Galvanic Interaction between Galena and Pyrite in the Presence of Sodium Lignosulfonate and Its Effects on Flotation

In the flotation process, there is galvanic corrosion between sulfide mineral particles, which increases the difficulty of separation between minerals. Therefore, the selection of suitable reagents to weaken this corrosion is of great significance. In this article, macromolecular organic reagent sodium lignosulfonate (SLC) was used to weaken the galvanic corrosion between galena and pyrite. Meanwhile, the effect of SLC on the mineral flotation behavior was studied, and the mechanism of SLC was further studied through ion dissolution tests, contact angle tests, infrared spectrum tests, and density functional theory (DFT) calculation. The adsorption of SLC on the mineral electrode increased the charge transfer resistance on the surface of the mineral electrode and hindered the resistance transfer; therefore, it could weaken the galvanic corrosion between galena and pyrite. SLC could selectively depress pyrite at low alkalinity. CaOH⁺ promoted the adsorption of SLC on the pyrite surface. When the pH of the slurry was adjusted by lime, SLC was more easily adsorbed on the pyrite surface, which hindered the adsorption of the collector on the surface of pyrite.