Abstract: In order to test the froth characteristics and flotation performance of a new cationic collector MZ-3 which was produced by Wuhan University of Technology in the reverse flotation of magnetic concentrate，selection and froth test was conducted on roasting-low intensity magnetic iron concentrate of Jiugang.Results indicated that:①Desilication by reverse flotation on magnetic concentrate with iron grade of 49.98% was conducted at pH=7，temperature of 25 ℃，MZ-3 dosage of 500 g/t，causticity starch dosage of 300 g/t，iron concentrate with iron grade of 57.01% and recovery of 74.66% was obtained via one-stage rough flotation.② Compared with collectors M-302B，amine，and dodecylamine，MZ-3 has characteristics of not only product produced is good，also defoaming fast.Therefore，MZ-3 is a new cationic collector with good collecting and foaming properties，and can improve the efficiency and stability of operations in concentrating mill.

Key words: Cationic collector MZ-3, Reverse flotation, Magnetic iron concentrate, Froth