Abstract: Aiming at the characteristics of refractory copper ore（copper grade is 0.31%） in Dexing Copper Mine， flotation experiment was conducted based on the analysis of ore property. The chalcopyrite is mainly disseminated distributed in the ore， and some of it is distributed as fine granule in the gangue or wrapped by gangue. A small amount of chalcopyrite and pyrite are adjacent to each other. Whole flow of closed circuit flotation results show that at the grinding fineness of 61.60% passing 0.074 mm， lime regulating slurry pH value of 8.0， using Mac-12 + butyl xanthate as collector， via one roughing two scavenging copper flotation， rough concentrate reground to 68% passing 0.037 mm， via one roughing two cleaning two scavenging copper flotation， copper concentrate with copper grade of 27.27% and recovery of 85.56% was obtained， copper grade and recovery increased by 1.68 and 3.95 percentage points respectively. Increase pulp pH or optimize collector mass ratio can improve foaming structure， increase flotation index.

Key words: Dexing Copper Mine, Recovery, Flotation reagents, Mac-12