JP6188214B2 - Wet construction repair agent and repair method - Google Patents

Description

  The present invention is applicable to repairing castable refractories and bricks for steel and coke oven furnace plates, various industrial furnaces (incinerator kilns, fluidized bed boiler cyclones, heating furnaces, etc.) at room temperature to low temperature. The present invention relates to a repair agent for wet construction and a repair method thereof.

Conventionally, as a method of lining or repairing furnace walls of various industrial furnaces, a method (cold construction) in which operation is temporarily stopped and repair work is performed in an atmosphere at a room temperature to a low temperature is generally used. Moreover, the method of repairing without stopping operation like a steel and coke oven is called hot construction.
Application of cold construction is limited to construction that uses a large amount of moisture (semi-dry type, wet type), but this includes spraying construction and pouring construction, as well as coating construction that performs partial small-scale construction. Yes.
On the other hand, since hot construction has a risk that a large amount of water may cause a steam explosion, it is limited to construction using only a small amount of water (dry type, semi-dry type), and spraying and coating are mainly used.

Spray construction includes dry construction methods (dry construction methods), semi-dry construction methods (semi-dry construction methods), and wet construction methods (wet construction methods), but dry construction is mainly performed only by hot construction. .
Such dry spray construction methods have problems such as poor work environment due to reband loss and dust generation, as well as poor durability of the construction body.

In addition, the semi-dry spraying method is a method in which a part of the required construction moisture amount is kneaded with a spraying material and a mixer in advance by air transportation to the spraying nozzle, and the remaining water or curing agent is added and sprayed in the nozzle. It is a construction method.
This construction method has some improvement in terms of preventing dust generation and reducing reband loss, but basically the water and material must be mixed instantaneously at the nozzle, so the degree of mixing is good. Rather, the amount of water is likely to fluctuate. As a result, the adherence of the spray material, the homogeneity and the filling property of the construction body are poor, and the construction body structure is non-uniform.

The wet spraying method is a construction method in which all of the required construction moisture amount is previously kneaded with the spraying material and sprayed with a spraying machine or a pump.
Conventional examples of this construction method include those disclosed in Patent Document 1, Patent Document 2, Patent Document 3, and the like. In any of these, the kneaded material is not room temperature curable, the compactness of the construction structure is inferior, and the durability is considerably poor.
In the construction method described in Patent Document 4, a small amount of an alkali silicate solution is added to the surface of the kneaded product to improve shape retention and adhesion. However, in these conventional examples, emphasis is placed on the denseness and compressive strength of the construction body structure, and there is almost no adhesive strength, and in fact, it is only attached to the uneven portion.

On the other hand, the pouring method is a method of pouring all of the necessary construction moisture amount in advance with the spraying material into the mold as in the wet spraying method. The repair agent used in this method is mainly composed of alumina cements, and in most cases, it takes a time of one day or longer for drying and curing.
As a conventional example of the pouring method, there is one described in Patent Document 5. In this method, a gas is generated by an organic foaming agent or foaming aid to form a vent in the structure of the molded body, but this is intended to reduce the risk of explosion due to the deaeration.
In addition, application | coating construction is the repair method which levels with a trowel etc. using a wet spraying material or a pouring material.

As described above, in these conventional dry to wet spraying methods, the main focus of the invention is on the denseness and compressive strength of the structure of the construction body, and in particular there is almost no adhesive strength, and in fact it adheres to the uneven parts. It ’s just that.
In addition, conventional casting materials using various inorganic materials place importance on strength, corrosion resistance, and wear resistance, and particularly emphasize compressive strength, bending strength, and hot strength. On the other hand, the adhesive strength is weak, and it is indispensable to install reinforcing bars such as anchor bolts in order to prevent the enforcement body from falling as a large lump.

The only conventional example that focuses on adhesive strength is the hot / dry construction method, which is described in Patent Document 6.
This method is a method of repairing a hearth of a coke oven carbonization chamber by laying a powdery repairing agent containing a fine powdered frit and a granular low melting point compound.

