JP2695627B2 - Spray refractory composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sprayed refractory composition applied to a furnace wall, a furnace bottom, etc. of steelmaking equipment such as a converter, an electric furnace, a ladle and the like, and in particular, has excellent durability, adhesion and corrosion resistance. Spray refractory composition.

[0002]

2. Description of the Related Art Conventionally, as a sprayed refractory composition used for repairing furnace walls, furnace bottoms, etc. of steelmaking equipment such as converters, electric furnaces, ladles, etc., inorganic materials such as phosphates or silicates are used for refractory aggregates. It is known that a binder is added at a ratio of 3% by weight to 10% by weight, but there is a problem that durability is insufficient due to severe operating conditions of a steelmaking furnace.

[0003] The reason is that the inorganic binder forms a low-melting substance at the time of heating and bonding, causing a shrinkage phenomenon. Further, since the inorganic binder is used in the form of an aqueous solution, the binder moves with rapid evaporation of water, It is considered that this reduces the adhesive strength and causes peeling. In addition, the liquid phase in the matrix portion due to the inorganic binder is large, and the matrix portion is easily melted and the durability is easily reduced.

Further, as a sprayed refractory composition, a refractory aggregate contains several weight% of an inorganic binder such as phosphate or silicate and 10 weight% of an organic binder such as pitch and phenol resin.
Addition is also known, but also in this type of composition, since the inorganic binder contributes greatly to the adhesiveness, the problem still remains as described above, and when a phenol resin is used as the organic binder, There is a problem that it inhibits the adhesiveness of the inorganic binder and easily falls off.
Further, there is a problem that carbon generated by carbonization of the organic resin is oxidized by the alkali component of the inorganic binder, and the effect of carbon becomes insufficient.

Further, a refractory composition in which pitch or novolac type phenolic resin is added to refractory aggregate is also known. It cannot be used as an object.

[0006] As an amorphous refractory using a phenol / formaldehyde resin, for example, Japanese Patent Publication No. Sho 62-62
Japanese Patent No. 38382 discloses a method in which only the resin powder is used as a binder in an inorganic material powder, or a water-soluble organic binder, a molding aid,
It is a method of combining with petroleum products and by-products to form a binder, and is disclosed for use in various furnace wall materials such as blast furnaces and converters, fireproof paints, and fireproof pads. When the mixture of the inorganic material powders is applied to the spraying material, if only the phenol / formaldehyde resin is used as the binder, the sprayed structure will be warped, and there is a problem in adhesiveness. Also, when used in combination with an auxiliary component other than the high melting point pitch, there is a problem in adhesiveness due to dripping because fluidity and shape retention as a spraying material cannot be obtained. No improvement in adhesion due to the effect of suppressing generation is obtained.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sprayed refractory composition having high peeling resistance, adhesive strength and corrosion resistance even in a high-temperature steelmaking furnace operation.

[0008]

According to the first aspect of the present invention, there is provided a sprayable refractory composition comprising a refractory material which exhibits a semi-molten state at 80 ° C to 500 ° C and a weight average molecular weight of 1,000 to 15,000.
A resol type phenol resin powder having a residual monomer of 1,000 ppm or less in an amount of 2% by weight to 10% by weight,
And a high softening point pitch of 100 ° C. to 500 ° C. is 2% by weight or more.
10% by weight, plasticizer 0.5 to 3% by weight, metal powder 0
-5% by weight, peptizer 0% by weight-1% by weight, fibers 0
It is characterized by being added at a rate of 0.2% by weight.

The second sprayable refractory composition of the present invention is characterized in that the refractory material shows a hot-melt / self-cured state at 100 ° C. to 500 ° C., a weight average molecular weight of 1,000 to 15,000, and a residual monomer. A phenol / formaldehyde resin powder containing 1,000 to 9 ppm by weight of a reactive phenol-formaldehyde resin powder of 1,000 ppm or less, and a high softening point pitch of 100 ° C. to 500 ° C. 2% to 10% by weight, plasticizer 0.5% to 3% by weight, metal powder 0% to 5% by weight, peptizer 0% to 1% by weight, fibers 0 to 0.2% by weight It is characterized by being added by. As the refractory material in the present invention, a refractory material usually used can be used, for example, fused alumina, sintered alumina, sintered mullite, calcia partially stabilized zirconia,
One of yttria partially stabilized zirconia, chamotte, silicon carbide and the like, or a mixture thereof can be used, but in particular, MgO, MgO having a particle size adjusted to 4 mm or less,
-CaO-based aggregates, for example, basic aggregates such as electrofused magnesia, sintered magnesia clinker, natural magnesia clinker, natural dolomite clinker, and synthetic dolomite clinker are preferred.

Next, the resole-type phenolic resin powder in the first sprayable refractory composition of the present invention is insoluble or hardly soluble in water, and is 80 to 500 ° C., preferably 80 to 500 ° C.
It shows a semi-molten state at a temperature of 200C to 200C. "Semi-molten state" refers to a state in which it is softened and has an adhesive property but is not completely melted. It is not preferable because it flows and flows down. Also, 500
Those softening at a temperature of not less than ° C have no adhesiveness in a temperature range where adhesiveness is required, and do not exhibit a function as a binder.

