Best Castable Material for Heat Furnace Castable Lining
The best castable material for heat furnace castable, its main feature is high early strength, 3-7 days maximum normal temperature compressive strength can reach more than 30MPa. The disadvantage is that the volume stability at medium temperature is poor, the strength is reduced, and the maximum reduction can reach about 40%. Therefore, it is required that the compressive strength at room temperature must meet the requirements of design and national standards.
Why is the best castable material for heat furnace castable can resistant to high temperatures?
The best castable material for heat furnace castable is able to withstand high temperatures, however, its moderate temperature strength drop is relatively low. The main factor is. When the low-calcium and high-alumina cement of the castable refractory reaches a certain temperature (about 350°C) during the heating process of the heating furnace, the hydrate begins to dehydrate and transform, which reduces the cement stone structure, compactness, and strength of the hydrate. When the volume of the castable changes, the strength of the castable body decreases to the lowest point and then tends to stabilize. As the heating temperature rises to 1100°C, the cement stone gradually sinters, and the heating furnace castable crystal form begins to transform into mullite crystals. As the temperature continues to rise, the mullite crystals continue to grow, and the matrix glass phase in the heat furnace castable is in a liquid state, forming a high-temperature ceramic sintering shape, and the strength is significantly improved. At around 1300°C, the strength of the best castable material for heat furnace castable body can reach more than 60MPa, which is also a significant feature of the heat furnace castable at high temperature.
Evolution and development of heat furnace castable
Refractories can be roughly divided into shaped refractories and unshaped refractories (or bulk refractories) according to their shapes. Among them, the unshaped refractory materials include refractory castables, refractory spray coatings, refractory ramming materials, refractory plastics, refractory projection materials, and refractory pressed materials. Refractory mud (refractory mortar), refractory mud, refractory dry mixture (or refractory dry vibrating material), refractory coating and ceramic fiber, and other varieties.
With the rapid development and improvement of the high-temperature smelting industry, especially the metallurgical industry, the requirements for unshaped refractories are getting higher and higher. Due to the use of high-quality raw materials (including ultra-fine powder), new binders, high-efficiency additives, and optimized particle composition. As well to perfect construction technology (including construction equipment), great progress has been made in the development of amorphous refractory materials (especially the best castable material for heat furnaces castable).
Unshaped refractory materials (especially best castable material for heat furnace castable) have entered the high-temperature environment (1600~1700℃), and have achieved good results in use. Even when used in harsh environments such as chemical attacks by slag or alkali, high-temperature airflow, high-temperature melt impact, and rapid thermal shock, its service life is improved.
The best castable material for heat furnace castable has developed from traditional refractory castables (CC) to low cement (LCC) and even ultra-low cement (ULCC), no cement (NCC) refractory castables. These refractories have better thermodynamic properties and corrosion resistance. At the same time, the development and application of self-flowing refractory castable (SFRC) and pumping refractory castable as well as refractory injection. In order to improve the construction of difficult-to-construct parts in the kiln, such as corners, slits, holes, etc., the reliability is improved, the quality can also be guaranteed, and the use effect is outstanding.
The goal of further development of the best castable material for heat furnaces castable is to develop better results for users. The refractory castable has lower manufacturing costs, higher performance, and can withstand more severe service conditions.
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