Abstract:The behavior of surface action between ethyl thiourea (ETU) and chalcopyrite was studied by means of measurement of adsorptive amount, IR and XPS. The adsorption behavior of ETU on chalcopyrite corresponds to Freundlich adsorption isothermal equation, which isГ=6.31×10-5c0.31mol/g. The adsorption is a covalent bond type of chemical one composed of twoσ-type bonds and a back donationπ-type, mainly occurs between sulfur and nitrogen atom
in ETU and copper atoms on the surface of chalcopyrite. For the twoσ-type bonds, one is formed by transferring a pair of electrons from sulfur atom in ETU to copper atoms on the surface of chalcopyrite, the other is from nitrogen atom. And theπ-type bond is caused by transfer of electrons from copper atoms on the surface of chalcopyrite to unoccupiedπ-type orbit of C S group in ETU. Theoretical index predicts that ETU can be an excellent kind of chelating collector for copper flotation.

Key words: ethyl thiourea; chalcopyrite; surface action; adsorption characteristic; flotation reagents