Abstract: In order to better develop and utilize the niobium ore resources in Baiyan Obo,the niobium flotation concentrate from Baiyan Obo rare earth tailings was studied by process mineralogy using chemical composition analysis,SEM,MLA and other testing methods,and the separation and recovery of this sample was explored and tested. The results showed that the niobium flotation concentrate from Baiyan Obo rare earth flotation tailings contained Nb2O5 of 1. 92% and TFe of 47. 80% . In addition,the contents of SiO2 and TiO2 were high of 9. 13% and 3. 89%,respectively,and the remaining S,P and Zn elements were low of 0. 22%,0. 09% and 0. 01%,respectively. Niobium elements are mainly distributed in the felsite,pyrochlore,niobium ferromanganese and niobium rutile,and a small amount of Nb exists in the silica-titanium-ceria felsite,and the niobium minerals have a low degree of dissociation of the monomers. In contrast,Fe is mainly present in magnetite / hematite and nepheline,while Fe minerals have a high degree of monomer dissociation. The main useful minerals,eclogite,are mainly contiguous with niobium rutile and magnetic / hematite,and the ratios of side lengths of niobium rutile and magnetic / hematite in contact with eclogite to the total side lengths of eclogite are 8. 28% and 6. 00%,respectively,while the magnetic / hematite is mainly contiguous with nepheline,and the ratio of side lengths of nepheline in contact with magnetic / hematite to the ratio of magnetic / hematite is 3. 30%. Due to the high content of iron minerals,niobium and iron embedded relationship is more complex,using the traditional beneficiation method is difficult to realize the effective separation of the two. Therefore,the process of " mineral phase transformation-magnetic separation" is adopted to make Nb enter into the magnetic separation tailings,with the content of Nb2O5 being 3. 72%,and most of Fe enter into the magnetic separation concentrate,with the content of TFe being 65. 56%, which can realize the effective separation of the two. 

Key words: mineral phase transformation,process mineralogy,niobium minerals,magnetic separation,iron minerals