Flotation separation of molybdenite from chalcopyrite using ferrate(VI) as selective depressant in the absence of a collector

The effect of ferrate on the flotation of chalcopyrite and molybdenite in the absence of a collector was studied in this work. Flotation tests on single minerals revealed that chalcopyrite was strongly depressed by the ferrate for pH ranging from 4 to 9, whereas molybdenite was only slightly affected. The flotation tests on mineral mixtures and real ore confirmed that ferrate could selectively depress chalcopyrite flotation without significantly affecting molybdenite floatation. Under the optimum conditions, a value of >60% was obtained for the difference between the recovery of chalcopyrite and molybdenite. X-ray photoelectron spectroscopy results revealed that the oxide and hydroxide content and iron content of the chalcopyrite surface increased from 55.42% to 74.80% and 2.56% to 5.15%, respectively. This confirmed that the ferrate-treated chalcopyrite surface was more hydrophilic than the untreated surface. Therefore, ferrate can be used as a selective depressant of chalcopyrite in copper-molybdenum separation within a wide pH range.