A new numerical method to predict the growth temperature of spontaneous combustion of 1/3 coking coal

Hazards caused by spontaneous coal combustion are of deep concern. To explore the process of spontaneous coal combustion, we focused on the key aspects of growth temperature (T-g) and the apparent activation energy (E-a), where T-g is associated with the E-a. We used four different heating rates to perform thermogravimetric (TG) experiments to calculate E-a values through an improved Kissinger-Akahira-Su nose method. The findings revealed a sudden change point in E-a values (that is, T-g), and comparisons between experimental data and calculated results demonstrated favorable agreement. The grey correlation analysis method was used to analyze the relationship between the samples' T-g and intrinsic properties. A quasi-Newton method and general global optimization model were adopted to derive a predictive relationship for spontaneous coal combustion. The results are beneficial and crucial for elucidating the mechanism of spontaneous coal combustion, which could facilitate a thorough understanding of this process and help provide proactive loss prevention measures. (C) 2017 Elsevier Ltd. All rights reserved.