内蒙古二连盆地砂岩型铀矿深穿透地球化学扫面技术的应用

Experiment of Prospecting Sandstone-Type Uranium Deposits by Deep-Penetrating Geochemistry in the Erlian Basin,Inner Mongolia

铀矿资源的勘查一直是全球矿业领域的一个重点和热点,砂岩型铀矿是我国铀矿勘查的主要矿床类型。砂岩型铀矿在我国主要分布在盆地当中,矿体埋藏较深,找矿难度较大。本文通过深穿透地球化学扫面技术在二连盆地开展砂岩型铀矿的试验,主要得出以下结论:(1)通过土壤微细粒分离技术分离土壤样品,可以实现对富含活动性铀的粘土矿物进行物理富集,方法简单高效;(2)地表铀地球化学异常的发现反映的是活动性铀迁移扩散的结果,即深部铀矿(化)体产生的易溶于水的铀酰阳离子,在地下水及蒸发蒸腾作用下通过垂向迁移至地表,而通过地表径流等水平运移形成了大面积的地表铀异常;(3)利用能捕捉来自深部铀矿(化)体发出的直接找矿信息的土壤微细粒分离技术能有效圈定盆地内砂岩型铀矿在地表引起的地球化学异常,可在盆地内快速有效地开展砂岩型铀矿地球化学扫面工作。

Exploration of uranium resources has always been a focused subject in the global mining field.Sandstone-type uranium deposits are the main type of uranium resources in China.Sandstone-type uranium deposits are mainly distributed in basins in China,where ore bodies are deeply buried,it is difficult to find ore.This paper presents an experiment of geochemical mapping for exploration of sandstone-type uranium deposits in the Erlian Basin,Inner Mongolia.The results show that(1)the separation of soil samples by fine particle separation technology permits to realize the physical enrichment of clay minerals in active uranium,which is simple and efficient.(2)The uranium geochemical anomalies discovered on the surface are the result of migration and diffusion of active uranium,i.e.,uranyl cations that are easily soluble in water produced by deep uranium minerals bodies migrate to the surface through vertical paths under groundwater and evapotranspiration,thus producing a large area of surface uranium anomalies by horizontal transport such as ground runoff.(3)The fine particle soil separate technology which can capture the direct prospecting information from deep uranium deposits bodies can effectively delineate geochemical anomalies on the surface caused by sandstone-type uranium deposits in the basin,and can aid in rapid and effective geochemistry reconnaissance of sandstone-type uranium deposits within the basin.