Abstract: Northeastern University has developed a new iron ore depressant DHY which has low price and stable property aiming to achieve reverse flotation enrichment of magnetic concentrate with high efficiency and low consumption.DHY has similar structure with starch.In order to demonstrate the feasibility for optimizing reverse flotation technology for mixed magnetic concentrate from Anqian Mining Company，reverse flotation experiments have been carried out on the basis of on-site regime of agent.The results indicated that Anqian Mining Company mixed magnetic concentrate with TFe grade of 47.64%，fine dissemination，obviously enrichment of iron mineral at fine size，main gangue mineral quartz，iron concentrate with grade of 68.21% and recovery of 88.01%，tailings of iron grade reducing to 14.82% was obtained by the closed-circuit reverse flotation experiment process of one roughing，one cleaning and two scavenging using DHY as iron depressant.Compared with the on-site process,it can not only reduce dosage of agents obviously but also simplify technological process by replacing industrial corn starch with DHY.

Key words: New iron mineral depressant DHY, Magnetite, Hematite, Quartz, Reverse flotation