Japanese Examined Patent Publication No. 62-21753 Japanese Patent Publication No. 2-33365 Japanese Patent Publication No.2-1795 Japanese Patent Laid-Open No. 9-315872 Japanese Examined Patent Publication No. 6-31177 JP 2007-145890 A

However, when adding an alkali silicate solution to a conventional powdery repair agent such as Patent Document 6 and attempting to perform wet construction, gelation and curing start simultaneously with mixing, and thus it is impossible to perform normal wet construction. is there. Therefore, when performing wet construction using such a repairing agent, after the repairing agent is spread to a thickness of 1 cm, an alkali silicate solution is dropped on the surface of the repairing agent and allowed to penetrate and cure.
However, in this dropping method, since the penetration thickness of the alkali silicate solution is limited, there is a defect that the adhesive strength is greatly influenced by the unevenness of the uneven surface and the thickness of the powdery repair agent, and a large amount of thick repair cannot be performed at once. Therefore, the workability is extremely bad and it is not practical.

By the way, the plate in front of the coke oven usually has a surface temperature of room temperature to 60 ° C. However, when a coke is taken out, a part of the burning coke falls on the plate, so it is suddenly exposed to a high temperature. It is put on and cooled rapidly.
Thus, the coke oven front plate is severely damaged due to repeated severe conditions of this rapid heating-cooling cycle. High adhesive strength and durability required in a wide temperature range are not realized.

  In addition, the above conventional repair agent for wet construction is not room temperature curable but inferior in the compactness of the construction body structure, and its durability is considerably poor. In addition, the emphasis is placed on the compactness and compressive strength of the structure of the construction body. In particular, there is almost no adhesion strength, and in fact, it is only attached to the rugged portion. It is necessary to weld reinforcing bars such as anchor bolts.

  On the other hand, when the alkali silicate solution is added, curing is accelerated, but when a large amount is added, it is cured too quickly, so that workability is poor, and adhesive strength and hot strength are deteriorated. This is because gelation of the alkali silicate solution abruptly occurs from the beginning of mixing, and gelation ends at the end of mixing, and the gelled product is mixed and pulverized. In addition, regarding the addition of a large amount of an alkali silicate solution, it is considered that sodium (Na) and potassium (K) components are particularly harmful to hot strength and corrosion resistance.

  As described above, at present, the adverse effects of such alkali silicate solutions are eliminated, and they are dried and cured in a short time at room temperature, and achieve high compressive strength as well as high adhesive strength in a wide temperature range (room temperature to high temperature). A repair agent and a repair method that are rich in water quality have not been realized.

  The present invention has been made in view of such problems of the prior art, and an object of the present invention is to realize high adhesive strength and compressive strength in a wide temperature range from room temperature to high temperature, as well as corrosion resistance and resistance. An object of the present invention is to provide a wet construction repair agent having excellent wear resistance and a repair method thereof.

  As a result of intensive studies to achieve the above object, the present inventor uses an alkali silicate, a predetermined flux component, an alumina cement component, and an aggregate component, and appropriately adjusts the particle size and composition thereof. Thus, the inventors have found that the above object can be achieved and have completed the present invention.

That is, the repair agent for wet construction of the present invention is a fireproof composed of 15 to 45% by mass of silica having a particle size of 0.01 to 5.0 mm and 40 to 70% by mass of alumina having a particle size of 0.05 to 5.0 mm. For 100 parts by weight of a powdery component comprising 2 to 7% by mass of a fine aggregate, 2 to 7% by mass of a fine powdered frit and 1 to 4% by mass of a granular low melting point compound, and 3 to 13% by mass of alumina cement,
It is characterized by containing 10 to 25 parts by weight of a liquid component comprising an alkali silicate solution.

  Moreover, the suitable form of the repair agent for wet construction of this invention further contains water as a liquid component in a proportion of 0.5 to 15 parts by weight.

