Abstract: The main iron mineral in an iron ore in Liaoning is magnetite，followed by specularite， and the main gangue mineral is quartz. The concentrate with iron grade about 65% and SiO2 content above 8% was obtained on site，which is difficult to be sold because of higher SiO₂ content. In order to solve the problem efficiently and inexpensively without changing the main structure of the process，the on-site iron concentrate from the second stage magnetic separation was treated as test sample with the process of mag⁃ netic field screening separation，screening of magnetic screen concentrate，regrinding of combinated medi⁃ um ore，low intensity magnetic separation，magnetic field screening cleaning，screening of magnetic screen concentrate and combinating medium ore. In the end，comprehensive iron concentrate with TFe grade of 66.73%，rocovery rate of 88.46% and SiO₂ content of 5.67% was obtained，indicating significantly effective for iron improvement and silicon reduction and achieving prospective experimental target.

Key words: iron concentrate, iron improvement and silicon reduction, magnetic field screening separa? tor