Abstract: Using sodium hexametaphosphate and caustic starch as regulators，and DEK，a new cationic agent，as collector for reverse flotation，the reverse flotation of magnetic separation iron concentrate from an iron ore concentrator in Anshan were studied. The results showed that，compared with the original anionic reagent system of reverse flotation，the cationic reagent system of reverse flotation，which using DEK as the core，was significantly simplified. Flotation could be operated in neutral environment and did not need steam heating to about 30 ℃.Using the determined process and regulation of agent to deal with the ore，iron concentrate with Fe grade of 66.02% and recovery of 90.16% was obtained.

Key words: Magnetic separation iron concentrate, Cationic reverse flotation, DEK