Insights into the adsorption mechanism of N-thiourea-maleamic acid on chalcopyrite surface in the flotation separation of Cu-Mo sulfide ores

Abstract

In this study, N-thiourea-maleamic acid (TMA) was first introduced as a chalcopyrite depressant in flotation separation of Cu-Mo sulfide ores. The effects of TMA on the separation of Cu-Mo were investigated by micro-flotation tests. The results indicated that TMA was beneficial to separate chalcopyrite and molybdenite in the flotation separation of artificially mixed minerals at pH around 9.0 with a Mo recovery of 95.56% and depressing 94.64% of Cu. Its adsorption mechanism was revealed by contact angle, UV–Vis spectra, FT-IR and XPS measurements, in which, the contact angle and UV–Vis spectra measurements further proved that TMA did adsorb on chalcopyrite surface. Moreover, FT-IR and XPS measurements demonstrated that S atoms in the thiourea group of TMA interacted with Cu sites on chalcopyrite surface. All these findings confirmed that TMA would be a highly effective chalcopyrite depressant. TMA could adsorb onto chalcopyrite surface thereby increase its hydrophilicity without significant influence on molybdenite.