The bench-scale and industrial flotation test results of Jiangxi Copper Corporation Yongping Copper Mine showed that the flotation separation of Cu/Fe sulfide minerals has been achieved at pH values above 13 for xanthates, about 11 for dialkyl thionocarbamates and around 8.5 for ethoxycarbonyl thionocarbamates (ECTC), respectively, and ECTC collectors were powerful for copper minerals and very selective against iron sulfide minerals at pH 8-9. The flotation results have been explained from the structure-reactivity relationship of collectors by generalized perturbation theory and density functional calculation at B3PW91/6-31G(D) level. (c) 2005 Elsevier Ltd. All rights reserved.