堆浸铀矿堆水力学特征参数的试验与反演研究

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

为了掌握堆浸铀矿堆非抱和区的水力学特性,根据多孔介质的液体流动控制方程和描述水力学性质的van Genuchten模型,阐述了堆浸铀矿堆水力学特征参数的数值反演模型。接着,选用来自某铀矿山新堆浸场分形维数D=1.8的铀矿石样,利用自制的一维液体非饱和渗流试验装置,测定了不同喷淋强度下试验柱底部的累计排水量和5个不同高度矿样内的含水率。最后,利用HYDRUS-1D软件获得了试验样本在注水期间和排水期间的水力学特征参数。结果表明:1数值反演方法确定的水力学特征参数能很好地与实际情况相匹配,参数估算结果可用于工程实际;2注水期间和排水期间需要分别确定对应的水力学特征参数;3注水期间反演估算获得的堆浸铀矿堆饱和渗透系数比排水期间的更接近饱和渗流试验获得的结果。

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.