Abstract: The iron tailings in Shangchang, Yunnan, with the very fine particle sizes, the low Fe content of only 16.56%, and the main Fe existing form of weak magnetic hematite, is belonging to a type of the micro-fine low-grade refractory iron tailings. Aiming at shortages of the existing re-concentration technologies, and the properties of the tailings, a new re-concentration technology of selective dispersion and flocculation-magnetic separation, was put forward. Then the effects of key factors on iron recovery were investigated, and the related reasons were also analyzed. The results show that under the optimum conditions:grinding fineness of -0.045 mm accounting for 95%, dosage of YL-1 of 800 g/t, frequency of stroke of 320 times/min, the concentrate with the Fe grade and recovery of 59.63% and 50.41%, was obtained. In the new technology, the fine grinding, which can improve the liberation degree of iron mineral, adding reagent YL-1 can well achieve the dispersion of slimes and the selective flocculation of fine iron mineral, and high frequency of stroke can reduce the mechanical inclusions of non-magnetic particles and the probability of adhesion to the surface of the magnetic mineral due to surface force, all improve the indexes.