With the rapid advancement of coal mine excavation technology, effective dust control at the working face has become increasingly challenging. To investigate dust migration under the coupled effects of turbulent airflow and water spray, this study employs an EDEM-Fluent coupling approach to develop a gas-liquid-solid three-phase numerical model. The model is applied to simulate dust transport characteristics in a fully mechanized excavation face equipped with long-pressure short-exhaust ventilation. The results reveal that dust migration under three-phase coupling differs significantly from that predicted by two-phase models. In the initial spray stage, droplets dominate, rapidly forming a dust-mist mixing zone near the cutting head. As ventilation proceeds, the forcing airflow drives dust toward the roadway walls for temporary accumulation, followed by gradual dispersion toward the roof and migration to the exhaust duct. Wall-induced vortex effects further transport residual dust toward the transfer point and pedestrian area, causing secondary pollution. The study also demonstrates that simply increasing spray pressure enhances droplet kinetic energy but reduces atomization coverage, ultimately decreasing capture efficiency and increasing dust escape near the cutting head. Based on the experimental platform of the long-pressure short-exhaust dust removal system, the numerical simulation results were validated and analyzed by detecting the variation patterns of dust concentration at multiple points under similar working conditions. The maximum deviation from the experimental data is 6.12%, confirming that the numerical simulation method is practical and reliable, and providing a new approach for studying dust migration patterns.

Open pit coal mining generates fine particulate matter (PM10 and PM2.5), whereas conventional dust suppressants exhibit poor wettability, weak film forming ability and limited durability. To address these issues, we developed a hydrogel dust suppressant (XPSG) based on sodium alginate (SA) and polyacrylamide (PAM) and reinforced with gallic acid (GA), and evaluated its performance. XPSG was prepared from PAM, SA, GA and the surfactant XP-80. A ternary network is formed via AM/MBA/APS free-radical polymerization, Ca2 + -mediated ionic coordination and GA-enabled it-it/hydrogen-bonding interactions. FTIR and TG-DTG confirm network formation and thermal stability. XPSG improves interfacial behavior: the solution surface tension is reduced to 28.63 mN/m, the coal-dust contact angle to 28.9 degrees, and the zeta-potential (with SiO2/AlOOH mineral doping) shifts to -58.49 mV, enabling rapid spreading and wetting. At 50 degrees C, XPSG-treated coal retains more than 40 % of its moisture after 6 h and forms a crust with a hardness of 57.0 HA. Wind-tunnel tests at 10 m/s show PM10 and PM2.5 suppression efficiencies exceeding 98 %. SEM and BET analyses reveal dust agglomeration, continuous surface films, and a decrease in specific surface area of 300-400 mesh coal from 12.5863 to 3.0850 m2/g, indicating diminished resuspension risk. Quantum-chemical electrostatic potential and IGMH analyses elucidate hydrogen-bonding and van der Waals interaction networks between GA/SA and water/coal surfaces, rationalizing the enhanced wettability, water retention and structural stability. Collectively, the XPSG system provides a low-toxicity, mechanism-informed route for improving dust control and air quality in open-pit coal mining, indicating promising potential for broader practical application.

The traditional safety guarantee technologies in mines rely on chemical reagents, which bring significant risks of environmental pollution. The micro-nano bubble technology (MNBT) introduces micro-nano bubbles (MNBs) into the liquid phase, providing an innovative strategy for non-chemically modified liquid media. MNBT has been successfully applied in multiple fields, and the core challenges in mining, at the level of scientific principles, are highly consistent with the capabilities demonstrated in successful cases. Currently, the degree of interdisciplinary integration is not high, which limits its application and promotion in mining. Based on this, we have reviewed the basic principles of MNBT and its beneficial effects in the engineering field, based on the universal mechanism of MNBs' action, and looked forward to the potential applications of MNBT in mining. Research shows that MNBT can be combined with the prevention and control technologies in the five key areas of mining. Future research should focus on the compatibility application of MNBT with the mine material system, the development of environmentally friendly non-chemical liquid medium materials, and promoting the integration and innovation of MNBT with traditional mining technologies, thereby facilitating the transformation of traditional mines to be safe, efficient, low-carbon, and environmentally friendly.

