Study on mercury emission characteristics during leaching slags disposal process in the rotary kilns of Zn smelters
WU Qing-ru1,2, WANG Shu-xiao1,2, WANG Zu-guang3, LI Ke4
1. State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China;
2. State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex, Beijing 100084, China;
3. Foreign Economic Cooperation Office, Ministry of Environmental Protection, Beijing 100035, China;
4. Solid Waste and Chemicals Management Technology Center of Ministry of Environmental Protection of China, Beijing 100029, China
Leaching slag disposal in rotary kiln is a significant atmospheric mercury emission process according to our filed experiments in three zinc smelters.Our study found that the release rates of mercury from leaching slag and fuel in rotary kiln were in the range of 80.3%~99.3%.The mercury removal efficiencies of dust collectors for flue gas were in the range of 2.3%~7.9%.The recycle of removed dust in the multiple hearth furnace significantly reduced the net mercury removal efficiency of dust collectors.The mercury removal efficiencies of flue gas desulfurization towers were from 19.0% to 58.0%.Atmospheric mercury emissions accounted for 41.6%~87.1% of total mercury outputs.Atmospheric mercury concentrations in the emitted gas of tested zinc smelters were in the range of 171~1186μg/m3,much higher than the mercury emission limit (50μg/m3) in Emission Standard of Pollutants for Lead and Zinc Industry.The dominant mercury speciation in the emitted gas was gaseous elemental mercury,which increases the difficulty of controlling atmospheric mercury emissions from rotary kiln.
吴清茹, 王书肖, 王祖光, 李克. 锌回转窑处理浸出渣过程汞排放特征研究[J]. 中国环境科学, 2017, 37(7): 2513-2519.
WU Qing-ru, WANG Shu-xiao, WANG Zu-guang, LI Ke. Study on mercury emission characteristics during leaching slags disposal process in the rotary kilns of Zn smelters. CHINA ENVIRONMENTAL SCIENCECE, 2017, 37(7): 2513-2519.
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