Research on a dual-factor method for assessing coal spontaneous combustion tendency based on low-temperature adsorption and high-temperature reaction Synergy

Compaction-breakage behaviors, spontaneous combustion characteristics, and correlation analysis of loose long-flame coal with different grain size gradations under the uniaxial stress

Parallel competing reaction kinetic mechanism in the weight loss phenomenon of coal spontaneous combustion

Study on multi-monitoring point coal spontaneous combustion grading early warning system and GRU model

Nanoscale effect of spontaneous combustion of sulfur corrosion products: Oxygen adsorption and activation mechanism dominated by mesopores

Erratum to “Nanoscale effect of spontaneous combustion of sulfur corrosion products: Oxygen adsorption and activation mechanism dominated by mesopores”. [Fuel 406, Part A (2026) 136879

Multi-parameter synergistic mechanism of igneous intrusion on the spontaneous combustion characteristics of coal

Quantitative analysis of microstructural influences on coal spontaneous combustion across coal ranks

Response surface optimizing XG/HPMC fly ash colloid to inhabit coal spontaneous combustion: An experimental study

Elucidating the independent role of low-concentration methane in coal spontaneous combustion under multi-gas atmospheres

Research on the release characteristics and prediction model of large molecular hydrocarbon gases during coal spontaneous combustion

ABSTRACT This study systematically examines the effect of a novel multi-dimensional synergistic inhibitor inspired by the combined acid-resistant mechanism of the gastric mucosa and gastric mucus barrier on suppressing coal spontaneous combustion, in order to evaluate its practical performance in addressing the shortcomings of traditional inhibitors in terms of long-term effectiveness and synergy. Through coal spontaneous combustion tendency tests and programmed temperature rise experiments, the macroscopic inhibitory effects of the anti-seepage and deoxidation inhibitor imitating gastric mucus and 15 wt% MgCl2 solution were compared and analyzed. The results show that this inhibitor forms a synergistic oxygen shielding structure of “anti-permeation – isolation – oxygen consumption – inertization” through a multi-dimensional synergistic mechanism composed of sodium alginate gel physical coverage, glucose oxidase catalytic oxygen consumption and magnesium chloride inertization and oxygen isolation, significantly increasing the intersection point temperature of the coal sample, delaying the release of characteristic gases, reducing the total release, and achieving an average inhibition rate of 76.2%. Its comprehensive performance is significantly superior to that of traditional magnesium chloride solution. Therefore, this biomimetic multi-dimensional synergistic inhibitor can achieve efficient and sustained suppression of coal spontaneous combustion, providing a promising new approach for the prevention and control of coal mine fires.

ABSTRACT To address the short lifespan and persistent effects of existing flame‐retardant materials, this study developed a novel dual‐network composite gel‐based inhibitor integrating physical barrier properties, chemical inhibition, and nano‐flame retardancy. Nano‐titanium dioxide (TiO 2 ) was used as a cross‐linker to prepare a nanocomposite gel using acrylamide (AM) and N ‐isopropylacrylamide (NIPA). This was then combined with polyacrylic acid (PAA) to form a dual‐network gel. Caffeic acid (CA), a compound with antioxidant properties, was then grafted onto the gel to form the P(AM‐NIPA)@TiO 2 /PAA‐CA dual‐network gel‐based inhibitor. Scanning electron microscopy (SEM) micromorphology revealed abundant wrinkles and pores on the gel surface, enhancing its water absorption capacity. Fourier transform infrared spectroscopy (FTIR) analysis revealed that CA was successfully grafted into the gel network, as evidenced by the peak at 1150 cm −1 , indicative of ether bond formation. X‐ray photoelectron spectroscopy (XPS) revealed a 3.26% increase in the peak ether bond area in the treated coal, indicating the effective suppression of reactive functional groups. Diffuse reflectance infrared spectroscopy revealed that the composite inhibitor effectively passivated reactive functional groups such as free hydroxyl groups and inhibited the oxidative degradation of aliphatic groups. This research may provide a new approach to comprehensive spontaneous coal combustion prevention and control.

ABSTRACT To unravel the veil on the phenomenon that water-immersed coal is prone to spontaneous combustion, the paper digitally re-constructed pore structure and quantitatively assessed the effects of water immersion on it. It was discovered that the pore cross-sectional area of water-immersed coal is 1.59 ~ 5.12 times larger than that of raw coal, which provided more opportunities for the coal-oxygen oxidation reaction. It well explained the reason why water-immersed coal is prone to spontaneous combustion. Besides, in order to find effective measures to suppress spontaneous combustion of water-immersed coal, closed isothermal oxidation experiment was conducted. It was found that oxidation reaction that generates CO and CO2 was dominated by different reaction mechanisms, which was completely inhabited when oxygen concentration is below 2% and 1%, respectively. But when the oxygen concentration is below 5%, the oxidation reaction that generates CO and CO2 was both inhabited, accompanied with declined growth rate. Therefore, oxygen concentration of 5% can be set as critical threshold for suppressing water-immersed coal oxidation. These research results provided solid theoretical foundation for preventing endogenous fire.

