鄂尔多斯盆地东胜砂岩型铀矿中铀矿物的电子显微镜研究

鄂尔多斯盆地东胜铀矿是我国一个重要的大型砂岩型铀矿床。通过电子显微技术,对该铀矿床中铀矿物的种类、产出特征进行详细的研究。研究确定东胜砂岩型铀矿床中铀矿物主要为铀石和水硅铀矿,两者紧密共生,它们均为表生铀矿物。铀矿物的颗粒十分细小,一般粒度均为微米级。铀石和水硅铀矿往往呈板状、不规则微粒状产出,铀矿物的表面溶蚀现象明显,有的还具纳米级的溶蚀孔。铀矿物的产出与蚀变黑云母、蚀变黄铁矿密切相关,也见到微脉状铀矿物集合体穿切碎屑石英等现象。研究表明在表生作用下,该铀矿床中的铀元素存在溶解(迁移)-沉淀(富集)的反复过程。

Electronic Microscopy Study on the Uranium Minerals of Dongsheng Sandstone-type Uranium Deposit in Ordos Basin

Dongsheng uranium deposit in Ordos basin is an important large sandstone-type uranium deposit.By electronic microscopy,the thesis has made a detailed research on the uranium mineral's category and output characteristics.It has been identified that the main uranium minerals are coffinite and ursilite which are both epigenetic mineral.The diameters of uranium mineral's granule are very tiny,usually at micron(μm) level.Coffinite and ursilite are commonly tabular and irregularly granular,with an obvious phenomenon that is eroded on their surface,and some of them have eroded pore at nanometer(nm) degree;they are closely associated and have a close relationship with biotite and pyrite eroding.It can also be found that micro-vein uranium assemblages penetrate through the quartz clast.It has been researched that the uranium element is dissolved(transferred) and deposited(enriched) repetitively under the epigene.