Transportation and transformation of mercury in a calcine profile in the Wanshan Mercury Mine, SW China.
Calcination of Hg ores has resulted in serious contamination of mercury (Hg) in the environment. To understand the mobilization of Hg in the calcine pile, the speciation of Hg in a profile of a large calcine pile in the Wanshan Mercury Mine, SW China was investigated using the X-ray absorption spectroscopy (XANES), to understand the mobilization of Hg in the calcine pile. Higher concentrations of Hg were observed at the 30-50 cm depth of the profile, corresponding to a cemented layer. This layer is observed in the entire pile, and was formed due to cementation of calcines. Hg species in calcines include cinnabar (α-HgS), metacinnabar (β-HgS), elemental Hg(0), and minor mercuric chloride (HgCl2), but these Hg species show dramatic changes in the profile. Variations in Hg speciation suggest that extensive mobilization of Hg can occur during weathering processes. We show that the cemented layer can prevent the leaching of Hg and the emission of Hg(0) from the pile. High MeHg concentrations were found near the cemented layer, indicating Hg methylation occurs. This study provides important insights into the environmental risk of Hg in mining areas.
State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Science, Guiyang 550002, China; Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, WI 53706, USA.
Runsheng
R
Yin
Department of Ecosystem Science and Management, University of Wyoming, Laramie, WY 82071, USA.
Chunhao
C
Gu
State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Science, Guiyang 550002, China. Electronic address: fengxinbin@vip.skleg.cn.
Xinbin
X
Feng
Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China.
Lirong
L
Zheng
State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Science, Guiyang 550002, China.
Ningning
N
Hu
D002681:China; D004784:Environmental Monitoring; D008628:Mercury / Q000737:chemistry*; D017669:Mercury Compounds / Q000737:chemistry*; D008906:Mining; D012989:Soil Pollutants / Q000737:chemistry*; D056928:X-Ray Absorption Spectroscopy
D017669:Mercury Compounds; D012989:Soil Pollutants; D008628:Mercury
Calcine pile; Mercury; Mobilization; Speciation; XANES