An Ionic Rare Earth’s Slope Stability Analysis And Controling Method Research

The slope stability of rare earth mine was a complex time-space mechanics problem under in-situ leaching condition. Although in-situ leaching method have been used for rare earth mining for a long time, the research of slope stability in rare earth ore was still not enough, especially about the reflect of in-site leaching to the slope. Several factors which reflecting slope stability were analysis based on a certain ionic rare earth mine’s slope. The current main research methods were introduced and then slices method was applied for slope safety factor calculation which considering underground water. The FLAC3 D, a famous finite difference software was used for rare earth mine’s slope stability numerical simulation in different leaching time. Stress, displacement and strain could be got by the simulation process.Meanwhile, The plant protecting project was also simulated, trying to explore the influence of plant protect effect, including ore-water pressure, Shallow security and deep security. The main results were as following:Lots of reasons could lead in-situ rare earth mine’s slope instability. And the key factors were including the chemical reaction of ore solution leaching and surface earth, rain which would lead the rare earth turn into saturation state and physical and mechanical parameters’ change with grouting time passing.The underground water was considered, and then the slices method was used for slope stability calculation which in-situ leaching under different construction time. So the factor of slope safety was coming out after those calculations. The result shown that the safety coefficient decreased only a bit at last. However it decreased a lot. The safety coefficient was under 1. It mean the slope was not safe anymore.The strength subtraction method was used for slope stability calculation. The results were clear got to know. The safety coefficient was 1.67 before the in-situ leaching construction. It would change with construction time passing. It’s 1.63 in the first day. It would turn to 1.60 in the second. Then it turned to 1.55 in the fifth day. It would become as1.11 in the 10 th day. It would turn into 0.97 in the half month. So the in-situ leaching should consider as a slow seepage effect. The soil would gradually become saturated state as leaching ore time increasing. At the same time, the mechanism of soil would become weak. The state of slope would became instability from stability.The plant protection could change the distribution of pore- water pressure in the rare-earthmine’s slope by the analysis of plant protection. It could improve the safety of swallow slope.However, it leaded no significant influence on deep slope.