Recyclable Naturally Derived Magnetic Pyrrhotite for Elemental Mercury Recovery from Flue Gas.
Magnetic pyrrhotite, derived from the thermal treatment of natural pyrite, was developed as a recyclable sorbent to recover elemental mercury (Hg0) from the flue gas as a cobenefit of wet electrostatic precipitators (WESP). The performance of naturally derived pyrrhotite for Hg0capture from the flue gas was much better than those of other reported magnetic sorbents, for example Mn-Fe spinel and Mn-Fe-Ti spinel. The rate of pyrrhotite for gaseous Hg0capture at 60 °C was 0.28 μg g min-1and its capacity was 0.22 mg g-1with the breakthrough threshold of 4%. After the magnetic separation from the mixture collected by the WESP, the spent pyrrhotite can be thermally regenerated for recycle. The experiment of 5 cycles of Hg0capture and regeneration demonstrated that both the adsorption efficiency and the magnetization were not notably degraded. Meanwhile, the ultralow concentration of gaseous Hg0in the flue gas was concentrated to high concentrations of gaseous Hg0and Hg2+during the regeneration process, which facilitated the centralized control of mercury pollution. Therefore, the control of Hg0emission from coal-fired plants by the recyclable pyrrhotite was cost-effective and did not have secondary pollution.
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology , Nanjing, 210094, P. R. China.
Yong
Y
Liao
Laboratory for Nanomineralogy and Environmental Material, School of Resources and Environmental Engineering, Hefei University of Technology , Hefei, 230009, P. R. China.
Dong
D
Chen
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology , Nanjing, 210094, P. R. China.
Sijie
S
Zou
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology , Nanjing, 210094, P. R. China.
Shangchao
S
Xiong
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology , Nanjing, 210094, P. R. China.
Xin
X
Xiao
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology , Nanjing, 210094, P. R. China.
Hao
H
Dang
Laboratory for Nanomineralogy and Environmental Material, School of Resources and Environmental Engineering, Hefei University of Technology , Hefei, 230009, P. R. China.
Tianhu
T
Chen
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology , Nanjing, 210094, P. R. China.
Shijian
S
Yang
D000327:Adsorption; D000393:Air Pollutants; D003031:Coal; D005740:Gases; D008280:Magnetics; D008628:Mercury; D011210:Power Plants; D059027:Recycling
D000393:Air Pollutants; D003031:Coal; D005740:Gases; D008628:Mercury