Deashing and desulfurization of subbituminous coal from the East field (Bogovina Basin, Serbia) - insights from chemical leaching

The study is focused on the determination of most effective chemical leaching process for simultaneous demineralization/deashing and desulfurization subbituminous coal from Bogovina Basin. Coal was treated 30 min, at different temperatures, using variable concentrations hydrochloric, nitric, acetic citric acids; hydrogen peroxide, mixture peroxide nitric acid (pH 2), as well by stepwise (nitric + acid, pH 2). changes in mineral composition, caused leaching, are followed X-ray diffraction, whereas alterations organic matter tracked Fourier-transform infrared spectroscopy content fixed carbon. Inorganic regardless temperature concentration, enabled successful deashing coal, percent insufficient. not satisfactory both, desulfurization. Leaching H2O2 H2O2/HNO3 2) resulted moderate desulfurization, but ash reduction low. suitable method (78 wt.%) sulfur (66 wt. %) removal two-step combining 10 vol. % HNO3 35 H2O2/10 2 60?C.