The influence of silicon carbide (SiC) on the properties of castables

⑴ Since SiC itself is water-repellent, it is not easy to be wetted, and it is not easy to form a water film layer, and the water consumption of the castable increases. Therefore, the higher the SiC content, the poor workability and fluidity of the castable, and the cold flexural strength will decrease.

⑵ Since the bulk density of SiC (2.6~2.8g/cm3) is greater than the density of ceramics (2.2~2.4g/cm3), the more SiC content, the greater the volume density of the material. When the temperature rises and the SiC content is higher, the volume density will increase to a certain extent. The SiC content shows a negative value for the influence of the material line change.

⑶ SiC content is beneficial to the strength of the castable, especially at high temperature (1100°C). Especially when the SiC particle size is 150 mesh, it cannot be completely oxidized, and some gaps are formed around the SiC particles, which improves the thermal shock resistance and strength of the castable. The unoxidized SiC also functions as a particle reinforcement.

⑷ The more SiC content, the better the material’s anti-skinning performance.

⑸ The more SiC content, the better the alkali resistance.