Investigation of structural characteristic and bond composition of coals of Gheshlagh region, Eastern Alborz: Using of XRD, FT-IR and Raman

Coal deposits in Gheshlagh region are embedded in the sediments of Shemshak formation with lithological units such as sandstone, conglomerate, siltstone, limestone and argillite. For investigation of mineralogy and structural characteristics of Gheshlagh coal seams sampled of eleven coal seams in four active mines. Occurrence of minerals with distribution and nature of organic – mineral bonds in coals seams of this region is considered by using of petrographic and XRD and FT-IR analyses. Study of hand specimen and polished section are approved the presence of clay minerals, pyrite, chalcopyrite, siderite and quartz. Also The presence of minerals like kaolinite, quartz, siderite, dolomite, calcite, pyrite, montmorillonite and biotite was revealed by XRD. Mineral–organic bands such as: OH, CO2, CH3, Si-O, S-S, C-S, Al-OH, carbonate minerals, C=C, aromatic and aliphatic CH have been identified by the FT-IR in Gheshlagh coal seams. Raman spectroscopic confirms the presence of the graphitic band (G) (1581 cm−1- 1585 cm−1) and the defect band (D1) (1341 cm−1 – 1352 cm−1) in Gheshlagh coal seams. Graphitic bands contain high intensity and insignificant broadening.