Participating patterns of trace elements in PM_2.5 formation during iron ore sintering process

Abstract

Patterns of trace elements participating in PM_2.5 (aerosol dynamic diameter ≤2.5 μm) formation during iron ore sintering process were investigated. For elucidating this property, PM_2.5 collected from before and after the flue-gas-temperature-rising point (stage-1 and stage-2) was examined. The results show that trace elements including Pb, K, Na, Cl and S presented an enriched tendency in PM_2.5 from stage-2, while characterised lower contents in PM_2.5 from stage-1. Owing to the tiny size of PM_2.5, trace elements participated in the formation of Fe-rich and Fe–Al–Si-rich particles in heterogeneous manner. Moreover, S participated in the formation of CaSO₄ particles from stage-1 and stage-2 in the form of homogeneous pattern, while Pb, K, Na and Cl participated homogeneously in the form of hybrid PbCl₂–KCl, KCl and NaCl particles only from stage-2. The finding results clearly showed the relationship between the formation mechanisms of PM_2.5 and the contribution of trace elements, which can serve as the guideline to control PM_2.5 in sintering plants.

Keywords:

• Iron ore sintering
• PM_2.5
• Trace elements
• Participating patterns

Acknowledgements

The authors are grateful to the National Natural Science Foundation of China (No. 51474237).