Dust Particle Size Research Articles

Experimental study of the effect of coal dust on the flame dynamics of partially premixed gas-coal dust explosion in a vertical pressure relief pipe-line

To further study the gas-coal dust explosion hazards under complex conditions. Experiments were conducted in pipe-line systems containing explosive pipe-line and pressure relief pipe-line. The effect of coal dust concentration and particle size on the flame dynamics of gas-coal dust explosion was investigated. The flame structure in the explosion pipe-line is divided into two-stages: spherical and round-finger. In the pressure relief pipe-line, the flame structure e varies at working conditions. Flame front position increases with time, showing a class exponential growth trend. The flame front velocity increases in the explosion pipe-line, has a short drop during the entry into the pressure relief pipe-line, and then increases. With the increase of coal dust concentration, flame propagation time has been increasing in the pipe-line system and the explosion pipe-line, with the shortest time at 25 g/m?. Flame propagation time first increases and then decreases in the pressure relief pipe-line, the shortest time at 50 g/m?. The maximum flame front velocity first increases and then decreases. The maximum flame front velocity is maximized at 50 g/m?. With the increase of coal dust particle size, flame propagation time has been increasing in the pipe-line system, and in the explosion pipe-line, flame propagation times have been decreasing in the pressure relief pipe-line. The maximum flame front velocity first increases, then decrease, and increases again. The maximum flame front velocity is minimal at 45 ?m.

Study on the Effects of Dust Particle Size and Respiratory Intensity on the Pattern of Respiratory Particle Deposition in Humans

Nowadays, dust exposure pollution is receiving a lot of attention due to its significant impact on public health. To investigate the impact of dust particle size and human respiratory strength on respiratory particle deposition patterns, data was collected through on‐site surveys. The study analyzed the equivalent respiratory strength, dust environment characteristics, and bronchial particle escape and deposition patterns of humans in fully mechanized mining faces at various operating times. This was done using ergonomic energy consumption simulation experiments and a fluid–solid interaction method of CFD‐DEM. The findings revealed that as humans worked continuously for 5, 15, 30, 45, and 60 min, their respiratory intensity corresponded to 8, 18, 30, 42, and 50 L/min, respectively. According to the field investigation and particle size analysis, the particle size distribution of 1~5, 5~10, 10~20, 20~30, and 30~40 μm particles accounted for 36%, 26%, 15%, 11%, and 10%, respectively. In general, the deposition rate of dust was highest in the main bronchus of the respiratory tract, followed by the trachea area. Particles ranging from 5 to 10 μm in size were observed to have a higher likelihood of escaping from the tertiary bronchioles and entering the secondary bronchial regions. Conversely, particles larger than 20 μm exhibited a deposition rate of up to 80% in the tertiary bronchial regions. It was noted that the bronchial deposition rate of particles of varying sizes increased with respiratory strength, with smaller particles showing greater sensitivity to changes in respiratory strength in terms of the deposition fraction. Among the different particle sizes, the deposition rate of 5–10 μm particles exhibited the most variation with increasing respiration intensity, ranging up to 17%.

Numerical simulation of the fine kinetics of dust reduction using high-speed aerosols.

A numerical model of single-particle fog-dust collision coupling in a high-speed airflow based on three-phase flow theory. The effect of the fog-to-dust particle size ratio, relative velocity between the fog and dust particles, collision angle and contact angle at the wetting humidity function of dust particles is investigated. Different particle size ratios are determined for achieving the optimal wetting humidity for the interaction of high-velocity aerosols with dust particles of different sizes, for differ, that is, kPM2.5 = 2:1, kPM10 = 3.5:1 and kPM20 = 1.5:1. The optimal humidity increases with the relative velocity U between the fog and dust particles in the high-speed airflow. The larger the collision angle is, the lower the wetting rate is.The smaller the contact angle between the solid and liquid is, the better droplet wetting on dust is. The fine kinetic mechanism of single-particle fog-dust collision-coupling in a high-speed airflow is elucidated in this study.

