Rheological characteristics of aqueous Ca-bentonite dispersions

Tulun T., Gungor N.

JOURNAL OF SCIENTIFIC & INDUSTRIAL RESEARCH, vol.58, no.8, pp.607-615, 1999 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 58 Issue: 8
  • Publication Date: 1999
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.607-615
  • Istanbul Technical University Affiliated: No


The rheological properties of Ca-bentonite suspensions in different volume concentrations have been studied as a function of pH and the concentration of added electrolytes. In addition,the conductance of suspensions was determined. The flow behaviour of suspensions with and without containing electrolytes fitted the Bingham plastic flow. The yield stress of suspensions, showed that the transition process from viscous flow to plastic flow required relatively high shear stress for the given volume concentrations. The suspension exhibited a shear-thinning behaviour in their native pH conditions. Below the pH value of 3, the stability of edge to face contact decreased. Apparent viscosity (eta(a)) values of suspensions were strongly pH dependent as plastic viscosity (eta(p)) values were nearly constant in the selected pH conditions. Apparent viscosity of suspensions exhibited different behaviour depending on the type of electrolytes. Although the highest increase in the specific conductivity was obtained with large amount of KCl addition, in case of NaCl addition, specific conductivity was increased largely more than in the KCl addition with increasing volume concentrations.