Abstract: There is little difficult-to-float pyrrhotite residual in copper and sulfur flotation tailings with iron grade of 26.06%,which will go to iron concentrate for its high magnetism during low intensity magnetic separation process,and cause sulfur content beyond the standard.In order to achieve qualified iron concentrate,desulfuration of iron concentrate from low intensity magnetic separation(LIMS) by reverse flotation is conducted.Results show that,through closed circuit process of one roughing-one cleaning-one scavenging and middles back to the flow-sheet in turn to deal with LIMS concentrate with 63.14% iron and 2.05% sulfur,qualified iron concentrate with iron grade of 64.53%,sulfur grade of 0.28% and iron recovery of 47.09% is achieved.Desulfuration of reverse flotation for LIMS iron concentrate has good index and can provide reference for on-site process transformation.

Key words: LIMS iron concentrate, Magnetite, Pyrrhotite, Desulfuration by reverse flotation