Известия Томского политехнического университета: Инжиниринг георесурсов (Dec 2022)
HIGH PRESSURE INFLUENCE ON THE CHANGE IN THE STRUCTURE OF THE PACKET, MINERAL, COLLOID AND AGGREGATE OF BENTONITE CLAY
Abstract
Relevance. Interest in obtaining the necessary «specified» adsorption properties of clays by pressing them with pressure is steadily growing. This is due to the fact that this method of forming properties is in great demand in human economic activity. The purpose of the work is to investigate the result of high load influence on modification of the defectiveness of the structural components of clay – package, mineral, colloid and aggregate. The object of the study is bentonite clay, which consists of 88 % of the mineral montmorilonite. Methods. The defectiveness in the montmorillonite mineral package was studied by X-ray fluorescence analysis and infrared spectroscopy, the peak height was taken as the evaluation criterion. The defectiveness of the montmorillonite mineral was studied by the diffractometric method, the colloid – by the electrokinetic method (zeta potential), and the aggregate – by atomic force microscopy. To assess the defectiveness of the aggregate, the adhesion force on its surface was taken. Results. In the montmorillonite mineral package, when exposed to a pressure of less than 150 MPa, defects are primarily formed due to the destruction of the Si-O-Al and Fe-OH bonds. The Si-O bond is stronger, because the peak height of the Si-O bond tends to decrease under loads up to 800 MPa or more. If a load of less than 150 MPa is applied to such a structural component of clay as a mineral, an increase in its defectiveness is observed, as evidenced by a decrease in the thickness (Mk) of a defect-free crystallite. With a further increase in pressure, defect formation dies out. In a colloid with a load of less than 300 MPa, the defectiveness increases, as evidenced by an increase in the zeta potential (ζ), with an increase in the load of more than 300 MPa, a change in the increment ζ is not fixed. It was not possible to identify any regularity in the change in the adhesion force with an increase in the load on the bentonite clay aggregate, since the range of change in the adhesion force with each load varies over a wide range for different samples of bentonite clay.
Keywords