Furthermore, another preferred embodiment of the repair agent for wet construction of the present invention is a borosilicate glass in which the fine powdered frit has a particle diameter of 0.001 to 0.07 mm and a melting point of 600 to 900 ° C. The melting point compound is boric acid and / or boron oxide having a particle diameter of 0.1 to 1 mm,
The ratio of these average particle diameters (granular low melting point compound / fine powder frit) ≧ 10.

Furthermore, in another preferred embodiment of the repair agent for wet construction according to the present invention, the alkali silicate solution is a sodium silicate solution or a potassium silicate solution, and a SiO ₂ / R ₂ O (R is alkali metal) molar ratio is 3 to 3. 4 and the solid content (SiO ₂ + R ₂ O (R is an alkali metal)) concentration is 30 to 40% by mass.

Further, the repair method of the present invention comprises mixing the powdery component and the liquid component of the wet construction repair agent as described above, and adding the obtained wet construction repair agent to room temperature to 100 ° C. within one hour from the start of mixing. It is characterized in that it is applied to the target refractory and dried and cured in 1 to 1.5 hours.

  According to the present invention, an alkali silicate, a predetermined flux component, an alumina cement component, and an aggregate component are used, and the particle size and composition thereof are appropriately adjusted, so that the temperature is high in a wide temperature range from room temperature to high temperature. It is possible to provide a repair agent for wet construction that achieves adhesive strength and compressive strength, and has excellent corrosion resistance and wear resistance, and a repair method thereof.

It is a side view and perspective view explanatory drawing which shows an example of preparation of a repair agent, and a construction method. It is perspective explanatory drawing which shows the test method of the adhesion | attachment and compressive strength of a repair agent.

Hereinafter, the repair agent for wet construction of the present invention will be described.
The repair agent for wet construction of the present invention does not cure immediately even when a large amount of alkali silicate solution is added, and typically cures in a short time (about 1 to 1.5 hours) after mixing and construction. It is what adjusted the particle size and blending of the adhesive component of the flux and alkali silicate, the alumina cement component and the refractory aggregate component, and can eliminate the adverse effects of adding the alkali silicate solution, Moreover, in a wide temperature range from room temperature to high temperature, it achieves high adhesion, high strength and durable repair (forms a construction body).

In the repair agent for wet construction of the present invention, the alkali silicate is present alone at a low temperature, but is highly reactive at a high temperature (about 600 ° C. or higher), and immediately surrounding components (a base material that is a refractory to be repaired) It causes a chemical reaction with (the object to be repaired) and the silica and alumina components in the construction body and other binder components.
Since this reaction product changes to a high melting point material with the passage of temperature, time, and number of days, a construction body having high adhesion, high strength and high durability is formed.

As described above, the repair agent of the present invention contains 10 to 25 parts by weight of a liquid component composed of an alkali silicate solution with respect to 100 parts by weight of a powdery component.
And said powdery component is refractory aggregate which consists of 15-45 mass% of silica whose particle diameter is 0.01-5.0 mm, and 40-70 mass% of alumina whose particle diameter is 0.05-5.0 mm. And a flux composed of 2 to 7% by mass of fine powdered frit and 1 to 4% by mass of a granular low melting point compound, 3 to 13% by mass of alumina cement, and optionally water 0.5 to 15% Part by weight can be added as a liquid component.
In the present application, the numerical range of the “particle diameter” means that the target particle passes through a sieve having an opening corresponding to the upper limit and does not pass through a sieve having an opening corresponding to the lower limit. To do.

Here, silica (SiO ₂ ) in the powdery component is a constituent powder, and the particle size diameter of SiO ₂ is in the range of 0.01 to 5.0 mm, preferably 0.05 to 3.0 mm. Although it is a range and it does not specifically limit, Silica stone powder, 3-7 cinnabar sand, and chamotte powder can be mentioned as a suitable specific example.

