Low cement castables refer to castables with lower cement content, and the amount of cement is about 5%. The purpose of reducing the amount of cement is to improve the fire resistance of the castable.

Low cement castables rely on the addition of several special materials for good performance:

First, pure calcium aluminate cement, because of the high content of effective mineral CaO·Al2O3, can be obtained with less strength to obtain the required strength.

Second, silica fume, glass beads having an SiO2 content of between 93% and 98% and an average particle size of about 0.5 [mu]m. After the addition of silica fume, the flowability of the castable is good, the water requirement for molding is low, the sintering temperature is low, and the performance after heat treatment is improved.

Third, alumina fine powder, which is relatively easy to participate in the reaction and improve the fire resistance of the material.

Fourth, the water reducing agent, which can adsorb on the surface of the powder, thereby generating an electrostatic repulsion to disperse the powder, thereby further exerting the function of the fine powder.