矿堆非饱和渗流中的界面作用

Interface effects of unsaturated seepage in dump leaching

为探明矿堆非饱和浸出渗流规律,以界面作用为切入点,分析了浸出液的运动状态.矿堆中吸力由界面作用产生的基质吸力和吸收扩散产生的渗透吸力组成.孔隙中介质分布的不均匀性和矿石形状的随机性是导致界面作用多样性以及浸出液运动状态复杂的原因.采用毛细上升实验很好地证明了矿堆中吸力的存在,在驱动力的作用下,浸润初期的液面上升速度较快,浸润后期液面上升相对平缓.通过拟合得知液面毛细上升高度与浸润时间符合幂函数关系.理论研究表明可以通过改变固相、液相和气相的物理性质来实现对矿堆非饱和渗流中界面作用的调控.

Starting with interface effects, the motion state of the leaching solution was analyzed to find out the seepage rule in unsaturated leaching. The total suction in ore heaps is composed of the matric suction from interface effects and the osmotic suction from absorption and diffusion of the ore and solution. The inhomogeneity of medium distribution in pores and the randomness of ore shape are causes for the diversity of interface effects, which make the motion state of the leaching solution complicated. Capillary rise experiment was conducted to prove the existence of suction in ore heaps. The result reveals that the capillary rise height increases faster at the beginning of infiltration under driving force than that at the later period of infiltration. Moreover, the fitting curve reveals that the capillary rise height increases by a power function with infiltration time. Theoretical studies show that the interface effects of unsaturated seepage in leaching can be regulated by changing the physical properties of solid phase, liquid phase and gas phase.