Mechanical behavior and particle breakage of tailings under high confining pressure: Fid-Bau Portal

Mechanical behavior and particle breakage of tailings under high confining pressure

Zhang, Chao / Chen, Qinglin / Pan, Zhenkai / Ma, Changkun

Abstract The mechanical behavior and particle breakage of tailings under high confining pressure are the theoretical reference to analyze the stability of high tailings dams. Consolidated drained (CD) triaxial compression tests were carried out using a high-pressure triaxial apparatus. The strength and deformation characteristics of tailings were studied. The constitutive relation of tailings was deduced under high confining pressure. The particle breakage of tailings was analyzed qualitatively and quantitatively. The tailings exhibit strain-softening under low confining pressure and strain-hardening under high confining pressure. A modified hyperbolic model was deduced to describe the stress-strain behavior under high confining pressure. Under high confining pressure the volumetric strain always decreases with an increase in axial strain. Under low confining pressure, only a few indentations are observed on the surface of marked calcite particles. By contrast, a lot of indentations are observed on the surface of marked calcite particles under the high confining pressure. The number of broken particles increases with an increase in the confining pressure, but the increasing tendency gradually decreases.

Highlights • A modified hyperbolic model was deduced to describe stress-strain behavior under high confining pressure. • The marked particle method was used to qualitatively study the particle breakage of tailings. • The number of particles breaking increases with the increase of confining pressure.