Skip to main content
Log in

Change Characteristics of Radicals in Different Stages of Coal Spontaneous Combustion

  • Original Paper
  • Published:
Natural Resources Research Aims and scope Submit manuscript

Abstract

Residual coal in mine goafs will be oxidized in the presence of air leakage, which can be well tracked through the radical reaction. This study aimed to explore the changes in radical parameters and the reactivity and persistence of newly produced radicals of coal at different temperature stages. To this end, an in situ electron spin resonance (ESR) spectrometer was adopted to measure changes in radical parameters at the heating, maintaining and cooling stages in real time. The following conclusions were drawn. At the heating stage, the radical concentration first rises slowly and then surges; the g factor remains small initially and increases rapidly later; the linewidth falls continuously. At the maintaining stage (230 °C), the radical concentration keeps increasing, while the g factor and the linewidth remain stable. At the cooling stage, the radical concentration first decreases and then stabilizes at a relatively high level, and both the g factor and the linewidth nearly return to the initial values. Based on the changes in radical parameters at different oxidation stages, the radicals in coal are divided into transient radicals and persistent radicals according to their survival times. Transient radicals, which are strongly reactive, are quickly consumed, while persistent radicals, which is of weak reactivity, can exist in the system for a long time. That is, the active radicals in coal are transient, while the stable ones are persistent. In addition, this paper gives insight into the changes in contents of active radicals and stable radicals at these stages. Finally, the changes in indicator gas and oxygen concentrations at these stages were analyzed. The research finding further explains the mechanism of radical reactions during coal spontaneous combustion.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9

Similar content being viewed by others

References

  • Butuzova, L., Makovskyi, R., Budinova, T., & Marinov, S. P. (2014). EPR and IR studies on the role of coal genetic type in plastic layer formation. Fuel Processing Technology, 125, 246–250.

    Article  Google Scholar 

  • Cai, J. W., Yang, S. Q., Zheng, W. C., Song, W. X., & Gupta, R. (2021). Dissect the capacity of low-temperature oxidation of coal with different metamorphic degrees. Fuel, 292, 120256.

    Article  Google Scholar 

  • Cappelli, C. I., Toropov, A. A., Toropova, A. P., & Benfenati, E. (2020). Ecosystem ecology: Models for acute toxicity of pesticides towards Daphnia magna. Environmental Toxicology and Pharmacology, 80, 103459.

    Article  Google Scholar 

  • Chang, Y. M., Shu, C. M., & You, M. L. (2021). Explosion prevention and weighting analysis on the inerting effect of methane via grey entropy model. Journal of Loss Prevention in the Process Industries, 71, 104385.

    Article  Google Scholar 

  • Chen, X. K., Ma, T., Zhai, X. W., & Lei, C. K. (2019). Thermogravimetric and infrared spectroscopic study of bituminous coal spontaneous combustion to analyze combustion reaction kinetics. Thermochimica Acta, 676, 84–93.

    Article  Google Scholar 

  • Cheng, J. W., Wu, Y. H., Dong, Z. W., Zhang, R., Wang, W. B., Wei, G. Y., et al. (2021). A novel composite inorganic retarding gel for preventing coal spontaneous combustion. Case Studies in Thermal Engineering, 28, 101648.

    Article  Google Scholar 

  • Deng, J. C., Ge, S. K., Qi, H. N., Zhou, F. B., & Shi, B. B. (2021). Underground coal fire emission of spontaneous combustion, Sandaoba coalfield in Xinjiang, China: Investigation and analysis. Science of the Total Environment, 777, 146080.

    Article  Google Scholar 

  • Deng, J., Ren, L. F., Ma, L., Lei, C. K., Wei, G. M., & Wang, W. F. (2018). Effect of oxygen concentration on low-temperature exothermic oxidation of pulverized coal. Thermochimica Acta, 667, 102–110.

