铀储层地质建模:揭示成矿机理和应对“剩余铀”的地质基础

野外露头和典型矿床的地质建模显示，铀储层存在着严重的沉积和成岩非均质性，即铀储层砂体存在物理结构和物质成分的差异，它们一方面通过制约铀成矿流体场和层间氧化作用达到对铀成矿的控制，另一方面也会影响地浸采铀的溶矿流体场以及对溶剂的选择.本文从铀成矿机理探讨和提高采收率的角度，遴选了地质模型表征的3大类、10余种关键要素，并总结了各参数的空间分布规律.研究表明，沉积作用和沉积环境是铀储层内部沉积界面和构成单元形成发育的主要控制因素，成岩作用会进一步增强铀储层结构和成分的复杂性.研究指出，与铀成矿密切相关的后生蚀变作用优先发育于物性条件好但还原介质丰度低的河道单元中，显示层间氧化带和铀矿的形成发育具有很强的选择性；地下地质建模受参数获取方法和精度约束而具有很大的预测性，但是在矿床尺度下系统总结关键参数的空间配置规律和相互制约关系，对服务找矿预测和地浸采铀才具有真正的实际应用价值. 

Geological Modeling of Uranium Reservoir: The Geological Foundation of Revealing the Metallogenic Mechanism and Solving "Remaining Uranium"

By the geological modeling of outcrop and typical uranium deposit, it can be found that there are serious sedimentary heterogeneity and diagenetic heterogeneity in uranium reservoir, that is, the differences in the structure and material composition of the uranium reservoir sandstone. On the one hand, they can control uranium mineralization by restricting uranium metallogenic flow field and interlayer oxidation, on the other hand they may also affect the dissolution flow field and selecting solvent for in-situ leaching uranium. From the discussion of uranium metallogenic mechanism and the angle of improving the recovery rate, three categories and more than ten key elements of the geological model are selected, and the spatial distribution rules of each parameter are summarized. It is found that sedimentation and sedimentary environments are the main controlling factors for the formation and development of the depositional interfaces and components of the uranium reservoir, and the diagenesis would further enhance the complexity of the structure and composition of the uranium reservoir. It is pointed out that the epigenetic alteration, which is closely related to uranium mineralization, is preferentially developed in channel units with good physical properties but low reductant abundances, indicating that the formation and development of interlayer oxidation zones and uranium deposits are highly selective. By fully comparative analysis of the characteristics of the geological modeling between outcrop and underground uranium reservoir, the research ideas which can be used for reference are summarized and the common modeling parameters are selected, which provides the basis for guiding the underground modeling. It is believed that the underground geological modeling is very predictable by the constraints of getting parameters and the precision of parameters, but it has real practical value for ore prospecting and in-situ leaching uranium when the spatial distribution and mutual restriction of key parameters are systematically summed up on the deposit scale.