Comparison of the inhibition mechanisms of five types of inhibitors on spontaneous coal combustion

Summary Five inhibitors—Zn/Mg/Al‐CO3 layered double hydroxides (LDHs), thermosensitive hydrogel (P(NIPA‐co‐SA)), diammonium phosphate ((NH4)2HPO4), sodium phosphate (Na3PO4), and magnesium chloride (MgCl2)—commonly used to forestall the spontaneous combustion of anthracite and coke coal were investigated in this study, and the inhibition effects were quantified. According to the results of thermogravimetry, differential scanning calorimetry, Fourier transform infrared spectroscopy, and kinetic analysis, Zn/Mg/Al‐CO3‐LDHs, P(NIPA‐co‐SA), and (NH4)2HPO4 all exert substantial inhibiting effects on anthracite and coke coal. Specifically, P(NIPA‐co‐SA) was altered during the liquid‐to‐gel phase, which isolated the oxygen from the coal surface and produced an endothermic reaction that decreased the environmental temperature; this reaction further inhibited spontaneous combustion. Conversely, MgCl2 promoted a combustion reaction and reduced the apparent activation energy of coal, increasing the risk of spontaneous combustion. This study provides a reference for selecting suitable inhibitors to prevent the spontaneous combustion of coal. Inhibition ability of 2 types of self‐prepared and 3 types of commercial inhibitors were determined as a prevention mechanism of coal spontaneous combustion. Zn/Mg/Al‐CO3‐LDHs and coke coal(NH4)2HPO4 had effective inhibition ability. STA technique as advanced thermal analysis method identified the inhibition mechanism of coal spontaneous combustion.