为了研究以活化能指标判定不同煤的自燃倾向性,选取了4 种不同变质程度烟煤煤样,通过煤自燃性升温实验,并结合公式计算得出不同温度时刻煤样氧化的耗氧速率;运用化学反应动力学原理计算出煤样的表观活化能.研究结果表明:以表观活化能表征煤自燃倾向性,在其他条件相同的情况下,若不同变质程度煤样的指前因子变化不大,则变质程度越高,煤表观活化能越大,煤越不易自燃;若不同变质程度煤样的指前因子变化较大,则需要综合考虑指前因子和表观活化能来判断煤自燃倾向性.煤的指前因子越大且表观活化能越小,表征煤越易自燃;反之,煤的指前因子越小且表观活化能越大,表征煤越不易自燃.
In this paper, four kinds of bituminous coal with different metamorphic grades were selected for studying the spontaneous combustion tendency of different coals which was determinate by the activation energy index. Through the programmed temperature rise experiment and by using the calculation formula, the oxygen consumption rate of different coal samples at different temperatures was obtained and then the apparent activation energy of coal samples was calculated according to chemical reaction kinetics theory. The results showed that when the spontaneous combustion tendency of coals was characteristics of the apparent activation energy, if the other conditions were the same and the change of the pre-exponential factor of the coals with different metamorphic was smaller, the higher the metamorphic grade of coals, the greater the apparent activation energy and the more nonflammable the coals; if the change of the pre-exponential factor of coals with different metamorphic grades was larger, it need to use the pre-exponential factor and apparent activation energy of coals to comprehensively judge their spontaneous combustion tendency. The larger the pre-exponential factor and the smaller the apparent activation energy of coal, the easier the spontaneous combustion of coals; on the contrary, the smaller the pre-exponential factor and the larger the apparent activation energy, the more difficult the spontaneous combustion of coals.