开滦矿区低级烟煤大分子结构演化特征及CO成因

针对开滦矿区CO超标现象,进行了煤分子结构演化特征及CO成因研究。通过对22个煤样的工业指标、元素组成、镜质组最大反射率(R_max)、红外光谱和扫描电镜分析,结果发现:煤样的H/C先随R_max增加,在R_max达到0.8%后又迅速减少;煤样中富含C=O、C-O、-O-等含氧基团,通过对芳碳率(f_a)、环缩合度指数(2(R-1)/C)与R_max的关联,发现随着R_max的增加,f_a先增加后减少,2(R-1)/C先减少后增加,拐点均在R_max为0.8%处;煤样孔隙结构为粒间孔。研究认为,开滦矿区煤层赋存CO的成因是,变质作用过程中(R_max为0.8%时),煤分子侧链因构造应力作用断裂、脱落产生大量自由基,进而结合生成CO,并赋存在煤层中保留下来。

Macromolecule structure evolution and CO origine of low rank bituminous coal in Kailuan mining area

Focusing on the phenomenon of CO content exceeding the standard in Kailuan mining area, based on proximate analysis, ultimate analysis, R_max, FT-IR, and scanning electron microscope (SEM) analysis of 22 typical coal samples, the authors analyzed the macromolecule structure evolution and the origin of CO. The results show that with the increase of R max, H/C increases first then decreases; content of C-O and C=O is high; with the increase of R max, f_a increases first then decreases, 2(R-1)/C decreases first then increases, the inflection points is at 0.8%; the pore type of the coal sample is inter-grain pore. It is considered that the CO of Kailuan mining area was formed from chemical combination of free radicals resulted side chains breaking by the actions of tectonic stress of different direction during the process of metamorphism.