Updated atmospheric mercury emissions from iron and
steel production in China during 2000–2015
Qingru Wu1,2, Wei Gao1,2, Shuxiao Wang1,2, and Jiming Hao1,21School of Environment, and State Key Joint Laboratory of Environment Simulation and Pollution Control, Tsinghua University, Beijing 100084, China 2State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing 100084, China
Received: 31 Jan 2017 – Accepted for review: 27 Mar 2017 – Discussion started: 27 Mar 2017
Abstract. Iron and steel production (ISP) is one of the significant atmospheric Hg emission sources in China. Atmospheric mercury (Hg) emissions from ISP during 2000–2015 were estimated by using a technology-based emission factor method. To support the application of this method, databases of Hg concentrations in raw materials, technology development trends, and Hg removal efficiencies of air pollution control devices (APCDs) were constructed through national sampling and literature review. Hg input to ISP increased from 21.6 t in 2000 to 94.5 t in 2015. In the various types of raw materials, coking coal and iron concentrates contributed 41 %–55 % and 22 %–30 % of the total Hg input. Atmospheric Hg emissions from ISP increased from 11.5 t in 2000 to 32.7 t in 2015 with the peak of 35.6 t in 2013. During the study period, although sinter/pellet plant and blast furnace were the largest two emission processes, emissions from roasting plant and coke oven accounted for 22 %–34 % of ISP’s emissions, which indicated that attention should also be paid on the emissions from these processes when estimating ISP’s emissions. Overall Hg speciation shifted from 50/44/6 (gaseous elemental Hg (Hg0)/gaseous oxidized Hg (HgII)/particulate-bound Hg (Hgp)) in 2000 to 40/59/1 in 2015, which indicated higher proportion of Hg deposition around the emission points. In the coming years, emissions from ISP are expected to decrease due to the projection of decreasing steel productions, increasing energy consumption efficiency, and improvement of APCDs. With the coming of high-yield-period of steel scrap production, the increasing application proportion of short process steel making method will not only reduce Hg emissions, but also increase the emission proportion of Hg0.
Wu, Q., Gao, W., Wang, S., and Hao, J.: Updated atmospheric mercury emissions from iron and
steel production in China during 2000–2015, Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2017-87, in review, 2017.