JP2020019684A - Galling repair material - Google Patents

Abstract

To provide a galling repair material capable of securing sufficient flowability.SOLUTION: In a galling repair material containing pitch of 5 mass% to 40 mass% and a flow assistant of 1 mass% and 20 mass% in 100 mass% of a fireproof material, the flow assistant contains a first flow assistant which is at least one of p-cumylphenol, cyclohexanone oxime, fluorene and dehydroacetic acid, and a second flow assistant which is at least one of p-tert-octylphenol, caprolactam and thymol, content of the first flow assistant is 50 mass% or more and less than 100 mass%, and content of the second flow assistant of over 0 mass% and 50 mass% or less as percentage in 100 mass% of the flow assistant.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a baking repair material for repairing various smelting furnaces and vessels.

As a method of repairing refractory lining such as various refining furnaces and containers, baking repair method in which a repair material made of irregular shaped refractory is put in, melted and solidified by residual heat of the repaired part, and locally damaged parts are repaired There is. The mainstream of baking repair materials used in baking repair methods is a mixture of a refractory material such as a basic refractory aggregate and a pitch that forms a carbon bond and a flow aid that promotes the spread of the material during heating. It is. The properties required for baking repair materials are that they have good fluidity (spreadability), have excellent adhesion to the repaired body and form a strong repaired body, and the time required for melting, bonding, and solidification ( Combustion time) is short.
Therefore, research and development of baking repair materials satisfying these required characteristics have been progressed, and as one of them, baking repair materials in which P-alkylphenol is added as a flow aid are disclosed in Patent Document 1.

Japanese Patent No. 4044151

However, as a result of investigations by the present inventors, when only p-tert-octylphenol, which is one type of P-alkylphenol described in Patent Literature 1, is added as a flow aid, the phase of p-tert-octylphenol and pitch is reduced. It was found that there was a problem that sufficient solubility could not be secured due to low solubility, and a strong repaired construction could not be formed.
Therefore, an object of the present invention is to provide a baking repair material capable of securing sufficient fluidity.

According to one aspect of the present invention, the following baking repair material is provided.
In a baking repair material containing a pitch of 5% by mass or more and 40% by mass or less and a flow aid of 1% by mass or more and 20% by mass or less with respect to 100% by mass of the refractory material,
The flow aid is a first flow aid that is at least one of paracumylphenol, cyclohexanone oxime, fluorene, and dehydroacetic acid;
a second flow aid that is at least one of p-tert-octylphenol, caprolactam and thymol;
The content of the first flow aid is 50% by mass or more and less than 100% by mass, and the content of the second flow aid is more than 0% by mass and 50% by mass in 100% by mass of the flow aid. % Or less.

  The flow aid to be added to the baking repair material of the present invention is a first flow aid which is at least one of paracumylphenol, cyclohexanone oxime, fluorene and dehydroacetic acid, and at least one of p-tert-octylphenol, caprolactam and thymol. When the second flow aid is included, the first flow aid has a high compatibility with the pitch, and the second flow aid has a low compatibility with the pitch. That is, at the time of baking repair, the first flow aid is compatible with the pitch, but the second flow aid is not compatible with the pitch, and is separated as a liquid layer on the surface side of the baking repair construction. Then, the liquid layer composed of the second flow aid separated without being insoluble is vaporized, and the heat of vaporization suppresses a rapid rise in temperature of the baked repair material, and as a result, the fluidity of the baked repair material is reduced. Is suppressed, so that sufficient fluidity can be secured.

The conceptual diagram which shows the effect | action of the baking repair material of this invention.

  The baking repair material of the present invention contains 5% to 40% by mass of the pitch and 1% to 20% by mass of the flow aid with respect to 100% by mass of the refractory material.

  The refractory material applied to the present invention is not particularly limited, and an appropriate material suitable for the base material applied to the repaired portion can be applied. For example, acidic oxides such as silica, zircon, and zirconia; neutral oxides such as alumina and chromia; basic oxides such as magnesia, calcia, and dolomite; and non-oxides such as carbon materials, silicon carbide, and silicon nitride. Or one or more of these. In addition, it is also possible to apply at least one of a metal powder, an inorganic binder and a fiber. In the present invention, at least one of the metal powder, the inorganic binder, and the fiber is included in the refractory material. The particle size composition of the refractory material may be the same as that of a normal baking repair material.

The pitch is added in an amount of 5% by mass to 40% by mass with respect to 100% by mass of the refractory material. If the added amount of the pitch is less than 5% by mass, the fluidity decreases, and if it exceeds 40% by mass, the burning time becomes longer. The preferable addition amount of the pitch is 10% by mass or more and 25% by mass or less based on 100% by mass of the refractory material.
As the pitch, a pitch generally applied to a baking repair material can be applied, but from the viewpoint of storage property and fluidity, it is preferable to use a pitch having a softening point of 100 ° C. or more and 300 ° C. or less.

