Generally, the rotary kiln is divided into several zones: the feed zone (pre-tropical zone), the lower transition zone, the upper transition zone, the firing zone, and the discharge zone (cooling zone).The refractory bricks used are different because of the different working conditions in each location.

Feeding zone: The zone is generally made of phosphate-bonded high-alumina brick, anti-flaking high-aluminum brick, and alkali-resistant brick. The kiln tail feeding port should adopt anti-skinning silicon carbide castable.

Lower transition zone: The temperature of the zone is relatively low, and the thermal conductivity of the brick lining is required to be small and wear-resistant; generally, the anti-stripping high-aluminum brick is used, and the silicon-moulder brick is superior in performance to the anti-flaking high-aluminum brick, and the life ratio is higher than the anti-flaking high-aluminum brick. The brick is about 1 times higher and the price is about 1.5 times that of the high alumina brick.

Upper transition zone: The kiln skin is unstable, the kiln lining is required to resist the change of atmosphere, the thermal shock stability is good, the thermal conductivity is small, and the wear resistance is high; the magnesium-aluminum spinel brick is recommended abroad, but the thermal conductivity of the brick is large. Domestic silicon bricks have small thermal conductivity and anti-wear, and the performance is comparable to imported materials to a certain extent.

Firing zone: The zone has high temperature and strong chemical reaction. It requires brick lining to resist clinker erosion, strong resistance to SO3 and CO2, environmental protection requirements without chromium pollution, magnesium chromium products have poor resistance to SO3 and CO2, and react with clinker. The production of CrO3 results in a short service life. Magnesium-aluminum spinel bricks are generally used in foreign countries, but the bricks are difficult to hang kiln skin, and the thermal shock stability of dolomite bricks is not good and easy to hydrate; foreign magnesium iron spinel The effect of bricks on the kiln skin is better, but the cost is too high. The use of low-chromium pericardite composite spinel bricks in China is better.

Unloading zone: The kiln skin is unstable and the temperature fluctuates greatly. The thermal conductivity of the brick lining is required to be small, wear-resistant and heat-resistant. The spinel brick is generally recommended abroad, but the thermal conductivity of the spinel brick is large. The wear resistance is not good. In recent years, the domestic use of silicon grinding bricks and anti-stripping wear-resistant bricks; the kiln mouth parts are made of heat-resistant castables.