地浸采铀井场溶浸范围的地下水动力学控制模拟研究

以内蒙某砂岩铀矿地浸井场中抽液孔和注液孔之间的天然地下水流场为研究对象,通过地下水动力学模拟研究地下水的流速场,根据井场边缘注液孔的地下水流速场特征来探讨溶浸范围的确定方法和影响机制。结果表明:单孔抽、注液量对井孔处水位降升、溶浸液运移速度及距离有决定性的影响,其次叠加了地下水流向对井场的影响;由井场边缘注液孔向外的地下水流速随距离增大呈指数下降,地下水的流速场变化控制了溶浸液向井场外的运移距离和井场的溶浸范围。井场溶浸范围在垂直于地下水流向的东、西两侧对称,下游溶浸范围略大于上游,在开采年限5~10年内溶浸范围为60 m左右,比较符合该矿山的浸出效益及环保要求。

Simulation Study on Groundwater Dynamics Control of Leaching Range of In-situ Uranium Well Field

Taking the natural groundwater flow field between the pumping hole and the injection hole in a sandstone uranium mine in-field in Inner Mongolia as the research object,the groundwater flow rate field was studied through groundwater dynamics simulation,according to the groundwater flow rate at the injection hole at the edge of the well field characteristics to explore the determination method and influence mechanism of the leaching range.The results show that the pumping and injection volume of a single hole has a decisive influence on the water level drop at the well bore,the migration speed and distance of the leaching solution,and the effect of the groundwater flow direction on the well site is superimposed;The groundwater flow rate decreases exponentially with increasing distance.The change of the groundwater flow rate field controls the migration distance of the leachate to the outside of the well site and the dissolution range of the well site.The leaching range of the well site is symmetrical on the east and west sides perpendicular to the groundwater flow direction.The leaching range of the downstream is slightly larger than the upstream.The leaching range is about 60m within 5-10 years of mining period,which is more in line with the leaching benefits and environmental protection requirements of the mine.