Unshaped refractories are usually called refractory castables and bulk refractories. They are made by mixing certain graded refractory aggregates and powdered materials with binders and additives. They are used directly without forming and firing processes. A type of refractory material.

Refractory castables are refractory mixtures composed of refractory aggregates, fine powder, additives and binders, which are mixed and kneaded. Refractory castable is a new type of refractory that does not need to be fired at high temperature, is directly used after construction and baking, and has simple production technology, energy and labor saving, mechanized construction, good integrity, easy repair and long life.

Refractory castables are usually classified according to the size of the porosity, the selected bonding agent or bonding method, the type of aggregate and the construction method.

According to the porosity, it can be divided into dense refractory castables and insulated refractory castables.

Classified by bonding method, refractory castables can be divided into hydration combined refractory castables, chemically combined (including polymerization combined) refractory castables, hydration and polymerization combined refractory castables (typically represented by low cement combined refractory castables) and agglomeration Combine four types of refractory castables.

Classified according to the special effects of binding agents and certain materials, they can be divided into the following 7 categories:

(1) Clay combined with refractory castable;

(2) Ultrafine powder (such as silica fume, etc.) combined with refractory castable;

(3) Cement combined with refractory castable;

(4) chemically combined with refractory castable;

(5) p-Al20: (hydrated A203) combined with refractory castable;

(6) Low cement combined refractory castable;

(7) Silicon and aluminum sol (sol-gel) combined with refractory castables.

According to the combination of raw materials, refractory castables can be divided into oxide refractory castables, non-oxide refractory castables and composite refractory castables. Oxide refractory castables can be subdivided into non-alkaline refractory castables and alkaline refractory castables.

According to the construction method, refractory castables (body) can be divided into vibration construction type refractory castables and self-flowing refractory castables.

According to whether the refractory castable contains cement content or CaO content, it can be simply divided into four categories: ordinary refractory castable, low cement refractory castable, ultra-low cement refractory castable and cement-free refractory castable.

Refractory cast components or integral linings are prepared by vibrating table, vibrator, vibration-pressurization molding or self-flow pouring construction and other processes.