A novel high polymer nanocomposite inhibitor for coal gangue spontaneous combustion prevention: A case study of Yangquan coal gangue in China

Summary Coal gangue spontaneous combustion produces toxic and harmful gases. This research aims to study a new type of polymer nanocomposite inhibitor to prevent and control coal gangue spontaneous combustion. Nanomodification of montmorillonite (MMT) was carried out on high polymer emulsion inhibitor polyacrylamide (PAM) to improve its thermal stability and overcome the short inhibition duration problem. First, through scanning electron microscope (SEM), energy‐dispersive spectrometer (EDS), and proximate analysis experiments, it was found that the coal gangue in the Yangquan mining area was prone to spontaneous combustion. Then, PAM/MMT was produced by an intercalation method. The results of X‐ray diffraction (XRD) and differential scanning calorimetry (DSC) showed that the interval spacing of MMT increased, which was sufficient for the insertion of acrylamide monomer. The vitrification temperatures of PAM and PAM/MMT prove that PAM/MMT exhibited higher thermal stability. The results of Fourier transform infrared spectroscopy (FTIR) experiments indicated that the PAM/MMT composite inhibitor agent effectively inhibited the oxidative activity of reactive groups on the coal gangue surface. As a result, PAM/MMT could suppress coal gangue oxidative spontaneous combustion, so as to reduce environmental problems caused by coal gangue spontaneous combustion. Furthermore, a spraying process is designed for the application of the inhibitor.