Alumina (Al ₂ O ₃ ) is a powder that is a constituent component together with SiO ₂ , and the particle diameter of Al ₂ O ₃ is in the range of 0.05 to 5.0 mm, preferably 0.15 to 3. Although it is in the range of 5 mm and is not particularly limited, calcined bauxite, electrofused alumina and sintered alumina are preferred.

The particle diameters of silica and alumina are in the range of 0.01 to 5.0 mm and 0.05 to 5.0 mm, respectively. However, if the particle diameter is too small than the lower limit of this range, the specific surface area increases. Since the packing density becomes small (porosity becomes high and porous) and the adhesive component is diluted (decreased), the strength of the entire repair agent layer is likely to be lowered.
That is, when the specific surface area of the repair agent is increased, the adhesive (binder) component, particularly the fine frit of the fine powder is easily diluted in the repair agent, and the expected strength of the entire repair agent layer cannot be obtained. It is not preferable to improve the strength by increasing the amount of the adhesive component because shrinkage and cracks are likely to occur after firing. On the other hand, if the particle size is too larger than the upper limit of the above range, the packing density increases due to the reduction of the specific surface area, but the surface of the construction body tends to be uneven, which is not preferable.

Next, the fine powdered frit is a flux that functions as a powdery adhesive component, and is a well-known borosilicate glass (SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ , CaO, Na _2). O, K ₂ O, etc.), zircon glass to which ZrO is further added, and glass in which MgO, SrO, BaO, etc. are blended with borosilicate glass, particle diameter is 0.001 to 0.07 mm, melting point Borosilicate glass having a temperature of 600 to 900 ° C. can be preferably used.

  The granular low melting point compound is also a flux functioning as a powdery adhesive component, and boric acid and / or boron oxide is preferable, but is not particularly limited and contains a large amount of boric acid and / or boron oxide. A compound having a similar melting point may be used, and boric acid and / or boron oxide having a particle diameter of 0.1 to 1 mm can be preferably used.

Furthermore, the alumina cement is a general product and is not particularly limited, but JIS No. 1 is suitable. Typical chemical composition, SiO ₂ 0-10 wt%, CaO 20 to 40 wt%, _Al 2 _{O 3} 40 to 80 wt%, _Fe 2 _{O 3} is 0 to 20 wt%.

On the other hand, the alkali silicate solution in the liquid component functions as a liquid adhesive component. Specifically, a sodium silicate solution or a potassium silicate solution can be preferably used.
Moreover, it is preferable to use one having a SiO ₂ / R ₂ O (R is alkali metal) molar ratio of 3 to 4 and a solid content (SiO ₂ + R ₂ O (R is alkali metal)) concentration of 30 to 40% by mass. can do. In particular, No. 3-5 water glass which is a general-purpose sodium silicate solution is preferable.

In the repair agent for wet construction of the present invention, the particle size and the average particle size of the frit and the low-melting-point compound constituting the powdery adhesive component as described above are each 0.005 to 0.05 mm (average particle size is 0.00. 02 to 0.04 mm) and 0.2 to 0.8 mm (average particle diameter of 0.4 to 0.6 mm).
The ratio of the average particle diameters is preferably (granular low melting point compound / fine powder frit) ≧ 10.

In this way, by providing a difference of 10 times or more to the average particle diameter of the two types of powdery adhesive components, the two types of components can be separately arranged in the repairing agent, and this is a factor governing the adhesiveness. Two types of physical properties such as melting point and high temperature viscosity (viscosity, stickiness, fluidity, and permeability at high temperature melting) can be exhibited separately, and the advantages of both properties can be brought out in a wide temperature range. .
In other words, when the particle sizes of the two types of adhesive components are similar, the repair agent acts as one type of component that exhibits intermediate physical properties between the two types of components, and can be applied only in a narrow temperature range. On the other hand, when the particle sizes of the two types of adhesive components are clearly different, two types of physical property peaks can be formed into twin peaks.
The low melting point compound functions as an adhesive in a low temperature to medium temperature range, and the frit functions as an adhesive in a medium temperature to high temperature range. As the low melting point compound, a compound having a clearly lower melting point, lower viscosity at high temperature, and higher permeability than frit is preferably selected, and in this respect, compounds containing boric acid and / or boron oxide as a main component are selected. Can be preferably used.

