Dispersants are widely used in refractory castables. By improving the rheological properties of refractory castables, the construction time of refractory castables and labor intensity of workers can be reduced. And choosing a suitable dispersant among the refractory castables of the corresponding system is the most direct and effective way to improve the rheological properties of the castable and reduce the water demand of the castable.
The adsorption of dispersants can generally be divided into two situations, one is the adsorption at the solution interface, and the other is the adsorption at the solid-liquid interface. The dispersion of dispersants in castables is mainly the result of solid-liquid adsorption of dispersants on the surface of particles.
The adsorption of the dispersant on the solid-liquid interface is mainly to use the inherent amphiphilic structure of the dispersant molecule to form an adsorption layer with a characteristic structure on the particle surface to change the solid the nature of the surface. There are three factors affecting the adsorption of dispersants on the particle surface. The first is the characteristics of the particle surface, such as chargeability, polarity or non-polarity; 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, and the particles with negative charges on the surface are easier 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.