Evolution law of carbon and oxygen groups on coal surface with increasing metamorphic grade and its effect on wettability
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摘要: 为探究煤自身结构差异对润湿性造成的影响, 针对煤尘中碳、氧两大主要元素展开研究.通过NMR以及XPS实验分别获得六种不同变质程度煤尘表面碳(氧) 基团的分布特征, 利用距离分析得到碳(氧) 基团的演化规律, 发现随变质程度加深, 一种基团的增减会伴随着其他基团的变化, 是聚类变化的过程.碳基团中的芳烃碳(Ar-C, H) 与羧基碳(-COOH)、次甲基碳(CH2)、醚基碳(Ar-O、R-O) 演化规律接近, 氧基团中的羟基氧(-OH) 和醚基氧(C-O-C) 的演化规律接近.利用因子分析研究碳、氧基团演化对润湿性的影响, 发现芳香基团(Ar-C, H) 作为解释碳基团对煤尘润湿性(接触角) 影响程度的公因子, 贡献95.366%的因素, 是碳基团的主要影响因子, 羟基(-OH) 作为解释氧基团对煤尘润湿性(接触角) 影响程度的公因子, 贡献94.818%的因素, 是氧基团的主要影响因子.Abstract: Carbon and oxygen elements were studied to explore the effect of structural differences on wettability of coal dust. Surface distribution characteristics of carbon and oxygen groups in 6 coal dusts with different metamorphic grades were examined through NMR and XPS. The evolution of different types of carbon and oxygen groups was obtained using distance analysis. With increasing metamorphic degree a kind of group changes along with variation of other groups in most case, which is a process of clustering. The carbon in Ar-C, -COOH, CH2 and Ar-O (R-O) has the similar evolution law, the oxygen in -OH and C-O-C is the same case. Factor analysis was used to know effect of group evolution on wettability of coal dust. It is found that Ar-C, as the common factor covering 95.366% to explain coal dust wettability (contact angle), is the main factor of carbon groups; while -OH covering 94.818% is the main factor of oxygen groups.
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Key words:
- coal dust /
- NMR and XPS /
- evolution of the groups /
- wetting influence degree
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表 1 实验用煤样
Table 1 Coal samples
Number Coal type Sample point Station HM Lignite 4301 working face of Beizao coal Longkou, Shandong CY Long flame coal 12207 working face of Shangwan coal Ordos, Inner Mongolia QM Gas coal 20102 working face of Yushuwan coal Yulin, Shanxi FM Fat coal 1301N working face of Xinjulong coal Heze, Shandong JM Coking coal 1013 working face of Wugou coal Huaibei, Anhui WY Anthracite 8124 working face of Yangquan coal Yangquan, Shanxi 表 2 煤尘的工业分析及元素分析
Table 2 Proximate and ultimate analyses of coal dust
Number Proximate analysis w/% Ultimate analysis wdaf/% Mad Ad Vdaf FCad C O H N S HM 17.16 13.19 57.39 30.64 72.88 15.02 8.66 2.36 1.08 CY 10.47 6.77 55.42 37.21 80.21 12.85 4.27 0.86 1.81 QM 5.49 7.35 40.11 52.44 83.89 10.09 4.96 0.82 0.24 FM 1.86 7.73 36.22 57.75 86.14 6.16 5.32 1.79 0.59 JM 1.55 5.69 27.53 62.29 87.34 4.80 5.71 1.56 0.59 WY 1.70 4.03 8.50 86.32 91.79 2.31 3.81 1.43 0.66 表 3 含碳官能团分布
