The performance advantages of breathable bricks

Slag resistance of breathable bricks

In order to improve the anti-slag performance of the material and the ability to resist the penetration of molten steel, Cr2O3 or some chromium 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 The slag resistance increases the wetting angle between the material and the molten steel, and has a significant improvement in the blockage of the pores of the breathable brick due to the infiltration of the molten steel.

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 in the molten steel smelting process, thereby preventing the molten steel from slag. Corrosion; 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, adding Cr2O3 to the material, after high temperature firing or use, Cr3 plus is oxidized to Cr6 plus, Cr6 plus 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 high temperature function without adding Cr2O3 can reach the level of adding Cr2O3.

Thermal shock resistance of breathable bricks

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

The oxides or non-oxides 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