In this study, the effectiveness of 4A zeolite as a single-component suppressant for coal dust explosions was evaluated using a 20 L spherical explosion system, thermogravimetric-derivative thermogravimetric (TG-DTG), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Macroscopic explosion test results indicated that 25 wt% 4A zeolite completely suppressed explosions. Subsequent thermal and kinetic analyses showed that the addition of 4A zeolite not only lowered the initial and peak pyrolysis temperatures of coal dust but also reduced its apparent activation energy from 158.47 to 135.82 kJ/mol. Although this suggested a catalytic effect on early pyrolysis, characterization of the solid residue after the explosion revealed that the prematurely released aliphatic volatiles were efficiently captured by the zeolite's ordered micropores, thereby reducing the availability of combustible precursors for the gas-phase explosion. Furthermore, the high-temperature structural collapse of the zeolite released active Na+ cations, achieving chemical ion quenching through the formation of stable Na-O bonds (530.5 eV). Consequently, this study proposes a multi-scale synergistic mechanism comprising four suppression stages across three spatiotemporal scales: macroscopic endothermic cooling; macroscopic kinetic regulation and physical barrier formation; microscopic in-situ volatile trapping within ordered micropores; and molecular-scale chemical ion quenching through Na-O bond formation. This study challenges the traditional view that powder suppressants are merely inert diluents and provides a solid theoretical basis for the development of highly efficient, single-component, and environmentally friendly explosion suppressants.

Mining-induced stress redistribution significantly alters the pore-fracture structure (PFS) of coal, thereby directly influencing gas extraction efficiency. However, the evolution of the PFS under stress constraints and its correlation with mechanical damage are not fully understood. Therefore, this study performed triaxial compression experiments under varying confining pressures (4-12 MPa) using an in-situ nuclear magnetic resonance imaging analyzer to monitor the spatiotemporal evolution of the PFS. Fractal theory was employed to characterize pore complexity and tortuosity, and a quantitative relationship between the damage variable and pore parameters was established. The results show that the PFS sequentially undergoes compaction, dilation, and severe failure, which corresponds to the dynamic change of T-2 spectral area. As confining pressure increases, pore compressibility decreases, and the failure pattern shifts from tensile-shear to shear-dominated. The porosity and proportion of seepage pores (PSP) both initially decrease and subsequently increase, while the geometric fractal dimension of seepage pores (D-gs) and tortuosity fractal dimension (D-T) exhibit the opposite trend. The evolution of the damage variable is coordinated with that of the pore parameters, and a cubic function accurately characterizes their relationship. Under high confining pressure (>6 MPa), the porosity and PSP display a secondary decrease before complete failure, while the D-gs exhibits a rebound followed by further decline. The re-compaction of microfractures and seepage pores in damaged coal is the primary reason behind secondary reduction or rebound of these pore parameters. These findings elucidate the stress-pore coupling mechanism in damaged coal and provide a theoretical basis for optimizing gas extraction strategies.

Improving the wettability of pulverized coal is essential for efficient wet dust suppression. This study investigates how pH adjustment (pH 3-11; HCl/ H2C2O4/NaOH/ Na2CO3) coupled with ionic surfactants (cationic CTAB and anionic AS) synergistically regulates the wettability and pore structure of anthracite using experiments and molecular dynamics (MD) simulations. Surface tension and static contact angle results show that wettability is strongly dependent on both pH and surfactant concentration, and CTAB consistently performs better than AS, especially under mildly acidic and mildly alkaline conditions. In 0.04 mol/L HCl (pH 3), CTAB reduces the contact angle from an initial value of 37.8 degrees (t = 0 s) to 4.1 degrees at t = 3 s, indicating a rapid hydrophobic-to-hydrophilic transition. Zeta potential measurements (|zeta|max 58.1 mV) and FTIR analyses reveal enhanced surface ionization and increased oxygen-containing functionalities after acid/alkali activation and surfactant adsorption. N2 adsorption-desorption shows promoted meso-/macropore development and an increased specific surface area from 1.33 to 1.62-1.70 m2/g. MD simulations suggest that ionic surfactants form ordered adsorption layers dominated by electrostatic interactions, thickening the interfacial water layer and enhancing water transport (diffusion coefficients up to 0.2918 and 0.2858 & Aring;2/ps for CTAB and AS). Overall, pH-driven charge regulation maximizes surfactant packing and hydration forces, providing mechanistic guidance for wetting-agent design.