Heavy Metals Pollution in Various Grain Sizes Under Different Land-Use Types in Urban Surface Dust in Shenyang City, China

ABSTRACT In this study, surface dust samples were collected within the second ring road of Shenyang City under different land-use types, and the concentration and chemical speciation of metals in different particle sizes under different land-use types were analyzed. Dust samples were separated into four particle size fractions (＜50, 50–100, 100–500, 500–2000 μm), and particles in the range of 100–500 µm were the highest representing one-third of the dust mass. The results revealed that metals were detected in order Zn > Cr > Pb > Cu > Ni > As > Cd in different particle sizes of dust under different land-use types. The relative contribution of individual particle-size fractions for seven metals was different, but the results showed preferential partitioning to small particle-size fractions. The relative contribution of metals in individual particle-size fractions and chemical speciation were significantly affected by the type of land use. Metals concentrated on the smaller particles in the traffic area, and the particles (<50 µm) contained the highest percentage of metals but Cr. The residual fractions (F5) of Ni, Cr, As and Cu overall represented the predominant portion in different particle size of fractions under different land-use types, Zn and Pb were mostly bound to the Fe–Mn oxides-bound fraction (F3), and the exchangeable fraction (F1) accounted for a relatively large proportion of Cd. The results of the risk assessment code (RAC) of Cd indicated that the risk of Zn was medium, and it was high for Cd in the dust of Shenyang City.

Characteristics of heavy metals in road dust: An overview of South Korean cases

The urbanization and industrialization of our society necessitate the extension of road traffic systems. Road dust generated by road traffic is harmful to the human respiratory system. In particular, heavy metals adsorbed on road dust can pose substantial risks to human health owing to their toxicity, environmental longevity, and ability to accumulate in the human body. Although the evaluation of the concentration of heavy metals in road dust is essential for understanding their sources and risks to human health, there is a lack of comprehensive information on the heavy metal content in road dust in South Korea. In this review, sampling methods and analytical techniques for characterizing the contents of various heavy metals in road dust collected from different regions of South Korea are discussed. Cu, Zn, Cd, Pb, Ni, Cr, As, and Hg are the most frequently found heavy metals in road dust, and their concentrations are strongly associated with the sampling locations (e.g., industrial vs. residential sites and rural vs. urban areas) and particle size of the road dust. Road dust samples collected from more industrialized regions tend to contain more heavy metals. Further, smaller dust particles are likely apt to contain more heavy metals. The application of non-destructive analytical techniques is also necessary for the accurate characterization of heavy metals in road dust.

Experimental and numerical study on airflow-dust migration behavior in an underground cavern group construction for cleaner production

A large amount of dust will be generated during the construction of underground cavern group. The understanding of the dust migration in the construction ventilation of the underground cavern group can help to optimize the cavern group’s ventilation design and improve the ventilation scheme of the cavern group’s rationality. In this paper, the effects of dust particle size, dust migration path, initial dust concentration in cavern, tunnel entrance wind speed and air duct outlet wind speed on dust migration were studied by combining a model test and numerical calculation. The results show that in the process of dust ventilation migration, the larger the diameter of the dust particles, the more difficult it is to discharge. The time of dust concentration reducing to 2 mg/m3 has a logarithmic distribution with ventilation conditions. The high-speed airflow from the outlet of the air duct is an important factor affecting the migration of dust. The development of airflow is divided into vortex region, recirculation region, collision region and stability region. Vortex region and collision region have lower wind speed and higher dust concentration, which are the unfavorable positions in the ventilation process. In the actual construction process, shortening the distance of dust migration can make the dust discharge quickly. The amount of dust generated by construction has a significant impact on the peak concentration of dust migration. During the ventilation process, the wind speed at the entrance of the tunnel and at the outlet of the air duct has a significant impact on the migration time of dust, at the same time, the ventilation efficiency should be considered while selecting the wind speed.

Total contents, fractionation and bioaccessibility of nine heavy metals in household dust from 14 cities in China

