Mercury flow network and its emission reduction in the steelworks

Abstract

The steel industry is an important source of anthropogenic mercury (Hg) emissions. Hg is harmful to human health, causing symptoms such as dizziness, pneumonia, and renal failure. So, how do we reduce Hg emissions from the steelworks? What possibilities exist for Hg emission reduction? Firstly, in this study, the flow paths of Hg in the steelworks were described quantitatively using the substance flow analysis method, and the characteristics of the input and output of Hg-containing subjects were analyzed. Secondly, based on the Hg flow network, the circulation characteristics of Hg and the emission characteristics of Hg-containing pollutants were analyzed in the steelworks. Finally, according to the distribution of Hg in the steelworks, the emission reduction potential was examined at the source and end-of-pipe. The results showed that Hg, which mostly originated from coal, limestone, and iron ore concentrate in the steel production process, was mostly exported with waste gas and wastewater, primarily in the form of waste gas. The input, circulation, and output of Hg were 362.77, 3.25, and 392.55 mg/t crude steel (CS), respectively. Through source reduction and end-of-pipe treatment, the reduction rates of pollutants in the steelworks were 28.74% and 75.37%, respectively.