Understanding the microstructural and oxidative kinetic evolution of lignite during surfactant wetting remains challenging, as the time-dependent structural and reactive changes have not been fully clarified. In this study, combined analytical and calculation methods, including surface area measurement instruments (BET), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR), were systematically used to investigate the microstructural changes and reactivity of lignite exposed to different wetting periods. The BET measurement results show that the treated coal powder exhibits an overall decrease in pore volume and specific surface area, while the average pore size increases, indicating a gradual rearrangement of the pore structure. As the wetting time prolongs, the rate of change in these parameters gradually decreases; TGA experiments indicate that, with increasing wetting period, the characteristic temperature related to oxidation and combustion continues to decrease. Through calculations using three thermodynamic methods, it was found that the apparent activation energy (E alpha) shows a trend of first increasing and then decreasing, reflecting a shift in reaction difficulty. FTIR experiments show that the C--C bond after wetting is more easily oxidized than aliphatic hydrocarbons, and the oxygen-containing functional group (OFG) content exhibits a continuous increasing trend. These findings elucidate the dynamic mechanisms of the morphological characteristics and chemical reactivity of coal particles under the action of surfactants, and provide an innovative framework for regulating oxidation processes and spontaneous combustion risks in coal storage, transportation, and utilization.

As the interface between environmental exposure and respiratory intake, the breathing zone is often simplified in respiratory CFD models, while the broader influence of model completeness on airflow and particle deposition remains insufficiently quantified. In this study, a comprehensive human respiratory model (hereinafter referred to as the "all-in-one model") encompassing the upper and lower respiratory tracts and the throat region was initially constructed and integrated with a spherical breathing zone. The effect of the breathing zone was evaluated by developing six computational models with varying anatomical completeness. Three particle release approaches were implemented, including nostril inlet release, volumetric release within the breathing zone, and surface-based release on the breathing zone boundary. The Eulerian-Lagrangian approach was adopted, and total and regional particle deposition patterns were carefully analyzed. The results revealed that the breathing zone, together with varying anatomical completeness, significantly alters airflow development in the nasal vestibule, valve region, and posterior turbinate zones, with sectional peak velocities reduced by up to 12%. While total nasal deposition for 10μm particles varies moderately (14.55%-45.55%), substantial regional discrepancies are observed, with nasal vestibule deposition differing by up to 14-fold between models with and without the breathing zone. Particle release strategy further influences deposition predictions, as nostril inlet release produces 956%-1345% higher vestibule deposition compared with breathing-zone-based release. These findings demonstrate that neglecting the breathing zone and adopting simplified particle release strategies can substantially degrade assessment accuracy. Incorporating physically consistent breathing zone representations is essential for improving the accuracy and reliability of CFD-based respiratory exposure assessments.

