Safe disposal of deactivated commercial selective catalytic reduction catalyst (VO-MoO/TiO) as a low-cost and regenerable sorbent to recover gaseous elemental mercury in smelting flue gas.

The reduction of Hg emissions from non-ferrous metal smelting was proposed in the Minamata Convention. Regenerable sulfureted MoO/TiO, which displayed excellent performance in capturing gaseous Hg, was once developed by us to recover gaseous Hg in smelting flue gas (SFG) for centralized control. Recently, a large amount of spent commercial selective catalytic reduction catalysts (for example VO-MoO/TiO) mostly deactivated by CaSO was formed, creating a need for their safe disposal. As the main constituent of deactivated VO-MoO/TiO is MoO/TiO, deactivated VO-MoO/TiO was sulfureted to capture gaseous Hg from SFG for its safe disposal and the effects of VO and CaSO on Hg adsorption onto sulfureted MoO/TiO were investigated. Although the capturing capacity of sulfureted MoO/TiO moderately decreased after the impregnation of VO and CaSO, sulfureted deactivated VO-MoO/TiO still displayed excellent performance and reproducibility in gaseous Hg capture. Meanwhile, the cost performance of sulfureted deactivated VO-MoO/TiO for Hg capture was outstanding as deactivated VO-MoO/TiO needs to be safely disposed. Therefore, deactivated VO-MoO/TiO can be sulfureted as a regenerable and low-cost sorbent that is effective in recovering gaseous Hg from SFG, as well as being a cost-effective and environmentally friendly method for the safe disposal of spent VO-MoO/TiO.