Abstract:
The Turpan-hami Basin is located in the Tianshan area in eastem Xinjiang, the Jurassic system in the basin is an important coal-bearing statum with abundant coal resources. Based on the theory of sedimentology, coal petrology, coal chemistry and coal petrography, the characteristics of quality, lithic facies and coal facies in seams have been analyzed by making full use of the test data of coal core samples and the identification of coal and rock. The study results show that the quality characteristics have exceptionally low-middle ash content, exceptionally low-middle total sulfir, middle-high calorific value and ash content, volatile matters, total sulfur. The analysis of microlithotype showed that the upper of seams are vitrite, the lower of seams are vitrineite. Through the analysis of coal facies, it is summarized that the swamp type of upper seam was water overlying forest swamp while the sedimentary environment was nearly limmic-telmatic, the swamp type of middle-lower seam was mainly wet forest swamp while the sedimentary environment was nearly telmatic. Through comprehensive analysis, we conclude that the forming process of seams was totality a slowly sinking water progressive process, the swamp environment was steady while the sedimentary environment was telmatie in the main coal-fomning period and thick Seam C8 has fomed, after that the degree of water overlying increases gradually, the sedimentary environment also develop to limnic-telmatic. Some basis have been provided for the coal assessment, the comparison of the seams and clean utilization of coal classification through the research.