  The flow aid is added in an amount of 1% by mass to 20% by mass with respect to 100% by mass of the refractory material. If the addition amount of the flow aid is less than 1% by mass, the fluidity decreases, and if it exceeds 20% by mass, the compactness of the construction after baking repair construction decreases, and a strong repair construction body cannot be formed. A preferable addition amount of the flow aid is 2% by mass to 15% by mass with respect to 100% by mass of the refractory material.

The present invention is characterized in that a first flow aid and a second flow aid are used in combination as flow aids.
The first flow aid added in the present invention is at least one of paracumylphenol, cyclohexanone oxime, fluorene, and dehydroacetic acid, and has a property of being highly compatible with pitch. On the other hand, the second flow aid added in the present invention is at least one of p-tert-octylphenol, caprolactam, and thymol, and has a property of low compatibility with pitch.
Here, "high compatibility with pitch" means that the pitch and the flow aid are mixed at a ratio of 2: 1 and are not separated from the pitch when visually observed after 1 hour in a state of being heated at 120 ° C. Means that two layers are formed, and the compatibility with the pitch is low. When the pitch and the flow aid are mixed at a ratio of 2: 1 and heated at 120 ° C. for 1 hour, the pitch is visually observed after 1 hour. And that separation occurs.

As described above, when the first flow aid having high compatibility with the pitch and the second flow aid having low compatibility with the pitch are used in combination, as shown in FIG. At the time of construction, the first flow aid is compatible with the pitch, but the second flow aid has a low compatibility with the pitch and separates as a liquid layer on the surface side of the baked repaired body (second Since the flow aid has a lower specific gravity than the compatible layer in which the pitch and the first flow aid are compatible, the second flow aid separates as a liquid layer on the surface side of the baked repair construction body.) . Then, the separated liquid layer composed of the second flow aid vaporizes, and the heat of vaporization suppresses a rapid rise in temperature of the baked repair material. As a result, a decrease in the fluidity of the baking repair material is suppressed, and sufficient fluidity can be secured.
In addition, such a temperature rise suppression effect (fluidity decrease suppression effect) due to heat of vaporization of the second flow aid becomes more remarkable as the temperature of the repaired part at the time of baking repair construction is higher than 1000 ° C. . That is, as the temperature of the repaired part is higher, the temperature of the baked repair material (fluidity decrease) proceeds more rapidly due to the heat received from the repaired part. The rapid rise in temperature of the baked repair material is suppressed by the heat of vaporization, and as a result, a decrease in the fluidity of the baked repair material is suppressed. Generally, the temperature of the repaired part at the time of baking repair work is about 800 to 1300 ° C., but the present invention is particularly effective when the temperature of the repaired part is 1100 ° C. or more.

In the present invention, the content of the first flow aid and the content of the second flow aid are percentages in 100% by mass of the flow aid, and the content of the first flow aid is 50% by mass to 100% by mass. And the content of the second flow aid is more than 0% by mass and 50% by mass or less. If the content of the second flow aid having low compatibility with the pitch exceeds 50% by weight in 100% by weight of the flow aid, the flowability of the baking repair material as a whole decreases.
The preferred content of the first flow aid and the second flow aid is a percentage in 100% by mass of the flow aid, and the content of the first flow aid is 50% by mass or more and 95% by mass or less, The content of the second flow aid is 5% by mass or more and 50% by mass or less.
The more preferable content of the first flow aid and the second flow aid is a ratio in 100% by mass of the flow aid, and the content of the first flow aid is 60% by mass or more and 85% by mass or less. And the content of the second flow aid is 15% by mass or more and 40% by mass or less.

  In the present invention, a flow aid other than the first flow aid and the second flow aid is used as long as the above-mentioned effects obtained by the combined use of the first flow aid and the second flow aid are not impaired. Agents can be used in combination. For example, at least one of acetoacetic anilide, acetanilide, p-tert-butylphenol and p-tert-pentylphenol can be used in combination.

  The baking repair material of the present invention can be obtained by an ordinary method for producing a baking repair material, in which pitch and a flow aid are added to a refractory material and mixed or kneaded. Further, the baking repair material of the present invention is applied to refractory linings such as various refining furnaces and vessels, and is melted and flowed by residual heat in the furnace or the vessel to repair the repaired portion (damaged portion). It can be applied to normal baking repair method.

  First, the compatibility between various flow aids and pitch was evaluated. As described above, this compatibility was evaluated by mixing the pitch and the flow aid at a ratio of 2: 1 and heating the mixture at 120 ° C. for 1 hour. It went by whether it became. As a result, it was confirmed that paracumylphenol, cyclohexanone oxime, fluorene, and dehydroacetic acid, which were the first flow aids, did not separate from the pitch but formed one layer, and were compatible with the pitch. On the other hand, it was confirmed that p-tert-octylphenol, caprolactam, and thymol, which are the second flow aids, all separated from the pitch and had low compatibility with the pitch.

