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.