Characterization of coals utilized in power stations of China

The petrographic composition of 21 types of typical Chinese coals obtained directly from the power stations was analyzed. The vitrinite reflectograms of them were measured and shows an obvious difference from that of single r ank coals, which suggests that the coals utilized in the power stations hav e the characterization of a blended coal in terms of coal rank. The index S M has been developed to describe the occurrence of mineral in the coals and the results show quite a difference in the occurrence of the mineral for t he coals studied. The petrographic constituents of different size fractions were analyzed for three coals and showed Little systematic change with the particle size, but revealed the trend that the large particles contained m uch more of the higher rank coal and the small particles contained much mor e of the low rank coal. (C) 1999 Elsevier Science Ltd. All rights reserved.