    Article  Google Scholar 

  • Deng, J., Ren, L. F., Ma, L., Qin, X. Y., Wang, W. F., & Liu, C. C. (2019). Low-temperature oxidation and reactivity of coal in O-2/N-2 and O-2/CO2 atmospheres, a case of carboniferous-permian coal in Shaanxim, China. Environmental Earth Sciences, 78(6), 1–2.

    Article  Google Scholar 

  • Du, W. Z., Zhang, J., Xie, Q. X., Zhang, Y. S., Niu, K., & Wang, H. W. (2020). Experimental study on optimizing the inhibition effect of pre-injection inhibitor on coal spontaneous combustion. Energy Sources Part a-Recovery Utilization and Environmental Effects. https://doi.org/10.1080/15567036.2020.1780350

    Article  Google Scholar 

  • Green, U., Aizenshtat, Z., Gieldmeister, F., & Cohen, H. (2011). CO2 adsorption inside the pore structure of different rank coals during low temperature oxidation of open air coal stockpiles. Energy & Fuels, 25(11), 5539.

    Article  Google Scholar 

  • Green, U., Aizenshtat, Z., Ruthstein, S., & Cohen, H. (2012). Stable radicals formation in coals undergoing weathering: Effect of coal rank. Physical Chemistry Chemical Physics, 14(37), 13046–13052.

    Article  Google Scholar 

  • Hao, M., Zhao, Y. C., Wei, C. M., Zhang, H., & Wang, Y. L. (2021). Multi-component gases competitive adsorption on residual coal under goaf conditions based on Monte Carlo simulation. Chemical Physics Letters, 771, 138557.

    Article  Google Scholar 

  • Hu, P. F., Li, Q., & Liang, L. (2021). A review of characterization techniques of heterocoagulation between mineral particles in mineral separation process. Separation and Purification Technology, 279, 119699.

    Article  Google Scholar 

  • James, R., Bolton, G., & Fraenkel, K. (1964). Assignment of hyperfine splittings in electron spin resonance spectra by linewidth analyses. The Journal of Chemical Physics, 41(4), 944.

    Article  Google Scholar 

  • Jiang, H. P., Bi, M. S., Gao, Z. H., Zhang, Z. L., & Gao, W. (2022). Effect of turbulence intensity on flame propagation and extinction limits of methane/coal dust explosions. Energy, 239, 122246.

    Article  Google Scholar 

  • Kong, B., Li, Z. H., Wang, E. Y., Lu, W., Chen, L., & Qi, G. S. (2018). An experimental study for characterization the process of coal oxidation and spontaneous combustion by electromagnetic radiation technique. Process Safety and Environmental Protection, 119, 285–294.

    Article  Google Scholar 

  • Kong, B., Li, Z. H., Yang, Y. L., Liu, Z., & Yan, D. C. (2017). A review on the mechanism, risk evaluation, and prevention of coal spontaneous combustion in China. Environmental Science and Pollution Research, 24(30), 23453–23470.

    Article  Google Scholar 

  • Li, J. H., Li, Z. H., Yang, Y. L., Kong, B., & Wang, C. J. (2018). Laboratory study on the inhibitory effect of free radical scavenger on coal spontaneous combustion. Fuel Processing Technology, 171, 350–360.

    Article  Google Scholar 

  • Li, Z. (1996). Mechanism of free radical reactions in spontaneous combustion of coal. Journal of China University of Mining & Technology.

  • Li, Z., Kong, B., Wei, A., Yang, Y., Zhou, Y., & Zhang, L. (2016). Free radical reaction characteristics of coal low-temperature oxidation and its inhibition method. Environmental Science and Pollution Research, 23(23), 23593–23605.

    Article  Google Scholar 

  • Lin, Q., Wang, S. G., Liang, Y. T., Song, S. L., & Ren, T. X. (2017). Analytical prediction of coal spontaneous combustion tendency: Velocity range with high possibility of self-ignition. Fuel Processing Technology, 159, 38–44.

