High-temperature air-leakage-proof expansion coating for tundish sleeve, and preparation method thereof

Abstract

The invention discloses a high-temperature air-leakage-proof expansion coating for a tundish sleeve. The expansion coatingcomprises, by weight, 2-3% of methyl cellulose, 2-4% of styrene-acrylic emulsion, 0.2-0.4% of a thickening agent, 20-30% of high-purity magnesium oxide, 20-40% of silica powder, 25-30% of kyanite, 15-25% of zirconium oxide, 0-4% of C and 25-30% of water. The invention aims to provide the high-temperature air-leakage-proof expansion coating for the tundish sleeve, which is free of environmental pollution, good in heat insulation effect, high-temperature-resistant and good in sealing effect, and a preparation method of the high-temperature air-leakage-proof expansion coating.

Description

technical field [0001] The invention relates to the field of refractory materials based on inorganic materials, and more specifically relates to a high-temperature leak-proof gas expansion coating for tundish casings and a preparation method thereof. Background technique [0002] With the continuous progress and development of steelmaking and continuous casting technology at home and abroad, the technological update of steel mills is getting faster and faster, and the quality of molten steel is also improving. The main problem in the process of using the steel pipe) is that there is a gap at the joint between the ladle nozzle and the shroud (casing), but both the shroud and the lower nozzle are steel structures. Due to various reasons such as production and processing errors, the sealing effect is not good. It is not ideal, the cooperation between the two cannot be perfect, and the air enters the long nozzle (casing) through the gap between the two, so that the molten steel ...

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Problems solved by technology

[0002] With the continuous progress and development of steelmaking and continuous casting technology at home and abroad, the technological update of steel mills is getting faster and faster, and the quality of molten steel is also improving. The main problem in the process of using the steel pipe) is that there is a gap at the joint between the ladle nozzle and the shroud (casing), but both the shroud and the lower nozzle are steel structures. Due to various reasons such as production and processing errors, the sealing effect is not good. Not ideal, the cooperation between the two cannot be perfect, the air enters the long nozzle (casing) through the gap between the two, and the molten steel is oxidized

[0004] 1. Most refractory fibers use cheap ordinary silicate fibers, and their long-term use temperature is low (<1250°C), while the sealing sleeve is in the long nozzle, the temperature is about 1300°C, and the casting time of a furnace of steel is 40 to 60 minutes. The fiber is easy to crystallize, become brittle, shrink in volume and lose elasticity;

[0005] 2. The chemical composition of the refractory fiber and the shroud (casing) is quite different, and it is easy to sinter and bond to each other at high temperature, and it is not easy to clean when changing the ladle

However, if the cleaning time is too long, the inner cavity of the long nozzle (casing) bowl will be seriously irregular, and when a new sealing ring is placed, the gap cannot be completely filled;

[0006] 3. There is a large porosity in the refractory fiber of the sealing sleeve. Due to the elasticity, the extrusion of the two nozzles cannot completely close the pores during use.

[0007] 4. The refractory fiber may also react with the iron oxide on the surface of the steel sleeve of the ladle's lower nozzle to bond, and the lower nozzle must be cleaned with a steel brush if it is used in multiple furnaces.

[0008] 5. When the site is cleaned with a steel brush, refractory fibers flying all over the sky are carcinogenic, and inhalation is harmful to human physical and mental health

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