Distributions of minor and trace elements in Chinese coals

The concentrations of forty-five elements in 137 Chinese coals collected fr om the main coal fields and representing the main coal-forming periods were determined using instrumental neutron activation analysis (INAA), atomic a bsorption spectrometry (AAS), inductively coupled plasma atomic emission sp ectrometry (ICP-AES), and atomic fluorescence spectrometry (AFS). Among the elements determined are the following minor and trace elements which are i mportant to environmental protection and human health: As, Cd, Ph, Hg, Se, Mn, Ni, Cu, Zn, Sb, Co, Mo, F, Cl, V, Ba, U and Th. The ranges and means of concentrations of these elements are given. Comparison with world averages and geometric means of concentrations in American coals shows that the con centrations of most elements are higher in Chinese coals. However, it is ne cessary to point out that although the samples are representative, the numb er of samples is small. Hence, these are only preliminary results. Finally, five major genetic types of enrichments of minor and trace elements in Chi nese coals are proposed on the basis of Chinese coal geology, namely, sourc e-rock-controlled type; sedimentation-controlled type; magmatic/hydrotherma l-controlled type; fault-controlled type; and groundwater-controlled type. (C) 1999 Elsevier Science B.V. All rights reserved.