LAUSR

Abstract Reducing Hg emissions from Zn smelting flue gas (Zn-SFG) is rigorously stipulated by the Minamata Convention. Currently, a little natural pyrite (FeS2) as the tailings after flotation of natural sphalerite (ZnS) is often regarded as solid wastes and discarded; therefore, another utilization of these natural FeS2 is preferable. In this study, magnetic pyrrhotite (Fe1-xS), formed by heat treatment of natural FeS2, was exploited to reclaim gaseous Hg0 from Zn-SFG. Magnetic Fe1-xS displayed outstanding ability to capture gaseous Hg0 due to the formation of surface new unsaturation coordination sites for gaseous Hg0 physical adsorption. Additionally, magnetic Fe1-xS can be separated magnetically from Zn-SFG after gaseous Hg0 capture owing to its acceptable magnetism. Furthermore, both the abundant S resources emitted from the transformation of natural FeS2 to magnetic Fe1-xS and those in magnetic Fe1-xS after gaseous Hg0 capture can be used for H2SO4 production. Moreover, the vast majority of gaseous Hg0 in Zn-SFG can be ultimately reclaimed as liquid Hg0 by the condensation unit in Zn smelteries. Therefore, magnetic Fe1-xS offered unparalleled advantages in gaseous Hg0 recovery from Zn-SFG, double as a feasible method for fully exploiting the resource utilization value of natural FeS2 as the tailings after flotation of natural ZnS.