Structure variation of coal particle packing during the spontaneous combustion

被引：0
|
作者：
Liang Y. [1 ]
Xin Q. [2 ]
Wang S. [2 ]
Hu P. [2 ]
Jiang S. [3 ]
Song S. [1 ,2 ]
机构：
[1] State Key Laboratory of Coal Mine Safety Technology, China Coal Technology & Engineering Group Shenyang Research Institute, Fushun
[2] Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian
[3] College of Civil Engineering, Dalian Minzu University, Dalian
来源：
Meitan Xuebao/Journal of the China Coal Society | 2020年 / 45卷 / 04期
关键词：
3D reconstruction; Coal spontaneous combustion; CT; Porous structure;
D O I：
10.13225/j.cnki.jccs.2019.1800
中图分类号：
学科分类号：
摘要：
During the process of coal mining, storage and transportation, the coal is exposed to the oxidation environment as packing structure, which is a critical factor for the formation and spreading of the high-temperature region and uncontrolled disasters. Hence, the variation law of packing structure during the period of spontaneous combustion stresses the importance of high-temperature region predicting and disaster prevention. 5 kinds of oxidized coal samples, with different oxidation temperatures, are made of the coal from 8404 working face of Madaotou Mine. Geometric mean filtering algorithm and Otsu algorithm are applied to the raw section series, obtained by the Micro-CT, to reduce the noise level and image binarization, respectively. Based on the series of binary image, 3D reconstruction algorithm was employed to build the packing structures of samples. The variation laws of structure parameters, such as porosity, mean particle volume, mean particle surface, which were quantitatively studied. The results showed that as the oxidation temperature increases, the porosity, the particle amount of the packing and the averaged particle specific surface area increase and the mean particle volume and mean particle surface area decrease. When the oxidation temperature is in the range of 300-400℃, the variation of the packing structure is the most obvious. The averaged particle volumes of packing structures, with the oxidation temperature of 300℃ and 400℃, are 14.95 and 2.50 mm3 respectively. The averaged particle surface area of packing structures, with the oxidation temperature of 300℃ and 400℃, are 36.17 and 9.13 mm2 respectively. Moreover, the variation of the porosity is closely related with the variation of the change of particle morphology and they both have a threshold value approximates to 300℃ for the tested coal samples. When the oxidation temperature is higher than the threshold, the enhanced particles cracking and the improved pore connectivity result in a more intense oxidation process. © 2020, Editorial Office of Journal of China Coal Society. All right reserved.
引用
收藏
页码：1398 / 1405
页数：7
相关论文
共 26 条
  • [1] Yuan L., Smith A.C., The effect of ventilation on spontaneous heating of coal, Journal of Loss Prevention in the Process Industries, 25, 1, pp. 131-137, (2012)
  • [2] Taraba B., Michalec Z., Michalcova V., Et al., CFD simulations of the effect of wind on the spontaneous heating of coal stockpiles, Fuel, 118, pp. 107-112, (2014)
  • [3] Li J., Li Z., Yang Y., Et al., Laboratory study on the inhibitory effect of free radical scavenger on coal spontaneous combustion, Fuel Processing Technology, 171, pp. 350-360, (2018)
  • [4] Sujanti W., Zhang D.K., Laboratory study of spontaneous combustion of coal: The influence of inorganic matter and reactor size, Fuel, 78, 5, pp. 549-556, (1999)
  • [5] Kucuk A., Kadio-Lu Y., Gulabo-Lu M.S., A study of spontaneous combustion characteristics of a turkish lignite: Particle size, moisture of coal, humidity of air, Combustion and Flame, 133, 3, pp. 255-261, (2003)
  • [6] Fehmi A., Arisoy A., Effect of particle size on the spontaneous heating of a coal stockpile, Fuel and Energy Abstracts, 36, 1, (1995)
  • [7] Liang Y., Wang S., Lin Q., Et al., Analysis and modeling of mesoscale phenomenon on coal spontaneous conbustion, Journal of China University of Mining & Technology, 46, 5, pp. 979-987, (2017)
  • [8] Zhao J., Feng Z., Yang D., Et al., Study of pyrolysis and internal structural variation of oil shale based on 3D CT images, Chinese Journal of Rock Mechanics and Engineering, 33, 1, pp. 112-117, (2014)
  • [9] Kang Z., Wang W., Zhao Y., Et al., Three-dimensional percolation mechanism in oil shale under different temperatures based on Micro-CT, Chinese Journal of Rock Mechanics and Engineering, 33, 9, pp. 1837-1842, (2014)
  • [10] Feng Z., Zhao Y., Pyrolytic cracking in coal: Meso-characteristics of pore and fissure evolution observed by micro-CT, Journal of China Coal Society, 40, 1, pp. 103-108, (2015)
123