JP4487158B2 - Amorphous refractory composition - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an amorphous refractory composition used in the steel industry.
[0002]
[Prior art]
Conventionally, casting, press-fitting work is usually performed when performing integral molding, partial molding, repairing and bonding of blast furnaces, converters, electric furnaces, ladles, tundishes and their associated walls and rivets. . In order to adjust the fluidity with respect to the aggregate during these operations, it is possible to ensure the workability suitable for the actual situation by increasing or decreasing the liquid binder. In such a case, the larger the amount of the liquid binder added together with the aggregate, the higher the fluidity.
[0003]
However, increasing the amount of liquid binder added decreases the aggregate density, leading to an increase in porosity, a decrease in strength, and a decrease in durability, and the adjustment of fluidity and aggregate density is a problem. It was.
[0004]
[Problems to be solved by the invention]
The present invention aims to improve the durability of the refractory, and if the amount of the binder resin is reduced, the fluidity is lost and the phenomenon is noticed, the fluidity is improved, the aggregate density is increased, and the durability is improved. It is an object of the present invention to obtain an amorphous refractory composition.
[0005]
[Means for Solving the Problems]
The inventors of the present invention have intensively studied in view of the above situation, and as a result, found that a specific additive can be added to improve the fluidity, and have completed the present invention.
[0006]
That is, [I] The present invention includes magnesia, carbonaceous material selected from the group consisting of earthy graphite, scaly graphite, artificial petroleum pitch and coal pitch, a resol type phenolic resin, and a fluorosurfactant. And the ratio of the resol type phenol resin to 8 to 25 parts by weight with respect to 100 parts by weight of the mixture of magnesia and the carbonaceous material , and the content of the fluorosurfactant is the resol An amorphous refractory composition having a ratio of 0.5 to 5.0 parts by weight with respect to 100 parts by weight of the type phenol resin is provided.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
The refractory aggregate used in the present invention is a mixture of magnesia, which is an aggregate usually used for refractories, and a carbonaceous material selected from the group consisting of earth graphite, scale graphite, artificial petroleum pitch and coal pitch. the recited Ru. Moreover, the resin binder used by this invention is preferable at the point which has dissolved the resol type phenol resin with water, alcohol, etc. and has a high residual carbon ratio.
[0008]
The resol type phenol resin that can be used in the present invention is generally a thermosetting phenol resin having a methylol group in the molecule obtained by reacting phenols and aldehydes in the presence of an alkali catalyst. Examples of the alkali catalyst used at this time include alkali metal and alkaline earth metal oxides and hydroxides, and organic compounds such as amines and ammonia.
[0009]
The resol type phenol resin is preferably in the form of an aqueous solution, and in this case, it may contain some organic solvent in order to assist solubility or control the volatility of water. Further, it may be in the form of an emulsion or dispersion dispersed in water by using a dispersant such as a suitable surfactant.
[0010]
The amount of the resin binder of the present invention is not particularly limited, but it is preferably 8 to 25 parts by weight based on 100 parts by weight of the refractory aggregate of the present invention. If the amount of the resin is less than 8 parts by weight, the entire system is insufficient to flow, and if it exceeds 25 parts by weight, the porosity becomes too high in a state of being fired by receiving high heat and the durability is inferior. .
[0011]
The fluorine-based surfactant of the present invention is not particularly limited, and any compound can be used as long as it is a fluorine-based surfactant composed of a compound containing a fluorine atom in the molecule. Examples thereof include EO-added compounds and fluorine-based surfactants composed of compounds obtained by adding a hydrophilic group EO to a fluorine-added acrylic oligomer.
[0012]
Further, the amount of the fluorosurfactant of the present invention is not particularly limited, but if the amount is less than 0.5% by weight based on the resin liquid, the expected effect cannot be obtained. On the other hand, if it exceeds 5.0% by weight, it is effective for improving the fluidity, but there is a limit to obtaining the durability corresponding to the amount added.
[0013]
A phenol resin aqueous solution is used as a binder in a fireproof aggregate composition, and after casting and press-fitting, a molded product is obtained by curing with a pre-added acid, alkali, or simply heat. It is to reduce the amount of resin liquid and finally improve the durability of the refractory. In the present invention, a fluorosurfactant is blended and kneaded into a kneaded mixture of a fire-resistant aggregate, graphite or carbon-based compound, and a resin binder to impart fluidity.
[0014]
The fluidity can be evaluated by a tap flow test of the blended refractory.
[0015]
The porosity can be measured by measuring the apparent porosity that should appear due to the difference in the amount of resin that can be reduced with the fired test piece. The durability can be observed by measuring the specific gravity of the fired test piece.
