Materials whose physical and chemical properties permit them to be used at high temperatures are called refractories.Unshaped refractory castable is also known as refractory castable, is a kind of granular and powder materials made by refractory materials to join a certain amount of binder, with higher fluidity, casting way of forming.Widely used in metallurgy, chemical industry, machinery manufacturing, power and other industrial fields, in the metallurgical industry, the largest amount.
Castable are mainly classified according to porosity, binder and aggregate type:
1. According to the porosity distribution, there are two types of dense refractory castable and heat-insulating refractory castable whose porosity is not less than 45%;
2. Hydraulically-bonded, chemically bonded and agglomeration-bonded refractory castable are divided according to the binder:
1) Hydraulic combined castable solidifies and hardens at room temperature through hydration. The main varieties are Portland cement, ordinary calcium aluminate cement, pure calcium aluminate cement, electrofused pure calcium aluminate cement castable, etc.;
2) Chemically bonded castables generally form a chemical reaction to harden at room temperature by adding hardening agents. The main varieties include sodium silicate, aluminum sulfate, phosphate castables, etc.;
3) Coagulated and combined castable is hardened by sintering in the calcining process, and the main varieties are clay castable, etc.
3, according to refractory aggregate divided into: clay castable, high aluminum castable, silicon castable, alkaline castable, special castable and insulation castable.