-
摘要: 碎软煤的完整原样制取困难，需要加工制成重塑煤体，为了研究不同压制荷载对煤体物性特征的影响，以重塑煤体为研究对象，基于低温液氮的孔隙测试实验和高压容量法的甲烷吸附实验，探讨不同成型荷载而成的重塑煤体的微小孔结构及其吸附特性的差异。结果表明：不同成型荷载压制而成的重塑煤体，其微孔和小孔的孔容随着成型荷载的增大而略微减少，孔比表面积随着成型荷载的增大而略微增加，总孔体积减少和孔比表面积增加的幅度不大；通过分形理论发现无论高压段还是低压段，孔隙结构具有明显的分形特征，且在高压段的分形维数普遍低于低压段，不同荷载压制而成的重塑煤体的分形维数差别不大；等温吸附线均符合第Ⅰ类等温吸附曲线，Langmuir模型适用于描述重塑煤体的等温吸附，成型荷载对煤的吸附常数有一定的影响，其对吸附常数b值的影响大于对a值的影响。研究不同成型荷载下重塑煤体的吸附特性，为不同条件下型煤制作及冷冻取心实验提供参考。Abstract: In view of the difficulty in preparing the coal with broken soft structure intact, it needs to be processed into remolded coal. In order to study the influence of suppression loads on the physical characteristics of coal, the micro-pore structure and adsorption characteristics of remolded coal under different molding loads were discussed based on the pore test experiment of low temperature liquid nitrogen and the methane adsorption experiment of high pressure capacity method. The results show that: The pore volume of micropores and pores decreases slightly with the increase of molding load, the specific surface area increases slightly with the increase of molding load, and the reduction of total pore volume and the increase of pore specific surface area are not obvious. According to the fractal theory, it is found that the pore structure has obvious fractal characteristics, and the fractal dimension in the high pressure section is generally lower than that in the low pressure section, and the fractal dimension of remolded coal formed by different loads has little difference. The adsorption isotherm curves conform to the first type adsorption curve, and Langmuir model is applicable to describe the reshape coal isothermal adsorption remolded coal. The molding load has a certain influence on the adsorption constant of coal. Its influence on adsorption constant b value is greater than that on a value. The study of the adsorption characteristics of remolded coal under different molding loads is of great engineering significance for gas extraction and treatment.
-
-
![]()
图 1 不同压制荷载重塑煤体的低温液氮吸附/脱附等温线
Fig. 1 The low-temperature liquid nitrogen adsorption-desorption isotherms of remolded coal under different compression loads
![]()
图 2 不同压制荷载下型煤的孔体积分布特征
Fig. 2 Pore volume distribution characteristics of remolded coal under different compression loads
![]()
图 3 不同压制荷载下重塑煤体的孔比表面积分布特征
Fig. 3 Pore area distribution characteristics of remolded coal under different compression loads
![]()
图 4 不同压力下重塑煤样液氮吸附分形维数拟合关系
Fig. 4 The relationship of fractal dimension of liquid nitrogen adsorption
表 1 煤样孔体积分布
Table 1 Pore volume distribution table of coal samples
类别 载荷/MPa 孔容/ (cm3∙g–1) 各孔径阶段孔体积分布/(cm3∙g–1) 各孔径阶段孔体积占比/% > 100 nm 10~100 nm ＜10 nm > 100 nm 10~100 nm ＜10 nm 颗粒煤 0.010 5 0.001 2 0.006 1 0.003 2 11.43 58.10 30.47 重塑煤体 50 0.012 4 0.001 7 0.007 2 0.003 5 13.71 58.06 28.23 70 0.011 9 0.001 6 0.006 9 0.003 4 13.45 57.98 28.57 90 0.011 2 0.001 5 0.006 4 0.003 3 13.39 57.14 29.46 110 0.010 7 0.001 4 0.006 1 0.003 2 13.08 57.01 29.91 
