Analysis of the methods to improve the physical and chemical properties of ladle breathable bricks

Analysis of the methods to improve the physical and chemical properties of ladle breathable bricks

The breathable bricks are classified according to the material. Luoyang Ke Innovation Materials Co., Ltd., focusing on the research and development, production and sales of breathable bricks for 17 years, is a professional breathable brick manufacturer.

Many steel mills are troubled by the inefficiency and high consumption caused by the frequent replacement of air-permeable bricks due to steel infiltration, peeling and other problems caused by the slits of the air-permeable bricks. .This paper analyzes the damage factors of residual bricks, and proposes methods to improve the physical and chemical properties of breathable bricks, so as to avoid stepping into the minefields stepped on by predecessors, so as to produce safer and more efficient breathable bricks.

1. Select tabular corundum as raw material

Tabular corundum is a kind of pure sintered corundum that is completely sintered without any additives such as MgO and B2O3. Its special 6-square tabular-Al2O3 mineral phase structure can greatly improve the thermal volume stability of breathable bricks. and thermal shock resistance.

When rapidly sintered, the coarse crystals formed by recrystallization of -Al2O3 contain small round, sealed spherical pores, and more closed pores, and the porosity is roughly the same as that of fused corundum, with high purity, good volume stability, and minimal reburning. Therefore, the refractory or castable produced with it has extremely strong thermal shock stability and flexural strength after high temperature treatment.

2. Add rare metal zirconium

Zirconium has amazing corrosion resistance, extremely high melting point, ultra-high hardness and strength and other characteristics. Because it has a special structure. There are many variants of its crystal form. It is monoclinic at low temperature and 4 at high temperature. The cubic crystal form, the higher temperature is the cubic crystal form. The monoclinic crystal form is heated to 1170 degrees Celsius and transformed into a 4 cubic crystal form, and then heated to 2370 degrees Celsius to transform into a cubic crystal form. The melting point of zirconium is above 1800 degrees, and 2 zirconia The melting point is as high as 2700 degrees.

In view of the situation that the breathable brick is damaged by thermal spalling caused by the thermal stress generated by the huge temperature difference (the ladle is baked before use, the tapping temperature of the converter increases sharply, and the temperature drops sharply after pouring the steel), by adding pre-synthesized zirconium-based material to pass Change the physical and chemical properties of the breathable brick, thereby greatly improving the thermal stability of the breathable brick. This is because although the corundum material and the zirconium-based material have different thermal expansion coefficients, microcracks will occur at high temperatures, but the cracks can absorb and disperse the main The energy of the crack part can be dispersed, and the problem of stress concentration can be dispersed, thereby inhibiting the expansion of the crack. In addition, the toughness of ZrO2 itself can be significantly improved.