Abstract: Through the process of stage grinding-low intensity magnetic separation-fine screen classification-elutriation magnetic separation was used by Ekou Iron Plant，Fe grade of iron concentrate reached above 66%，while the SiO₂ content is high，at about 7%. In order to decrease the SiO₂ content at final iron concentrate to be below 5%，experiments of iron increase and silicon reduction were conducted using feed of elutriation magnetic separator as the sample. The results showed that mixed iron concentrate with 69.58% of iron，4.23% of SiO₂，iron recovery of 97.05% was received through the inverse flotation process of one roughing，one cleaning，three scavenging，and then one roughing，one cleaning of low intensity magnetic separation for reverse flotation tailings after regrinding to 82.60% 0.038 5 mm，using collector MD，developed by Sinosteel Maanshan Institute of Mining Research Co.，Ltd.，sodium hydroxide，corn starch，and lime as reagents. By this method，SiO₂ content in iron concentrate can reach the expected target.

Key words: Iron concentrate, Iron increase and silicon reduction, Reverse flotation, Regrinding, Low intensity magnetic separation