Abstract: The mineral compositions and grain gradation distribution were preliminary analyzed, the dispersant type and reagent dosage were researched specially, and the separation mechanism of iron minerals with gangue minerals was discussed by means of SEM and EDS.The results show that the dispersant plays an important role in the selective separation of useful minerals from gangue minerals because it could desorb the fine gangue particles adsorbing on the mineral surface and disperse agglomeration. When the Fe grade of magnetic separation concentrate is 42.88%, it could obtain iron concentrate with a grade of Fe 66.26%, a recovery of Fe 70.23% through one roughing-two cleanings-two scavengings closed-circuit flowsheet, during which all of the middlings returned to the previous flotation operations accordingly.

Key words: Magnetic separation iron concentrate, Reverse flotation, Dispersant, Sodium silicate, Covering, Agglomerate