Coupled CFD-DEM simulation and experimental study of particle distribution and accumulation during tailings seepage process

Abstract

The movement of tailings particles in waste rock systems under different flow rates was studied using experimental and numerical methods, aiming to provide theoretical guidance for preventing particle infiltration. The research results established a calculation relationship between pressure drop, porosity, and waste rock thickness. They also revealed the self-similarity of blockage accumulation within the waste rock. The overall study indicates that smaller particles can pass through the waste rock, but larger particles face greater difficulties. It becomes highly challenging for particles to pass through when they exceed the pore spaces between the largest waste rock particles. The distribution pattern of blockage decreases gradually from the upper part to the lower part of the waste rock pile, with proportions of blockages at different depths being 35.2%, 22.7%, 15.5%, 15%, and 11.6%. The study also examined the cumulative distribution of tailings particles passing through the waste rock under varying flow velocities (0.2 m/s, 0.3 m/s), showing that the quantity of tailings particles passing through the waste rock at 0.3 m/s is approximately 1.15 times that at 0.2 m/s. Additionally, the effectiveness of using geotextile for sealing was investigated, providing theoretical support for determining the application of waste rock particle size, thickness, and geotextile in sealing tailings particles. Moreover, understanding the self-similarity and velocity variation patterns of particles helps in selecting suitable waste rock characteristics.