The weight-average molecular weight of such a resol-type phenol resin is 1,000 to 15,000, preferably 1,000 to 10,000. A normal novolak-type phenol resin having a weight-average molecular weight of less than 1000 (a weight-average molecular weight of 300 to 800) or a resol-type phenol resin having a weight-average molecular weight of 200 to 700 melts completely at 100 ° C or lower. , Which is in a fluid state and flows down during heating and bonding, which is not preferable as a sprayable refractory composition.

In the second sprayable refractory composition of the present invention, the heat-meltable / self-curable phenol / formaldehyde resin powder contains 6% by weight of a methylol group which is insoluble or hardly soluble in water and has reactivity. -9% by weight, preferably 8-9% by weight, 100 ° C-500 ° C,
Preferably, it melts at 100 ° C. to 200 ° C. and shows gelation (self-hardening). If the amount of the methylol group exceeds 9% by weight, the reactivity becomes too high, and the gelled cured body becomes brittle, and there is a problem in the adhesive strength of the construction or the strength of the construction. If the amount is less than 6% by weight, the reactivity for gelling is poor, so that there is a problem in adhesion and strength of the construction. Further, those that melt at a temperature exceeding 500 ° C. have poor adhesiveness in a temperature range where adhesiveness is required, and do not exhibit a function as a binder.

[0013] Such a hot-melt / self-curing phenol
The weight average molecular weight of the formaldehyde resin powder is 1,000 to 15,000, preferably 3,000.
１５15,000. If the weight average molecular weight is less than 1,000, the reactivity of the resin composition becomes too high due to the high content of methylol groups, and the gelled cured product becomes brittle, which is not preferable as a sprayable refractory composition.

The residual monomer in the above-mentioned resol-type phenol resin powder and hot-melt / self-curing phenol-formaldehyde resin powder is 1,000 pp.
m, preferably 500 ppm or less. If the residual monomer exceeds 1,000 ppm, the foaming is remarkably foamed at the time of heating and bonding, which causes deterioration of the structure of the construction of the sprayed material, and furthermore, the bonding strength is unpreferably reduced.

The resole type phenol resin powder is a powder having an average particle size of 15 μm to 20 μm, and commercially available products include, for example, PR-Q-731 manufactured by Sumitomo Durres Co., Ltd.
PR-Q-731V and the like. The hot-melt / self-curable phenol-formaldehyde resin powder is a powder having an average particle size of 15 μm to 20 μm. As a commercially available product, for example, “Belle Pearl” S-87 manufactured by Kanebo Co., Ltd.
0, S-890, S-895 and the like.

The resol-type phenol resin powder or the hot-melt / self-curing phenol-formaldehyde resin powder is added in an amount of 2 to 10% by weight, preferably 3 to 7% by weight, based on the refractory aggregate. You. If the addition amount is less than 2% by weight, the adhesion is poor when the sprayed refractory composition is applied to a vertical wall, and if it exceeds 10% by weight, the porosity becomes too high, so that the corrosion resistance is reduced and the economical efficiency is reduced. Not.

Next, when the spraying refractory composition is formed by using only a resol type phenol resin powder or a hot-melt / self-curing phenol / formaldehyde resin powder, the high softening point pitch warps the construction body after bonding. Is generated for the purpose of preventing the occurrence of peeling, and is used for the purpose of preventing the peeling, and one having a softening point (SP) of 100 ° C to 500 ° C, preferably 120 ° C to 400 ° C is used. . A pitch having a softening point of more than 500 ° C. has almost no volatile components, and thus loses expandability, so that the effect of preventing warpage of the construction after bonding cannot be obtained.

The high softening point pitch is 2% for the refractory aggregate.
% By weight, preferably 3% by weight to 7% by weight. The ratio of the high softening point pitch / resole type phenolic resin powder or hot melt / self-curing type phenol / formaldehyde type resin powder is as follows. 70/30 by weight
It is good to be 30/70. If the ratio of the high softening point pitch / resole type phenol resin powder or the heat melting / self-curing phenol / formaldehyde type resin powder is more than 70/30, the resin will flow down the vertical wall at the time of heat bonding, and the bonding rate will decrease. If the ratio is less than 30/70, the shrinkage of the resol-type phenol resin powder or the hot-melt / self-curing phenol-formaldehyde resin powder exceeds the expansion obtained from the high softening point pitch, and the contraction of the construction body due to the shrinkage occurs. , Peel off.

In addition to these components, the spray refractory composition of the present invention contains additives such as a plasticizer, a metal powder and, if necessary, a small amount of a deflocculant and a small amount of fibers.

The plasticizer is added for the purpose of improving the adhesiveness. For example, silica flower, clay, sepiolite,
Bentonite, calcium hydroxide, and the like, and 0.5% to 3% by weight, preferably 0.1% by weight, based on the refractory aggregate.
It is added in a ratio of 5% by weight to 2% by weight.

