JP2743209B2 - Carbon containing refractories - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a carbon-containing refractory for lining a molten metal furnace having excellent slag resistance and structural stability.

(Prior Art) Conventionally, limestone, high-alumina, and zircon-type bricks have been used as lining bricks for hot metal pots and steel melting pots. However, recently, lining furnace materials for the production of high-grade steel, such as hot metal pretreatment in a hot metal ladle or secondary refining in a hot metal ladle, have been exposed to severe operating conditions and have been consumed intensely.

For this reason, Japanese Patent Application Laid-Open No. 54-77609 discloses a method of improving slag resistance and spalling resistance by combining a carbon material with a silica-alumina raw material containing fluorite.

(Problems to be Solved by the Invention) However, although the slag resistance can be improved by combining the rosacea raw material with the carbon raw material, the rosslag material itself has a low slag resistance, and the use amount is limited in a portion easily affected by the slag. In the case where the amount of the wax is small, there is a disadvantage that in this case, the residual swelling characteristic of the wax material cannot be obtained, and the joint tends to open. That is, joint wear can be suppressed by the residual expansion characteristics when the wax is used, but erosion is large in a portion where slag resistance is required, and slag resistance and joint wear prevention cannot be simultaneously satisfied.

(Means for Solving the Problems) In view of this situation, the present invention has conducted various studies and studies in order to solve the problems of the prior art, and as a result, the expansion characteristics of the rosette depend on the particle size of the roseite used. The larger the larger, the larger the expansion coefficient and the particle diameter of 1 mm or less does not greatly affect the expansion coefficient.

It was found that the corrosion resistance of brick to which rosacea was added depends on the particle size of rosacea, and as the particle size of 1 mm or less increases, the corrosion resistance decreases significantly.

Based on the above findings, the present inventors have confirmed that a carbon-containing refractory having excellent expansion characteristics, suppressing joint wear and having excellent slag resistance can be obtained, and completed the present invention.

That is, 5 to 90% by weight of a waxy material containing 50% by weight or more of a particle diameter of 1 mm or more, 3 to 40% by weight of a carbonaceous material and / or a silicon carbide material, a high alumina material, a magnesia material, and a zirconia material. A carbon-containing refractory comprising 100% by weight of a compound comprising 7 to 92% by weight of one or more of the above, and a binder. Or 5 to 90% by weight of a waxy material containing 50% by weight or more of a particle diameter of 1 mm or more, 3 to 40% by weight of a carbonaceous material and / or a silicon carbide material, a high alumina material, a magnesia material, and a zirconia material. A carbon-containing refractory comprising 0.5 to 10% by weight of a metallic material and / or a vitreous material and a binder with respect to 100% by weight of a compound comprising 7 to 92% by weight of one or more kinds. .

The pyroxene material used in the present invention is produced after crushing and rectifying naturally occurring materials. As described above, if the particle diameter is less than 1 mm, the expansion property of the roseite cannot be exhibited, and the slag resistance is limited. This is because it is significantly reduced. Although the maximum particle size is not particularly limited by the size usually used for refractories, it is preferable to use 5 mm or less. The reason for limiting the addition amount to 5 to 90% by weight is that if the amount is less than 5% by weight, the effect of adding the rosacea cannot be obtained, and the expansion characteristics are insufficient. This is because the strength of the resin decreases.

The carbonaceous material and / or carbon siliconaceous material is for making it difficult to wet the slag, and the addition amount is limited to 3 to 40% by weight.
If the content is more than the weight percentage, the strength and wear resistance as a refractory are reduced. As the carbonaceous material, natural graphite, artificial graphite, pitch coke, anthracite, carbon black and the like can be used.

High alumina materials include synthetic mullite, bauxite, sillimanite, andalusite, kyanite,
Electrofused alumina, sintered alumina, and calcined alumina can be used.

As the magnesia material, sintered magnesia, electrofused magnesia, and natural magnesia can be used.

As the zirconia material, a stabilized or unstable material of sintered zirconia and electrofused zirconia can be used.

The reason why these high alumina materials, magnesia materials, and zirconia materials are used alone or in combination is that the slag resistance is superior to that of the rubble, and the combination of the slag with the slag makes it possible to achieve both residual expansion characteristics and corrosion resistance. The reason for limiting the amount of addition to 7 to 92% by weight is that if the amount is less than 7% by weight, the effect of the addition cannot be obtained, and if it exceeds 92% by weight, the effect of the rubble is reduced.

The reason for adding a metal material and / or a vitreous material is to prevent oxidation of carbon, and to limit the amount of addition to 10% by weight or less. If it exceeds 10% by weight, strength and slag resistance are reduced. is there. As the metal material, silicon, aluminum, magnesium, calcium, chromium, zirconium, iron, etc., alone or in combination, or an alloy can be used.