Table 3 Distribution of carbon-containing functional groups
Number C=O -COOH Ar-O Ar-C, H CH3 CH2 R-O HM 1.2 3.1 10.7 38.9 7.4 32.4 6.3 CY 0.8 2.3 9.4 51.1 14.1 17.8 4.5 QM 0.4 1.5 9.0 60.5 7.6 16.6 4.4 FM 1.5 1.3 3.5 68.3 7.2 14.5 3.7 JM 0.5 0.7 3.4 77.2 5.5 9.5 3.2 WY 0.8 0.3 0.6 91.0 3.5 2.8 1.0 表 4 碳基团距离分析的近似矩阵
Table 4 Approximate matrix of distance analysis on carbon groups
Group Correlation between variables C=O -COOH Ar-O Ar-C, H CH3 CH2 R-O C=O C=O 1.000 0.337 -0.038 -0.252 0.039 0.357 0.233 1.000 -COOH 0.337 1.000 0.909 -0.985 0.629 0.962 0.933 0.337 Ar-O -0.038 0.909 1.000 -0.950 0.678 0.869 0.912 -0.038 Ar-C, H -0.252 -0.985 -0.950 1.000 -0.660 -0.961 -0.971 -0.252 CH3 0.039 0.629 0.678 -0.660 1.000 0.434 0.540 0.039 CH2 0.357 0.962 0.869 -0.961 0.434 1.000 0.967 0.357 R-O 0.233 0.933 0.912 -0.971 0.540 0.967 1.000 0.233 C=O 1.000 0.337 -0.038 -0.252 0.039 0.357 0.233 1.000 表 5 煤尘表面含氧官能团分布
Table 5 Distribution of oxygen-containing functional groups in coal dust surface
Number Mole percentage wmol/% C-OH COOH C=O C-O-C HM 38.40 27.57 11.52 22.51 CY 30.00 31.29 8.24 30.48 QM 28.92 22.78 15.31 32.98 FM 22.79 14.89 12.37 49.94 JM 18.05 8.02 25.14 48.79 WY 13.02 6.19 29.38 51.41 表 6 氧基团距离分析的近似矩阵
Table 6 Approximate matrix of distance analysis on oxygen groups
Group Correlation between variables C-OH COOH C=O C-O-C -OH 1.000 0.909 -0.834 -0.946 COOH 0.909 1.000 -0.897 -0.911 C=O -0.834 -0.897 1.000 0.698 C-O-C -0.946 -0.911 0.698 1.000 表 7 煤尘平衡接触角
Table 7 Equilibrium contact angle of coal dust
Number Contact angle /(°) 1 2 3 average HM 46.7 48.12 46.34 47.05 CY 55.19 56.43 56.22 55.95 QM 56.58 58.75 56.12 57.15 FM 62.07 62.67 62.38 62.37 JM 65.48 64.17 66.74 65.46 WY 72.34 74.12 72.19 72.88 表 8 碳基团与润湿性的相关性分析
Table 8 Correlation between wettability and carbon groups
Group Regression equation R2 C=O - - -COOH Y=72.92-8.33x 0.92 Ar-O Y=72.59-2.04x 0.87 Ar-C, H Y=29.67+0.47x 0.98 CH3 Y=70.69-1.4x 0.15 CH2 Y=73.83-0.88x 0.95 R-O Y=79.41-5x 0.97 表 9 氧基团与润湿性的相关性分析
Table 9 Correlation between wettability and oxygen groups
Group Regression equation R2 -OH Y=84.51-0.97x 0.98 COOH Y=74.05-0.75x 0.72 C=O Y=45.4+0.87x 0.59 C-O-C Y=33.68+0.67x 0.82 表 10 公因子方差表
Table 10 Communality table
Component Communality initial extraction Ar-C, H 1.000 0.994 -COOH 1.000 0.962 Ar-O 1.000 0.902 CH2 1.000 0.951 R-O 1.000 0.960 -OH 1.000 0.956 COOH 1.000 0.932 C-O-C 1.000 0.957 表 11 解释的总方差表
Table 11 Explained variance table
Component Total variance explained initial eigenvalues extraction of square and loads total variance /% component /% total variance /% component /% Ar-C, H 4.768 95.366 95.366 4.768 95.366 95.366 -COOH 0.144 2.871 98.237 Ar-O 0.069 1.381 99.617 CH2 0.019 0.374 99.991 R-O 0.000 0.009 100.000 -OH 2.845 94.818 94.818 2.845 94.818 94.818 COOH 0.101 3.381 98.199 C-O-C 0.054 1.801 100.000 extraction method: principal component analysis -