Filling and sealing ventilation leakage are critical strategies for preventing coal spontaneous combustion. Based on the essential conditions for coal self-heating and ignition, this paper comprehensively reviews the research progress, fire-suppression mechanisms, and application limitations of currently used colloidal fire-prevention materials. These materials are categorized into four types: inorganic gels, organic gels, organic/inorganic composite gels, and bioinspired self-adhesive gels. Their respective advantages, disadvantages, and applicabilities are thoroughly discussed. Focusing on bioinspired self-adhesive gels, this review elaborates on their design principles, performance regulation strategies, and potential applications under complex geological conditions. While most existing studies have centered on coal mines in China, the proposed material design philosophy and the integrated "inhibition-sealing-suffocation" fire-prevention system are also highly relevant to other major coal-producing countries, such as India, Australia, and the United States, which face similar challenges of coal fires. Future research should focus on material optimization, green synthesis, multitechnology integration, and intelligent implementation to promote the global engineering application and industrialization of these advanced gel materials.

Spontaneous coal combustion accounts for more than 90% of mine fires, and at the same time, the ‘dual carbon’ strategy requires fire prevention and extinguishing materials to have both low-carbon and environmentally friendly functions. To meet on-site application needs, a composite gel with fast injection, flame retardant, and CO2 adsorption functions was developed. PVA-PEI-PAC materials were selected as the gel raw materials, and an orthogonal test with three factors and three levels was used to optimize the gelation time parameters to identify the optimal formulation. The microstructure of the gel, CO2 adsorption performance, as well as its inhibition rate of CO, a marker gas of coal spontaneous combustion, and its effect on activation energy were systematically characterized through SEM, isothermal/temperature-programmed/cyclic adsorption experiments, and temperature-programmed gas chromatography. The results show that the optimal gel formulation is 14% PVA, 7% PEI, and 5.5% PAC. The gel microstructure is continuous, dense, and rich in pores, with a CO2 adsorption capacity at 30 °C and atmospheric pressure of 0.86 cm3/g, maintaining over 76% efficiency after five cycles. Compared with raw coal, a 10% gel addition reduces CO release at 170 °C by 25.97%, and the temperature-programmed experiment shows an average CO inhibition rate of 25% throughout, with apparent activation energy increased by 14.96%. The gel prepared exhibited controllable gelation time, can deeply encapsulate coal, and can efficiently adsorb CO2, significantly raising the coal–oxygen reaction energy barrier, providing an integrated technical solution for mine fire prevention and extinguishing with both safety and carbon reduction functions.

ABSTRACT This study aims to develop an efficient mineralized fly ash slurry with enhanced flame retardancy, investigate effective measures to prevent coal spontaneous combustion, minimize resource waste, and ensure personnel safety. Through the coal spontaneous combustion heating experiment, the optimal particle size of the fly ash in the mineralized fly ash was determined to be (200–400 mesh), the concentration of fly ash was (30%), and the increase in CaO content was (5%). Techniques such as Fourier-transform infrared spectroscopy (FTIR), electron spin resonance (ESR), and simultaneous thermal analysis (STA) have been employed to evaluate the resistive properties from both micro and macro perspectives. The experimental results show that the inhibitory effect of mineralized fly ash slurry on coal spontaneous combustion is reflected in the synergistic inhibition of macroscopic heat release and microscopic structural changes. At the macroscopic level, when the temperature exceeds 150°C, the maximum heat release power of coal samples treated with mineralization is significantly lower than that of raw coal, with the heat release rate reduced by 20%. At the microscopic level, the addition of the inhibitor significantly delays the generation of nascent radicals in raw coal, and the coal samples treated with mineralization exhibit better radical inhibition effects than other samples. Meanwhile, the growth rate of the g-value value of the treated coal samples in the high-temperature range decreases significantly. Particularly importantly, the mineralized fly ash slurry can effectively reduce the change rate of C = O and -OH groups during coal oxidation. In the critical temperature range of 130–180°C for coal spontaneous combustion, its inhibition efficiencies reach 79.5% and 85.2% respectively, significantly delaying the overall process of coal spontaneous combustion.

To address safety hazards such as gas leakage and spontaneous combustion of coal seams in coal mining, silane-modified tannin phenolic foam (T-KPF), a three-dimensional flexible crosslinked network, was prepared by modifying phenolic resin with tannic acid and the silane coupling agent KH-560. Surprisingly, the formation of Si-O-C bonds with the resin endows the foam with outstanding properties during the hydrolyzation of KH-560. The optimal properties were achieved with a 6% KH-560 loading, showing a compressive strength of 134 kPa, a powdering rate of 3.2%, a water absorption of 25.6%, a limiting oxygen index of 43.2%, and a uniform pore structure. This modification strategy overcomes the brittleness and high-temperature decomposition limitations during the traditional phenolic foam preparation procedure, providing a high-performance material for coal mine safety sealing and promoting the sustainable application of natural polymer materials.

Self-heating characteristics of sub-bituminous coal C during spontaneous combustion in stockpiles

Multi-stage indicator gas selection and early-warning method for coal spontaneous combustion