Formation of Cross-linked Gel from Complex Water-Solution of Sodium Metasilicate Nonahydrate and Polyvinyl Alcohol to Inhibit Spontaneous Coal Combustion
Formation of Cross-linked Gel from Complex Water-Solution of Sodium Metasilicate Nonahydrate and Polyvinyl Alcohol to Inhibit Spontaneous Coal Combustion
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DOI：
10.1080/00102202.2020.1867544
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发表时间：
2020-12
影响因子：
1.9
通讯作者：
Hemeng Zhang;K. Sasaki;Xiaoming Zhang;Y. Sugai;Yongjun Wang
中科院分区：
文献类型：
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作者：
Hemeng Zhang;K. Sasaki;Xiaoming Zhang;Y. Sugai;Yongjun Wang
摘要：本研究提出了一种新型交联凝胶来防止煤自燃。采用九水偏硅酸钠（SMN）和聚乙烯醇（PVA）的复合水溶液（C-WS）润湿煤颗粒，与煤氧化产生的CO2和自然大气反应，形成交联凝胶（SMN/PVA凝胶），并通过丝网篮试验测量临界自燃温度（CSIT）来检测交联凝胶。采用内蒙古白银花褐煤研究SMN/PVA凝胶的抑制效果。丝网篮测试结果表明，C-WS 的 SMN/PVA 凝胶的防火效果优于预成型的 SMN/PVA 凝胶。它紧密地覆盖煤颗粒表面和微孔入口，防止氧气进入和水分排出，从而表现出优异的稳定性和相容性。根据目前的测试，C-WS 中 SMN-16 wt% 和 PVA-0.5 wt% 的浓度最佳，可使原煤的 CSIT 提高 26°C。润湿 C-WS 对不同煤堆体积和颗粒尺寸的 CSIT 的影响已作为经验方程提出，用于估计 SMN 和 PVA 浓度的 CSIT，以考虑现场应用。
ABSTRACT This study presents a novel cross-linked gel to prevent coal spontaneous combustion. Complex Water-Solution (C-WS) of sodium metasilicate nonahydrate (SMN) and polyvinyl alcohol (PVA) was used to wet coal particles and reacted with CO2 from coal oxidation and natural atmospheric air to form the cross-linked gel (SMN/PVA gel), which was examined by measuring critical self-ignition temperature (CSIT) through the wire-mesh basket test. Baiyinhua lignite coal excavated from Inner Mongolia was used to investigate the inhibitory effect of SMN/PVA gel. Wire-mesh basket test results indicated the fire-prevention effectiveness of the SMN/PVA gel from C-WS was superior to those of pre-formed SMN/PVA gels. It snugly covered the coal particle surface and inlets of micropores to prevent oxygen ingress and water emission, and thus exhibited excellent performance in stability and compatibility. Based on the present tests, the concentrations of SMN-16 wt% and PVA-0.5 wt% in C-WS were best and increased the CSIT of raw coal by 26°C. The effect of wetting C-WS on CSIT for different including coal pile volume and particle size has been presented as an empirical equation to estimate the CSITs for SMN and PVA concentrations to consider field applications.