Sustainability and environment trace element geochemistry of some Chinese coals

A suite of 305 raw coal samples and 22 washed coal samples were collected from 24 provinces and autonomous regions and 2 municipalities of China in 2000. The run-of-mine samples were primarily collected from the larger coal mines and are believed to represent about 80% of China's coal production at that time. Detailed chemical analysis of the samples was performed at the U.S. Geological Survey's laboratories in Denver, CO, USA. The analytical data indicate relatively low to modest concentrations for most trace elements, including potentially hazardous elements. For example, the mean concentration of arsenic in these samples is 4.3 ppm (the mean concentration for arsenic in in-ground U.S. coal samples is 24 ppm); mercury, 0.16 (0.17 for U.S. coals); selenium, 4.1 ppm (2.8 for U.S. coals); lead, 13.9 ppm (11.0 for U.S. coals); thallium 0.34 ppm (1.2 for U.S. coals); beryllium, 1.8 ppm (2.2 for U.S. coals); cadmium, 0.14 ppm (0.47 for U.S. coals); chromium, 21.0 ppm (15.0 for U.S. coals); nickel, 12.5 ppm (14.0 for U.S. coals) and; uranium, 3.1 ppm (2.1 for U.S. coals).