The main reference indexes of refractory bricks are the following three points:
1. Refractoriness
The refractoriness of high alumina bricks is higher than that of clay refractory bricks and semi-silica bricks, reaching 1750~1790℃, which is a high-grade refractory material.

2. Load softening temperature
Because high-alumina products have high Al2O3, fewer impurities, and fewer fusible glass bodies, the load softening temperature is higher than that of clay bricks. However, because mullite crystals do not form a network structure, the load softening temperature is still not as high as that of silica bricks.

3. Slag resistance
High-alumina refractory bricks contain more Al2O3, which is close to neutral refractory materials and can resist the erosion of acidic slag and alkaline slag. Because it contains SiO2, the ability to resist alkaline slag is weaker than that of acidic slag.

Therefore, refractory bricks have a wide range of uses, mainly used for lining blast furnaces, hot blast furnaces, electric furnace roofs, blast furnaces, reverberatory furnaces, and rotary kilns. In addition, high alumina bricks are also widely used as open-hearth regenerative checker bricks, plugs for pouring systems, nozzle bricks, etc.