下载: 导出CSV
表 2 煤样孔比表面积分布
Table 2 Pore area distribution table of coal sample
类别 载荷/MPa 比表面积/ (m2∙g–1) 各孔径阶段孔比表面积分布/(m2∙g–1) 各孔径阶段孔比表面积占比/% > 100 nm 10~100 nm ＜10 nm > 100 nm 10~100 nm ＜10 nm 颗粒煤 4.240 6 0.032 4 0.903 7 3.304 5 0.76 21.31 77.93 重塑煤体 50 4.483 4 0.054 7 1.009 0 3.419 7 1.22 22.51 76.27 70 4.522 7 0.048 8 0.973 8 3.500 1 1.08 21.53 77.39 90 4.565 3 0.040 6 0.962 8 3.561 9 0.89 21.09 78.02 110 4.614 1 0.037 8 0.960 8 3.615 5 0.82 20.82 78.36
下载: 导出CSV
表 3 液氮吸附实验孔隙分形结果
Table 3 Results of pore fractal dimension of liquid adsorption
压力分段 荷载/MPa A D R2 p/p0 < 0.5 50 –0.167 3 2.832 7 0.998 3 70 –0.151 9 2.848 1 0.997 7 90 –0.092 4 2.907 6 0.990 5 110 –0.104 3 2.895 7 0.956 1 p/p0≥0.5 50 –0.192 8 2.807 2 0.975 5 70 –0.205 3 2.794 7 0.981 4 90 –0.214 2 2.785 8 0.959 5 110 –0.198 0 2.802 0 0.980 1
下载: 导出CSV
表 4 不同重塑煤体瓦斯吸附常数测定结果
Table 4 Determination results of gas adsorption constants of different coal samples
煤体类型 荷载/MPa 吸附常数a/(m3∙ t–1) 吸附常数b/MPa–1 相关系数R2 颗粒煤 24.144 6 0.429 9 0.995 6 重塑煤体 50 24.472 3 0.445 3 0.995 2 70 24.490 6 0.481 1 0.993 6 90 24.515 6 0.547 6 0.995 4 110 24.548 1 0.577 1 0.992 0
下载: 导出CSV
-
[1] 侯泉林, 李会军, 范俊佳, 等. 构造煤结构与煤层气赋存研究进展[J]. 中国科学: 地球科学, 2012, 42(10): 1487-1495. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK201210004.htm HOU Quanlin, LI Huijun, FAN Junjia, et al. Structure and coalbed methane occurrence in tectonically deformed coals[J]. Science in China: Earth Science, 2012, 42(10): 1487-1495. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK201210004.htm
[2] 郭品坤, 程远平, 卢守青, 等. 基于分形维数的原生煤与构造煤孔隙结构特征分析[J]. 中国煤炭, 2013, 39(6): 73-77. DOI: 10.3969/j.issn.1006-530X.2013.06.021 GUO Pinkun, CHENG Yuanping, LU Shouqing, et al. Based on the fractal dimension of primary coal and tectonically deformed coal pore structure characteristics analysis[J]. China Coal, 2013, 39(6): 73-77. DOI: 10.3969/j.issn.1006-530X.2013.06.021
[3] 王玲玲, 王兆丰, 霍肖肖, 等. 高温高压下煤孔隙结构的变化对瓦斯吸附特性的影响[J]. 中国安全生产科学技术, 2018, 14(12): 97-101. https://www.cnki.com.cn/Article/CJFDTOTAL-LDBK201812015.htm WANG Lingling, WANG Zhaofeng, HUO Xiaoxiao, et al. Influence of pore structure change on gas adsorption characteristics of coal under high temperature and high pressure[J]. Journal of Safety Science and Technology, 2018, 14(12): 97-101. https://www.cnki.com.cn/Article/CJFDTOTAL-LDBK201812015.htm
[4] 李子文, 林伯泉, 郝志勇, 等. 煤体孔径分布特征及其对瓦斯吸附的影响[J]. 中国矿业大学学报, 2013, 42(6): 1047-1053. DOI: 10.3969/j.issn.1000-1964.2013.06.024 LI Ziwen, LIN Boquan, HAO Zhiyong, et al. Characteristics of pore size distribution of coal and its impacts on gas adsorption[J]. Journal of China University of Mining & Technology, 2013, 42(6): 1047-1053. DOI: 10.3969/j.issn.1000-1964.2013.06.024
