High alumina bricks are a crucial component in rotary kiln cement plants. They are used to line the interior of the kiln, which can reach extremely high temperatures (up to 1500°C or 2732°F) during the cement production process.
Here’s why high alumina bricks are particularly suited for this application:
High Alumina Content: As the name suggests, high alumina bricks contain a high percentage of alumina (aluminum oxide, Al2O3), typically ranging from 75% to 95%. Alumina is a refractory material, meaning it has a very high melting point and can withstand intense heat without melting or deforming.
Excellent Thermal Properties: High alumina bricks have excellent thermal shock resistance, which is the ability to withstand rapid changes in temperature without cracking or spalling. This is essential in a rotary kiln environment where the temperature fluctuates constantly.
Strong and Durable: High alumina bricks are also very strong and durable, withstanding the high compressive loads and abrasive wear that occur inside a rotary kiln.
Corrosion Resistance: They exhibit good resistance to chemical attack from the raw materials and clinker (the intermediate product) used in cement production.
However, it’s important to note that high alumina bricks are not the only type of refractory brick used in a rotary kiln. Different zones within the kiln experience different conditions, so other types of bricks, such as magnesia and magnesia-chrome bricks, are used in specific areas to optimize performance and lifespan.