Abstract: The copper concentrate products of a sulfide copper ore dressing plant in Anhui province containing 18.20% Cu，0.25% F，9.26% MgO.Not only the copper grade is low，but also the content of fluorine and magnesium exceeds the standard of the smelting plant requires (content of F＜0.1%，content of MgO＜5%).Studies have shown that easy mudding and easy floating talc，serpentine and chlorite exist in the form of fine particles，these minerals containing F，MgO and in large mixed into the copper concentrate，which is the main cause of fluoride，magnesium content in on-site copper concentrate exceeds the standard.Using DG11 developed by Guangdong Institute of Resources Comprehensive Utilization as inhibitor of the gangue minerals which contain fluorine and magnesium.Through the process of one roughing-one cleaning-one scavenging，and middling returning in proper order into the flow，the results show that the copper concentrate have 25.11% grade and 97.45% recovery rate，including 0.082% F，2.02% MgO.It not only improves the grade of copper concentrate，but also greatly reduces the content of fluorine and magnesium in the concentrate，and reached the requirements of copper smelting plant.

Key words: Copper concentrate, Fluorine, Magnesium, Inhibitor DG11