    Article  Google Scholar 

  • Liu, H. W., Wang, F., Ren, T., Qiao, M., & Yan, J. J. (2021). Influence of methane on the prediction index gases of coal spontaneous combustion: A case study in Xishan coalfield, China. Fuel, 289, 119852.

    Article  Google Scholar 

  • Liu, J. X., Jiang, X. M., Han, X. X., Shen, J., & Zhang, H. (2014a). Chemical properties of superfine pulverized coals. Part 2. Demineralization effects on free radical characteristics. Fuel, 115, 685–696.

    Article  Google Scholar 

  • Liu, J. X., Jiang, X. M., Shen, J., & Zhang, H. (2014b). Chemical properties of superfine pulverized coal particles. Part 1. Electron paramagnetic resonance analysis of free radical characteristics. Advanced Powder Technology, 25(3), 916–925.

    Article  Google Scholar 

  • Morgan, T. J., George, A., Davis, D. B., Herod, A. A., & Kandiyoti, R. (2008). Optimization of H-1 and C-13 NMR methods for structural characterization of acetone and pyridine soluble/insoluble fractions of a coal tar pitch. Energy & Fuels, 22(3), 1824–1835.

    Article  Google Scholar 

  • Mou, P. W., Pan, J. N., Niu, Q. H., Wang, Z. Z., Li, Y. B., & Song, D. Y. (2021). Coal pores: Methods, types, and characteristics. Energy & Fuels, 35(9), 7467–7484.

    Article  Google Scholar 

  • Onifade, M., & Genc, B. (2020). A review of research on spontaneous combustion of coal. International Journal of Mining Science and Technology, 30(3), 303–311.

    Article  Google Scholar 

  • Qi, X. Y., Wang, D. M., Xin, H. H., & Qi, G. S. (2014). An in situ testing method for analyzing the changes of active groups in coal oxidation at low temperatures. Spectroscopy Letters, 47(7), 495–503.

    Article  Google Scholar 

  • Ruiz-Morales, Y., & Mullins, O. C. (2007). Polycyclic aromatic hydrocarbons of asphaltenes analyzed by molecular orbital calculations with optical spectroscopy. Energy & Fuels, 21(1), 256–265.

    Article  Google Scholar 

  • Song, Y. H., Lei, S. M., Li, J. C., Yin, N., Zhou, J., & Lan, X. Z. (2021). In situ FT-IR analysis of coke formation mechanism during Co-pyrolysis of low-rank coal and direct coal liquefaction residue. Renewable Energy, 179, 2048–2062.

    Article  Google Scholar 

  • Tadyszak, K., Augustyniak-Jablokow, M. A., Wieckowski, A. B., Najder-Kozdrowska, L., Strzelczyk, R., & Andrzejewski, B. (2015). Origin of electron paramagnetic resonance signal in anthracite. Carbon, 94, 53–59.

    Article  Google Scholar 

  • Tahmasebi, A., Yu, J. L., Han, Y. N., Yin, F. K., Bhattacharya, S., & Stokie, D. (2012). Study of chemical structure changes of chinese lignite upon drying in superheated steam, microwave, and hot air. Energy & Fuels, 26(6), 3651–3660.

    Article  Google Scholar 

  • Tzeela, T., Sharon, R., & Haim, C. (2018). The involvement of carbon-centered radicals in the aging process of coals under atmospheric conditions: An EPR study. Physical Chemistry Chemical Physics, 20, 27025–27035.

    Article  Google Scholar 

  • Wang, H. Y., Chen, C., Huang, T., & Gao, W. (2015). CO2 emission of coal spontaneous combustion and its relation with coal microstructure, China. Journal of Environmental Biology, 36(4), 1017–1024.

    Google Scholar 

  • Wang, H. H., Dlugogorski, B. Z., & Kennedy, E. M. (2003). Coal oxidation at low temperatures: Oxygen consumption, oxidation products, reaction mechanism and kinetic modelling. Progress in Energy and Combustion Science, 29(6), 487–513.