[5] 姜家钰, 雷东记, 谢向向, 等. 构造煤孔隙结构与瓦斯耦合特性研究[J]. 安全与环境学报, 2015, 15(1): 123-128. https://www.cnki.com.cn/Article/CJFDTOTAL-AQHJ201501027.htm JIANG Jiayu, LEI Dongji, XIE Xiangxiang, et al. Coupling features of the pore structure with gas of the deformed coals[J]. Journal of Safety and Environment, 2015, 15(1): 123-128. https://www.cnki.com.cn/Article/CJFDTOTAL-AQHJ201501027.htm
[6] 降文萍, 张群, 姜在炳, 等. 构造煤孔隙结构对煤层气产气特征的影响[J]. 天然气地球科学, 2016, 27(1): 173-179. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201601021.htm JIANG Wenping, ZHANG Qun, JIANG Zaibing, et al. Effect on CBM drainage characteristics of pore structure of tectonic coal[J]. Natural Gas Geoscience, 2016, 27(1): 173-179. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201601021.htm
[7] PYUN S I, RHEE C K. An investigation of fractal characteristics of mesoporous carbon electrodes with various pore structure[J]. Electrochimica Acta, 2004, 49(24): 4171-4180. DOI: 10.1016/j.electacta.2004.04.012
[8] 张晓辉, 要惠芳, 李伟, 等. 韩城矿区构造煤纳米级孔隙结构的分形特征[J]. 煤田地质与勘探, 2014, 42(5): 4-8. DOI: 10.3969/j.issn.1001-1986.2014.05.002 ZHANG Xiaohui, YAO Huifang, LI Wei, et al. Fractal characteristics of nano-pore structure in tectonically deformed coals in Hancheng Mining Area[J]. Coal Geology & Exploration, 2014, 42(5): 4-8. DOI: 10.3969/j.issn.1001-1986.2014.05.002
[9] 樊亚庆, 王兆丰, 陈金生, 等. 水分对煤中瓦斯的置换作用实验研究[J]. 煤矿安全, 2017, 48(12): 25-27. https://www.cnki.com.cn/Article/CJFDTOTAL-MKAQ201712007.htm FAN Yaqing, WANG Zhaofeng, CHEN Jinsheng, et al. Experimental study on replacement effect of water to gas in coal[J]. Safety in Coal Mines, 2017, 48(12): 25-27. https://www.cnki.com.cn/Article/CJFDTOTAL-MKAQ201712007.htm
[10] 岳基伟, 王兆丰, 陈金生, 等. 用水敏指示剂快速测定重塑煤体渗吸高度的研究[J]. 中国安全科学学报, 2017, 27(11): 126-131. https://www.cnki.com.cn/Article/CJFDTOTAL-ZAQK201711023.htm YUE Jiwei, WANG Zhaofeng, CHEN Jinsheng, et al. Study on rapid determination of imbibition height of remolded coal by water sensitive indicator[J]. China Safety Science Journal, 2017, 27(11): 126-131. https://www.cnki.com.cn/Article/CJFDTOTAL-ZAQK201711023.htm
[11] 王彬, 王兆丰, 岳基伟, 等. NMR成像技术测试煤样渗吸过程中水分变化规律研究[J]. 中国安全生产科学技术, 2018, 14(10): 32-38. https://www.cnki.com.cn/Article/CJFDTOTAL-LDBK201810005.htm WANG Bin, WANG Zhaofeng, YUE Jiwei, et al. Study on change laws of moisture during imbibition process of coal samples tested by NMR imaging technology[J]. Journal of Safety Science and Technology, 2018, 14(10): 32-38. https://www.cnki.com.cn/Article/CJFDTOTAL-LDBK201810005.htm
[12] 李小军, 王兆丰, 祁晨君, 等. 干冰为冷源的含瓦斯型煤低温冷冻试验[J]. 煤炭学报, 2017, 42(增刊1): 160-165. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB2017S1021.htm LI Xiaojun, WANG Zhaofeng, QI Chenjun, et al. Freezing experiments on moulded coal with methane using dry ice as cold source[J]. Journal of China Coal Society, 2017, 42(Sup. 1): 160-165. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB2017S1021.htm
