Trace elements of Carboniferous-Permian coal from the Adaohai Mine, Daqingshan Coalfield, Inner Mongolia, China

A total of 48 samples of Carboniferous-Permian coal was taken from the Adaohai Mine, Daqingshan Coalfield, Inner Mongolia, China. Cu2 coal is the major coalseam of the Daqingshan Coalfield. The samples were analyzed by the inductively coupled plasma-mass spectrometer method. The results indicate the content of V, Cr, Cu, Zn, Ga, Se, Ag, Cd, In, Ba, Pb and U of the Cu2 coals from Adaohai Mine is higher than that of the common Chinese coals. Compared to the world hard coals, the content of V, Cu, Zn, Ga, Se, Sr, Ag, Cd, In, Ba and U is relatively high. Compared to the clark values of the crust, only elements Se, Ag, Pb and Bi are enriched in the coal. Most of the elements in coal benches are lower than in those in roofs and partings. The statistical analysis and clustering analysis showed that the modes of trace elements occurrence for the Cu2 coal correlated positively with the minerals. The values of Sr/Ba show that the coal forming environment was influenced both by sea water and fresh water.