Study of Dispersion Characteristic of Clays Used in Traditional Ceramics

This study is concerned with the dispersion characteristics of ceramic clay minerals used in tile making, and also effect of ageing on Rheological behavior, pH of clay Suspensions. The effect of dehydrated sodium phosphates on dispersion was also investigated. For this reason, four types of ceramic clay samples, of different characteristics were chosen and four commercial dispersants namely, sodium hexametaphosphate (SHMP) marked as D1, sodium Tripolyphosphate (STPP) as D2 and two anionic dispersants (sourced from elsewhere) marked as & B were used for clay suspensions. Each dispersant was studied to determine its effect on B₁ & B₂ dispersion characteristics of different clay-water system utilized in the experiments. The deflocculates varied in dispersion efficiency depending upon the interaction of the clay-waterphosphate system. But before the studies on ageing, rheological behavior of clay samples were studied systematically, depending on the type and amount of dispersants. Suspensions with four different dispersant concentrations were prepared for rheological and ageing studies. These suspensions were aged for 24 hours to observe the changing of their rheological behavior. The result indicated that the rheological and ageing behavior of suspensions changed for different clay samples with the changes in concentration of water and dispersant. It was also found that at lower pH the viscosity of clay suspension were more and vice versa. The suspensions prepared by using an optimum amount of dispersant showed a non-Newtonian flow character independent of the type and amount of dispersant present.