Fire accidents caused by coal spontaneous combustion usually lead to a large loss of coal resources and casualties. Not only that, the greenhouse effect is polluted while the environment is polluted. At present, the commonly used fire-extinguishing materials such as water, inhibitors, and organic foams have the disadvantages of poor stability and short fire-extinguishing cycles. It is difficult to effectively suppress coal spontaneous combustion and quickly extinguish the fire for a long time. To suppress the spontaneous combustion of coal, the research team proposed an inorganic three-phase foam with a high foam expansion rate, good cohesiveness, and excellent stability. In the formulation, pulverized fly ash (PFA) is used as the matrix, sodium dodecyl benzene sulfonate (SDBS) and α-olefin sulfonate (AOS) are used as foaming agents, curdlan is used as the foam stabilizer, and sodium silicate is the binder. The compound foaming agent with the best performance is optimized, through the two-group compounding test. The composite foaming agent’s optimal compound ratio is SDBS/AOS (3:2). The optimal ratio of inorganic three-phase foam (ITPF) components was obtained through the control variable method experiment. The water–cement ratio is 5:1, the composite foaming agent is 0.2%, the curdlan is 0.5%, and the sodium silicate is 1.6%. In addition, it has been determined by experiments that ITPF has the strongest foaming ability when the pH value is 9 and the temperature is 60 °C. The fire-extinguishing performance of the new material ITPF was investigated by thermogravimetry and coal spontaneous combustion tendency test. It has been observed that the new material has the effect of cooling down and isolating coal from contact with oxygen. The results show that the new material ITPF has the potential to prevent coal spontaneous combustion.

The spontaneous combustion parameters of lignite at different oxygen concentrations and temperatures were studied by temperature-programmed oxidation experiments. The characteristic parameters, tendency, oxygen consumption rate, kinetic parameters of oxidation reaction, and heat release intensity of coal’s spontaneous combustion were studied. The results show that the variation of export oxygen volume fraction of coal samples under different oxygen concentrations is similar. It has a general s-shaped downward trend. The change trend of the CO concentration of the coal sample export is basically the same at different oxygen concentrations. The CO concentration at the outlet of the coal sample increases with the increase in coal temperature. The CO concentration at 0–200 °C increased exponentially with the coal temperature. The distribution pattern of CO/CO2 ranging from 0 to 320 °C was similar at different oxygen concentrations. With the increase of coal temperature, CO/CO2 first increases and then decreases after reaching the extreme point. The change curve of CH4 with coal temperature under different oxygen concentrations meets the exponential change rule. At different oxygen concentrations, the concentration of ethylene at 0–300 °C changes exponentially, but at 300–400 °C there is no rule. When the oxygen concentration is 20.9%, according to the comprehensive judgment index method and cross temperature method, the comprehensive determination of the spontaneous combustion trend of coal samples is grade II. Under different oxygen concentrations, the oxygen consumption rate of coal increases with the increase of temperature; the oxygen consumption rate increases with the increase of oxygen concentration at the same temperature. The activation energy of coal samples increases with the decrease of oxygen supply concentration or the increase of temperature. The thermal strength of the coal sample is consistent with the change trend of the oxygen consumption rate. The heat release intensity of coal samples conforms to an exponential function and polynomial function in the early and late stages, respectively.