With the continuous update and progress of cement production technology, the single production line of cement kiln is developing towards large-scale. The new dry-process cement production technology has the advantages of high kiln temperature, fast kiln speed, complex system structure, and serious erosion of volatile components such as alkali. and other characteristics, which puts forward more stringent requirements for refractory materials for cement kilns. Unshaped refractory materials have been widely used in the cement industry due to their excellent performance, convenient construction and energy saving, accounting for about 50%.
However, unshaped refractory materials have higher requirements on site construction quality, and are prone to excessive water addition on site, resulting in rapid performance degradation of castables and bursting during the baking process. The prefabricated part is to shape the unshaped refractory material. The preparation process is between the shaped refractory material and the unshaped refractory material. It has the advantages of both shape and shape in terms of performance. The new direction has developed rapidly in recent years.
Refractory prefabricated parts are to divide the pre-constructed parts into small pieces in advance, and design a suitable shape, and then make a mold according to the shape, and then pour it in the factory, after curing, and baking, it is transported to the site for construction and installation. The application of refractory prefabricated parts changes the method of on-site pouring construction of traditional castables, making the construction simple and easy, eliminating the need for on-site stirring, pouring or ramming and the corresponding equipment required, greatly saving construction time, and making on-site construction. The conditions are not affected by the construction environment and season, which is more conducive to ensuring the construction quality. In order to facilitate production, transportation and installation, the shape of the prefabricated parts should not be designed to be too large and complicated, and the size should be as uniform as possible. In addition, the combination of blocks should be considered to enhance the integration effect after construction. The construction site needs to be cleaned, otherwise the installation accuracy and effect of the refractory prefab will be affected.
Most of the parts used in refractory prefabricated parts are in special parts under severe environments such as high temperature, cement clinker erosion, abrasion, rapid cooling and rapid heating, which are prone to mechanical deformation and need to have good erosion resistance, good wear resistance and high temperature gas resistance. Washability and excellent thermal shock stability. In order to meet the performance requirements, the ratio of raw materials is the basis, which is similar to the requirements of castables, but the castables need to pay attention to the performance of the whole temperature range from construction to use conditions, and refractory prefabricated parts are used as castables. , pay attention to the performance after baking. Many manufacturers list the performance indicators of prefabricated parts under different temperature conditions, but in fact, it is of little reference for cement manufacturers. In view of this situation, the raw materials and proportions used in refractory preforms can be adjusted on the basis of castables, and more attention needs to be paid to the performance after baking.
The refractory materials in the key parts of the cement kiln require high construction quality during the construction process. During the maintenance period of the cement kiln, the general construction period is short, and the construction quality of on-site pouring is difficult to guarantee. The quality of the construction quality has a great impact on the service life of the refractory materials. Impact. The increase of water addition will increase the porosity of the castable, reduce the strength, and seriously affect the wear resistance of the castable. After the construction of the castable is completed, there must be a certain curing time. After the curing is completed, it must be baked, otherwise it is easy to burst.
Since the production process of refractory prefabricated parts is carried out in the production enterprise, it can overcome the adverse effects caused by the tight construction time on site, environmental seasonal temperature changes, and on-site construction management. The quality problems caused by non-standard construction make the performance of refractory materials fully exerted. After installation, it is directly ignited and used, which shortens the maintenance time and can create good economic benefits.