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云南某地铀矿床均位于某经向构造隆起带上以富铀花岗岩为基底的晚第三纪盆地内。由于富铀花岗岩长期隆起风化,形成厚4—20米(局部达70米)的古风化壳,促使岩石中的晶格铀转化为活性铀。大气降水使固态铀变成液态铀,以铀酰碳酸盐络合物的形式沿盆地建造底部孔隙度发育、透水性良好的岩层中渗透。在盆地基底古地形突起的平缓部位和突起两侧的低凹部位及其前缘,以及两种不同岩相的过渡带或两种不同渗透性岩层的界面处,含铀水溶液流速变慢及出现循环流动,致使铀浓度增大;在氧化——还原过渡带中,含铀水溶液与H_2S、FeS_2等还原剂发生作用,生成再生铀黑和沥青铀矿(沉淀),以及被有机质、炭质、粘土质等分散吸附。经这样的多次叠加而富集成铀矿床。
The uranium deposits in a certain place in Yunnan are located in a late Tertiary basin basing on enriched uranium granite in a warp tectonic uplifted belt. Due to the long uplift weathered uranyl granites, an ancient weathering crust with a thickness of 4-20 meters (70 meters locally) was formed, prompting the conversion of crystalline uranium into active uranium. Atmospheric precipitation turns solid uranium into liquid uranium, infiltrating into rock formations with well-developed bottom permeability and porosity in the form of uranyl carbonate complexes. The flow velocity of uranium-bearing aqueous solution slowed down and appeared at the interface between the paleo-relief of the basement paleo-terrain and the low-lying parts on both sides of the protuberance and its leading edge, as well as the transition zone of two lithofacies or two different permeability strata In the oxidation-reduction transition zone, uranium-bearing aqueous solution interacts with reducing agents such as H 2 S and FeS 2 to generate reclaimed uranium black and pitch uranium deposits (precipitates), and is enriched by organic matter, carbonaceous matter, Clay and other dispersed adsorption. After such a number of superimposed and enriched into uranium deposits.