School of Earth and Space Sciences;
University of Science and Technology of China;
Hefei 230026;
Anhui;
China;
Green Mining Engineering Technology Research Center of Anhui Province;
Exploration Research Institute;
Anhui Provincial Bureau of Coal Geology;
Hefei 230088;
Anhui;
China;
Coal cleanliness; Hazardous trace elements; Evaluation method; Huainan coalfield;