In the repair agent for wet construction of the present invention, the alkali silicate solution constituting the liquid adhesive component gradually undergoes a gelling / curing reaction upon contact with two types of powder adhesive components, particularly low melting point compounds. .
The alkali silicate solution exhibits the effect of increasing the curing rate, and greatly affects the improvement of the adhesive strength and the compressive strength from the room temperature range to the high temperature range. In general, the curing speed is slow better low _{SiO 2} / _R 2 O molar ratio described above, it is fast _{SiO 2} / _R 2 O molar ratio is larger.

In the present invention, those having a molar ratio of 3 to 4 are preferably used. The gelling / curing reaction is also related to the amount of the two powdered adhesive components, particularly the low melting point compound, and the larger the amount, the faster the curing speed.
The curing rate of the repair agent of the present invention is typically about 1 hour at maximum as a quality retention time when mixing at room temperature of a cement mixer, etc., and about 1-1. The target is 5 hours (construction amount, construction thickness, and range depending on ambient temperature conditions).

For example, in the case of a compound represented by sodium silicate Na ₂ O.nSiO ₂ (n = 3), the gelation / curing reaction of the alkali silicate solution is caused by hydrolysis of a part of sodium silicate as shown in the following formula. It decomposes into caustic soda and silicate sol.
Na ₂ O.3SiO ₂ + H ₂ O⇔NaOH + NaHSiO ₃ + 2SiO ₂
Na ₂ O.3SiO ₂ + 3H ₂ O⇔NaOH + NaHSiO ₃ + 2H ₂ SiO ₃
Further, some of them undergo hydrolysis, and NaHSiO ₃ + H ₂ O⇔NaOH + H ₂ SiO ₃
In the first stage, SiO ₂ , NaHSiO ₃ and H ₂ SiO ₃ form colloidal particles (sol), and in the second stage, these particles gather together to form a continuous structure, spread through water and gelled. It reaches.

Further, the alkali silicate solution constituting the liquid adhesive component greatly affects the improvement of the adhesive strength and the compressive strength from the low temperature range to the high temperature range. Since the alkali silicate solution is in a liquid state, it is evenly distributed throughout the repair agent when mixed, and when sprayed, applied, or poured, it partially penetrates the base material and surrounding refractory before gelling, drying, and curing. And contributes to the adhesive strength and compressive strength in the room temperature to low temperature range. At that time, most of the two powdery adhesive components are present in the construction body, but a very small amount penetrates into the base material and the surrounding refractory.
When the temperature is raised after drying / curing, the alkali silicate solution undergoes a curing reaction due to gelation in the room temperature to medium temperature range, but in the medium temperature to high temperature range, it exists in the vicinity of the base material, the surrounding refractory, and the construction body. It causes chemical reaction with almost all components including SiO ₂ , Al ₂ O ₃ , CaO, MgO and the like and changes to a high melting point compound, which contributes to adhesive strength and compressive strength.

As described above, the two powdery adhesive components act in the low temperature to medium temperature range and the medium temperature to high temperature range, respectively, and contribute to the adhesive strength and compressive strength.
That is, the main role of the above three types of adhesive components is that the liquid adhesive component (alkali silicate solution) is in the room temperature to high temperature range, the low melting point compound is in the low temperature to medium temperature range, and the frit is adhesive strength and compression in the medium temperature to high temperature range. It contributes to strength.

Alumina cement is a strength strengthener, and contributes mainly to compressive strength in the drying / curing reaction at room temperature and in all temperature ranges after the temperature rise.
Silica and alumina are aggregate powders that are the main components of the repair agent, and affect the physical properties such as crack prevention, low shrinkage and wear resistance, as well as the adhesive strength and compressive strength of the construction body, depending on the particle size and blending amount. .