    Article  Google Scholar 

  • Wang, J., Zhang, Y. L., Wang, J. F., Zhou, C. S., Wu, Y. G., & Tang, Y. B. (2020). Study on the chemical inhibition mechanism of DBHA on free radical reaction during spontaneous combustion of coal. Energy & Fuels, 34(5), 6355–6366.

    Article  Google Scholar 

  • Wang, K., Han, T., Deng, J., & Zhang, Y. (2022). Comparison of combustion characteristics and kinetics of Jurassic and Carboniferous-Permian coals in China. Energy, 254, 124315.

    Article  Google Scholar 

  • Wang, W., Ma, Y., Li, S., Shi, J., & Teng, J. (2016). Effect of temperature on the EPR properties of oil shale pyrolysates. Energy & Fuels, 30(2), 830–834.

    Google Scholar 

  • Wang, Y. Y., Wu, J. M., Xue, S., Wang, J. F., & Zhang, Y. L. (2017). Experimental study on the molecular hydrogen release mechanism during low-temperature oxidation of coal. Energy & Fuels, 31(5), 5498–5506.

    Article  Google Scholar 

  • Wu, D., Liu, G. J., Sun, R. Y., & Fan, X. (2013). Investigation of structural characteristics of thermally metamorphosed coal by FTIR Spectroscopy and X-ray diffraction. Energy & Fuels, 27(10), 5823–5830.

    Article  Google Scholar 

  • Xia, T. Q., Zhou, F. B., Wang, X. X., Zhang, Y. F., Li, Y. M., Kang, J. H., & Liu, J. S. (2016). Controlling factors of symbiotic disaster between coal gas and spontaneous combustion in longwall mining gobs. Fuel, 182, 886–896.

    Article  Google Scholar 

  • Xu, Q., Yang, S. Q., Tang, Z. Q., Cai, J. W., Zhong, Y., & Zhou, B. Z. (2018). Free radical and functional group reaction and index gas co emission during coal spontaneous combustion. Combustion Science and Technology, 190(5), 834–848.

    Article  Google Scholar 

  • Zhang, L. L., Wu, W. J., Wei, J., Bian, Y. P., & Luo, H. G. (2021). Preparation of foamed gel for preventing spontaneous combustion of coal. Fuel, 300, 121024.

    Article  Google Scholar 

  • Zhao, X. S., Liu, Z. Y., Lu, Z. H., Shi, L., & Liu, Q. Y. (2018). A study on average molecular structure of eight oil shale organic matters and radical information during pyrolysis. Fuel, 219, 399–405.

    Article  Google Scholar 

  • Zhou, B., Liu, Q. Y., Shi, L., & Liu, Z. Y. (2019). Electron spin resonance studies of coals and coal conversion processes: A review (vol 188, pg 212, 2019). Fuel Processing Technology, 190, 93.

    Article  Google Scholar 

  • Zhou, B. Z., Yang, S. Q., Wang, C. J., Hu, X. C., Song, W. X., Cai, J. W., et al. (2020). The characterization of free radical reaction in coal low-temperature oxidation with different oxygen concentration. Fuel, 262, 116524.

    Article  Google Scholar 

  • Zhu, H. Q., Wang, H. Y., Song, Z. Y., & Shen, J. (2013). Effects of oxygen concentration on oxidation characteristics of loose coal at low temperatures. Disaster Advances, 6, 219–225.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Shengqiang Yang.

Ethics declarations

Conflict of Interest

We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work. There is no professional or other personal interest of any nature or kind in any product, service, and/or company that could be construed as influencing the position presented in, or their view of, the manuscript entitled “The change characteristics of radicals in different stages of coal spontaneous combustion.”

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Jiang, X., Yang, S. & Zhou, B. Change Characteristics of Radicals in Different Stages of Coal Spontaneous Combustion. Nat Resour Res 32, 283–294 (2023). https://doi.org/10.1007/s11053-022-10130-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11053-022-10130-y

Keywords

Navigation