Following are constantly improvements of the cement industry, the rotary kiln as the core part of cement production lines is developing to be large scale short kiln, but the process is more complicated and more strictly requirement on refractory materials. our recommended REFRACTORY analyzed the matched refractory materials for rotary kiln linings for reference.
Normally, rotary kiln can be with wet process and dry process types, both include below working zones: Discharge end/outlet zone, Lower transition zone, central burning zone, Upper transition zone, Safety Zone, Preheating zone/Calcining zone, Chain zone, Inlet zone, Inlet
Refractory lining recommendation for different zones:
Inlet zone
Phosphate combined with high alumina brick
Anti-spalling high alumina brick
Alkali-resistant fire brick
Anti-skinning SiC castable
Lower transition zone
Lower transition zone operating temperature is lower, but ling bricks should be with lower thermal conductivity and wear resistance. The economic choice is anti-spalling high alumina brick, but high alumina brick with SiC is superb in chemical and physical properties and longer service life.
Anti-spalling high alumina brick
High alumina brick with SiC/ Silica-mullite brick
Upper transition zone
Upper transition zone lining is quite unstable, it requests lining bricks with good thermal shock resistance, also lower thermal conductivity, and wear resistance characteristics. In the global market, Magnesia spinel brick is widely used in cement kiln linings, but Magnesia brick is with higher thermal conductivity compared with China’s high alumina with SiC. And today silica-mullite brick is also the best option for large-scale cement rotary kiln.
Magnesia spinel brick
High alumina with SiC/Silica-mullite brick
Burning zone
Burning zone operating temperature max approx. to be 1650℃， with intense chemical reaction in this area. In this strict condition, lining bricks should be with multiple characters of anti-erosion, environment protection without chromium. Magnesia spinel brick is applied by the global market but with poor performance on hanging kiln skin. Magnesia-Fe spinel brick is a better choice, but costly.
Magnesia spinel brick
Magnesia-Fe spinel brick
Outlet zone
Outlet zone lining is quite unstable, the temperature is easily up and down due to operating necessaries, thus lining bricks have to be with good thermal shock resistance, also lower thermal conductivity, and wear resistance characteristics. In the global market, Magnesia spinel brick is widely used in cement kiln linings, but Magnesia brick is with higher thermal conductivity compared with China’s high alumina with SiC. Today silica-mullite brick is the best option for large-scale cement rotary kilns. And thermal shock-resistant castables are widely used for the outlet zone.
Anti-spalling high alumina brick
High alumina brick with SiC/ Silica-mullite brick
Thermal shock resistant castable