[1] 王雪涛, 马骏, 关砚生, 刘卫东, 张岩松, 刘丽华.我国地方煤矿职业危害现状调查报告[J].中国安全生产科学技术, 2008, 4(1): 91-94. http://www.cnki.com.cn/Article/CJFDTOTAL-LDBK200801027.htmWANG Xue-tao, MA Jun, GUAN Yan-sheng, LIU Wei-dong, ZHANG Yan-song, LIU Li-hua. Study on current situation of the occupational hazards of local state-owned coal mines in China[J]. J Saf Sci Technol, 2008, 4(1): 91-94. http://www.cnki.com.cn/Article/CJFDTOTAL-LDBK200801027.htm [2] 段旭琴, 王祖讷, 孙春宝.神府煤显微组分表面性质研究[J].中国矿业大学学报, 2007, 36(5): 630-635. http://www.cnki.com.cn/Article/CJFDTOTAL-ZGKD200705015.htmDUAN Xu-qin, WANG Zu-ne, SUN Chun-bao. Surface properties of macerals from Shenfu coal[J]. J China Univ Min Technol, 2007, 36(5): 630-635. http://www.cnki.com.cn/Article/CJFDTOTAL-ZGKD200705015.htm [3] 周刚.综放工作面喷雾降尘理论及工艺技术研究[D].青岛:山东科技大学, 2009.ZHOU Gang. Research of theory about dust Prevention by water-cloud and relevant techniques for fully-mechanized caving coal face[D]. Qingdao: Shandong University of Science and Technology, 2009. [4] JAMES O G, LEIGHTON H H. Studies of coal dust wetting by surfactant solutions[J]. Colloids Surf, 1982, 4(3): 209-212. doi: 10.1016/0166-6622(82)80018-8 [5] 陈云富, 陈永平, 张程宾, 施明恒.粗糙表面形貌对湿润性的影响[J].工程热物理学报, 2011, 32(7): 1188-1190. http://www.cnki.com.cn/Article/CJFDTOTAL-GCRB201107029.htmCHEN Yun-fu, CHEN Yong-ping, ZHANG Cheng-bin, SHI Ming-huan. Influence of rough surface topogarphy on wettability[J]. J Eng Thermophys, 2011, 32(7): 1188-1190. http://www.cnki.com.cn/Article/CJFDTOTAL-GCRB201107029.htm [6] PHILIP O, BRUCE F, GRAHAM O, CLINT M, ANH V. Assessing the hydrophobicity of petrographically heterogeneous coal surfaces[J]. Energy Fuels, 2010, 24(11): 5965-5971. doi: 10.1021/ef100793t [7] 杨静, 谭允祯, 王振华, 商岩冬, 赵文斌.煤尘表面特性及润湿机理的研究[J].煤炭学报, 2007, 32(7): 737-740. http://www.cnki.com.cn/Article/CJFDTOTAL-MTXB200707013.htmYANG Jing, TAN Yun-zhen, WANG Zhen-hua, SHANG Yan-dong, ZHAO Wen-bin. Study on the coal dust surface characteristics and wetting mechanism[J]. J China Coal Soc, 2007, 32(7): 737-740. http://www.cnki.com.cn/Article/CJFDTOTAL-MTXB200707013.htm [8] 聂百胜, 何学秋, 王恩元, 张力.煤吸附水的微观机理[J].中国矿业大学学报, 2004, 33(4): 379-383. http://www.cnki.com.cn/Article/CJFDTOTAL-ZGKD200404004.htmNIE Bai-sheng, He Xue-qiu, Wang En-yuan, Zhang Li. Micro-mechanism of coal adsorbirig water[J]. J China U Min Techno, 2004, 33(4): 379-383. http://www.cnki.com.cn/Article/CJFDTOTAL-ZGKD200404004.htm [9] 相建华, 曾凡桂, 梁虎珍, 孙蓓蕾, 张莉, 李美芬, 贾建波.兖州煤大分子结构模型构建及其分子模拟[J].