What's the refractory material in common use currently?
According to its category, raw material of basic refractory: Mainly magnesite (magnesia), dolomite, lime, olivine, serpentine, high alumina material (sometimes neutral); main neutral raw material: chromite, graphite, silicon carbide (artificial).
(1) Alumina-silica refractory brick: Except the transition band, hot end and firing zone of the rotatory cement kiln, it can be applied to the whole burning system of the precalcining kiln, such as the fixed wall lining, wicket, cooling machine, tertiary air duct, burner, etc. It mainly includes alkali-resisting brick, high alumina (anti stripping) brick, silica-mullite brick, etc. (2) Basic refractory: For the upper transition band close to the part of burning zone and the burning zone, its inner lining can endure the highest flame temperature of 2000℃ and material temperature of 1350℃-1400℃, and it also has to withstand the permeation of sulfur and alkali compounds, permeation, thermal shock and oxidoreduction of hot-melt clinkers (liquid phase), mechanical stress of elliptic cylinder deformation, etc. Therefore, inner linings are the most demanding parts to withstand stress, and only basic refractory can meet with requirements under this working condition. (3) Fireclay insulating refractory: Its microstructure has notable characteristics of high porosity, large pore size and thermal insulation performance. For its low volume density and light weight, it is usually referred to as lightweight refractory. Fireclay insulating refractory product has great varieties, and it is usually classified and named according to its chemical and mineral compositions or production raw materials, and it is also classified according to its operating temperature and material form. Currently, the most used main thermal insulation material for the precalciner kiln system at home and abroad is calcium silicate board; besides, light weight castable and insulating fire brick are increasingly used year by year. Other thermal insulation materials are mainly ceramic fiber products.