The potential health risk caused by long-term exposure to heavy metals in household dust is not only depended on their total content, but also bioaccessibility. In this study, twenty-one dust samples were collected from residential buildings, schools, and laboratories in 14 provincial-capital/industrial cities of China, aiming to evaluate the total contents, fractionation, bioaccessibility and health risks of nine heavy metals (As, Cd, Cr, Ni, Pb, Mn, Zn, Fe, and Cu). Results showed that the highest levels of Cd, Cr, Ni and Zn were found in laboratory dust, As, Pb and Mn in school dust, and Fe and Cu in residential dust, indicating different source profiles of the heavy metals. The mean bioaccessibility of the heavy metals across all samples as evaluated using SBRC (Solubility Bioavailability Research Consortium), IVG (In Vitro Gastrointestinal), and PBET (Physiologically Based Extraction Test) assays was 58.4%, 32.4% and 17.2% in gastric phase (GP), and 24.9%, 21.9% and 9.39% in intestinal phase (IP), respectively. Cadmium had the highest content in the fractions of E1+C2 (43.7%), as determined by sequential extraction, and Pb, Mn, and Zn had a higher content in E1+C2+F3 (64.2%, 67.2%, 78.8%), resulting in a higher bioaccessibility of these heavy metals than others. Moreover, the bioaccessibility of most heavy metals was inversely related to dust pH (R = −0.18 in GP; −0.18 in IP; P < 0.01) and particle size, while a positive correlation was observed with total organic carbon (R = 0.40 in GP; 0.38 in IP; P < 0.01). The exposure risk calculated by the highest bioaccessibility was generally lower than that calculated by the total content. However, Pb in one school dust sample had an unacceptable carcinogenic risk (adult risk = 1.19 × 10−4; child risk = 1.08 × 10−4). This study suggests that bioaccessibility of heavy metals in household dust is likely related to geochemical fractions and physical/chemical properties. Further research is needed to explore the sources of bioaccessible heavy metals in household dust.

Predictive atmospheric dispersion and deposition characteristics of activated tungsten dust

Tungsten is considered to be the most promising material for plasma-facing components of fusion reactors in addition to other industrial and military uses. Activated tungsten dust produced by plasma-wall interaction and released under accidental conditions would be the emerging environmental pollutant with both chemical and radiation toxicity. For the first time, atmospheric dispersion and deposition characteristics were investigated for tungsten dust with various particle size spectrum similar as generated in fusion reactors. Euler-Lagrange approach was adopted to describe parcels motion and deposition behaviors. Proper numbers of parcels were determined for the atmospheric dispersion and various parcel diameters scale. Near-surface concentration distribution and dry deposition velocity were predicted for tungsten dust with both single size dust and realistic particle size spectrum dust. Influences of chemical forms and release factors on atmospheric dispersion and deposition of tungsten dust were preliminary identified at last. It is indicated that 150 million parcels are needed for 10 μm dust under 5 km scale. Dry deposition velocity of tungsten dust is up to 11.3 cm s−1 and increase along with particle diameter because of its high density and gravitational deposition effect. The critical diameter judging whether gravitational deposition could appear for tungsten dust is 1 µm. Deposited particle size spectrum would be completely different along the downwind distance which would result in differences in subsequent behaviors in other environmental compartments.

Influence of Air Volume and Temperature in the Air Inlet Tunnel on the Characteristics of Dust Movement.

In order to clarify the movement characteristics of dust particles in the intake tunnel and improve the underground intake tunnel environment, the main intake tunnel of Wulihou Coal Mine was taken as the engineering background, the COMSOL simulation software was adopted to establish a model, the influence of air volume and temperature on dust movement characteristics was studied, and the critical air volume and particle size of dust at room temperature were determined. The results show that with the ventilation air volume being the same, when the dust reaches the exit of the tunnel, its falling height is positively correlated with the particle size. When the dust particle size is the same, the height of the dust falling is negatively correlated with the ventilation air volume. As the particle size of dust increases, the impact of changes in air volume on its movement decreases and the trajectory of dust movement gradually becomes consistent. The height of dust falling is negatively correlated with the air flow temperature. Therefore, when other factors remain unchanged, dust pollution in the tunnel is relatively severe during the day and the dust concentration in the tunnel is higher in summer. The critical air volume for dust emission in the intake tunnel of Wulihou Coal Mine is 75.84 m3/s, corresponding to a central wind speed of 5.29 m/s in the tunnel. The critical particle size for dust emission is 1.4 μm.

Experimental study of friction performance degradation in sliding layer of CRTS II slab track considering dust incursion

The track-bridge interaction force in the China Railway Track System II slab track can be significantly reduced due to the effect of the sliding layer, thus its friction performance is crucial for the operational safety of the track. However, because of the micro delamination between the base plate and bridge deck under certain conditions, the dust inevitably infiltrates the sliding layer. This study performed abrasion experiments to investigate the influence of dust incursion on the friction performance of the sliding layer. The experimental apparatus was designed to simulate repeated sliding and normal pressure between the base plate and the bridge under actual working conditions. Different sizes of dust particles were employed, and the friction performance, characterized by the friction coefficient and surface topography of the geomembrane, was obtained and analyzed. The experimental results show that the growth rate of the friction coefficient was 1.46–2.88 times greater than that without dust incursion. The results of this study can serve as a reference for the actual friction performance degradation of the sliding layer and shed light on maintenance decision-making.

