Coal Oxidation and Its Variation Under Constant Temperature

Two types of samples of lean coal and lignite were selected and heated under a serial of constant temperature (155-300 degrees C) to know their oxidation character. Under the same heating condition, the temperature histories of two coal samples have great difference, which can be ascribed to the kind of coal. But the temperature curves of two coal samples also have the same character. Both the temperature rise rates have the peak values at some points. This phenomenon indicates that the reaction would be more violent near these temperatures. The masses of two coal samples were measured after heated under a serial of constant temperature from low to high. Both the masses firstly increase, secondly slowly decrease, then quickly decrease with the temperature. According to the coal temperature curves, there is much heat release at all these three stages. This shows that different components of coal are oxidated under different temperature stages.