[13] 王兆丰, 刘勉, 韩恩光, 等. 含瓦斯煤低温取芯过程煤心温度变化规律实验研究[J]. 中国安全生产科学技术, 2018, 14(11): 101-107. https://www.cnki.com.cn/Article/CJFDTOTAL-LDBK201811016.htm WANG Zhaofeng, LIU Mian, HAN Enguang, et al. Experimental study on change laws of coal core temperature during low temperature coring process of coal containing gas[J]. Journal of Safety Science and Technology, 2018, 14(11): 101-107. https://www.cnki.com.cn/Article/CJFDTOTAL-LDBK201811016.htm
[14] 郭海军, 王凯, 崔浩, 等. 型煤孔裂隙结构及其分形特征实验研究[J]. 中国矿业大学学报, 2019, 48(6): 1206-1214. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGKD201906005.htm GUO Haijun, WANG Kai, CUI Hao, et al. Experimental investigation on the pore and fracture structure of the reconstructed coal and its fractal characteristics[J]. Journal of China University of Mining & Technology, 2019, 48(6): 1206-1214. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGKD201906005.htm
[15] 岳基伟, 王兆丰, 谢策, 等. 含瓦斯型煤吸附/解吸特性研究[J]. 煤矿安全, 2018, 49(9): 31-34. https://www.cnki.com.cn/Article/CJFDTOTAL-MKAQ201809008.htm YUE Jiwei, WANG Zhaofeng, XIE Ce, et al. Study on adsorption and desorption characteristics of briquette coal containing gas[J]. Safety in Coal Mines, 2018, 49(9): 31-34. https://www.cnki.com.cn/Article/CJFDTOTAL-MKAQ201809008.htm
[16] 许江, 陆漆, 吴鑫, 等. 不同颗粒粒径下型煤孔隙及发育程度分形特征[J]. 重庆大学学报, 2011, 34(9): 81-89. https://www.cnki.com.cn/Article/CJFDTOTAL-FIVE201109013.htm XU Jiang, LU Qi, WU Xin, et al. The fractal characteristics of the pore and development of briquettes with different coal particle sizes[J]. Journal of Chongqing University, 2011, 34(9): 81-89. https://www.cnki.com.cn/Article/CJFDTOTAL-FIVE201109013.htm
[17] 袁梅, 许江, 李波波, 等. 粒径对含瓦斯型煤力学性质及渗透特性的影响试验研究[J]. 煤矿安全, 2016, 47(9): 24-27. https://www.cnki.com.cn/Article/CJFDTOTAL-MKAQ201609007.htm YUAN Mei, XU Jiang, LI Bobo, et al. Experimental study on influence of particle size on mechanical properties and permeability of briquette coal containing gas[J]. Safety in Coal Mines, 2016, 47(9): 24-27. https://www.cnki.com.cn/Article/CJFDTOTAL-MKAQ201609007.htm
[18] 翟盛锐. 不同粒度型煤煤样瓦斯吸附-解吸变形特征实验研究[J]. 中国安全生产科学技术, 2018, 14(6): 84-89. https://www.cnki.com.cn/Article/CJFDTOTAL-LDBK201806013.htm ZHAI Shengrui. Experimental study on gas adsorption-desorption deformation characteristics of briquette coal samples with different granularity[J]. Journal of Safety Science and Technology, 2018, 14(6): 84-89. https://www.cnki.com.cn/Article/CJFDTOTAL-LDBK201806013.htm
[19] PFEIFER P, WU Y J, COLE M W, et al. Multilayer adsorption on a fractally rough surface[J]. Physical Review Letters, 1989, 62(17): 1997-2000. DOI: 10.1103/PhysRevLett.62.1997
[20] 李子文, 郝志勇, 庞源, 等. 煤的分形维数及其对瓦斯吸附的影响[J]. 煤炭学报, 2015, 40(4): 863-869. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201504025.htm LI Ziwen, HAO Zhiyong, PANG Yuan, et al. Fractal dimensions of coal and their influence on methane adsorption[J]. Journal of China Coal Society, 2015, 40(4): 863-869. https://www.cnki.com.cn/Article/CJFDTOTAL-MTXB201504025.htm
计量
- 文章访问数: 134
- HTML全文浏览量: 12
- PDF下载量: 9
