Interaction mechanism of the adopted reagents in the flotation recovery of sphalerite and pyrite from a galena flotation tailing: First-principles calculations

Sphalerite (ZnS), galena (PbS) and pyrite (FeS2) are the important metallic sulphide minerals. These three sulphide minerals are often associated with each other, and large amounts of sphalerite and pyrite are lost in the galena flotation tailings. In this study, the flotation method was employed to recover sphalerite and pyrite from a galena flotation tailing waste. The reagent scheme, including Cu2+ activator and butyl xanthate (BX) collector, can efficiently recover sphalerite and pyrite to obtain a two-mineral mixed concentrate with the Zn and Fe grades of ∼17 % and ∼26 %, respectively, in the sphalerite-pyrite bulk rough flotation. Quicklime (CaO) depressant in combination with BX collector can efficiently separate sphalerite and pyrite to obtain the two products in the sphalerite/pyrite separation rough flotation: the sphalerite concentrate with the Zn grade of ∼33 % and the pyrite concentrate with the Fe grade of ∼36 %. The first-principles calculations were employed to study the interaction mechanism of the adopted reagents in the recoveries of sphalerite and pyrite from the galena flotation tailing. This study provides an important reference for the recoveries of sphalerite and pyrite from similar galena tailings.