Type of refractory castable
Mainly classified according to porosity, binder and aggregate. In actual use, it is often classified by the use temperature or functional characteristics.
According to the porosity, there are two kinds of dense refractory castables and insulated refractory materials with a porosity of not less than 45%.
According to the bonding agent, there are hydraulically bonded, chemically bonded, and agglomerated bonded refractory castables.
The hydraulically bonded castables are coagulated and hardened at normal temperature and hardened by hydration. The main varieties are Portland cement, ordinary calcium aluminate cement, pure calcium aluminate cement, and fused pure calcium aluminate cement castables. The chemically bonded castable is generally hardened by adding a hardening agent to form a chemical reaction at a normal temperature, and the main varieties are water glass, aluminum sulfate, phosphate castable, and the like. The coagulation combined with the castable is hardened by sintering during the calcination process, and the main varieties are clay castables and the like.
According to refractory aggregate, there are clay aggregate (Al2O3 30%~45%), high alumina aggregate (Al2O3%26ge; 45%), siliceous aggregate (SiO2%26ge; 85%, Al2O3%26lt; 10 %), alkaline aggregates (with magnesia, dolomite, etc.), special aggregates (with carbon, carbide, spinel, zircon, nitride, etc.) and insulating aggregates (with perlite, enamel) Stone, ceramsite, floating beads, lightweight brick sand, porous clinker, alumina hollow spheres, etc.). In actual use, certain mixed aggregates are allowed according to engineering requirements.
Technical characteristics and application of refractory castables
As a main type of refractory castable of unshaped refractory material, in addition to the common features that can be directly used without firing, the production process is simple in many types of amorphous refractory materials, no special equipment is required, the degree of mechanization is high, and the construction is the most Simple, high material utilization rate, in addition, generally has a high room temperature strength, can be made into prefabricated parts installed in the kiln spinning site, such as continuous casting of the intermediate tank with refractory castable slab prefabricated parts installed (see color map insert page 20 pages). Refractory castables are mainly used in metallurgical industrial furnaces and are also widely used in kiln and thermal equipment in petroleum, chemical, building materials, power and machinery industries.
