Temperature rising characteristic of coal powder during microwave heating

Temperature is an important index to evaluate the microwave heating characteristics and affection of Formation microwave heating treatment. Experiments on microwave heating of coal powder were conducted to investigate the temperature rising characteristics of coal powder. The results indicated when the microwave heating power ranged from 1 kW to 5 kW, the temperature rising rate of the coal sample with grain size 0.18 mm?0.25 mm was larger than that with grain size 1.00 mm?2.00 mm. However, this relation was the opposite when the microwave power was 6 kW. The temperature rising rate increased with the increased moisture and pyrite content of the coal sample, while it decreased with the increased calcium carbonate, silicon dioxide, and potassium chloride of coal samples. Moreover, the correlation between oxygen concentration and the temperature rising was not obvious in this study. Finally, empirical equations between various factors and the heating temperature are given.