Institute of Disaster Prevention Science and Safety Technology, Central South University, Changsha, 410075, China.
College of Forestry, Inner Mongolia Agricultural University, Hohhot, 010019, China.
Environ Sci Pollut Res Int. 2021 Jul;28(26):34489-34500. doi: 10.1007/s11356-021-12964-0. Epub 2021 Mar 2.
In this study, an experimental model about the coal gangue stockpiles in semi-open storage was developed. According to the model's requirements, the corresponding coal gangues were piled up in the factory building, the heat source and collection points were arranged, and the four operating temperatures were selected from 70 to 350 °C for heating. A series of fire experiments concerning the temperature distributions of the coal gangue piles were conducted systematically. The spontaneous combustion tendency of coal gangue samples under kinds of the four heat sources was analyzed using scanning electron microscope (SEM), thermal gravity analysis, and differential thermal gravity (TG-DTG). Under the action of thermal damage, the surface of micropores in coal gangue becomes rough. Heat accumulation is, in nature, most likely to occur near 0.1~0.4 m away from the heat source of coal pile. Simultaneously, on each of the measured flat layers, the greater the horizontal distance from the heat source is, the lower the heated temperature of gangues is, and the lower the temperature change rate is, indicating that the horizontal heat conduction is also gradually weakened. The experimental model provides an empirical basis for studying the distribution of temperature field in the depth of gangue pile and kinetics reaction mechanism of spontaneous combustion.
本研究开发了一种半开放储存煤矸石堆的实验模型。根据模型的要求，在工厂建筑中堆积相应的煤矸石，布置热源和采集点，并选择 70 至 350°C 的四个运行温度进行加热。系统地进行了一系列关于煤矸石堆温度分布的火灾实验。使用扫描电子显微镜（SEM）、热重分析和差热重（TG-DTG）分析了四种热源下煤矸石样品的自燃倾向。在热损伤的作用下，煤矸石微孔的表面变得粗糙。热量积聚自然最容易发生在距煤堆热源 0.1~0.4 m 附近。同时，在每个测量的平面层上，离热源的水平距离越大，矸石的加热温度越低，温度变化率越低，表明水平热传导也逐渐减弱。该实验模型为研究矸石堆深度内温度场分布和自燃动力学反应机制提供了经验依据。
