Abstract: A study was made of the changes in viscosity of Wyoming bentonite suspensions with variations in cation ionization, base saturation, clay concentration, sodium chloride concentration and type of exchangeable cation. There is little change in the viscosity with decreasing cation ionization until a certain threshold value is reached. Below this value the viscosity increases rapidly, indicating that the repulsive potential barrier has been reduced to the order of the kinetic energy of the particles. Unfortunately, a quantitative estimate of the ionization was not possible at this value because of the high salt content of the system.
Exchangeable aluminum was found to act as a strong bonding agent between clay particles in the pH range 4.50–5.50. This was explained on the basis of the formation of multivalent, aluminum-hydroxyl complex ions.