Many parts of the cement rotary kiln require the use of refractory materials, such as smoke chambers, kiln head covers, grate coolers, tertiary air ducts, etc. The smoke chambers generally use high alumina refractory castables, crust-resistant castables, Calcium silicate board, kiln head cover uses high-aluminum high-strength castable, calcium silicate board, grate cooler uses vault alkali-resistant brick, high-alumina refractory castable, steel fiber reinforced castable and other refractory materials Then, what kind of performance do these refractory materials need to meet the production requirements? Let's take a look together.
1.High temperature resistance
In general, the fire resistance of alkaline bricks used in fired belts is as high as 1750 to 1790 degrees, so in general, the fire resistance of fired materials used in fired belts should be 1730 degrees.
2, easy to hang the kiln skin
For the new dry-process Quartz Grinding Machine , if there is no kiln skin to protect its alkaline bricks, it will cause cracking and spalling because the temperature difference stress in the brick is too large, because the flame temperature in the new dry-process rotary kiln is higher than 1700 ° C. The kiln skin protects the alkaline transition. When the temperature of the kiln changes frequently, the kiln skin is not easy to hang, which will make the alkaline bricks often exposed, which will greatly reduce the life of the alkaline transition.
3. Chemical resistance
Refractory materials must have good chemical resistance. The clinker and kiln skin are still sintered into the refractory bricks after melting at high temperature, because the clinker or kiln skin is chemically characterized by strong alkalinity. We all know that strong chemical attack will change the chemical composition of refractory materials. Especially when the material in the firing zone contains about 20-25% liquid phase. At the same time, the gases produced by combustion and sulfur, chlorine, and alkali volatilized from clinker will also attack various refractory materials.
4. Thermal shock stability
The refractory used must have good thermal shock stability, because under normal circumstances, the refractory in the kiln will be exposed to the hot kiln gas once every turn of the rotary kiln, and the rest will be covered by the material. This will cause the surface temperature of the refractory material in the kiln to be periodically fluctuated, which requires the refractory material to have high thermal shock stability.
In addition to the above points, refractory materials are required to have higher mechanical strength, lower thermal expansion coefficient, and lower porosity.
The Wall