DIRECT MEASUREMENT OF IGNITION TEMPERATURES OF PULVERIZED COAL PARTICLES

The use of a captive technique for direct measurement of ignition temperatures of pulverized coal and char particles is described. Coals of different rank, their corresponding chars and a metallurgical coke were used. The measurements were made in air on particles of 60 mum mean size. The values obtained ranged from 685-degrees-C for a high-volatile bituminous coal to 1090-degrees-C for the metallurgical coke. The ignition point was not perfectly defined at a specific temperature, occurring instead over a transition range, with the measured values providing a useful indicator of the onset of ignition. An increase in the ignition temperature with coal rank was clearly observed and differences were noted in the ignition temperatures of the char and corresponding parent coal for the higher-volatile bituminous samples.