The capture and sedimentation efficiency of traditional spray technology for respirable dust (PM2.5/PM10) in coal mine is too low, which seriously affects mine safety and occupational health. In this study, a discrete foam dust removal technology was innovatively proposed. A discrete foam dust suppressant was developed with APG0810/ SDS as foaming agent (SAP), natural polymer guar gum (GG) and quaternary ammonium modified cationic guar gum (CGG) as foam stabilizer. Through experiments and molecular simulation studies, it is shown that compared with SAP/GG system, SAP/CGG system adds quaternary ammonium salt groups, the contact angle is reduced by 7.73 %, the apparent viscosity is increased by 27.61 %, and the wetting and adhesion properties of bituminous coal are enhanced. Considering the economic benefits, and through the three-factor orthogonal experiment of roadway wind speed, discrete foam number and half-life, 0.5 % SAP + 0.3 % CGG was determined as the best ratio. The foam cluster formed by this system can effectively wet, wrap and settle the respirable dust. Compared with spray dust reduction, the dust reduction efficiency of discrete foam dust removal for fine particle dust is increased by 42.48 %, and the visibility of roadway is improved. This study is of great significance for the treatment of underground respirable dust.

Dust particles in coal mine roadways typically exhibit a broad particle size distribution (PSD) that evolves along the transport path. Current dust risk assessments primarily focus on environmental/individual external concentrations and time-weighted average (TWA) exposure. However, the true determinants of upper respiratory tract (URT) health effects are the deposition mass (DM) and flux within functional regions following inhalation. A CFD-DPM-based numerical model was developed and validated to simulate transient dust transport and deposition at measurement points (MPs) under varying respiratory flow rates, and the XGBoost-SHAP method was applied to analyze deposited mass per breath (DMPB) in nasal functional regions. Results show that increased respiratory flow significantly elevates vortex volume proportion (V Omega* ), average wall shear stress (AWSS), and secondary flow intensity (Se) in the nasal cavity. Compared with exhalation, inhalation yields lower peak V Omega* , while Se follows a sinusoidal pattern over time. PSD is the dominant factor for deep nasal deposition, and high exposure concentration does not necessarily increase DMPB, particularly at high breathing flows. The cut-off particle size for penetration into lower respiratory tract (LRT) decreases exponentially with respiratory flow. SHAP analysis reveals that nasal deposition prediction is mainly driven by the aerodynamic diameter (da), with dust concentration (CMP) as a secondary factor for anterior deposition and impaction parameter (IP) as a secondary factor for middle and posterior deposition. These findings indicate concentration alone is insufficient for assessing respiratory deposition risk; PSD must also be considered to better capture deposition patterns and health implications across nasal regions.

The impact dynamics of surfactant-laden droplets on dusty surfaces play a critical role in optimizing spray-based dust suppression systems. In this study, the interactions between sodium dodecyl sulfate (SDS)-containing droplets and coal flakes were investigated using high-speed imaging, while numerical simulations were employed to validate the droplet behavior and velocity evolution. The results revealed oscillatory decreases in droplet height and contact angle, accompanied by the expansion of the three-phase contact line-findings that were consistent with the simulation results. Two distinct droplet states were identified: the maximum diffusion state (beta max) and the steady-state (beta e). Quantitative analysis demonstrated that it exhibits a positive correlation with the Weber number, while it scales with the Reynolds number. Increasing both the impact velocity and SDS concentration enhanced the diffusion and penetration rates but reduced their respective durations. Dynamic force analysis further indicated that impact forces primarily drive droplet spreading, whereas oscillatory forces induce expansion-contraction behavior and suppress penetration. These findings provide essential theoretical insights for improving the performance and efficiency of spray-based dust suppression technologies.

Coal dust is difficult to suppress using conventional water spraying due to its strong hydrophobicity, limiting dust control efficiency in mines. A composite dust suppressant (XPC/TO-10) featuring a gel-based interpenetrating network was developed using xanthan gum (XG), phytic acid (PA), sodium carboxymethyl cellulose (CMC), and isomeric tridecanol polyoxyalkylene ether (TO-10). Response surface methodology (RSM) with a quadratic model was used to optimize the formulation. The optimized blend achieved a settling time of 16 s. Peak fitting analysis of the bituminous coal samples showed that, compared with the samples treated with pure water, the proportion of oxygen-containing groups increased by 12.40% after treatment with XPC/TO-10 solution. The pretreatment contact angle test results showed that solution pretreatment significantly improved the wettability of coal. Compared with the contact angle of 74.87 degrees between the surface of raw coal and pure water droplets, the contact angle between the coal flakes and pure water droplets after XPC/TO-10 treatment decreased to 57.72 degrees, a reduction of 22.91%. In spray dust suppression experiments, the optimized formulation achieves a total dust removal efficiency of 73.97%, surpassing water by 19.30%. This indicates that XPC/TO-10 has excellent performance in promoting the aggregation and settling of dust particles, making it suitable for the high-efficiency dust suppression requirements in mining environments.

