Research on performance and engineering application of spray air leakage plugging self-healing material for mining
HU Xiangming;JIANG Yongmao;WU Mingyue;ZHANG Qian;YANG Zhenyu
喷涂堵漏风是防止煤自燃的有效手段之一。针对传统水泥基喷涂堵漏风材料脆性大、易开裂、堵漏风效果差的弊端,提出以微生物及结晶矿物为自愈合剂,研制出生物胶囊和矿物胶囊以及一种生物–矿物–纤维协同自修复材料。研究了不同养护湿度和养护时间对材料裂缝自修复能力的影响。结果表明:当养护湿度为100%相对湿度、养护时间为35 d时,研制的生物胶囊和矿物胶囊可以将裂缝完全修复,裂缝最大修复宽度为μm。采用扫描电子显微镜(SEM)和X射线能谱仪(EDS)探究了自修复材料裂缝区域修复产物的晶型及元素组成,发现裂缝处的修复产物为球碳镁石、花瓣状的水菱镁矿以及大量由细菌矿化产生的球形方解石,这些修复产物在一定程度上起到了密闭裂缝的作用;EDS能谱分析证实了修复产物为MgCO3和CaCO3。当养护湿度为100%时,材料具有最高的堵漏风率(97.15%),比同养护条件的对照组试样高出73.62%。最后将自修复材料用于沿空煤柱喷涂堵漏风,结果显示该材料在6个月内未发现明显裂隙,与传统水泥砂浆相比,该材料具有更长的使用寿命和更好的预防效果。
Spray air leakage plugging is one of the effective means to prevent coal spontaneous combustion. Aiming at the drawbacks of high brittleness, easy cracking, and poor air leakage plugging effectiveness of traditional cement-based spraying air plugging material, biological capsule, mineral capsule and bio-mineral-fiber synergistic self-healing material were developed with microorganisms and crystalline minerals as self-healing agents. The influence of different curing humidity and curing time on the self-healing ability of material cracks was studied. The results showed that when the curing humidity was 100%, and the curing time was 35 days, the biological and mineral capsules could completely heal the cracks, with a maximum healing width ofμm. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) were used to investigate the crystal structure and elemental composition of the healing products in the crack area of self-healing material. It was found that the healing products at the crack were spherical magnesite, petal-shaped hydromagnesite, and a large amount of spherical calcite produced by bacterial mineralization, which to some extent played a role in sealing the crack. EDS analysis confirmed that the healing products were MgCO3 and CaCO3. When the curing humidity was 100%, the material had the highest air leakage plugging rate (97.15%), which was 73.62% higher than the control group samples under the same curing conditions. Finally, self-healing material was used for spraying and plugging air leakage along the coal pillar, and the results showed that no obvious cracks were found within 6 months. Compared with traditional cement mortar, self-healing material has a longer service life and better prevention effect.
spray air leakage plugging material;coal spontaneous combustion;crack repair;healing agent;microorganism;crystalline minerals
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会