Abstract: The ore from Meishan iron mine is a compound of magnetite and hematite, and the iron grade is 37.82%. Preconcentration on-site was conducted for 50~20 mm, 20~2 mm and 2~0.5 mm size fraction, respectively, with different process. The results show that the iron grade of preconcentration tailing was high, and discarding tailings in 50~20 mm size fraction jig preconcentration is lower, high water consumption, unstable production index and high equipment failure rate. In order to improve the preconcentration efficiency, system test was carried out. The 50~20 mm size fraction ore was crushed to 20~0 mm then was relatively classified. -0.5 mm size fraction via drum-type low intensity wet magnetic separation and vertical ring-pulsating high gradient magnetic separation, 2~0.5 mm via drum-type low intensity magnetic separation and vertical ring-pulsating high gradient magnetic separation, 20~2 mm via drum-type medium intensity dry magnetic separation and roll-type high intensity dry magnetic separation, respectively. Iron concentrate with grade and recovery was 56.31% and 3.65%, preconcentration with grade and recovery was 40.81% and 89.92%, tailings with iron grade of 16.75% and yield rate 11.59%. The preconcentration results index is satisfaction.

Key words: Compound iron ore, Medium intensity dry magnetic separation, Roll-type high intensity dry magnetic separation, Coarse grained wet magnetic separation