Abstract: In order to improve the copper beneficiation performance of the refractory ore from Daye Co.'s Tonglushan Open-Pit Mine, detailed laboratory flotation test was made. The results show that mixed collector can be beneficial to the improvement of copper recovery, addition of SB-1 regulator can well solve the interference of mica type gangues to the copper flotation. The application of the collector mixed by isobutyl xanthate and butylammonium aerofloat in 2∶1 ratio and SB-1 in the flowsheet including closed-circuit middling regrinding obtained rather good copper separation indexes. The concentrate has a copper grade of 20.51%, copper recovery of 93.37%, gold grade of 12.48 g/t and gold recovery of 73.60%.

Key words: Refractory ore from open-pit mining, Copper separation, Mixed collector, Regulator SB-1, Middling regrinding