  In the present invention, by using the silica particles and alumina particles having the above predetermined particle diameter and blending amount as the refractory aggregate which is the main component of the powdery component, frit, low melting point compound, alumina cement, alkali silicate solution, etc. The physical properties (melting point, high temperature viscosity, strength strengthening property, permeability, gelation / drying / curing property) can be effectively and maximized.

Further, by selecting the refractory aggregate in this way, the disadvantages (hot strength, corrosion resistance) of the alkali silicate solution can be rendered harmless in a short time.
That is, the alkali component of the alkali silicate solution is generally said to have an adverse effect on the hot strength and corrosion resistance, but in the middle to high temperature range, the nearby SiO ₂ existing in the base material, the surrounding refractory and the construction body. , Al ₂ O ₃ , CaO, MgO, etc., and chemical reaction with almost all components to gradually increase the melting point, some alkali components evaporate, the construction body structure is a high melting point compound over time It changes to.
The time required for detoxifying the disadvantages (hot strength, corrosion resistance) of the alkali silicate solution is several tens of hours in the high temperature range, depending on the temperature conditions.

Next, the repair method of the present invention will be described.
The repair method of the present invention is a method using the repair agent for wet construction described above, and the powdery component and the liquid component of the repair agent are mixed, and the resulting repair agent for wet construction is started from this mixing start. It is a method of applying to a target refractory at room temperature to 100 ° C. within 1 hour, and drying and curing in about 1 to 1.5 hours.

  Here, typically, the mixing of the powdery component and the liquid component of the repair agent may be performed immediately before the start of repair work. In addition, the refractory to be repaired is not particularly limited, and castable refractories and refractory bricks, particularly these surfaces can be mentioned.

The repair method of the present invention belongs to a wet construction method and can be applied by a pouring method, a trowel coating method, or the like. Preferably, a vertical surface construction is a pouring method, a horizontal surface construction is a trowel coating method, or an inclined surface. In the case of, it is better to select either method according to the inclination angle and the field conditions.
The repair method of the present invention can be applied to the wet spraying method, but when sprayed with a spraying machine, a pump, or the like, scattering or rebound to a part other than the predetermined part may occur. Since the repair agent of the present invention is a type that dries and cures in a short time and has a high adhesive strength type, it is preferable to avoid a wet spray method that easily causes scattering and rebound if possible.

As mentioned above, the repair agent for wet construction of the present invention can be constructed for about 1 hour from the start of mixing with a cement mixer or the like.
In addition, for a mixture of a powdery component and a liquid component, 1 to 5 parts by weight of water may be further added to 100 parts by weight of the powdery repair agent depending on the desired fluidity. it can.
When mixing is performed for 1 hour or longer, gelation progresses rapidly and drying / curing speeds up, so it is necessary to apply within 1 hour. After construction by pouring or coating, the amount of repair agent, construction thickness, mixing time, construction atmosphere temperature, etc. will vary slightly, but typically it will dry and cure in about 1 to 1.5 hours, completing the repair. .

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these Examples.

(Examples 1-7, Comparative Examples 1-6)
As shown in FIG. 1, a steel can φ75 mm of a tennis ball is cut into a square frame (59 × 59 × height h20 mm, adhesion area S = 34.8 cm ² ) and chamotte brick 2 (66 × 73 × thickness) 20mm).
Next, 20 to 27 g of a liquid component (water glass and / or water) was added to 100 g of the powdery component of each example shown in Table 1, and mixed and stirred with a drug sledge (preparation of a repair agent). The repair agent 3 was filled into the steel frame 1 after 10 minutes with light stirring every few minutes. After filling, it was naturally dried at room temperature for about 1 hour, then dried at 40 ° C. for 18 hours, then placed in an electric furnace, heated from room temperature and held at a predetermined firing temperature for 3 hours. Thereafter, it was allowed to cool overnight in an electric furnace to obtain repairs for each case. The obtained repaired product is subjected to the following physical property evaluation, and the obtained results are shown in Tables 1 and 2.

