extrude, or knead by adding a binder to the above-mentioned preparation and then molding with a briquette machine. The desired clinker can be obtained as a fired product by firing at a temperature of about 1500 to 2000 ° C. according to the firing operation.

As the binder used in the production of the clinker, various known binders can be mentioned. For example, lignins, starches, polyvinyl alcohol, methyl celluloses, various phenolic resins, molasses, etc. can be used. Used in proportions, it will be advantageously shaped into the desired shape.

In the refractory material according to the present invention, the clinker as described above is used as the refractory material, and it is advantageously formed by the following method.

That is, first, the above-mentioned clinker according to the present invention is pulverized and sized according to a conventional method to obtain a refractory material consisting of powder or granules of the clinker, and then obtaining the refractory material. A molded refractory material such as bricks is obtained by molding the obtained refractory material into a predetermined shape by a conventionally known method, and then heating and sintering it as required.

As another method, various cements, binders and the like are mixed with the refractory material of the clinker according to the present invention obtained as described above, and an amorphous powder or a clay There are ways to obtain refractories. In addition,
As is well known, in this amorphous refractory material, water is then added, and a molding operation such as a stamp molding method or a vibration molding method is carried out, whereby a refractory product having a desired shape is obtained. Will be formed.

As described above, the refractory material according to the present invention can be advantageously manufactured as a regular refractory material or an irregular refractory material in any shape, and moreover, such refractory material can be manufactured. As described above, is excellent in digestion resistance, corrosion resistance, slag infiltration resistance, and spalling resistance.

[0038]

EXAMPLES Some experimental examples including typical examples of the present invention will be shown below to clarify the present invention in more detail. However, the present invention is not limited to such experimental examples. It goes without saying that the description does not impose any restrictions. In addition to the following experimental examples, in addition to the above specific description, the present invention also includes various changes and modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention. It should be understood that improvements and the like can be added.

Experimental Example 1 As a raw material, magnesium hydroxide was used as a magnesia source material, and titania (rutile flower) and calcined alumina were used as a titania source material and an alumina source material, respectively, and silicate glass powder was used as an anti-digestive agent. , Monoaluminum phosphate, and basic aluminum lactate were blended at a blending ratio shown in Table 1 below (however, magnesium hydroxide is converted into magnesia), and then polyvinyl as a binder was blended. Alcohol was added together with water, kneaded, and then molded in a briquette machine, and the resulting molded product was dried at a temperature of 150 ° C. for 10 hours, and then at a temperature of 1600 ° C. in a rotary kiln. Various clinker (baked product) was obtained by baking. Then, with respect to various clinker made of the obtained fired product, respective properties, namely apparent porosity, digestion resistance, spalling resistance and slag (infiltration) resistance were examined, and the results are shown in Table 1 below. Also shown.

The apparent porosity in the characteristic evaluation of the clinker is a physical property of particles obtained by pulverizing the clinker obtained by firing and sieving the clinker to 3.35-1.70 mm, according to JIS-R- It was obtained by measuring in accordance with 2205, and has a digestion resistance of 45 μm.
The following particles are used and are shown as the rate of weight increase after they have been autoclaved in steam at a pressure of 3 atmospheres and a temperature of 131 ° C. for 3 hours. 2.80 mm when the operation of throwing into water after repeating for 30 minutes by using particles of 3.35 to 2.80 mm for 30 minutes at a temperature of 1000 ° C.
It is shown as the following powder generation rate (pulverization rate).

The slag resistance is 60% by weight of particles of 1 mm or less of each clinker, and mill powder (45 μm).
40% by weight of clinker powder of m or less) is kneaded with an aqueous solution of polyvinyl alcohol, and then molded into a predetermined shape, which is obtained by firing at a temperature of 1650 ° C. On the fired product of such a molded body, a slag having a composition of iron: 60% by weight, lime: 30% by weight, and silica: 10% by weight is placed,
It is shown as the result of evaluation by the slag infiltration depth (mm) obtained by performing the slag infiltration experiment under the condition of 1600 ° C. × 2 hours.

