Study on the Removal Efficiency of Heavy Metals in Flue Gas of Small Sintering Machines

Abstract

Heavy metal pollutants such as Hg, Pb, Cr, and Cd contained in flue gas from the sintering equipment bring about environmental hazards. In this paper, 4 small sintering machines with different control technologies were selected, and the US EPA 29 method was used to analyze the emission concentration of heavy metals from the sintering machines, and the removal efficiency of the different flue gas control technologies on the of heavy metal pollutants was analyzed. The results show that the dry flue gas desulfurization combining baghouse dedusting method has high removal efficiency of heavy metals in flue gas, with mercury removal efficiency of 60.06%, Pb removal efficiency of 92.92%, Cd removal efficiency of 92.20%, Cr removal efficiency of 55.14%. The removal efficiency of heavy metals is obviously higher than that of conventional electrostatic precipitation combining wet desulfurization. This is mainly ascribed to those heavy metals are mainly concentrated in the fine particulate matters of the fly ash. Dust removal technology can effectively coordinate the control of Hg, Cr, Pb and Cd in the flue gas. The semi-dry desulphurization and baghouse dedusting technology can promote the enrichment of Hg and Cr in fly ash. The results of this study can provide theoretical guidance for the control of Hg, Cr, Pb, Cd and other heavy metal pollutants control in sintering equipment, and for flue gas ultra-low emission transformation.