Colloidal Particle-Stabilized Foam To Control the Coal Spontaneous Combustion: Stability Mechanism Analysis and Extinguishing Properties
Colloidal Particle-Stabilized Foam To Control the Coal Spontaneous Combustion: Stability Mechanism Analysis and Extinguishing Properties
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DOI：
10.1021/acs.energyfuels.0c02694
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发表时间：
2020-11-19
期刊：
影响因子：
5.3
通讯作者：
Gu, Wangxin
中科院分区：
文献类型：
--
作者：
Yang, Fan;Lu, Yi;Gu, Wangxin
利用海藻酸钠（SA）和粉煤灰（FA）在溶液中形成宽网络结构，制备了稳定的凝胶悬浮液（SGS），并对其悬浮机理进行了分析。根据悬浮机理，SA分子由于螯合作用大量聚集在FA颗粒表面，使FA颗粒均匀分散在溶液中。然后将一定量的SGS与水性泡沫混合，制备了胶体颗粒稳定泡沫（CPSF）。考察了不同发泡倍率对CPSF半衰期和粘度的影响。泡沫稳定性研究表明，随着发泡倍率的增加，CPSF的半衰期发生了显著变化。考虑到泡沫半衰期>20 h，CPSF的有效泡沫膨胀比范围被确定为4.51-7.06。较高的泡沫膨胀比导致发泡溶液的粘度较差。同时，剪切稀化特征也更为显著。灭火实验和加速氧化实验结果表明，CPSF能很好地附着在煤粒表面，有效提高煤样的CPT，显著延迟CO的出现时间，快速减少CO的生成，表现出良好的抑制性能。
The stable gel suspensions (SGS) were prepared by using sodium alginate (SA) and fly ash (FA) to form a wide network structure in solution, and the suspension mechanism was analyzed. According to the mechanism of suspension, a large number of SA molecules gathered on the surface of FA particles due to chelation, which made FA particles evenly dispersed in the solution. Then the colloidal particle-stabilized foam (CPSF) was prepared by a certain amount of the SGS and aqueous foam. The effects of different foam-expansion ratios on the half-life time and viscosity of the CPSF were investigated. The foam stability showed that the half-life time of the CPSF changed significantly with the increase of the foam-expansion ratio. Considering a foam half-life time >20 h, the effective foam-expansion ratio range of CPSF was determined as 4.51-7.06. A higher foam-expansion ratio resulted in a poorer viscosity of the foaming solution. Meanwhile, the shear-thinning characteristics were more significant. The results of fire-extinguishing experiments and accelerated oxidation experiments indicated that the CPSF could be well-attached to the surface of coal particles, effectively increase the CPT of coal samples, delay the appearance time of CO significantly, reduce the generation of CO rapidly, and show good inhibition performance.