Zheng Wenjin, Gan Shishun, Jia Xueqi, Liu Xianfeng
Power China Huadong Engineering Corporation Limited, Hangzhou, Zhejiang 310014, China.
State Key Laboratory of Coal Mine Disaster Dynamics and Control, School of Resources and Safety Engineering, Chongqing University, Chongqing 400044, China.
ACS Omega. 2024 Nov 8;9(46):46447-46453. doi: 10.1021/acsomega.4c07832. eCollection 2024 Nov 19.
The exposed accumulation of coal gangue undergoes changes when it is soaked by rainwater, exhibiting varying tendencies for spontaneous combustion in different precipitation regions. This study investigates the effects of moisture on the oxidation and spontaneous combustion of coal gangue in high-sulfur coal gangue from the Qipanjing area of Inner Mongolia. Initially, coal gangue samples were subjected to soaking and air-drying treatments at different moisture contents. The dried coal gangue samples were then placed into a self-designed programmable heating furnace for thermal experiments, during which the gases generated were collected and characterized using gas chromatography. By comparing the oxygen consumption and volume fractions of gases such as CO, CH, and CH produced from coal gangue treated at different moisture contents, it was found that the low-temperature oxidation characteristics were optimal at a moisture content of 25%. At this level, the initial formation temperatures of gases like CO, CH, and CH were the lowest, with peak concentrations observed at 390 °C. Conversely, when the moisture content exceeded 70%, a significant amount of combustible material in the coal gangue was dissolved and dispersed by water, leading to a marked decrease in the concentrations of indicator gases produced at 390 °C. In fact, these concentrations fell below those of the control group, which was not subjected to water soaking or subsequent drying. The water immersion treatment also lowered the initial temperature points for the generation of various indicator gases by approximately 15 °C, making spontaneous combustion more likely.
露天堆放的煤矸石在被雨水浸泡后会发生变化，在不同降水区域呈现出不同的自燃倾向。本研究调查了水分对内蒙古棋盘井地区高硫煤矸石中煤矸石氧化和自燃的影响。首先，对煤矸石样品进行不同含水量的浸泡和风干处理。然后将干燥后的煤矸石样品放入自行设计的程控加热炉中进行热实验，期间收集产生的气体并用气相色谱进行表征。通过比较不同含水量处理的煤矸石产生的气体如CO、CH₄和C₂H₄的耗氧量和体积分数，发现含水量为25%时低温氧化特性最佳。在此水平下，CO、CH₄和C₂H₄等气体的初始生成温度最低，在390℃时观察到峰值浓度。相反，当含水量超过70%时，煤矸石中的大量可燃物质被水溶解和分散，导致390℃时产生的指标气体浓度显著降低。实际上，这些浓度低于未经过水浸和后续干燥的对照组。水浸处理还使各种指标气体的初始生成温度点降低了约15℃，使自燃更易发生。