The metal powder is added for the purpose of improving the strength and preventing oxidation of carbon obtained from a resol type phenol resin powder or a hot-melt / self-curing phenol / formaldehyde resin powder and a high softening point hitch. For example, powder of aluminum, silicon, aluminum-magnesium alloy and the like, for refractory aggregate,
It is added at a ratio of 0% to 5% by weight, preferably 0% to 3% by weight. If it is more than 5% by weight, the structure of the construction body becomes too porous, which is not preferable.

The deflocculant is added as needed for the purpose of improving the compactness of the construction body structure. For example, inorganic deflocculants such as sodium hexametaphosphate and sodium silicate, sodium polyalkylallyl sulfonate, Organic deflocculants such as polyacrylates are mentioned, and are added at a ratio of 0% by weight to 1% by weight, preferably 0% by weight to 0.5% by weight based on the refractory aggregate.

Fibers are added as necessary for the purpose of preventing the spray slurry from dripping on vertical walls.
Examples thereof include inorganic fibers such as alumina fibers and carbon fibers, natural fibers such as hemp, and organic fibers such as organic synthetic fibers, and 0% to 0.2% by weight based on the refractory aggregate.
Preferably, it is added at a ratio of 0% by weight to 0.1% by weight.

The sprayed refractory composition of the present invention is obtained by adding water to a mixture of the above-described components, spraying the mixture on a furnace wall, a furnace bottom, etc. of a steelmaking facility by a conventional method, and then heating and hardening the composition.

[0025]

The spray refractory composition of the present invention comprises 8
Water-insoluble resol-type phenol resin powder in a semi-molten state at 0 ° C to 500 ° C, or hot-melt / self-curing phenol
By using formaldehyde-based resin powder, it is possible to improve the adhesiveness at the time of heat bonding, and by adding a high softening point pitch for the purpose of preventing peeling of the construction body after bonding, It can be said to have high peeling resistance, adhesive strength and corrosion resistance to the steelmaking furnace wall at high temperature.

[0026]

Examples 1 to 18 and Comparative Examples 1 to 6 Aggregates having the weight ratios shown in Tables 1 to 4 below were blended with the respective additives at the weight ratios also shown in Tables 1 to 4. Spray refractory composition (1
18) was prepared.

Further, each additive was added to the aggregates having the weight ratios shown in Tables 4 and 5 below in the same weight ratios as shown in Tables 4 and 5 to obtain a sprayed refractory composition for comparison (comparative 1 to 5). Comparative 6) was prepared.

Water was added to each sprayed refractory composition in an amount of 22% by weight to 24% by weight and sprayed on a panel in a test furnace at 1,000 ° C.

Adhesion rate (%), adhesion strength (MP
a), the result of measuring the apparent porosity (%), and 175
Tables 1 to 5 also show the results of the slag test at 0 ° C for 3 hours and the results of the actual furnace test using a 250-ton converter (durability test results at 1700 ° C high-temperature tapping). In the slag test results, the smaller the index, the better the corrosion resistance, and the higher the index in the actual furnace test results, the higher the durability.

The physical properties of "Bellpearl" S-890 and "Bellpearl" S-895 used in the following examples are as follows.
It is as follows. "Bellpearl" S-890: weight average molecular weight 10,000
0, softening temperature 100 ° C, residual monomer amount 300ppm,
Average particle size 15-20 μm “Bellpearl” S-895: weight average molecular weight 6,000
0, softening temperature 100 ° C, residual monomer amount 500ppm,
Average particle size 15-20 μm

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

[0034]

[Table 4]

[0035]

[Table 5]

[0036]

EFFECT OF THE INVENTION The sprayed refractory composition of the present invention has a high adhesive strength, is hardly peeled off from the bonded surface, has a low slag penetration, and has excellent hot volume stability, so that it can be peeled off from the intermediate layer. It is less damaged, has 3-5 times the durability against ordinary steel, compared to conventional sprayed materials,
It has sufficient durability for high-temperature tapping materials of 1,700 ° C or higher.

Claims (2)

(57) [Claims] 1. A refractory material which exhibits a semi-molten state at 80 ° C. to 500 ° C. and has a weight average molecular weight of 1,000 to 15,000.
A resol type phenol resin powder having a residual monomer of 1,000 ppm or less in an amount of 2% by weight to 10% by weight,
And a high softening point pitch of 100 ° C. to 500 ° C. is 2% by weight or more.
10% by weight , plasticizer 0.5% by weight to 3% by weight, metal powder 0
-5% by weight, peptizer 0% by weight-1% by weight, fibers 0
A sprayed refractory composition characterized by being added at a ratio of 0.2% by weight . 2. A refractory material having a weight-average molecular weight of 1,000 to 1 which shows a heat-melted and self-cured state at 100 ° C. to 500 ° C.
2 to 10% by weight of a phenol-formaldehyde resin powder containing 5,000, a residual monomer of 1,000 ppm or less, and 6 to 9% by weight of a reactive methylol group, and 100 ° C. 2% by weight to 10% by weight of high softening point pitch at 500 ° C. , plasticizer 0.5 weight
% -3% by weight, metal powder 0-5% by weight, peptizer 0% by weight
A sprayable refractory composition characterized by being added at a ratio of 0 to 1% by weight and fibers at 0 to 0.2% by weight .