Separation of Molybdenite from Chalcopyrite, using Graphene Oxide as a Novel Depressant

In this research, graphene oxide was introduced as an efficient flotation reagent for the selective separation of molybdenite from chalcopyrite. The performance of graphene oxide and its adsorption mechanism on chalcopyrite were investigated by flotation tests, FTIR spectra, and XPS measurements. First, graphene oxide was synthesised, and then its performance was evaluated by SEM, XRD, and EDX. Flotation tests were carried out in a hallimond flotation cell with a volume of 300 ml. Optimum flotation values were achieved at pH = 9 by adding 250 g/t of PAX (Potassium Amyl Xanthate) as a collector and 50 g/t of A65 (Poly Propylene Glycol) as a frother. The results showed high recovery, around 80% for molybdenite, while chalcopyrite was depressed in high amounts by employing 11 kg/t of graphene oxide as a depressant. Compared to common chalcopyrite depressants such as NaHS, Na2S, and C2H3NaO2S, graphene oxide had a higher potency in depressing, which can be applied as a green-depressant in the separation of molybdenite from chalcopyrite by the flotation process. Also, the validity of the depressing effect on chalcopyrite was verified by XPS and FTIR spectra.