Silica fume has extremely high activity. As an important component of castables, it can significantly improve the construction performance of castables, such as improving fluidity, improving construction efficiency, improving thixotropic properties, and reducing cracks and pores in castables.
Silica fume has a high specific surface area and surface energy, which makes it play a filling and lubricating role in the castable. Silica fume dispersed in the castable can fill the gaps between particles, reduce the friction between castable particles, and reduce the viscosity of the castable. Under the action of the water reducer, a water film will form on the surface of the silica fume particles, further improving the fluidity of the castable. Better fluidity makes it easier for the castable to fill the mold, improve the molding quality and density, and also improve the construction efficiency and reduce the construction period.
Silica fume can also improve the thixotropy of castables, have better fluidity during mixing, maintain a certain viscosity in a static state, and prevent stratification and segregation during construction. Silica fume fills the tiny gaps in the castable, improves the density and structural strength of the refractory material, and thus reduces cracks and pores.
The performance of refractory castables is affected by many factors, including the characteristics of silica fume itself, the interaction with other components, the molding process, the application environment, etc. The reasonable use of silica fume can significantly improve the performance of castables, making them more reliable and superior in various kiln projects.
