Cement Rotary Kiln Firing Belt Refractory Materials Need To Meet These 9 Requirements

        During the working process of cement rotary kiln, the refractory bricks at the pallet are subjected to the extrusion effect of the kiln body, and when the refractory bricks are turned to the top of the kiln, they are subjected to the stretching of the kiln skin and the weight of the bricks. Therefore, the refractory bricks in the firing zone of large dry-process cement kilns are subjected to the comprehensive mechanical stresses of kiln deformation, extrusion between bricks and bricks, and torsion and tension in the kiln. Therefore, the refractory bricks in the firing zone should have high mechanical strength at room temperature and high temperature, so that they can withstand the role of mechanical stress generated between the kiln lining materials, kiln lining and rotary kiln cylinder.

        When the cement plant for some reason kiln maintenance, due to temperature changes, may cause a large number of refractory bricks on the surface of the kiln skin off, in the process of kiln skin off will probably be accompanied by a part of the refractory bricks flaking, which will greatly affect the refractory bricks of the use of the length of time. So the refractory bricks must have a strong resistance to spalling performance, so that with the kiln skin off and spalling refractory bricks layer is thinner, the service life of the refractory bricks can also get a better guarantee.

        In the production process of large dry-process cement rotary kiln, whether the hot working surface of the refractory material of the rotary kiln firing belt can be glued with a layer of uniform, stable and suitable thickness of kiln skin is crucial to improving the service life of the refractory material and thus the working life of the cement rotary kiln. The existence of stable kiln skin can reduce the erosion of high temperature cement clinker on the refractory material, at the same time, stable kiln skin can hinder the conduction of heat, reduce the working temperature of refractory material, which reduces the temperature of the rotary kiln cylinder, thus preventing the rotary kiln cylinder from localized overheating and resulting in deformation, reducing the service life.

        Refractories in cement kilns will be eroded by cement clinker when the kiln is in operation. The erosion of cement clinker will change the internal structure of the bricks and deteriorate the performance of the bricks, so the refractories applied in the firing zone of the cement rotary kiln must be strong in resistance to the chemical erosion of the high-temperature clinker.

        Large dry process cement rotary kiln in the rotation of a week, the refractory brick hot surface can produce 200 ~ 300 ℃ temperature change, especially in the cement kiln operation when there is no regularity, constantly stopping the kiln for inspection and maintenance, the refractory bricks withstand the temperature difference is very large, so the refractory bricks in the cement rotary kiln must have a good thermal shock stability performance.

06 Low thermal conductivity and coefficient of expansion

        In order to reduce the heat loss of the kiln barrel, the thermal conductivity of the refractory bricks is required to be low, which can reduce the temperature of the surface of the kiln barrel and reduce the energy consumption. Refractory bricks after heat expansion, will form a huge extrusion stress between the refractory bricks, if the refractory bricks itself is not strong enough, will cause damage to the brick body, and lower coefficient of thermal expansion of the refractory bricks after heat expansion will be much smaller, the brick and the brick between the stress generated will be much smaller, the refractory bricks to achieve a good service life is also a great help.

07 Good resistance to hydration

        In some cases, the refractory bricks may take about one year from production to masonry to be used in the rotary kiln, during which the quality of the refractory bricks must be ensured to be stable without obvious quality degradation problems. The hydration of alkaline bricks is a problem that must be considered, especially dolomite bricks and magnesium-rich dolomite bricks, etc., the resistance to hydration should be good.

08 The overall appearance of the brick type is regular, the difference of the size of the tolerance is small

        The construction process inside the cement rotary kiln cylinder requires the refractory bricks to have the correct brick type and small size tolerance, otherwise the masonry process of refractory bricks will result in a ring of bricks that can't be closed, or cause the rotary kiln body to cause draws and drop bricks during operation, all of which will seriously affect the normal production operations of the cement kiln.

09 Low or even no chromium as far as possible to minimize chromium hazards

        New dry-process cement rotary kiln firing belt large-scale use of direct bonded magnesium-chromium bricks, this material after use will cause Cr6+ pollution, serious pollution of the environment. Therefore, it is required that the refractory materials in the cement kiln are chromium-free or low-chromium to reduce the chromium pollution.