Ethyl　isobutyl　xanthogenic　acetate　(EIBXAC)　was　used　as　a　novel　collector　in　the　flotation　of　secondary　copper　sulfide　minerals　owing　to　its　ability　to　separate　copper　and　sulfur.　The　collectivity　and　selectivity　mechanisms　of　this　novel　collector　were　investigated　using　single-mineral　and　artificial　mixed-mineral　tests,　combined　with　adsorption　tests,　fourier　transform　infrared　spectroscopy　(FTIR)　tests,　and　density　functional　theory　(DFT)　calculations.　The　results　of　the　flotation　indicated　that　EIBXAC　had　a　better　collecting　effect　than　ammonium　dibutyl　dithiophosphate　(ADD)　on　covellite　and　digenite,　which　had　an　insignificant　effect　on　pyrite.　The　artificial　mixed-mineral　experiment　indicated　that　EIBXAC　could　improve　the　grade　of　the　copper　concentrate　while　maintaining　the　same　recovery,　it　had　higher　efficiency　and　selectivity.　Based　on　the　results　of　the　adsorption　and　FTIR　tests,　the　adsorption　capacities　of　EIBXAC　on　the　surfaces　of　covellite,　digenite,　and　pyrite　were　quite　different:　Cu-S　bonds　were　formed　on　covellite　and　digenite,　and　Fe-O　bonds　were　formed　on　pyrite,　which　was　also　verified　that　EIBXAC　was　chemically　adsorbed　on　the　mineral　surface.　DFT　calculations　indicated　that　the　adsorption　capacity　of　EIBXAC　for　covellite　and　digenite　was　stronger　than　that　of　ADD,　which　had　a　weaker　adsorption　capacity　for　pyrite.　This　study　can　provide　theoretical　guidance　for　the　application　of　EIBXAC.