Experiments and inverse methods for hydraulic characteristic parameters of uranium ore heaps using heap leaching technology

In order to understand the hydraulic characteristics of the unsaturated zone in uranium ore heaps using heap leaching technology, a numerical inverse model is established according to the fluid flow control equation for porous medium and van Genuchten model describing hydraulic properties. Then, the self-designed experimental devices consisting of a column for one-dimensional unsaturated flow of liquid are fabricated and used to measure the accumulative flux at the bottom of the column through the uranium ore with the fractal dimension of 1.8 from a uranium ore heap using heap leaching technology and the water moisture of ore samples at 5 different heights of the column. The hydraulic characteristic parameters in the water flooding period and the drainage period are obtained using HYDRUS-1D. The results show that the hydraulic characteristic parameters determined by the numerical inverse method are in good agreement with the actual situations, and the estimated parameters can be applied to the engineering practice. The hydraulic characteristic parameters in the water flooding period and the drainage period should be determined, respectively. The saturated permeability coefficient of the uranium ore heap for heap leaching obtained by inverse modeling in the water flooding period is more close to the result obtained by the saturated seepage experiments than that in drainage period.