Effective dust control in continuous miner (CM) tunnels necessitates strict prioritization of source management, as the unsteady turbulent perturbations induced by the rotating transverse-axis cutting drum (TCD) and its multiple pick assemblies (MPAs) fundamentally govern source-dust dispersion. To elucidate the multiscale aerodynamic effects of the TCD and MPAs, this study develops a rotor-stator numerical framework by coupling the Sliding Mesh (SM) technique with a CFD-DPM approach for airflow-particle interaction. This method is employed to quantify how rotation-induced disturbances modulate flow-field topology and particle dispersion during deep-slot cutting across varying rotational speeds. Results indicate that drum rotation enhances the aerodynamic response and turbulent diffusion of particulate matter throughout the tunnel, with a particularly pronounced diffusion-promoting effect on finer dust particles. Relative to the stationary-drum (SD) baseline, the rotating-drum (RD) condition mitigates dust concentration within the slotting zone but drastically amplifies the resuspension of micron-scale particles. The temporal accumulation of dust parcels within the breathing zones of the CM and shuttle-car operators adheres to a Hill-type growth function. As rotational speed increases, the 1000 mg/m3 isoconcentration zone beneath the drum mid-span contracts, shifting toward the drum extremities and expanding radially outward. Concurrently, increasing speed reduces parcel abundance in the near-drum periphery while elevating mean parcel velocity. Under RD conditions, the axial parcel distribution, turbulent kinetic energy profiles, and concentration fields exhibit a distinct trend toward homogenization. These findings clarify the source-to-tunnel multiscale coupling mechanisms, providing a theoretical basis for optimized source control strategies and localized ventilation design.

Respirable dust concentration monitoring in underground coal mines is essential for guiding dust prevention measures, safeguarding miners' occupational health, and reducing environmental pollution. However, existing dust image-based models are limited to task-specific outputs and cannot exploit natural language cues for error compensation, which leads to suboptimal accuracy and weak interpretability. Thus, a dust-aware vision-language monitoring framework, termed DUST-VLM, is proposed to integrate laser-scattering dust imagery with an instruction-guided multimodal large model for end-to-end concentration estimation and health risk interpretation. DUST-VLM adopts a unified architecture consisting of a LoRA-adapted vision encoder to extract dust-aware visual tokens, a cross-attention-centered multimodal bridge to align and fuse visual and textual representations, and a language decoder equipped with chain-of-thought prompting and LoRA fine-tuning to generate structured outputs. Given a dust image with a user query to the DUST-VLM, the current respirable dust concentration with the corresponding health risk level can be reported. The prevention and control recommendations can also be output. A laser-scattering respirable dust dataset was constructed by utilizing a self-designed monitoring platform. Experimental results demonstrate that DUST-VLM achieves 93.18% accuracy, 93.42% precision, and 92.91% F1-score, with MAE of 4.659 mg/m3 and RMSE of 9.947 mg/m3, outperforming nine representative baselines. DUST-VLM provides accurate and interpretable decision support for autonomous dust monitoring and targeted control, showing strong potential for smart mine deployment and occupational health protection.

