Experimental study of thermophysical properties of coal gangue at initial stage of spontaneous combustion

• Published in: Journal of hazardous materials Vol. 400; p. 123251
• Main Authors: Li, Bei, Wang, Jia-Hua, Bi, Ming-Shu, Gao, Wei, Shu, Chi-Min
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05-12-2020
• Subjects: Heat transfer; Self-ignition potential; Sensitivity analysis; Thermal conductivity; Transient plane source method; Thermal conductivity; Transient plane source method; Sensitivity analysis; Self-ignition potential; Heat transfer
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2020.123251

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•Thermal behaviors and thermophysical properties of CG were investigated.•Comprehensive combustion index Sn of CGs were calculated.•Cp of the CG tended to increase with the elevated temperature.•Correlations for Cp, λ, and D were determined by appropriate prediction models.•Sensitivity analysis of the thermophysical parameters were performed.
The specific heat capacity (Cp), thermal conductivity (λ), and thermal diffusion coefficient (D) of coal gangue (CG) are the main factors that affect the self-ignition potential for heat transferring from burning center to the ground surface. In this paper, the thermophysical properties of CG were investigated by transient plane source method. The correlations and sensitivity analysis were performed to characterize the degree of influence of the thermophysical parameters (Cp, λ, and D) dependence on temperature. The mean values of Cp, λ, and D for CG were at a range of 0.73–0.89 J g−1 K−1, 0.44–0.76 W m−1 K−1, and 0.26–0.43 mm2 s−1, respectively. Compared with coal, CG were located in the low area (Sc < 2) with higher value of λ and D, but lower value of Cp. Results also showed that 70 °C was a critical point for CG at which some kinds of mutation took place in thermophysical properties. The comparison between the experimental data and the correlation outputs exhibited consistency.