What are the main performances of breathable bricks

Breathable bricks have been widely used, today Luoyang Quantong Kiln Industry Co., Ltd. will take you to understand the functions of breathable bricks:

Slag resistance

In order to improve the material's slag resistance and resistance to molten steel penetration, Cr2O3 or part of chrome corundum is usually added to the corundum spinel permeable brick. Cr2O3 and a-Al2O3 have the same crystal structure, Cr2O3 not only improves the material's performance The slag resistance increases the wetting angle between the material and the molten steel, and has a significant improvement on the blocking of pores due to the penetration of molten steel in the breathable brick.

The aluminum-chromium solid solution formed by Cr2O3 fine powder and Al2O3 at high temperature and the independent chromium-containing glass phase are used to form a liquid phase with a certain viscosity when it contacts with the slag during the tempering process of molten steel, thereby hindering the slag in the molten steel. At the same time, it can absorb iron oxide and magnesium oxide in the slag, and form fine spinel in the working layer of the breathable brick, which improves the slag resistance of the breathable brick.

However, when Cr2O3 is added to the material, after high temperature firing or use, Cr3 is oxidized to Cr6, and Cr6 is toxic and will pollute the environment. Therefore, in order to save energy and protect the environment, Cr2O3 should be avoided as much as possible, and by replacing raw materials, the The high temperature function without adding Cr2O3 reaches the level of adding Cr2O3.

Thermal shock resistance

The main damage method of the breathable brick is thermal shock damage. With the continuous increase of the tapping temperature, there is a large temperature difference between the working surface of the breathable brick and the intermittent, which requires the material to have extremely high thermal shock resistance. The introduction of spinel phase in the ventilation brick will improve the thermal shock resistance.

The oxides or non-oxides participating in the breathable brick form a solid solution phase with the aggregate at high temperature, which increases the high temperature strength of the brick, improves the permeability of the brick, and resists the corrosion of the slag in the ladle to the breathable brick. After the brick is heat treated at high temperature, its use function is improved to meet its use requirements.

The above is the introduction of the use function of the breathable brick