Abstract: The cationic inverse flotation techniques on the roasting-magnetic separation system is adopted to improve quality and reduce impurities in dressing plant of Jiusteel. The practices show that this technique has such advantages as good efficiency on removing silicon, simple reagents system, never heating, no fouling and smooth production. Compared with the original single magnetic separation technique, this one can improve the grade of concentrates by 4.04%, and reduce SiO₂ contents by 4.74%. From separation to iron-making, about 92.25 million yuan at costs can be saved per year.

Key words: Roasting-magnetic separation, Iron concentrate, Cationic inverse flotation, Practice