  Next, baking repair materials were prepared according to the composition shown in Table 1, and each evaluation described later was performed. Note that magnesia was used as the refractory material and a material having a specific gravity of 3 was used. Further, a pitch having a softening point of 110 ° C. was used.

  Regarding the evaluation, 400 g of the baking repair material composition of each example in Table 1 was put into a refractory (repaired portion) installed in an experimental furnace maintained at a temperature of about 1200 ° C., and baking repair work was performed. Was evaluated for fluidity, burning time and compactness. And comprehensive evaluation was performed from these evaluations. The outline of each evaluation is as follows.

[Liquidity]
The area of the construction body after the completion of baking was determined, and evaluated by an index with the area of Comparative Example 1 being 100. The higher the fluidity index, the better the fluidity. Specifically, the case where the liquidity index was more than 105 was evaluated as ○ (good), the case where the liquidity index was more than 100 and 105 or less was evaluated as Δ (acceptable), and the case where the liquidity index was 100 or less was evaluated as × (improper) .
[Burning time]
After the baking repair work, the time until smoke generation due to the burning of the pitch was completed was defined as the burning time, and the burning time of Comparative Example 1 was evaluated as an index with 100 as the burning time. The smaller the burning time index is, the shorter the burning time is. Specifically, the case where the burning time index was less than 95 was evaluated as （(good), the case where the burning time index was 95 or more and less than 100 was evaluated as Δ (acceptable), and the case where the burning time index was 100 or more was evaluated as x (impossible).
[Denseness]
The porosity of the construction body after the completion of baking was evaluated. The porosity was measured according to JIS-R2205-1992. Specifically, the case where the porosity is less than 30% is indicated by ○ (good), the case where the porosity is 30% or more and less than 32% is indicated by Δ (acceptable), and the case where the porosity is 32% or more is indicated by × (impossible). did.
[Comprehensive evaluation]
When all the evaluations were ○, △, when any of the evaluations did not have ×, and when Δ included, △, when any one of the evaluations was ×, ×, when the overall evaluation was ○ or △ Pass, the case where the comprehensive evaluation is x is judged as reject.

  In Table 1, Examples 1 to 12 are examples in which the first flow aid and the second flow aid were used together within the scope of the present invention, and only the first flow aid was added as the flow aid. As compared with Comparative Example 1, the fluidity was excellent, and as a result, the burning time was short, and the overall evaluation was at a pass level.

As described above, Comparative Example 1 was an example in which only the first flow aid was added as a flow aid, and the flowability was not sufficient, and as a result, the burning time was prolonged.
Comparative Example 2 is an example in which only the second flow aid was added as a flow aid, and Comparative Example 3 was an example in which the amount of the second flow aid added was excessive. It became longer.
Comparative Example 4 was an example in which the flow aid was added in an excessive amount, and the compactness was reduced.
Comparative Example 5 was an example in which no flow aid was added, and the fluidity was lowered and the burning time was prolonged.
Comparative Example 6 was an example in which the amount of pitch added was too small, did not form a body as a baking repair material, and could not be evaluated.
Comparative Example 7 was an example in which the amount of pitch added was excessive, and the burning time was long and the compactness was not sufficient.

  In the above Examples 1 to 12, the minimum amount of the pitch added is 10% by mass. Can solve the problem of the present invention even if it is reduced to 5% by mass.

According to one aspect of the present invention, the following baking repair material is provided.
In a baking repair material containing a pitch of 5% by mass or more and 40% by mass or less and a flow aid of 1% by mass or more and 20% by mass or less with respect to 100% by mass of the refractory material,
The flow aid is a first flow aid that is at least one of paracumylphenol, cyclohexanone oxime, fluorene, and dehydroacetic acid;
a second flow aid that is at least one of p-tert-octylphenol, caprolactam and thymol;
The content of the first flow aid is 50% by mass or more and 97.5% by mass or less , and the content of the second flow aid is 2.5 % by mass in 100% by mass of the flow aid. %, And not more than 50% by mass.

Claims (3)

In a baking repair material containing a pitch of 5% by mass or more and 40% by mass or less and a flow aid of 1% by mass or more and 20% by mass or less with respect to 100% by mass of the refractory material,
The flow aid is a first flow aid that is at least one of paracumylphenol, cyclohexanone oxime, fluorene, and dehydroacetic acid;
a second flow aid that is at least one of p-tert-octylphenol, caprolactam and thymol;
The content of the first flow aid is 50% by mass or more and less than 100% by mass, and the content of the second flow aid is more than 0% by mass and 50% by mass in 100% by mass of the flow aid. % Or less.   The content of the first flow aid is 50% by mass or more and 95% by mass or less, and the content of the second flow aid is 5% by mass or more and 50% by mass in 100% by mass of the flow aid. %. The baking repair material according to claim 1, which is less than or equal to%.   The content of the first flow aid is 60% by mass or more and 85% by mass or less, and the content of the second flow aid is 15% by mass or more and 40% by mass in 100% by mass of the flow aid. %. The baking repair material according to claim 1, which is less than or equal to%.

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