Refractory castable is a new refractory with good fluidity without calcination and water agitation. It is an important variety of amorphous refractories. The mixture of refractory aggregate, refractory powder and cementing agent (or admixture) is made up of a certain proportion. It can be produced in the form of scattered form, and can also be made into prefabricated parts.

Refractory castables are usually classified according to the type of cementing agent, the variety of refractory aggregate and the size of the porosity. According to the type and combination of cementing agent, it can be divided into:

(1) water-bonded castables, such as portland cement-bonded refractory castables; Aluminate cement combined with refractory castable; p - Al2O3 combined with refractory castable.

(2) The combination of hydration and coagulation combined castables, such as low cement combined with refractory castables, ultra- low cement combined with refractory castables.

(3) Aggregate - bonded castables, such as clay - bonded refractory castables, ultrafine powder - bonded refractory castables, silica sol or aluminum sol - bonded refractory castables.

(4) Chemical -bonded castables, such as soluble glass combined with refractory castables, phosphoric acid and phosphate -bonded refractory castables, polyphosphate -bonded refractory castables, sulfate- bonded refractory castables and phenolic resin castable

According to the variety of refractory raw materials divided into silicon refractory, semi –silica refractory , clay refractory, high- alumina refractory, corundum refractory, spine refractoyl, magnesia refractory, and special assembly refractory castable (special assembly including silicide of carbon, chromite slag and zircon according to porosity can be devided into dense castable and lightweight castable.