[0016]
The amorphous refractory composition of the present invention can be used for blast furnace, converter, electric furnace, ladle, tundish repair and molding by casting.
[0017]
【Example】
Next, examples will be described. Hereinafter, unless otherwise indicated, parts and% are expressed by weight.
[0018]
Example 1
First, an aggregate for flow test in which 80 parts of MgO containing from a maximum particle size of 3 mm to fine powder and 20 parts of earth graphite were mixed (A). Next, Phenolite UG-9537 (B: water-soluble phenol resin, manufactured by Dainippon Ink & Chemicals, Inc.) was added in increments of 12 parts to 18 parts and kneaded for 10 minutes with a planetary mixer. Megafac F171 (C: fluorine surfactant, manufactured by Dainippon Ink & Chemicals, Inc.) was added to these kneaded materials, and kneaded for 3 minutes with the same planetary mixer to prepare the composition of the present invention.
[0019]
Comparative Example 1
A composition was prepared in the same manner as in Example 1 except that the fluorosurfactant C was not included.
[0020]
Next, a fluidity test, a porosity test, and a bulk density test were performed on these compositions.
<Fluidity test and evaluation>
The above composition is taken out into a mortar tap flow test cone according to JIS-R-5201, and tapping once per second is repeated 15 times according to the test method, and the diameter mm immediately after flowing is measured to obtain a flow value. did.
[0021]
To the kneaded material obtained by adding 12 parts, 13, 14, 15, and 16 parts of resin liquid B to 100 parts of aggregate A, 1.0% of fluorosurfactant C is added to resin liquid B. %, 1.5%, 2.0%, 3.0%, and 4.0% are added to the mixture, and 17 parts of the resin liquid B is added to the aggregate A. A composition to which 1.0% of surfactant C was added was prepared, the amount of the resin liquid added to the aggregate was taken on the horizontal axis, and each flow value was taken vertically to create FIG.
[0022]
Taking the case of carrying out with a flow value of 150 mm as a reference, the flow value obtained by the tap flow test requires 15.8 parts of B liquid when no surfactant C is added. By adding 1% of C agent to this, it became 14.5 parts of B liquid, and if the fluidity is the same, 1.3 parts could be reduced. Furthermore, when 2% of C agent is added, B liquid is 13.4 parts and has fluidity. Similarly, when 4% of the C agent was added, a fluid formulation capable of working with the B liquid amount of 12.8 parts was obtained. That is, it was easily guessed that the aggregate density was increased by the amount of resin blending.
<Porosity test and evaluation>
The above-mentioned composition was placed on a PVC-type JIS-R-5201 testing machine having a height of 2.5 cm and a diameter of 2.5 cm, and a test piece formed by tapping 15 times was dried at 80 ° C. for 2 hours. Then, it was removed from the PVC mold and completely cured at 150 ° C. While being embedded in coke, the temperature was raised from room temperature to 800 ° C. over about 3 hours, held for 1 hour, and allowed to cool naturally to room temperature. The apparent porosity was measured by the refractory test method of JIS-R-2205.
[0023]
As a result, a cured product obtained by adding 16 parts of the resin liquid B and not adding the fluorosurfactant C had a porosity of 22%. In the case of the same treatment with 4% addition of Activator C, it decreased to 17%. This indicates that the pores are decreasing, and the reduction in the amount of the resin liquid B shows a good direction in which the porosity is lowered as it is.
[0024]
These differences in porosity prevent molten steel from penetrating into the pores and preventing refractories from being corroded by about 20% or more, and the increase in the bulk specific gravity can surely improve the durability in actual situations. It is suggested.
<Test and evaluation of bulk density>
In a product obtained by calcining a cured product obtained by adding 16 parts of the resin liquid B and not adding the fluorosurfactant C when calculated from the vertical and diameter dimensions of the molded test piece obtained by the porosity test, Its specific gravity was 2.11. On the other hand, the same specific treatment with 13 parts of the resin liquid B and 4% of C added had a bulk specific gravity of 2.35. As a result of increasing the density by 10%, it was shown that the durability was improved.
[0025]
【The invention's effect】
The amorphous refractory composition of the present invention has improved fluidity by adding a fluorosurfactant, and increased aggregate density to improve durability.
[Brief description of the drawings]
FIG. 1 is a diagram showing the flow value depending on the amount of resin and surfactant added in a tap flow test.
1; 4.0% fluorosurfactant added to resin liquid 2; 〃 ３．０ 3.0% added 3; 〃 ２．０ 2.0% added 4; 〃 １．５ 1.5% added 〃 １．０ 1.0% added 6; 〃 し な い not added

Claims (1)

Comprising magnesia, carbonaceous earth, scaly graphite, carbonaceous material selected from the group consisting of artificial petroleum pitch and coal pitch, resol-type phenolic resin, and fluorosurfactant, magnesia and carbonaceous material The amount of the resol type phenol resin is 8 to 25 parts by weight with respect to 100 parts by weight of the mixture , and the content of the fluorosurfactant is 100 parts by weight of the resol type phenol resin. An amorphous refractory composition having a ratio of 0.5 to 5.0 parts by weight.

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