Penetrating Properties Of Heap Leaching Process Of Ore Granular Media

Compared with the traditional mining methods, heap leaching can reclaim the mineral resources perfectly. Because of its notable advantages, such as lower cost, better working conditions and safety, heap leaching is applied widely. During the heap leaching, the leaching process is realized by the seepage of the solution in the heap. The permeability of the heap can influence the solution's velocity and flow route. So the permeability of the heap is very important for the leaching rate. Combining with the "973 Project" -strong relationship of many factors in microbe metallurgy system and "National Excellence Youth Science Foundation Project"-multipole seepage dynamics of granular multiphase medium and "National Innovation Population Foundation Project"- basic research of sulphide ore biological extractive, Investigation on the granular media's seepage characteristic is valuable for the society, economy and science, and the main achievements are as follows:The Log-normal distribution model of granular particle is established based on rock fragmentation mechanism and the fundamental theory system through introducing related theories of granular dynamic theory, some useful results including distribution density and statistical eigenvalue of grain diameter are worked out. It well forecast the gradation distribution of blasted granular medium. All the results are fundamental to further research.Based on the hydrodynamics in porous medium and the permeability characteristic of ore-rock granular medium, this paper analyzes the rule of solvent seepage in heap leaching and the mechanism of the change of stress field act on seepage field. Moreover, the partial differential equation for the unsteady-seepage in anisotropic granular medium is established in this paper, and the relation of seepage varies with void ratio of granular medium is also developed. At last, the conclusion can be drawn that stress field affects the seepage field in respect that it affects granular permeability through working on it's volumetric strain and voidratio.Comprehensive experimental research is carried out in this thesis to study the permeability characteristic of ore-rock granular medium, acknowledge as the ore-rock granular medium has the anisotropic characteristic, and the influence rule of the permeability is proved up by simulate heap leaching in the lab. At last, the conclusion can be drown that the permeability coefficient will dwindle away in heap leaching, all the results are helpful to further research and provide necessary data for engineering project.The processes and mechanism of porosity evolution in ore-rock granular medium during dump leaching is studied. It is concluded that the processes of porosity evolution can be divided into two stages: initialization and stabilization, and there are behaviors feedback of reaction-transport-mechanism(RTM) during the stage of stabilization. Based on the hypothesis that the fluid head of the flow in the granular porous medium is constant, a mathematical model of porosity evolution is created for heap leaching and flow-reaction-deformation process is reflected well in this model.Be dead against the field situation in heap leaching, Simulating the solution flow in the granular media through Fluent liquid computing software, this paper analyzes the distribution of fluid pressure and seepage rate varies with ore-heap height and porosity. Based on the numerical simulation result, several kinds technique route is brought forward to improve the permeability in heap leaching.