Abstract: This paper studies the flotation tests of hematite using Sodium Dodecyl Sulfonate（SDS) as collector.and the following effect factors as pH,Ca²⁺,NaF,Na₂SiF₆ and（NaPO₃)₆ are investigated.In the process of hematite flotation using SDS as anionic collector,the optimum pH value lies between 3～4, the concentration increase of NaF can activate the hematite flotation，however Ca²⁺ and（NaPO₃)₆ can depress the chloride flotation.FT-IR analysis displays that the force of the SDS collector is electrostatic adsorption.

Key words: Sodium dodecyl sulfonate, Flotation, Hematite, Depressor, Activator