Factors Affecting the Effect of Argon Blowing Bricks at the Bottom of Ladle

The quality of use of argon-blown breathable bricks at the bottom of the ladle is very important for steel manufacturers, and the unfavorable factors should be avoided or dealt with as much as possible in the process of use; the factors that affect the effect of argon-blown breathable bricks at the bottom of the ladle include steel infiltration on the working face of the breathable bricks , The ventilation brick (slit type) is blocked by slag, the change of material, the fluctuation of air source pressure, the long stop time and other factors.

The working conditions of the breathable bricks are very harsh. The static pressure of the molten steel in the large ladle is large, and the required stirring intensity is also large. Therefore, the key to ensuring the air permeability is that the breathable bricks must have strong anti-seepage steel ability. In practice, steel is often formed on the working surface of the breathable brick, so it is necessary to clean the working face with an oxygen gun.

After the continuous casting of the ladle, the working surface of the permeable brick is fully in contact with the molten slag, and the molten slag will continue to infiltrate into the permeable brick. As a result, the amount of air blowing at the bottom of the next ladle is small or airtight.

The breathable brick is a multi-phase composite material, and has the structural characteristics of particles, organic matter, interface, pores, etc. The main chemical component contained in the breathable brick is alumina, followed by a certain amount of magnesium oxide. The density, compressive strength, and flexural strength of bricks will vary.

During the actual use of the breathable brick, the argon gas supply pressure will fluctuate for many reasons. When the argon gas pressure is too low, the molten steel cannot be blown, resulting in the failure of bottom blowing; when the argon gas pressure is too large, it is easy to cause the molten steel to turn over. Seriously, after contact with air, the molten steel will be oxidized twice.

When the ladle is stopped for too long, the baking time is insufficient or not baked, the temperature of the ladle lining is not enough. After the steel is connected, the temperature of the molten steel at the bottom of the ladle is low, and the cold steel is knotted at the bottom of the ladle, which hinders the bottom blowing of the ventilation bricks from blowing air, resulting in ventilation fail.