吐哈盆地十红滩铀矿床铀成矿过程中微生物—有机质相互作用研究

生物、有机质成矿作用是目前国际成矿作用研究前沿领域。本文以我国典型层间氧化带砂岩型铀矿床——吐哈盆地十红滩铀矿床为研究对象,分析了矿床的有机质、微生物地球化学特征,探讨了有机质和微生物的相互作用。认为好氧微生物积极地参与了矿床层间氧化带的形成。氧化带铁的生物氧化作用催化了铀的氧化、溶解以及迁移,为铀成矿提供了重要的铀源条件。在氧化还原过渡带,硫酸盐还原菌利用有机质生物化学作用的产物——轻烃和可溶有机物作为碳源,使容矿层地下水中硫酸盐发生还原作用形成硫化氢,地下水Eh降低和pH向弱酸性转化,导致铀的还原成矿和吸附成矿作用,有机质和微生物的相互作用对矿床的形成具有重要的控制作用。

Study on the Interaction of Microbes and Organic Matter in the Process of Uranium Mineralization at Shihongtan Uranium Deposit,Turpam-Hami Basin

On the current international,the mineralization of microbes and organic matter is metallogeny research frontier. As the research object,Shi Hongtan uranium deposit is the typical interlayer oxidation zone sandstone type uranium deposit in China.The author analyzes geochemical characteristics of the organic matter and microbes in the deposit, discusses the interaction between organic matter and microbial,thinks that the aerobic micro organisms actively participate in the formation of interlayer oxidation zone and the uranium activation migration. Thought that in the oxidized zone,the iron catalysed uranium oxidation,dissolution and move,which provided the important source for uranium mineralization. In redox transitional zone, using light hydrocarbon and soluble organic compounds which are the products of organic matter biological chemistry as carbon source,sulfate reducting bacteria makes the sulfate be reduced and form the hydrogen sulfide in groundwater of ore hosting bed.With Eh ruducing and pH being to weak acid in groundwate,uranium is reduced and adsorbed mineralization.The interaction of organic matter and microbes controls the uranium mineralization for uranium deposit.