Microbial degradation could effectively change the microstructure of coal and improve the permeability. The effects of microbial degradation on the surface functional groups, crystal structure, and nanopore structure of coal were investigated by various test methods. Multiscale pore heterogeneity parameters under biogenic influence were calculated based on multifractal theory. Meanwhile, the correlations between different microstructure parameters were analyzed using Spearman correlation analysis. The results show that the C--O group and aromatic-CH group content decrease following microbial degradation. The aromaticity I of samples S2 and S3 increases from 1.57 to 2.56 and 1.77, respectively, while the aromaticity I of Y1 and Y2 decreases. The DOC value of the samples becomes smaller, the length of fatty chains increases, and the skeletal structure of coal becomes looser. Microbial activity can lead to a reduction in ink-bottle pores while increasing the proportion of open and semi-closed pores, improving pore connectivity. Microorganisms convert micropores and transitional pores into meso-and macropores by consuming small-molecule organic matter in coal, significantly reducing the content of micropores and increasing the average pore size. After biotransformation, the connectivity H value of coal samples increases, and the heterogeneity Delta alpha value of meso-macropores decreases. Microorganisms enhance the uniformity and connectivity of meso-macropore spaces by digesting organic matter and enlarging pores, simplifying the pore structure. Relevant results are of guiding importance for elucidating the evolution of coal matrix microstructure during biotransformation and the mechanism of efficient coalbed methane extraction.

This study systematically elucidates the mechanism by which HCl-modified SiO2 nanofluid efficiently suppresses dust through synergistic optimization of coal surface properties and pore structure. A series of experiments were conducted, including wettability characterization, pore structure analysis, dust generation evaluation, and surface morphology observation. Findings reveal that at low concentration of 0.01 wt%, this HCl-modified SiO2 significantly enhances coal hydrophilicity. Compared to deionized water, surface tension decreases by 16.83 % and contact angle reduces by 37.34 %. The HCl-modified SiO2 nanofluid induces a more complex pore structure in coal, expanding the hydrophilic surface area. This reduces surface roughness to form a stable, uniform wetting film, ultimately enhancing both wetting and water retention capabilities of the coal. Drop weight tests demonstrate that treated coal samples produce the largest dust particle size and the least respirable dust, achieving remarkable dust suppression. This study also elucidates the molecular-level mechanism of nanofluid's enhance wetting and optimize pore structure of coal. The findings provide experimental evidence for the practical application of HCl-modified SiO2 nanofluid in coal mine dust control.

During coal transportation, prolonged air exposure accelerates moisture evaporation and secondary dust dispersion. Conventional suppressants often fail under these conditions due to inadequate moisture retention. To address this limitation, we developed a synergistic composite dust suppressant comprising non-ionic AEO9, ionic MgCl2, and glycerol. Optimized via response surface methodology, the ideal formulation (0.30% MgCl2, 0.20% AEO9, 0.10% glycerol) exhibited superior wettability. Mechanistically, AEO9 reduces surface tension to facilitate the rapid wetting of coal dust. Simultaneously, MgCl2 provides ions to form a stable hydrogen-bond network with glycerol, water, and coal active sites. This ternary synergistic interaction promotes efficient wetting while prolonging moisture retention. Microstructural analyses (FTIR/SEM) confirmed that relative hydrophilic groups increased to 96.66%, facilitating dispersed particle aggregation. Molecular dynamics and electrostatic potential analyses revealed that MgCl2 plays a crucial ion-mediated role, modulating hydrogen-bond interactions between the components, water, and coal active sites. The MA-Glycerol system also exhibited the highest water diffusion coefficient (DMA-Glycerol = 0.245), indicating that this coupled network enhances wetting kinetics and water retention properties. These findings elucidate the interfacial mechanisms underlying the suppression of secondary coal dust and provide a practical theoretical framework for the design of sustainable dust suppressants for industrial coal transport.

