Abstract
The methods of nuclear gamma-resonance spectroscopy (MS), X-ray diffraction (XRD) and X-ray fluorescence analysis (XRF) have been used to study the Kazakhstan’s coal from the deposits Ekibastuz, Shubarkol and Karazhyrinsky. It has been established that iron in the coals is contained in the divalent and trivalent states. The bivalent iron forms siderite mineral FeCO3, the trivalent iron forms pyrite mineral FeS2. During combustion of coal both pyrite and siderite decompose into Fe, sulfur oxide SO2 and carbon dioxide CO2 at the temperature of ~500 °C. The process of coal combustion occurs at high temperatures with formation of ash that contains the newly formed minerals – magnetite Fe3O4, hematite α-Fe2O3, mullite Al6Si2O3, hercynite FeAl2O4 in the composition of the ferro- and cenospheres.