Abstract: The technological mineralogy of iron ores from Bayan Obo Mine was studied for better development and utilization of iron resources.The results showed that：①Valuable minerals in the ores mainly include magnetite,hematite and rare earth minerals,while the gangue minerals mainly include fluorite,quartz,aegirite,calcite and feldspar；②The iron mineral was mainly magnetite,over 70% of which was fragmental and breccia magnetite closely coexisting with columbite,apatite,monazite and barite,while sometimes magnetite aggregates existed；most of hematite was closely embedded in the fragmental and breccia magnetite；③Granular monazite as the most widespread rare earth minerals in the ores,have complex inlaying and paragenesis relationship with other minerals；④The gangue minerals appeared in irregular and xenomorphic granular structure,are closely inlayed with other gangue and valuable minerals；fluorite as the most widespread gangue mineral,sometimes encapsulated rare earth minerals；⑤The dissemination size of iron mineral is very small；However,disseminated at the size of over 10 μm,magnetite accounting for only 54%,was slightly coarser than hematite accounting for only 40%；⑥Because of its complicated embedment,superfine dissemination,and difficulty in liberation,Bayan Obo mine should be reduced deeply firstly to aggregate the micro-fine iron particles together and then be recovered.

Key words: Bayan Obo iron ore, Magnetite, Rare earth minerals, Technological mineralogy, Close Paragenesis, Superfine dissemination size