Abstract
It has been experimentally confirmed that steady viscosity of clay suspensions usually decrease with elapsed time, but sometimes increase for a certain clay suspension. To explain this phenomenon, Moore (1959) introduced the particle structure model in suspension in which build-up and destroy of links are balanced under steady state. Then he succeeded to express time dependence of viscosity quantitatively and graphically. From his model, changes of viscosity should decrease with elapsed time, and converge on a certain value.
In this study, we examined time dependence of viscosity for kaolinite suspensions experimentally, under the various conditions of temperature and shear rate. As a result, obtained curves of viscosity as a function of elapsed time could be categolized into three types of regression formulae including Moore model. Two patterns ofcurves, except Moore model, could not be explained using Moore's supposition. It suggested that these tendenciesof experimental results are much influenced by temperature and shear rate out of estimation.
