What are the Advantages of Lightweight Mullite Castables? Lightweight mullite castables can be used for working linings or thermal insulation linings of various flame kilns and other industrial furnaces. The use temperature is high, it can directly contact the flame, and the performance is excellent. The energy-saving effect of the kiln is enhanced, and it has the characteristics of high strength, good heat insulation, and long service life.
Advantages of Lightweight Mullite Castables
- ①Suitable for working lining or thermal insulation lining of various flame furnaces and other industrial furnaces, realizing high temperature and energy saving.
- ②High strength and small unit weight. It can be used as the roof, wall, and door of an industrial kiln, and its structural weight is reduced by more than 30% compared with ordinary low cement castable. Hidden dangers such as structural broken bricks and collapse are eliminated.
- ③Using high-quality porous mullite as aggregate, combined with a variety of micro-powders and dispersants, it has low thermal conductivity and a good heat preservation effect. Compared with ordinary castables, it can reduce the heat loss of the kiln by 25% to 35% and save fuel by about 10%.
- ④The construction is simple. It can not only be cast as a whole on-site but also be combined and installed with any shape of prefabricated parts.
The variety and quality of aggregate have a significant impact on a series of properties of lightweight castables, such as bulk density, strength, heat insulation, and maximum use temperature. The aggregate is artificially synthesized from selected natural raw materials at a high temperature of 1680°C. The aggregate mullite chemical reaction is good, the main crystal phase reaches more than 70%, and the composition is uniform and stable. Mullite crystals are needle-like interlaced to form a network structure, which is very beneficial to the strength and high-temperature indicators of lightweight castables.
In order to meet the high-temperature use environment, the cement adopts pure calcium aluminate type cement with Al2O3 content greater than 75%, and the main powder is mullite powder and aluminum powder. Adding a proper amount of silicon powder and dispersant can reduce the water consumption of the castable and improve fluidity. A variety of micro-powder compounding methods can ensure the construction and use performance of lightweight castables.
In view of the large water absorption rate of the light aggregate itself, the line shrinks greatly after burning, which is likely to cause shrinkage cracks in the entire masonry. While selecting a variety of micro-powders to improve the performance, the appropriate addition of a part of aluminum-containing fine powder and high-quality kyanite imported from the United States can promote the continuous expansion of the cast body in high-temperature use. Ensure the volume stability of lightweight castables at different temperatures.