Mineralogy and geochemistry of Galand-rud coal basin, central Alborz, Mazandran Province

The Galand-rud coal mine is one of the coal producing areas of central Alborz coal basin which is located in Mazandran Province. Based on mineralogical and geochemical studies pyrite is the main sulfide mineral in the mine. Based on correlation matrix, cluster analysis and principle component analysis (PCA), SiO2, Al2O3, Na2O, K2O and TiO2 are associated with alluminosilicate minerals, CaO, MgO and MnO with carbonate minerals (calcite and dolomite) and Fe2O3 and SO3 with pyrite. Ambiguous correlation between P2O5 and other major oxides and also the presence of apatite in Galand-rud coals indicate two sources for P2O5. A negative correlation between SiO2, Al2O3, Na2O, K2O, TiO2 and Cl indicate organic origin of Cl. Also, V and Rb originate from alluminosilicate minerals, Ni, Cu, Co, Cr, Pb, Ce, Y and Zn from sulfide minerals and Ba, Sr from carbonate and phosphate –bearing minerals. Galand-rud coals enriched in most of trace elements respect to China and America coals and Clark coals, whereas, exhaustion in Cl and Nb.