JP2003137666A - Monolithic refractory for blast furnace runner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the service life of a blast furnace runner by increasing its corrosion resistance, and to save manpower by reducing the frequency of its restoration. SOLUTION: The monolithic refractories for a blast furnace runner contain a >=1 wt.% SiC raw material and 0.01 to 10.0 wt.% NiO powder of a <=0.5 mm length. If required, the powder or coarse grains of alumina and/or spinel can be incorporated therein by >=5 wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of refractories, and relates to an amorphous refractory for a blast furnace gutter, in which the wear rate of the blast furnace gutter is reduced, the unit consumption of the gutter material is reduced, and the frequency of gutter repairs is reduced. Is.

[0002]

2. Description of the Related Art Conventionally, a blast furnace gutter has an alumina-SiC-
C-quality casting materials, stamp materials, and spray materials have been used. Then, the wear rate has been reduced by incorporating spinel into it. On the other hand, as refractory used in a pyrolysis gas melting system for waste treatment, NiO
-Al ₂ O ₃ refractory is being put to practical use.

[0003]

However, in order to further reduce costs and save labor, it is necessary to improve the life of the gutter by reducing the rate of wear, reduce the basic unit of gutter material, and reduce the frequency of gutter repairs. On the other hand, the NiO-Al ₂ O ₃ -based material was inapplicable because of its poor corrosion resistance in the blast furnace gutter usage environment.

[0004]

The inventors have found that the use of NiO powder with a SiC-based raw material greatly improves the corrosion resistance even under the condition of blast furnace gutter. It has also been found that by adding a spinel-based material to this, the corrosion resistance is further improved.
(EN) An amorphous refractory for a blast furnace gutter, characterized in that it contains 0.01 to 10.0% by weight of NiO powder of 1% by weight or more and 0.5 mm or less of a quality raw material.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The amorphous refractory for a blast furnace gutter according to the present invention contains 1% by weight or more of SiC raw material and 0.5 mm or less of N.
It is characterized by containing 0.01 to 10.0% by weight of iO powder.

The amorphous refractory for the blast furnace gutter is made of 0.01 to 10 NiO powder having a grain size of 0.5 mm or less together with SiC.
It can be included by weight percent. The SiC is preferably powder or coarse particles in an amount of 1% by weight or more. Since C is contained in the blast furnace gutter, the inside of the material is in a CO atmosphere, and SiC and NiO become vapor such as SiO (g) and Ni (g).

The SiO (g) and Ni (g) react directly in the vapor phase to uniformly disperse the SiO ₂ —NiO glass inside the material. Since this glass is produced from the gas phase, the pores are selectively filled, and the structure is densified.

Further, evaporation of SiC and precipitation of SiO ₂ and C are performed. First, SiC reacts with CO (g) according to the following formula (1) to become SiO (g). This S
Although iO (g) flows out of the material, if the reaction of the formula (2) continues, it will remain inside the material as SiO ₂ and C. SiC (s) + CO (g) → SiO (g) + 2C (s) ... (1) SiO (g) + CO (g) → SiO ₂ (s) + C (s) ... (2)

1% by weight or more of SiC and 0.01% of NiO
The content of ˜10.0% by weight is sufficient to form SiO ₂ —NiO glass, and the precipitation of C (s) is also promoted by advancing the reaction of the formula (2). The densification is also promoted by the precipitation of C in the pores. The densification of the material suppresses the invasion of slag and reduces the surface area that reacts with the slag, thus improving the corrosion resistance.

It is preferable that the above-mentioned alumina powder and coarse particles are contained in an amount of 5% by weight or more. Further, the combined use of spinel powder and coarse particles can greatly improve the corrosion resistance. Therefore, it is preferable to use spinel, but since the raw material cost becomes high, it is preferable to use it in combination with alumina.

The C-based raw material may be contained in an amount of 1% by weight or more. Inorganic substances such as earth-like graphite, flake-like graphite and carbon black, those obtained by secondary treatment, and organic substances such as pitch and resin. May be used as the C source.

Alumina cement is suitable as the binder, but in view of other characteristics, the same effect of improving corrosion resistance can be obtained even with an inorganic binder such as silica sol or alumina sol or an organic substance such as resin.

At this time, by adding a dispersant and a curing modifier as conventionally used, it is possible to secure fluidity during construction with low water content and further adjust a curing time suitable for construction. it can. Further, aluminum powder or organic fibers may be added to prevent explosion during drying.

The above is an example of the casting material, but it is also possible to adjust the particle size blending, clay, and binder by a known technique to make it possible to apply by stamping or dry or wet spraying.

