College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China.
China Coal Technology and Engineering Group Chongqing Research Institute, Chongqing, 400037, China.
Environ Sci Pollut Res Int. 2023 Aug;30(38):88548-88562. doi: 10.1007/s11356-023-28585-8. Epub 2023 Jul 12.
Coal gangue, as an associated product of coal mining, can cause a large number of piles to undergo slow oxidation and spontaneous combustion, resulting in the production of toxic and harmful gases, leading to casualties, environmental damage, and economic losses. Gel foam has been extensively employed as a fire-retardant material in coal mine fire prevention. The thermal stability and rheological properties of the newly developed gel foam were investigated in this study, as well as its oxygen barrier properties and fire extinguishing effect which were evaluated through programmed temperature rise and field fire extinguishing experiments. The experiment indicated that the temperature endurance of the new gel foam was around twice that of the ordinary gel foam, and this resistance decreased with the increment of foaming times. Moreover, the temperature endurance of the new gel foam with a stabilizer concentration of 0.5% was superior to that of 0.7% and 0.3%. Temperature has a negative effect on the rheological properties of the new gel foam, while the foam stabilizer concentration has a positive effect. The oxygen barrier performance experiment results showed that the CO release rate of coal samples treated with the new gel foam rose relatively slowly with temperature, and the CO concentration of coal samples treated with the new gel foam was only 159 ppm at 100 °C, which was significantly lower than 361.1 ppm after two-phase foam treatment and 715 ppm after water treatment. Through simulating the spontaneous combustion experiment of coal gangue, it was demonstrated that the new gel foam has a much better extinguishing effect than water and traditional two-phase foam. The new gel foam cools gradually and does not re-ignite during the fire extinguishing process, while the other two materials re-ignite after being extinguished.
煤矸石是采煤过程中的一种伴生品，大量堆积会发生缓慢氧化和自燃，产生有毒有害气体，造成人员伤亡、环境污染和经济损失。凝胶泡沫作为一种阻燃材料，在煤矿防火中得到了广泛应用。本研究考察了新研制的凝胶泡沫的热稳定性和流变性能，通过程序升温实验和现场灭火实验评价了其氧屏障性能和灭火效果。实验表明，新凝胶泡沫的耐温时间约为普通凝胶泡沫的两倍，且随着发泡次数的增加，其耐温性能逐渐降低。此外，稳定剂浓度为 0.5%的新凝胶泡沫的耐温时间优于 0.7%和 0.3%。温度对新凝胶泡沫的流变性能有负面影响，而泡沫稳定剂浓度则有积极影响。氧屏障性能实验结果表明，经新凝胶泡沫处理的煤样的 CO 释放率随温度升高而相对缓慢，在 100°C 时，经新凝胶泡沫处理的煤样的 CO 浓度仅为 159ppm，明显低于两相泡沫处理后的 361.1ppm 和水处理后的 715ppm。通过模拟煤矸石自燃实验，证明了新凝胶泡沫比水和传统两相泡沫具有更好的灭火效果。新凝胶泡沫在灭火过程中逐渐冷却，不会复燃，而其他两种材料在灭火后会复燃。
