This article presents the results of laboratory studies of clay slurries. Based on measurements made on a rotational viscometer, it is noticed that mixtures with a high concentration of solid particles exhibit the properties of non-Newtonian fluids. The possibilities of describing such mixtures by the well-known Bingham rheological model are considered. The article defines the parameters of the model (initial shear stress and structural viscosity) and establishes the dependence of the parameters on the concentration of the solid phase. After that, methods are given for determining the resistance coefficient of the studied mixtures in pressure and non-pressure flows. Finally, these techniques are illustrated with numerical examples.