[0042]

[Table 1]

As is clear from the results of Table 1, the sample No. In No. 1, the clinker obtained is inferior in digestion resistance because the raw material composition in which the anti-digestion ingredient is not blended is adopted. On the contrary,
Sample No. In the case of 2 or less, the digestion resistance of the obtained clinker is improved because the digestion-preventing component such as silicate glass powder is mixed. Further, regarding silicate glass powder and monoaluminum phosphate, the digestion resistance is slightly improved by increasing the addition amount, but the apparent porosity, spalling resistance, and slag resistance are reduced. In addition, it is recognized that with respect to basic aluminum lactate, any of the digestion resistance, apparent porosity, spalling resistance and slag resistance is improved by increasing the addition amount thereof.

Experimental Example 2 As the clinker raw material, magnesium hydroxide, titania, calcined alumina, and silicate glass powder similar to those in Experimental Example 1 were used, and iron (III) oxide was further added as an additive.
(Fe ₂ O ₃ ), chromium oxide (III) (Cr ₂ O ₃ ), or baddelite (zirconium oxide) was mixed in various mixing ratios shown in Table 2 below, and then fired in the same manner as in Experimental Example 1. Then, various clinker was obtained. Then, the obtained various clinker was evaluated for apparent porosity, digestion resistance, spalling resistance, and slag resistance in the same manner as in Experimental Example 1, and the results are also shown in Table 2 below. .

[0045]

[Table 2]

As is clear from the results in Table 2, sample No. containing iron (III) oxide, chromium (III) oxide, or baddelite was added. In Sample Nos. 9 to 15, sample Nos. It is recognized that it exhibits digestion resistance, spalling resistance, and slag resistance that are as high as or higher than those of No. 8.

[0047]

As is clear from the above description, in the magnesia-titania-alumina clinker according to the present invention, the main component is magnesia having excellent corrosion resistance, to which titania and alumina are added, and further, , Glass component, phosphoric acid or phosphate, and basic aluminum lactate are mixed to form one or two or more, thereby effectively preventing the digestion of magnesia, and the digestion resistance of the obtained clinker. Was significantly improved,
Further, by further blending one or more of iron oxide, chromium oxide, and zirconium oxide,
A basic refractory raw material having excellent digestion resistance, corrosion resistance, spalling resistance, and slag resistance could be realized.

Further, even the refractory obtained by using such a clinker inherits the characteristics of the clinker as a raw material as it is, and therefore it is excellent not only in corrosion resistance but also in digestion resistance, spalling resistance and slag resistance. From the point of exhibiting characteristics, as refractory in various applications, for example, molten steel containers and refining furnace containers, or refractory for linings such as firing kilns, or amorphous refractory such as castables and spraying materials, It will be advantageously used as a basic refractory material suitably used as a repair material and the like.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Nakamoto             4 Itochu, 11 Shiogusa-cho, Seto City, Aichi Prefecture             Within LATEC Co., Ltd. (72) Inventor Toyoyasu Obana             4 Itochu, 11 Shiogusa-cho, Seto City, Aichi Prefecture             Within LATEC Co., Ltd. (72) Inventor Masato Mori             4 Itochu, 11 Shiogusa-cho, Seto City, Aichi Prefecture             Within LATEC Co., Ltd. F-term (reference) 4G030 AA07 AA16 AA17 AA22 AA27                       AA36 AA37 AA41 AA67 BA25                       CA01 GA04 GA09 GA14 GA22                       GA27                 4K051 BE03

Claims (5)

[Claims] 1. A glass component, phosphoric acid or phosphoric acid or 100 parts by weight of a composition giving a chemical composition of 25 to 95% by weight of magnesia, 2 to 50% by weight of titania, and 3 to 73% by weight of alumina. One or two or more of phosphate and basic aluminum lactate are blended in a proportion of 0.2 to 10 parts by weight, which is a fired product obtained by firing. Magnesia-titania-
Alumina-based clinker. 2. The magnesia-titania-alumina clinker according to claim 1, wherein the basic aluminum lactate contains polyethylene glycol and / or monoethanolamine. 3. The magnesia-titania-alumina clinker according to claim 1, wherein the basic aluminum lactate contains silica. 4. One or more of iron oxide, chromium oxide and zirconium oxide is further blended in a ratio of 0.2 to 10 parts by weight with respect to 100 parts by weight of the composition. The magnesia of any one of claims 1 to 3, wherein a composite spinel is formed.
Titania-alumina clinker. 5. A refractory material comprising the magnesia-titania-alumina clinker according to any one of claims 1 to 4 as a refractory material.