Parameter for judging reactivity of coal and coke

Abstract

To eliminate the judgment error of char reactivity arising from different carbon content of samples, a new parameter called specific maximum weight loss rate was introduced. It is defined as the quotient of the maximum weight loss rate in non-isothermal thermogravimetric analysis (TGA) experiment to the carbon content of the corresponding sample. The reactivity of different kinds of coal, the reactivity of the same coal type with different lithotype, and the reactivity of the char with different carbon conversion rates were checked by using the specific maximum weight loss rate, and the results were analyzed and compared with those obtained by using other criteria. The results show that the specific maximum weight loss rate can be used as a commonality parameter to evaluate and distinguish the reactivity of different coal and char. The heating rate selected in TGA experiment has no effect on the judgment. The experiment was conducted on a Mettler TOLEDO TGA/ SDTA 851 Thermo-balance analyzer. The reactivity of different coal; including Long-Yan anthracite (LY), Yang-Quan anthracite (YQ), Shao-Yang anthracite (SHY), Yi-Ma bituminous (YM); and the reactivity of the coal with different lithotypes, including the clarain coal of Long-Yan anthracite (LY-Clarain), the culm coal of Long-Yan anthracite (LY-Culm), and the dull coal of Long-Yan anthracite (LY-Durian); were measured in the experiment.The non-isothermal TGA method was applied in experiment. The sample (with a particle diameter of less than 200 mesh and a weight of 10 ¡ 0.5 mg) was heated from environmental temperature to 1000uC in air at a flow rate of 80 mL/min. Three different heating rates (10 K/min, 25 K/min and 40 K/min) were selected respectively.