There is a high demand for developing a more effective and environment-friendly technology to substitute the complicated and hazardous Boliden–Norzink technology for recovering gaseous Hg0 from smelting flue gas. In this work, a low-cost and reproducible sorbent (FeMoS x /TiO2) was developed to recover gaseous Hg0 from smelting flue gas. FeMoS x /TiO2 exhibited a superior ability for capturing high concentrations of Hg0, with an adsorption rate of 72.2 μg g–1 min–1 and a capacity of 41.8 mg g–1 at 60 °C. These were generally larger than the sums of those of FeS x /TiO2 and MoS x /TiO2. The kinetic model of Hg0 adsorption by FeS x /TiO2, MoS x /TiO2, and FeMoS x /TiO2 were constructed according to the adsorption mechanism. Then, the structure–activity relationship of FeMoS x /TiO2 for Hg0 capture was determined by comparing the kinetic parameters. The intrinsic adsorption of Hg0 by MoS x /TiO2 (i.e., physically adsorbed Hg0 was oxidized by MoS3 to HgS) was inhibited marginally after FeS x was incorporated. However, another Hg0 adsorption route (i.e., physically adsorbed Hg0 was oxidized by FeS2 to HgS) appeared on FeMoS x /TiO2. Its rate was significantly higher than that of FeS x /TiO2. Thus, a novel synergistic effect of Fe and Mo in FeMoS x /TiO2 for Hg0 capture was observed.

No abstract

To replace the hazardous and complicated Boliden−Norzink technology, the technology of Hg 0 recovery from smelting flue gas by a magnetic and reproducible sulfureted MoO 3 /Fe−Ti spinel was employed to keep the produced H 2 SO 4 free of Hg. The sulfureted MoO 3 /Fe−Ti spinel showed excellent performance in capturing gaseous Hg 0 , with an average adsorption rate of 93.3 μg g −1 min −1 and an adsorption capacity of 66.3 mg g −1 at 60 °C, which were much better than those of most of the other reported sorbents. Meanwhile, the sulfureted MoO 3 /Fe−Ti spinel exhibited excellent superparamagnetism and magnetization of 19.9 emu g −1 , which ensured that it could easily be magnetically separated without a specialized precipitator or the molding of pulverous sorbents to monolithic sorbents. To investigate the promotion mechanism of MoO 3 loading on Hg 0 adsorption onto the sulfureted Fe−Ti spinel, the Hg 0 adsorption kinetic parameters of the sulfureted MoO 3 /Fe−Ti spinel and sulfureted Fe−Ti spinel, resulting from the fitting of the adsorption breakthrough curves based on the kinetic model, were compared. The promotion of MoO 3 loading was attributed to the remarkable increase in the adsorption sites on the sulfureted Fe−Ti spinel for Hg 0 physical adsorption, which was mainly related to the formation of the MoS 3 layer.

No abstract

No abstract