There are significant differences in composition, performance and application between high-alumina nozzle brick and aluminum-carbon nozzle brick. The following are their main differences:

I. Composition differences

High alumina nozzle brick: The main component is alumina (Al₂O₃), and the content is usually above 48%. It belongs to neutral refractory material and contains a small amount of impurities and glass phase.

Aluminum-carbon nozzle brick: mainly composed of aluminum oxide (Al₂O₃) and carbon materials (such as graphite), and materials such as silicon carbide (SiC) are usually added. This material combines the corrosion resistance of alumina with the high thermal conductivity and low expansion coefficient of carbon materials.

II. Performance differences

Fire resistance: The fire resistance of high-alumina nozzle brick is between 1750℃ and 1790℃.

The fire resistance of aluminum-carbon nozzle brick is usually higher, which can reach above 1700℃.

Corrosion resistance: The high-alumina nozzle brick has certain corrosion resistance to both acidic and alkaline slag, but its resistance to alkaline slag is relatively weak due to a small amount of SiO₂.

Aluminum-carbon nozzle brick has excellent corrosion resistance, especially the corrosion resistance of alkaline slag and TiO₂ slag.

Thermal shock resistance: the thermal shock resistance of high-alumina nozzle brick is better, but it is not as good as that of aluminum-carbon nozzle brick.

Aluminum-carbon nozzle brick has higher thermal shock resistance and erosion resistance because of its carbon composition.

Oxidation resistance: The oxidation resistance of high-alumina nozzle brick is better, but not as good as that of alumina-carbon nozzle brick.

The oxidation resistance of aluminum-carbon nozzle brick is significantly better than that of magnesium-carbon brick, and it is suitable for use in high temperature oxidizing atmosphere.

III. Application differences

High-alumina nozzle brick: suitable for pouring ordinary steel grades, especially when the requirements for corrosion resistance of refractories are not particularly high.

Widely used in blast furnace, hot blast stove, electric furnace top, blast furnace and other equipment.

Aluminum-carbon nozzle brick: it is mainly used for slide gate, submerged nozzle and integral stopper of continuous casting system.

Suitable for high manganese steel, stainless steel and other steels with higher requirements for refractory properties.

IV. Differences in production processes

High alumina nozzle brick: The traditional firing process is adopted, and the production process is relatively simple.

Aluminum-carbon nozzle brick: it can be fired or unfired, which has the advantages of short production cycle and environmental protection.

V. Summary

High-alumina nozzle brick and alumina-carbon nozzle brick have their own advantages and disadvantages, and which material to choose depends on the specific use scenarios and performance requirements. High-alumina nozzle brick is suitable for pouring ordinary steel, while alumina-carbon nozzle brick is more suitable for continuous casting process with higher requirements on refractories.