THE PETROGRAPHY AND MINERALOGY OF 2 INDIAN COALS

Two coals, Kathara bituminous middlings from north-eastern India (Damo dar Valley) and Neyveli lignite from south-eastern India (Tamil Nadu), were petrographically characterized. The Kathara sample is a high-ash coal produced in the beneficiation of a bituminous coking coal. It is relatively high in inertinite and mineral matter, with an unusually l arge amount of iron oxides in the form of hematite, magnetite and hydr ated iron oxides. The Neyveli sample is relatively low in ash and sulf ur, and consists mostly of the huminite group of macerals, with a cons iderable amount of liptinite also present. Low-temperature ashes and b ottom ash samples of both coals were analysed by X-ray diffraction to help in interpreting the petrographic data. These coals were also test ed for combustion characteristics.