To reduce the combustion and explosion risks of accumulated coal dust after wetting, this study selects four typical types of surfactants: anionic, cationic, zwitterionic, and nonionic, to investigate their regulatory effects on coal dust explosion. Through 20 L spherical explosion tests, thermogravimetric analysis (TGA), and systematic surface physicochemical characterizations, the influences of surfactants on the thermal reactivity and explosion characteristics of coal dust are systematically analyzed. The results show that the charge type and polarity of the hydrophilic groups fundamentally determine the action pathways affecting combustion and explosion. Among them, the nonionic surfactant APG extends the explosion induction period to 153 ms via its polyhydroxyl structure, nearly a 7-fold increase compared with raw coal dust. The anionic surfactant SDS forms a stable chemical flame-retardant barrier by raising the apparent activation energy to 105.53 kJ/mol. In contrast, the cationic surfactant (DTAB) promotes the agglomeration of coal dust particles through electrostatic adsorption, reduces the specific surface area, and directly lowers the maximum explosion pressure physically.It is revealed that physical agglomeration-induced pressure reduction and chemical barrier-induced delay are the two core mechanisms of coal dust explosion suppression by surfactants. The microscopic interaction mechanisms revealed in this paper can provide an important theoretical basis for the targeted development of high-efficiency dust suppression and explosion-proof agents for coal mines.

To investigate the effects of cyclic loading on pore-fracture structure and seepage characteristics of coal, cyclic loading tests were carried out using a coal-rock multiphase and multi-field triaxial dynamic seepage experimental system. The evolution laws of pore-fracture structure and seepage characteristics of coal under different confining pressures and cyclic loading amplitudes were analyzed, and the relationship between permeability and effective stress was quantitatively discussed based on sensitivity coefficients. The results show that: under a cyclic loading amplitude of 40% of the peak strength (σs), the pore-fracture space of coal samples is compressed, the proportion of meso-macropores in the three coal samples decreases by 12.63%, 28.49%, and 42.91%, respectively, while the P-wave velocity increases; the compression degree is positively correlated with confining pressure. Permeability changes inversely with axial stress and decreases continuously with increasing cycle number, but the decreasing gradient gradually diminishes; with the increase of cyclic loading amplitude (60%σs, 70%σs), new pores and fractures are generated in coal samples, and the proportion of meso-macropores gradually recovers and rises, with coal sample Y3 showing the highest increase (26.53%), and the P-wave velocity decreases in all samples; the higher the cyclic loading amplitude, the more severe the coal damage, and the larger the P-wave velocity attenuation coefficient and ratio; however, high confining pressure has a certain inhibitory effect on damage, and the degree of P-wave velocity attenuation decreases with increasing confining pressure; in the 60%σs and 70%σs stages, permeability first decreases and then increases during loading, and first increases, then decreases, and then increases during unloading, showing an overall irreversible downward trend; the permeability stress sensitivity coefficient generally decreases during the loading stage, while it changes relatively gently during the unloading stage, and gradually decreases and tends to stabilize with increasing cycle number; the first cycle has the most significant effect, the sensitivity coefficient during loading is generally higher than that during unloading, with the increase of peak load, the difference in sensitivity coefficients between the two stages becomes smaller.

In this study, based on the ammonium polyphosphate composite material (APP-Co-ZIF) developed in the previous research, the dry water material was further modified, and three kinds of explosion suppressant samples, namely, agent DW, ADW, and ZDW were prepared respectively in order to study their effects on the explosion suppression characteristics of coal dust. It was found that ZDW has good physical properties. 20 L explosion experiment showed that the addition of 5 % of the mass fraction of ZDW, the explosion was completely suppressed. Thermogravimetric analysis showed that the mass loss was reduced to 91.37 % after the addition of ZDW, and the shortening of Ti-Tmax was the most obvious. Comprehensive pyrolysis kinetic analysis and explosion products of X-ray photoelectron spectroscopy (XPS), infrared spectroscopy, revealing the synergistic explosion suppression mechanism of dry water materials and explosion suppressants. The study proved that the physical properties of the dry water material and the synergistic effect of the explosion suppression significantly improved the explosion suppression performance, in which the ZDW showed excellent explosion suppression performance due to its thermal stability and synergistic effect between the components. This study provides new ideas and technical paths for the development of efficient and safe explosion suppression materials.