Sodium silicate, sodium phosphate,
One or more of sodium borosilicate and sodium borophosphate can be used.

The particle size of the refractory material other than the rosacea material is appropriately used, and the particle size is not particularly limited.

As the binder, a liquid or powdery binder such as phenol resin, aluminum phosphate, and sodium silicate can be used, and non-fired or fired brick which is dried after kneading and molding can also be used.

Binders such as phenolic resins, which have residual carbonaceous properties, form carbon bonds when hot and exhibit strength, which suppresses the expansion and creep characteristics of the rosette. Is preferably a binder having no carbon residue such as sodium silicate.

(Action) As described above, the present invention relates to the case where the particle diameter is 1 mm or more and 50% by weight.
5 to 90% by weight of the waxy material, 3 to 40% by weight of the carbonaceous material and / or silicon carbide material, and 7 to 92% by weight of one or more of high alumina, magnesia and zirconia materials. % By weight and a binder and a carbon-containing refractory or a combination of the above-mentioned composition and a metal material and / or a glassy material of 10% by weight or less. It can be used to open joints and reduce joint wear, 1mm
Since the slag resistance is not significantly impaired by limiting the above to the waxy material containing 50% by weight or more, the life as a lining material of a hot metal pot or a molten steel pot can be greatly extended.

The carbon-containing refractory of the present invention is generally used as an unfired brick, but the same effect can be obtained as an amorphous refractory, so that it is also effective as an amorphous refractory.

(Example) Hereinafter, an example is described.

The compounds of the present invention, the comparative product and the conventional product were mixed and kneaded according to the compounding ratios shown in Table 1, kneaded, and then pressed into a regular shape by a conventional method, dried at 250 ° C. for 24 hours and dried. did. For the slag resistance, the specimen was subjected to an erosion test using an erosion agent (hot metal slag) at 1500 ° C. for 5 hours by a rotary erosion method, and the erosion size after the test was measured. Residual expansion rate, 30 × 20 × 114mm cut from the specimen, SiC
Embedded in quality Saya's Breeze Coke 1400 in electric furnace
After firing at 3 ° C. for 3 hours, the product was cooled and taken out, and the dimensional change before and after firing was measured. Compared with the conventional product, the product of the present invention was able to achieve both the residual expansion characteristic peculiar to rubble and excellent slag resistance.

Furthermore, the product No. 1 of the present invention and the product No. 14 of the prior art were used in a slag line portion of a 300T hot metal ladle. As a result of measuring the dimensions after use, the product of the present invention was improved in corrosion resistance by 50% compared to the conventional product No. 14 by having both the residual expansion property and the slag resistance.

(Effects of the Invention) As described above, a waxy material, a carbonaceous material and / or a silicon carbide material, a high alumina material, a magnesia material, having a particle diameter of 1 mm or more and 50% by weight or more as described above,
By combining one or more of the zirconia materials, the life of the carbon-containing refractory is remarkably increased, and its industrial value is great.

Continuing from the front page (72) Inventor Yoshikazu Miyagawa 1 Nishinosu, Oita, Oita City, Oita Prefecture Inside Nippon Steel Corporation Oita Works (72) Inventor Masato Tanaka 1-3-1 Shinhama, Araimachi, Takasago-shi, Hyogo Harima Ceramic Co., Ltd. (72) Inventor Toshiyuki Hogii 1-3-1 Shinhama, Arai-machi, Takasago City, Hyogo Prefecture Inside Harima Ceramics Co., Ltd. (72) Inventor Akihiro Donari 1-3-1 Shinama, Arai-machi, Takasago City, Hyogo Prefecture Harima Inside Ceramic Co., Ltd. (56) References JP-A-57-56378 (JP, A) JP-A-3-205356 (JP, A)

Claims (3)

(57) [Claims] 1 to 5% by weight of a waxy material containing 50% by weight or more of a particle diameter of 1 mm or more, 3 to 40% by weight of a carbonaceous material and / or a silicon carbide material, a high alumina material, a magnesia material, A carbon-containing refractory comprising 100% by weight of a compound comprising 7 to 92% by weight of one or more of zirconia materials and a binder. 2. A waxy material having a particle diameter of 1 mm or more and 50% by weight or more, 5 to 90% by weight, a carbonaceous material and / or a silicon carbide material 3 to 40% by weight, a high alumina material, a magnesia material, One or more of zirconia-based materials: 0.5 to 10% by weight of a metallic material and / or a vitreous material and a binder, based on 100% by weight of a blend of 7 to 92% by weight. Refractory. 3. The carbon-containing refractory according to claim 1, wherein the binder is a binder having no residual carbon property.