JPS602274B2 - Composition for preventing molten metal splash from adhering to the inner wall of a tandate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a coating agent that prevents molten metal from adhering to the inner wall of a tundish.

Continuous casting, especially tundishes used for steel lotus coins, requires long hours of operation, during which time droplets of port steel gradually adhere to the lid or the side wall above the hot water level and grow, causing damage to the inside of the tundish. When replacing the refractory lining of the main body, it takes a great deal of effort to remove the deposits of deposits and remove the lid at the same time. It may be difficult to handle the equipment, waste maintenance time on the tundish, and the cycle of use of the equipment may become unsmooth, which may impede operations.

The present invention is applied to the inner walls of tundishes that require long hours of work, especially the inside of the lid or the surface of the refractory lining, which is exposed to splashes from the setting sun, and is applied to the surfaces of tundishes that are exposed to falling sun and hot water during work hours. This provides an optimal composition for a paint that allows droplets to drop or adhere to the area they hit without causing any droplets to fall or adhere to the area where they hit, but to the extent that they easily fall off with only a light impact afterwards.

In other words, the optimum formulation of the present invention consists of silica sand, chamots, perilla rock, with a smaller degree of approximately 0.3 m/m.
20% of one or more refractory substances such as magnesia, magnesite, dolomite, calcined dolomite, alumina, etc.
A mixture of 10 to 70% of graphite, 5 to 70% of graphite, and 10 to 30% of one or both of kaolin and bentonite clays, and optionally inorganic materials such as sodium silicate, sodium phosphate, aluminum phosphate, and magnesium chloride. Add an appropriate amount of water to a mixture of 1 to 7% of one or more binders to form a paste or slurry, make a paint, and apply it to the inside of the lid of the tandate or the like by troweling, spraying, etc. It is applied to the surface of the fire-resistant or heat-insulating plastic material, mainly on the surface of the fire-resistant or heat-insulating plastic material, in areas where the lining of the tundish main body is not exposed to hot water, i.e., above the hot water level, and allowed to dry naturally. By doing this, the melt droplets flying onto the coated surface become obstacles between the molten metal surface and the tundish wall surface due to the powdery and reducing properties of the coating agent, preventing contact, and also reducing the reducing atmosphere at the contact point. When the melted droplets come into contact with the paint due to the formation, no iron oxide is produced on the surface of the droplets, or the existing iron oxide is reduced to metallic iron, and the iron oxide that provides adhesion becomes metallic iron, and the adhesion is significantly reduced. It falls immediately after contact. In the composition of the paint to give this property, fire resistance lower than the above 0.3 can be used regardless of whether it is acidic, neutral or basic, and it can be used under high temperatures by imparting heat resistance. Particles larger than 0.3 particles/kite are unsuitable because when a coating film is formed, its ability to form a coating decreases and it tends to collapse. As mentioned above, the composition ratio should be between 20 and 70%, and if it is less than 20%, the coating will become soft and its durability will be affected, and if it exceeds 70%, it will not be possible to satisfy the required amount of other active ingredients. Not suitable. Graphite has the effect of forming a reducing atmosphere and can be used regardless of whether it is natural or artificial. If the blending ratio is less than 5%, the formation of a reducing atmosphere is weak, and the ability to prevent oxidation and restore the melted wound droplets is poor;
If it exceeds this, the coating film will become soft and both are unsuitable. Among the clays, kaolin is used in all cases, and bentonite is mainly used for basic fire resistance, and acts as a binder when the paint is wet.After the paint film dries, it has the property of providing heat resistance on top of the action of the binder, and collapses. It has a preventive effect. If the blending ratio is less than 10%, the bonding strength will be poor, and if it exceeds 30%, the coating will crack during drying and will be unsuitable. Furthermore, if a large tundish is used for lotus casting for a long time, the inside of the tundish will be at a higher temperature and there will be many large melted droplets, so it is better to add an inorganic binder to make the coating stronger. .

This can be arbitrarily selected from water glass, sodium phosphate, aluminum phosphate, magnesium chloride, etc., but if it is 1% full, the binding strength is poor, and even if it exceeds 7%, no increase in binding strength is observed, so it is unnecessary. It is the meaning. Table 1 NQIN02 No3 Nu4N05 N
Q6 Nu7 neighbor Kay sand Ku03 thing
50 10 20 30 20
Kanheung person 〃 − − − − 27 18
5 Magnenya 〃 1 − − − 1
0 - 5 Calcined Dolomite 〃 - -
− − − − 10 Alumina
20 25 40 10 graphite
〃 5 10 20 26 40 55 69 power Orin 9 10 15 20 12 10
"Pentonite 9 14 15 10
8 5 10 Tertiary Sodium Phosphate
4 3 2
No. 13 Sodium Silicate 7 6
5 Water (% outside) 20 20 40 40
40 40 40 Conditions Paste paste Mud bran Mud ring Mud bran Mud pseudo Coatings with the above composition are placed in an anhydrous mixed powder state and kneaded with water added just before use.

Water is added in an amount of 25 to 100% by weight to the mixed powder to form a paste or muddy acid water, and the mixture is applied by the method described above. The coating thickness is generally 2 to low/skin to withstand use. After applying the paint with the composition shown in Table 1 above, the tundish is set with the lid closed and the interior is preheated to 1300°C or less using gas or other means, but it does not collapse or burn out and the mirror work begins. It was possible to pass through the melt wound for more than 3 hours, and there was almost no adhesion of base metal, and even the adhesion could be easily removed by hand.

Claims (1)

[Claims] 1. Silica sand having a particle size of approximately less than 0.3 m/m;
siyamoto, peridotite, magnesia, magnesite,
20 to 70% of one or more refractory substances such as dolomite, calcined dolomite, alumina, etc. and 5 to 70% of graphite
% and one or both of kaolin and bentonite clay materials in a composition of 10 to 30%, and an appropriate amount of water is added to form a paste or slurry. 2. Silica sand having a particle size of approximately less than 0.3 m/m,
siyamoto, peridotite, magnesia, magnesite,
20 to 70% of one or more refractory substances such as dolomite, calcined dolomite, alumina, etc. and 5 to 70% of graphite
%, and 10 to 30% of one or more types of clay such as kaolin and bentonite, and 1 to 7% of one or more types of inorganic binders such as sodium silicate, sodium phosphate, aluminum phosphate, and magnesium chloride. 1. A composition for preventing molten metal splash from adhering to the inner wall of a tundish dish, which is prepared by adding an appropriate amount of water to a mixture having a composition of