The results shown in Table 1 are the results of physical appearance evaluation such as appearance observation, shrinkage rate, adhesive strength, compressive strength, and wear resistance when the firing temperature is 900 ° C.
On the other hand, Table 2 shows the results of investigating the adhesive strength and compressive strength in a wide temperature range from a low temperature range (40 ° C., 1 day) to 300 ° C. to 1100 ° C. (3 hr holding). The size of the repair agent after high-temperature firing is about 59 × 59 × 13 mm.

Comparative Example 1 was an example in which a powdery component described in JP-A-2007-145890 was used and mixed using water glass as a liquid component, and was stopped because it was cured immediately after mixing.
Therefore, Comparative Example 2 uses the same powdery component and liquid component as Comparative Example 1, and the liquid part (half amount) is dropped (without mixing) on the surface of the powdery component (half amount: 50 g, about 1 cm thickness). Shower ring), an example in which the same operation was repeated to construct a 2 cm thickness. Since the liquid part could not completely penetrate when dripped at a thickness of 2 cm at a time, it was carried out twice with each half amount.
Comparative Example 6 is a blending example containing a large amount of alumina cement.

<Performance evaluation>
[Appearance observation]
The appearance of the repair agent after firing, particularly the state of the repair agent surface (presence or absence of cracks, blisters, or irregularities) was visually observed for relative evaluation.
Judgment criteria were as follows: ◎: very good, ○: good, △: somewhat bad, x: obviously bad.

[Shrinkage factor]
Measure the dimensions of the repair agent before and after firing at 900 ° C., that is, two points in the horizontal direction (length L) in the center of the repair agent cube and four points in the vertical direction (height h) at the same point with calipers. The average shrinkage was calculated.
Judgment criteria are ◎: L <0.5% and h <1%, ○: One of Lh is ◎ △, Δ: L = 0.5 to 1%, h = 1 to 2%, ×: L > 1% or h> 2%.

[Adhesive strength]
As shown in FIG. 2, the brick 2 and the repair agent 3 after firing are set up vertically, and a universal testing machine (maximum strength 1,000 kgf) is set so that the fulcrum is parallel along the repair agent bonding surface (brick) It was set so that the repair agent was peeled off from the surface), and the adhesive strength [kgf] was measured. The adhesion surface is about 59 × 59 mm≈34.8 cm ² .

[Compressive strength]
As shown in FIG. 2, after measuring the adhesive strength, the repair agent 3 peeled off from the surface of the brick 2 was set up vertically, and the compressive strength [kgf] was measured with a universal testing machine (maximum strength 1,000 kgf). Note that the compression surface when the adhesive surface is peeled off is approximately 59 × 13 mm≈7.67 cm ² .

[Abrasion resistance]
The repair agent after firing at 900 ° C. is cut from the brick, a cut area of a predetermined size (about 31 × 31 mm, S = 9.5 to 9.8 cm 2) is created, and this cut surface is sandpaper (P-100, 230 × 280 mm) was evaluated by performing reciprocal polishing 500 times by hand pressure.
Judgment criteria were: A: wear loss <0.5 g, O: wear loss = 0.50-0.69 g, Δ: wear loss = 0.70-0.99 g, x: wear loss ≧ 1 g.

[Workability]
Relative evaluations were made based on the work time from the mixing of the repair agent to the end of the construction and the drying / curing time from the end of the construction.
Judgment criteria were ◎: very good, ○: good, △: somewhat bad, x: obviously bad, xx: extremely bad.

[Comprehensive evaluation]
Each evaluation was relative.
Judgment criteria were as follows: ◎: very good, ○: good, △: somewhat bad, x: obviously bad.

