Changes of energy potential on clay particle surfaces at high pressures

Abstract Bentonite and kaolin were treated by high pressure (to 2200 MPa). Using the XRD parameters (full width at half maximum, integrated intensity, interplanar distance, diffraction angle 2θ of reflection maximum), a significant pressure effect on the crystallite size of main clay minerals (montmorillonite and kaolinite) was established. The crystallite size is closely related to the energy activity of the clay particles. The boundaries with a pressure of 125 and 750 MPa were identified, which divide the measurements into three classes. Each class has its own regularities for changing parameters. Mathematical models for predicting changes in energy activity of clay particles have been developed.