Abstract: The major chemical composition,mineral composition and rare earthniobium mineral characteristics of Potassiumrich slate in Bayan Obo Mine were studied by means of multielement chemical analysis,automatic mineral analysis system,partial reflection microscope,field emission scanning electron microscope and energy spectrometer.The results show that the K2O content in the Potassiumrich slate in Bayan Obo Mine is up to 13.15%,and the content of SiO2 and Al2O3 is high.The rock is mainly composed of microcline and biotite.The content of REO and Nb2O5 in Potassiumrich slate is 0.076% and 0.012%,rare earth minerals and niobium minerals have low content,fine particles,diverse morphology and occurrence,complex mineral association and contact relationship,indicating that the Potassiumrich slate has suffered the late hydrothermal alteration and transformation.

Key words: Mineralogical characteristics,Rare earth and niobium minerals,Potassiumrich slate,Bayan Obo Mine