The role of commonly used dispersants in refractory castables

Dispersants are widely used in refractory castables. By improving the rheological properties of refractory castables, the construction time of refractory castables and the labor intensity of workers can be reduced. Choosing the appropriate dispersant among the refractory castables of the corresponding system is the most direct and effective way to improve the rheological properties of the castables and reduce the water demand of the castables.

The adsorption of dispersants can generally be divided into two situations, one is the adsorption at the solution interface, the other is the adsorption at the solid-liquid interface, and the dispersion of the dispersant in the castable The effect is mainly the result of solid-liquid adsorption of the dispersant on the particle surface.

The adsorption of dispersants on the solid-liquid interface mainly uses the inherent amphiphilic structure of the dispersant molecules to form an adsorption layer with a characteristic structure on the particle surface to change the solid surface nature. There are three factors that influence the adsorption of dispersants on the particle surface. The first is the characteristics of the particle surface, such as charged, polar or non-polar; the second is the molecular structure of the dispersant, such as the hydrocarbon chain of the dispersant. Length, generally speaking, the longer the hydrocarbon chain, the easier it is to adsorb; the third influencing factor is the type of dispersant. Particles with negatively charged surfaces are more likely to adsorb cationic dispersants. In addition, the properties of the solution, such as pH value, temperature, and electrolyte content, will also have a certain impact on the adsorption characteristics of the dispersant.