Selective flotation separation of molybdenite and chalcopyrite using O3 oxidation method
(School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China)
Abstract: The effect of O3 oxidation on the flotation recovery of chalcopyrite and molybdenite was investigated. The results of single-mineral flotation tests showed that under the conditions that O3 concentration was about 90 g/m3 and the gas flow rate was 4 L/min, after chalcopyrite and molybdenite were oxidized for 2 min, the flotation recovery of the chalcopyrite dropped to 16%, while the flotation recovery of molybdenite did not change much. The results of flotation tests for the artificially mixed ores showed that O3 oxidation pretreatment could replace the Na2S reagent as a chalcopyrite depressant in the selective flotation separation of chalcopyrite and molybdenite. The contact angle measurements revealed that the O3 oxidation treatment selectively rendered the surfaces of the chalcopyrite to be hydrophilic. The Zeta potential and X-ray photoelectron spectroscopy analyses revealed that the chalcopyrite surface most likely became hydrophilic due to the formation of water-insoluble hydrophilic oxides and hydroxides on the mineral surface after the oxidation treatment. In addition, although the surface of the molybdenite was slightly oxidized, its surface remained good hydrophobicity.
Key words: chalcopyrite; molybdenite; O3 oxidation; selective flotation; hydrophilicity