Corundum-spinel breathable bricks for ladle bottom blowing

Corundum-spinel breathable bricks for ladle bottom blowing are very critical functional components in the off-furnace refining process. Their performance has an important impact on the smooth implementation of the refining process, the quality of steel and the output. The following is a detailed analysis of the breathable brick:

1. Material composition

Corundum-spinel breathable bricks are mainly composed of raw materials such as fused corundum, spinel, magnesia, α-Al₂O₃ powder, CA80 cement, silicon powder, zircon powder, etc. Among them, fused corundum and spinel are the main aggregates with excellent properties such as high melting point, high hardness and wear resistance; magnesia and α-Al₂O₃ powder are used as matrix materials to improve the density and slag resistance of the material.

2. Performance characteristics

Wear resistance and erosion resistance: Corundum-spinel breathable bricks have strong wear resistance and erosion resistance, and can maintain a long service life in harsh smelting environments.

Chemical stability: The air brick has good chemical stability, which can avoid carbonization of molten steel or adversely affect the total oxygen content of molten steel.

Slag resistance and thermal shock resistance: It has excellent slag resistance and thermal shock resistance, and can withstand the erosion of high-temperature molten steel and slag and the thermal stress caused by rapid temperature changes.

Volume stability and thermal shock stability: Although the volume stability of corundum-spinel air bricks may be slightly inferior to that of traditional chrome corundum bricks, its thermal shock stability is superior. This is mainly due to the good stability and thermal shock performance of the spinel phase at high temperatures.

3. Preparation process

The preparation process of corundum-spinel air bricks usually includes steps such as raw material ratio, mixing, molding, drying and firing. During the preparation process, the particle size and ratio of the raw materials need to be strictly controlled to ensure that the performance of the air bricks is optimal. At the same time, the use of advanced molding technology and heat treatment technology is also an important means to improve the performance of air bricks.

4. Application effect

In practical applications, corundum-spinel air bricks have shown good use effects. For example, in the ladle bottom argon blowing process, the air brick can effectively stir the molten steel and promote the rapid dispersion and melting of additives such as alloys, deoxidizers, and desulfurizers, so as to achieve the purpose of degassing, decarburization, and removal of oxide inclusions. In addition, corundum-spinel air bricks also have the advantages of high blowing rate, safe and reliable operation, and long service life, which can significantly improve the production efficiency and product quality of the off-furnace refining process.

V. Precautions

When using corundum-spinel air bricks, the following points should be noted:

Regular inspection and maintenance: Regularly check the wear and permeability of the air bricks, and replace damaged air bricks in time to ensure the smooth progress of the refining process.

Avoid excessive thermal shock: Try to avoid excessive temperature fluctuations of air bricks in a short period of time to reduce the destructive effect of thermal stress on the material.

Reasonable control of smelting conditions: Reasonable control of temperature, pressure and other conditions during the smelting process to reduce erosion and damage to the air bricks.

In summary, corundum-spinel air brick for ladle bottom blowing is a refractory material with excellent performance and significant use effect. In the future development, with the continuous improvement of preparation technology and the continuous emergence of new materials, the performance and application scope of this air brick are expected to be further improved and expanded.