[Test results]
As shown in Table 1, when baking at 900 degreeC, it turns out that Examples 1-7 of this invention are excellent in all the physical properties compared with Comparative Examples 1-6, and are especially excellent in adhesive strength.
As shown in Table 2, the adhesive strength and compressive strength from low temperature (40 ° C.) to high temperature (1100 ° C.) were also compared with Comparative Examples 1-6 in Examples 1-7 of the present invention in all temperature ranges. It can be seen that it has excellent strength.

<Real machine test>
Incinerator kiln (fuel kiln length: 12.5m, kiln inner diameter: 1.8m) fueled with waste oil, waste plastic, etc., construction area at room temperature, 2m behind the exit, 4m behind the exit, and near the center Repair of about 1 m ² (thickness 5 to 10 cm) was performed. On the next day, the operation was started from the burning of heavy oil, followed by a transition to normal operation and follow-up. The obtained results are shown in Table 3.

[Evaluation method]
Usually, the operation of this kiln is a hard operating condition that stops in about 30 to 45 days and repeats repairs, and in each case, the repair agent was evaluated by visual observation.
Judgment criteria were as follows: ◎: very good, ○: good, △: somewhat bad, x: obviously bad.

[Test results]
The result of having carried out an actual machine test using Examples 3, 5, and 7 and Comparative Examples 2 and 5 of the present invention is shown. Usually, it is a hard operating condition in which repair is repeated in about 30 to 45 days, but the repair agent of the present invention maintains a long-term repair effect and can be said to be a repair agent with excellent durability.

As mentioned above, although this invention was demonstrated with some embodiment and an Example, this invention is not limited to these, A various deformation | transformation is possible within the range of the summary of this invention.
For example, for silica compounds and alumina compounds that are constituents of the repair agent of the present invention, a small amount of minerals (eg, clays such as kaolin) containing silica, alumina as main components and a small amount of Mg, Ca, Fe, etc. (2 to 5% by mass) can be used even if blended.

  The repair agent of the present invention is a repair agent having high adhesive strength and compressive strength even in a wide temperature range from room temperature to high temperature, and even in rapid heating. In particular, the adhesive performance is remarkably excellent, and it is suitable for repairing a base material with little or no anchor bolt. The normal repair agent can be applied to repair a part that is easily peeled off by a large lump, and can be used for repairing a coke oven front plate or a part where the impact of fluid sand of a cyclone is severe.

1 Steel frame 2 Brick 3 Repair agent

Claims (5)

A refractory aggregate comprising 15 to 45% by mass of silica having a particle size of 0.01 to 5.0 mm and 40 to 70% by mass of alumina having a particle size of 0.05 to 5.0 mm, and a fine powdered frit 2 to 7 To 100 parts by weight of a powdered component consisting of 3 to 13% by mass of alumina cement and 3 to 13% by mass of a flux consisting of 1 to 4% by mass and granular low melting point compound
A repair agent for wet construction comprising a liquid component comprising an alkali silicate solution in a proportion of 10 to 25 parts by weight.   The wet repair agent according to claim 1, further comprising 0.5 to 15 parts by weight of water as the liquid component. The fine powder frit is a borosilicate glass having a particle size of 0.001 to 0.07 mm and a melting point of 600 to 900 ° C., and the granular low melting point compound is boric acid and / or boron oxide having a particle size of 0.1 to 1 mm. And
The ratio of these average particle diameters (granular low melting point compound / fine powdered frit) ≧ 10, The repair agent for wet construction according to claim 1 or 2. The alkali silicate solution is a sodium silicate solution or a potassium silicate solution, the SiO ₂ / R ₂ O (R is alkali metal) molar ratio is 3 to 4, and the solid content (SiO ₂ + R ₂ O (R is alkali metal)) concentration The repair agent for wet construction according to any one of claims 1 to 3, wherein is 30 to 40% by mass. A powdery component and a liquid component of the wet construction repair agent according to any one of claims 1 to 4 are mixed, and the obtained wet construction repair agent is mixed at room temperature to 100 within one hour from the start of mixing. A repair method characterized in that it is applied to a target refractory at ℃ and dried and cured in 1 to 1.5 hours.

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