Synthesis, Characterization And Properties Of3,3’-dialkoxypropy1-1,1’-oxydiethylenedicarbony1Bis(Thiourea)

Thiourea derivatives have strong complexing properties, and are valuable metal chelating agent and flotation collector. With the support of National Natural Science Foundation of China and863Program,3,3’-dialkoxypropyl-1,1’-oxydiethylenedicarbonyl bis(thioureas)(DAOPECTU) were synthesized. The synthesis technology of the novel thiourea and the optimal conditions were evaluated. While the interactions of the novel collectors with metal ions and the adsorption mechanism on monominerals were researched. Then the flotation tests of monominerals and actual minerals were also carried out using these novel thioureas as collectors.Using oxydiethylene bis(chloroformate) and NaSCN as reactants, N,N-dimethylaniline(DMA) as a catalyst, an oxydiethylenedicarbonyl bis(isothiocyanate) intermediate was synthesized by a phase transfer catalytic reaction. Then, through a nucleophilic addition reaction, this intermediate reacted with alkoxyl propylamine to produce DAOPECTU. And the preferred conditions were as follows:molar ratio of sodium thiocyanate to oxydiethylene bis(chloroformate)2.5:1, molar ratio of alkoxyl propylamine to oxydiethylene bis(chloroformate)2.2:1, the molar ratio of DMA to the bischloroformate is6%, the first react time is2.5hours, and the second is2hours. The whole reaction was carried out in the ice bath(2～3℃). Under these preferred conditions, the yields of five novel3,3’-dialkoxypropyl-1,1’-oxydiethylenedicarbonyl bis(thiourea)(DMOPECTU, DEOPECTU, DiPOPECTU, DBOPECTU and DMEOPECTU) were74.95%,76.15%,86.23%,69.95%and78.50%respectively. Their structures and properties were characterized by UV, infrared spectra, mass spectrum and1H NMR to be proved to be the target compounds.UV-visible spectra indicated that novel DAOPECTU chemically reacted with Cu2+ions in solution, but no reaction of the compound with Fe2+、Fe3+、Co2+、Ni2+、Zn2+or Pb2+ions was observed. The results of infrared spectra demonstrated that the compound bonded Cu atom with its S and N atoms to form chelated rings.The analysis of UV-visible measurements, IR spectroscopic analysis and the adsorption dynamics and thermodynamics all revealed that the novel DAOPECTU could chemically adsorbed on chalcopyrite surface, While the adsorption of the compound on the suface of pyrite, sphalerite or galena was very weak. The flotation tests of monominerals and actual minerals verifying that it has higher flotation recovery and better selectivity to chalcopyrite than the common collectors.