Regarding the amount of such NiO powder added,
If the amount is less than 0.01% by weight, the amount of addition is insufficient to fix SiO (g), and the desired effect of improving the structure cannot be obtained. On the other hand, if it is added in excess of 10% by weight, no further effect can be obtained. Since NiO has a high specific gravity of 6.7, if the amount of fine powder added is too large, the volume balance of the particle size design will be lost, and the work will be hindered during pouring, stamping, and spraying.

Regarding the particle size, fine particles having high reactivity are preferable, but they may be made coarse to secure the above-mentioned workability. However, in order to obtain a sufficient effect, it is preferable to design such that the amount of 0.5 mm or less, preferably 0.1 mm or less, is included in an amount larger than 0.01% by weight.

As the other components relating to the present invention, known design techniques can be used. That is, as the aggregate, an alumina-based or silica-based natural or artificial raw material, or a basic substance such as magnesia, calcia, or dolomite can be added. Furthermore, plasticizers such as clay,
Silica fume can also be used. In addition, it can be used in combination with a metal powder such as silicon or aluminum.

[0018]

EXAMPLE As an example of the present invention, the effect of adding NiO powder will be illustrated and described. Table 1 is a blast furnace trough amorphous refractory composition tested in practice. In this example, a casting material was used. 4 kg of each of these compounds was kneaded for 3 minutes with a universal kneader. Then, it was cast into a mold having a predetermined shape. After curing at room temperature for 24 hours, after confirming the curing, the mold was removed and dried in a dryer at 110 ° C. for 24 hours. afterwards,
It was placed in a silicon carbide sagar filled with coke breeze and heated at 500 ° C. in an electric furnace to remove pitch volatile matter. Then, the corrosion resistance was compared by the lining method using a high frequency furnace. The result is shown in FIG.

Table 1 Formulation table of examples of the present invention and comparative examples

[Table 1]

As shown in Table 1, Comparative Examples k and l in which a large amount of NiO powder was added were not practical because of poor fluidity.
In comparison with the alumina of Comparative Example m containing no NiO powder and the spinel of Comparative Example n, the alumina of the present invention added with 0.01 to 10% by weight of NiO powder,
The spinel materials of Examples a to j each have a reduced melting loss ratio, and by adding NiO, 0.01 to 10% by weight of both the alumina aggregate and the spinel aggregate,
It has been confirmed that the addition of 0.1 to 10% by weight preferably improves the corrosion resistance.

Further, as shown in FIG. 1, it can be seen that the spinel material has better corrosion resistance. For this reason, it is practical to use spinel and alumina in an appropriate ratio at the same time in consideration of raw material costs, and the alumina-based aggregate and the spinel-based aggregate are mixed in a ratio of 90 to 10 to 90. Is preferred.

[0022]

As described above, according to the present invention, SiC
Since it contains 0.01 to 10.0% by weight of NiO powder having a quality raw material of 1% by weight or more and 0.5 mm or less, densification of an amorphous refractory can be achieved, intrusion of slag can be suppressed, and reaction with slag can be achieved. The surface area of the surface can be reduced and the corrosion resistance can be improved.
Therefore, the wear rate of the blast furnace gutter can be reduced, the life of the gutter can be improved, the unit of refractory can be reduced, and the gutter repair frequency can be reduced to save labor.

Further, by using spinel as the main component, the above-mentioned corrosion resistance can be greatly improved. However, 90 to 10: 1 alumina-based raw material and spinel-based raw material are used.
It is preferable to use them together in a ratio of 0 to 90 because the cost of raw materials can be reduced and the corrosion resistance can be improved economically.

[Brief description of drawings]

FIG. 1 is a comparison diagram of a NiO powder addition amount and a melting loss ratio of an example of the present invention and a comparative example.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Seijiro Tanaka             Two rivers at 1576, East off Nakahiro, Ako City, Hyogo Prefecture             Inside Saki Furnace Co., Ltd. F-term (reference) 4G033 AA01 AA02 AA09 AA17                 4K015 EC08

Claims (4)

[Claims] 1. A SiC-based raw material of 1% by weight or more and 0.5 m
An amorphous refractory for a blast furnace gutter, characterized by containing 0.01 to 10.0% by weight of NiO powder of m or less. 2. The amorphous refractory for a blast furnace gutter according to claim 1, which contains alumina powder or coarse particles in an amount of 5% by weight or more as a main component. 3. The amorphous refractory for a blast furnace gutter according to claim 1, which contains spinel powder or coarse particles in an amount of 5% by weight or more as a main component. 4. Alumina raw material and spinel raw material 90
4. The composition according to claim 1, wherein the content is 10 to 10 to 90.
An amorphous refractory for a blast furnace gutter according to any one of 1.