TY - JOUR A1 - Butuzova,L. A1 - Bechtel,A. A1 - Turchanina,O. A1 - Safin,V.A. A1 - Butuzov,G. A1 - Isayeva,L. T1 - Organic sulphur as a main index for determining the genetic type of low-rank coals JF - Bulletin of Geosciences JA - Bull. Geosci. Y1 - 2005 VL - 80 IS - 1 SP - 3 EP - 8 CY - Prague PB - Czech Geological Survey SN - 1803-1943 (online), 1802-6222 (print) AV - Free KW - bituminous coals KW - statistical analysis KW - organic sulphur KW - volatile matter yield KW - dibenzothiophene/phenanthrene ratio KW - hopanes KW - 13C-isotopes AB - A statistical analysis of the quality of Donetz low-rank coals has been carried out using catalogue data and freshly-sampled coals. Thirty seven samples of bituminous coals with volatile matter contents ranging from 37.2% to 44.2% were used. All coals are closely clustered into groups of samples with different ranges of (O+N) daf/Cdaf atomic ratio. It has been shown that linear correlations exist between the Sîdaf and Sîdaf/Cdaf ratio and Vdaf. The correlation coefficients within the different sample groups have been found to be r1=0.87; r2=0.92, and r3=0.98. They increase as the Odaf/Cdaf interval is narrowed down, i.e. as the coal rank is more exactly defined. Similarly, a statistical dependence between the volatile matter yield and the organic sulphur content has been found for the Donetsk DG and G brand coals, with the correlation coefficients being r = 0.91 and r = 0.95, respectively. It was also found that some structural parameters of the coals correlate with Sodaf. ER -