Rotary kilns provide material transfer while increasing the material temperature as it is transferred to the discharge. Cement rotary kilns are commonly referred to as the largest piece of rotating equipment in the world. Ranging in diameter from 10 feet to more than 20 feet, they are often many hundreds of feet long. As the kiln rotates on its rollers, material is transported due to the kiln’s low, gradual slope. Material entering the kiln at a few hundred degrees Celsius is heated to 1450°C as it nears the discharge where the burner pipe is located. Once the material reaches 1450°C (at which point it is referred to as “clinker”), it is quickly cooled to quench the material, providing a quality product.
Nonbasic bricks belong to the alumina-silica group of refractories containing more than 45 percent alumina. This class of multipurpose refractories is useful for service temperatures extending to about 1800°C. HarbisonWalker International offers a wide range of nonbasic or alumina bricks—from super-duty (KX-99®-BF) in the inlet area to 80 percent (ALADIN® 80 and CORAL® BP) as you move toward the outlet of the kiln. Often chosen for their resistance to spalling, impact, and abrasion resistance, our products’ main appeal is their high refractoriness.
Basic bricks are also commonly used in rotary kilns. These refractories are composed primarily of basic oxides and used in high-temperature applications. HWI’s basic bricks include the MAGNEL® and VESTA families. Magnel® RS, Magnel® Ultra AF, and Magnel® Ultra are known for being highly resistant to the corrosive action of chemically basic slags, solid or liquid oxides, dusts, and fumes.