High alumina bricks and clay bricks are two common refractory materials. They have significant differences in composition, performance and application. Here are their main differences:
Differences in ingredients
High alumina bricks: The main component of high alumina bricks is alumina (Al2O3), whose content is usually more than 48%. In addition, high alumina bricks may also contain other ingredients, such as sillimanite, kyanite, etc.
Clay bricks: The main component of clay bricks is aluminum silicate, with the alumina content usually ranging from 30% to 40%. Clay bricks also contain a certain amount of impurities, such as potassium, sodium, calcium, titanium and iron oxides.
Performance differences
Refractory resistance: The refractory resistance of high-alumina bricks is usually higher than that of clay bricks. The fire resistance of high alumina bricks can reach 1750-1790 degrees, while the fire resistance of clay bricks is relatively low.
Load softening temperature: The load softening temperature of high alumina bricks is also higher than that of clay bricks. The load softening temperature of high alumina bricks is generally above 1420-1550 degrees, while the load softening temperature of clay bricks is lower.
Slag resistance: The slag resistance of high alumina bricks (especially against acidic slag) is good and increases with the increase in alumina content. Clay bricks have relatively weak slag resistance.
Thermal stability: The thermal stability of clay bricks is better than that of high alumina bricks, and they can maintain good performance under rapid cooling and heating conditions.
Application differences
High alumina bricks: High alumina bricks are mainly used in applications requiring high temperature and high strength, such as blast furnaces, hot blast furnaces, electric furnace tops, blast furnaces, reverberatory furnaces and rotary kiln linings. In addition, high alumina bricks are also widely used in open-hearth furnace regenerative checker bricks, plugs for pouring systems, etc.
Clay bricks: Clay bricks are usually used in secondary parts of coke ovens, such as regenerator sealing walls, small flue lining bricks, regenerator checker bricks, furnace door lining bricks, furnace roof and riser lining bricks, etc. Due to its low softening temperature under load, clay bricks are not suitable for use in high-temperature load-bearing areas.
price difference
High alumina bricks: Due to the particularity of their composition and manufacturing process, the price of high alumina bricks is usually higher than that of clay bricks.
Clay bricks: Relatively speaking, clay bricks are relatively cheap and suitable for some occasions that do not require high-performance refractory materials.
To sum up, there are significant differences between high alumina bricks and clay bricks in terms of composition, performance, application and price. Which brick you choose depends on your specific application needs and budget.