Numerical Study of Percolation and Seepage Behaviors in Ion‐Adsorption‐Type Rare Earth Ore Leaching Process

Abstract

Ionic rare earth ore is a type of featured rare earth ore in China. Its mining process suffers from a long leaching cycle and considerable consumption of leaching agents. Improving mining efficiency requires a sound physical understanding of the leaching process. In this study, the CFD-based numerical model is used to analyze the physical process of leaching through porous media formed by particles. The simulation results indicate that a lower packing porosity and smaller particles packed granular porous medium result in much larger energy dissipation during seepage, and the energy dissipation increases with seepage velocity. It is found that when the seepage velocity increases to a certain high value, the energy dissipation exceeds the value predicted by Darcy’s law, which is mainly caused by liquid turbulence. Additionally, the effect of particle shape is examined. The results show that the granular medium composed of prolate particles causes larger energy dissipation than oblate particles, and spherical particles play the least role. This phenomenon may result from the particle shape affecting the area of the frontal contact surface between particles and liquid. The results provide new insights into the fundamental understanding of percolation and seepage behaviors in the ion-adsorption-type rare earth ore leaching process.

Exploration and research on ammonium free green leaching agent for ionic rare earth ore and influencing factors of soil slope stability

“…Ionic rare earth mine landslide belongs to shallow landslide and small landslide, mainly concentrated in high hilly terrain areas, landslide original terrain slope angle is concentrated in the range of 20 ~ 40 degrees, and the top of the landslide is mostly located in the foothill concave slope, the landslide is located in the strongly weathered residual accumulation and granite fully weathered layer, and the rainfall has a certain synchronization, the greater the rainfall with the injection of magnesium sulfate extraction solution, the bottom of the shallow well of liquid injection and fully weathered ore layer contact The stability of the slope on the datum surface is greatly affected and becomes landslide (Dianyu et al, 2023). In this paper, we monitored the earth pressure changes and fractures of two typical steep slopes, and the results showed that the steep slopes in magnesium sulfate extract leaching are easy to produce pushing landslides in the upper slope to the gentle slope system, and on the steep slopes with uniform slope, the intensity of magnesium sulfate extract is too large in the early stage is easy to produce pushing landslides, and the slope angle, slope height, the angle and the weight of internal friction of the fully weathered layer, during the magnesium sulfate extract leaching are taken as factors affecting the stability.…”