In this paper, a novel surfactant, N,N-diethyl-N0-cyclohexylthiourea (DECHTU) was synthesized and firstintroduced as a collector for chalcopyrite flotation. The micro-flotation results demonstratedchalcopyrite with adsorbed DECHTU exhibited good hydrophobicity and was effectively concentratedby nitrogen bubbles under pH 4–8. The adsorption of DECHTU onto chalcopyrite surfaces was fitted wellby the pseudo-second-order model and Langmuir isotherm, and was a spontaneously exothermicchemisorption process. The adsorption enthalpy change, entropy change and free energy change wereDH = 31.10 kJ mol 1, DS = 6.32 J mol 1 and DG (298 K) = 29.41 kJ mol 1, respectively. The activa-tion energy of the adsorption process was 17.39 kJ mol 1. The zeta potential results implied thatDECHTU adsorbed onto chalcopyrite surfaces as its anionic species with the release of H+ ion of NH–C(55S)–N group into aqueous solutions. The XPS spectra confirmed that there existed Cu(I)–DECHTUsurface complexes on chalcopyrite surface by bonding of copper atom with the sulfur atom of DECHTU,accompanying with the reduction of cupric to cuprous.