Fire extinguishing with the superior performance of fly ash composite colloid material is a cost‐effective colloid fire prevention technology. In this paper, a new powder additive (suspending agent (XK‐XJ) and gelling agent) was developed for the existing fire extinguishing technology of fly ash compound colloid. Tests show that the best additions to the fly ash slurry were 0.3% and 0.1∼0.3%, respectively. The grouting technical scheme of adding a suspending agent on the ground and gelling agent downhole was proposed to solve the problems of solid material settlement and blockage in the long‐distance pipeline transportation process. Finally, the optimized fly ash colloid fire prevention and extinguishing technology was successfully applied to the fire control engineering examples of close‐range coal seam groups, and the rationality of the developed powder and its proportion was tested, and the feasibility in coal fire control was tested.

Data in this article presents the characteristic parameters of spontaneous combustion of coal with different ranks, including lignite, long flame coal, and anthracite. The coal samples were tested by the temperature programmed method. The gas concentration data produced at different temperature points during the heating process are obtained. Through monitoring the spontaneous combustion of coal in a coal mine, the field data in goaf are obtained. Through processing on the data from the experiment and field, three gas indices were obtained, which include CO/CO2, Graham value and Alkane ratio. The data is made available for further use and for furthering the understanding of the key findings of the related research, such as the early warning for spontaneous combustion of coal. For more insight please see A method for evaluating the spontaneous combustion of coal by monitoring various gases (Guo et al., 2019).

High-temperature poisonous smoke produced by coal mine roadway fire seriously affects miners' lives and safety. Studying the development law of high-temperature smoke in the process of mine roadway fire and then exploring the danger of roadway are of great significance to personnel safety and post-disaster rescue. In order to study this problem, the CFD numerical simulation method is used to establish a fire calculation model based on ANSYS Fluent software in the development stage of mine fire. The high-temperature flue gas flow in the roadway during the development stage of mine fire is simulated, and the variation law of temperature field and gas concentration field with time and space position under different levels of roadway in the development stage of fire is revealed. The variation rules of environmental parameters, such as temperature, CO, and CO₂, are obtained by numerical calculation. Based on these, the danger zones of smoke spread in fire development stage are divided by the critical values of high-temperature smoke and toxicity evaluation index, and the mathematical fitting analysis of the evolution of the dangerous area with time is carried out. The research results have certain theoretical guiding significance for reducing underground environmental pollution and ensuring the personal safety of workers and rescuers.

Spontaneous coal combustion adversely affects coal mine safety and restricts safe, efficient, and green coal mining. Inert gas fire prevention and extinguishing technology is a widely used fire prevention and extinguishing method in coal mines. CO₂ is often used as the primary raw material for inert gas fire prevention and extinguishing, owing to its good inerting and cooling characteristics. However, the lack of data on the physical and chemical properties and fire extinguishing mechanism of CO₂ by field personnel has limited the efficient application of CO₂ in coal mine fire prevention and extinguishing. To explore the practical application effects of CO₂ fire prevention and extinguishing technology on coal mine sites, this paper summarised and analysed the research and development status of CO₂ fire prevention and extinguishing technology and expounded the physical and chemical properties, phase characteristics, and fire prevention and extinguishing mechanisms of CO₂. The CO₂ pipeline, CO₂ pipeline intelligent monitoring and control system, CO₂ inerting mechanism, and comprehensive gas fire prevention and extinguishing technology are summarised and discussed. This study provides a systematic theoretical basis for the field application of CO₂ fire prevention and extinguishing technology.

In the mine fire period, the smoke plume temperature, critical air velocity, back-flow layer and other fire parameters in the lanes are subjected to environmental factors such as lane dip angle and airflow conditions, coupled with uncertain evolution process. In view of this, a numerical simulation is performed for exploring the dynamic evolution law of fire possibly occurred in the mine. The ANSYS Fluent PDF non-premixed combustion model is applied to reveal the fire development in the lanes with different dip angles under different air velocity. The temperature distribution in the lanes and the evolution law of the fire back-flow layer are also analyzed. Here introduces the dimensionless number-Richardson number (Ri value) to determine the critical value of the development of the fire back-flow layer. The results show that there is a regular relationship of the spatiotemporal evolution properties of fire in the inclined lane with the two factors: dip angle, airflow velocity, According to this law, the calculation model of smoke back-flow layer length with respect to air velocity and inclination angle is established, and the critical air velocity prediction model under the condition of large inclination angle is revised. Based on the critical air velocity and critical angle, the critical value of the Richardson number is determined to be 91.6. When Ri is greater than 91.6, the fire back-flow layer appears, otherwise, it disappears. The findings provide certain clues to identifying the fire in the underground tunnel and predicting the fire development and smoke spread.