燃料化学学报, 2011, 39(7): 481-488. doi: 10.1016/S1872-5813(11)60031-5XIANG Jian-hua, ZENG Fan-gui, LIANG Hu-zhen, SUN Bei-lei, ZHANG Li, LI Mei-fen, JIA Jian-bo. Model construction of the macromolecular structure of Yanzhou coal and its molecular simulation[J]. J Fuel Chem Technol, 2011, 39(7): 481-488. doi: 10.1016/S1872-5813(11)60031-5 [10] 朱银惠, 王中慧.煤化学[M].北京:化学工业出版社, 2013.ZHU Yin-hui, WANG Zhong-hui. Coal Chemistry[M]. Beijing: Chemical Industry Press, 2013. [11] 滕英跃, 廉士俊, 宋银敏, 刘全生, 余海燕, 李阳, 智科端, 张永强.基于~1H-NMR的胜利褐煤原位低温干燥过程中弛豫时间及孔结构变化[J].煤炭学报, 2014, 39(12): 2525-2530. http://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201412031.htmTENG Ying-yue, LIAN Shi-jun, SONG Yin-min, LIU Quan-sheng, YU Hai-yan, LI Yang, ZHI Ke-rui, ZHANG Yong-qiang. Relaxation time and pore structure evolution of Shengli lignite during in situlow temperature drying using 1H-NMR[J]. J China Coal Soc, 2014, 39(12): 2525-2530. http://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201412031.htm [12] MIECZYSLAW K. XPS study of reductively and non-reductively modified coals[J]. Fuel, 2004, 83(3): 259-265. doi: 10.1016/j.fuel.2003.08.004 [13] 李小明, 曹代勇.不同变质类型煤的电子顺磁共振特征对比分析[J].现代地质, 2009, 23(3): 531-534. http://www.cnki.com.cn/Article/CJFDTOTAL-XDDZ200903019.htmLI Xiao-ming, CAO Dai-yong. Contrast study on the EPR characteristics of coals of different metamorphism types[J]. Geoscience, 2009, 23(3): 531-534. http://www.cnki.com.cn/Article/CJFDTOTAL-XDDZ200903019.htm [14] 薛薇. SPSS统计分析方法及应用[M].北京:电子工业出版社, 2009.XUE Wei. SPSS Statistical Analysis Method and Its Application[M]. Beijing: Electronics Industry Press, 2009. [15] 段旭琴, 王祖讷.煤显微组分表面含氧官能团的XPS分析[J].辽宁工程技术大学学报(自然科学版), 2010, 29(3): 498-501. http://www.cnki.com.cn/Article/CJFDTOTAL-FXKY201003046.htmDUAN Xu-qin, WANG Zu-ne. XPS analysis of oxygen contained functional group in coal macerals[J]. J Liaoning Technol Univ (Nat Sci), 2010, 29(3): 498-501. http://www.cnki.com.cn/Article/CJFDTOTAL-FXKY201003046.htm [16] 程卫民, 薛娇, 周刚, 聂文, 刘林胜.基于红外光谱的煤尘润湿性[J].煤炭学报, 2014, 39(11): 2256-2262. http://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201411018.htmCHENG Wei-min, XUE Jiao, ZHOU Gang, NIE Wen, LIU Lin-sheng. Study of coal dust wettability based on FTIR[J]. J China Coal Soc, 2014, 39(11): 2256-2262. http://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201411018.htm [17] 陈一, 唐飞, 李铁刚, 贺玖明, 再帕尔·阿不力孜, 刘力涛, 王晓浩.因子分析法在质谱成像数据分析中的应用[J].分析化学, 2014, 42(8): 1099-1103. doi: 10.1016/S1872-2040(14)60757-XCHEN Yi, TANG Fei, LI Tie-gang, HE Jiu-ming, ABLIZ Zeper, LIU Li-tao, WANG Xiao-hao. Application of factor analysis in imaging mass spectrometric data analysis[J]. Chin J Anal Chem, 2014, 42(8): 1099-1103. doi: 10.1016/S1872-2040(14)60757-X