Synthesis, characterization and properties of 3,3′-diethyl-1,1′-oxydiethylenedicarbonyl bis(thiourea)

In this paper, 3,3'-diethyl-1,1'-oxydiethylenedicarbonyl bis(thiourea) (DEOECTU), was synthesized by phase transfer catalysis and then characterized by UV, elemental analysis, infrared spectra, mass spectrum, H-1 NMR and TGA. DEOECTU properties, such as response to metal ions, adsorption on sulfide mineral surfaces, and hydrometallurgical performance as flotation collectors, were also investigated. The results indicated that DEOECTU reacted chemically with Cu2+ ions through its S and N atoms in the C(=S)-NH-C(=O) group to form a new chelate compound, but no reaction of DEOECTU with Zn2+, Pb2+, Fe3+ or Fe2+ ions was observed. The results of adsorption and flotation experiments demonstrated, that compared to pyrite, sphalerite and galena, DEOECTU exhibited a superior collecting power for chalcopyrite and might attach on chalcopyrite surface by chemisorption. The further theoretical analysis from Pearson's HSAB view point briefly explained the experimental results of the selective response of DEOECTU to Cu2+ ions and chalcopyrite.