The head-on collision between droplet and stationary particle under mesoscopic scale: Effect of sample size, velocity, viscosity, and wettability

Understanding the collision dynamics between a water mist droplet and a dust particle is crucial for uncovering the mechanisms of water mist dust suppression. However, studies involving mesoscopic-scaled samples have been rarely explored in the past. To address this gap, we performed numerical simulations and experiments to investigate collisions using realistic sizes of water mist and dust particles. Based on our findings, we proposed collision outcome regime maps to illustrate the different collision outcomes. These outcomes were categorized into four distinct regimes: rebounding, complete coalescence, ligament ripping, and skirt splashing. We have proposed both physical equations and fitting equations to describe the thresholds for rebounding, ripping, and splashing. Wettability was found to have a significant impact on the regime boundary equations, while the effects of sample size, collision velocity, and viscosity were minimal. Within the skirt splashing regime, we have proposed a power function to predict the residual liquid fraction of a collision based solely on the Reynolds number, and we have introduced a function combining the Weber number and the Ohnesorge number to predict the non-dimensional momentum transfer. By integrating the equations governing regime boundary, residual liquid fraction, and dimensionless momentum transfer, we can elucidate the dust suppression mechanism of water mist and offer optimized parameters for its effective use in mitigating dust. Interestingly, the study suggests that increasing droplet viscosity holds promise for enhancing dust suppression, rather than solely focusing on improving wettability. This introduces a new perspective to the development of additives for dust suppression.

Effect on ignition sensitivity of combustible dust particle size reduction due to dispersion in the 20-L chamber

This work simulates the particle breakage process caused by the dispersion of several typical combustible dusts in a 20-L chamber. Some operations in the process industry that involve gas turbulence and particle interactions can cause dust particles to break, resulting in a decrease in minimum ignition energy (MIE) and minimum ignition temperature (MIT). Particle breakage classification should attempt to correlate changes in D3,2 (Sauter mean diameter) values with the brittleness index. The descending order of particle breakage severity is as follows: ascorbic acid > anthraquinone > tobacco > nicotinic acid > lignite. The percentage decrease in MIE and MIT values is generally proportional to the degree of particle breakage. However, the decrease in MIT values was not as significant as in MIE values. This is because of the various dust-ignition source interaction patterns between a dust cloud and an ignition source.

Fine and Coarse Dust Effects on Radiative Forcing, Mass Deposition, and Solar Devices Over the Middle East

AbstractIn desert regions like the Middle East, dust has a profound impact on the environment, climate, air quality, and solar devices. The size of dust particles determines the extent of these effects. Dust deposition (DD) measurements show that coarse dust particles with geometric radius r &gt; 10 μm comprise most of the deposited mass. Still, these particles are not represented in the current models that are tuned to fit the observed aerosol optical depth (AOD). As a result, the existing models and reanalysis products underestimate DD and dust emission (DE) almost 3 times. This is the first study to constrain the dust simulations by both AOD and DD measurements to quantify the effect of coarse and fine dust using the WRF‐Chem model. We found that, on average, coarse dust contributes less than 10% to dust shortwave radiative forcing (RF) at the surface but comprises more than 70% of DE. Annual mean net RF over the Arabian Peninsula and regional seas locally reaches −25 W m−2. Airborne fine dust particles with radii r &lt; 3 μm are mainly responsible for the significant dimming (5%–10%) of solar radiation, cooling the surface, and hampering solar energy production. However, dust mass deposition is primarily linked to coarse particles, decreasing the efficiency of photovoltaic panels by 2%–5% per day. Therefore, incorporating coarse dust in model simulations and data assimilation would improve the overall description of the dust mass balance and its impact on environmental systems and solar devices.

Separating micrometer-sized particles utilizing a dusty plasma ratchet

Directional transport-dominated particle separation presents major challenges in many technological applications. The Feynman ratchet can convert the random perturbation into directional transport of particles, offering innovative separation schemes. Here, we propose the design of a dusty plasma ratchet system to accomplish the separation of micrometer-sized particles. The dust particles are charged and suspended at specific heights within the saw channel, depending on their sizes. Bi-dispersed dust particles can flow along the saw channel in opposite directions, resulting in a perfect purity of particle separation. We discuss the underlying mechanism of particle separation, wherein dust particles of different sizes are suspended at distinctive heights and experience electric ratchet potentials with opposite orientations, leading to their contrary flows. Our results demonstrate a feasible and highly efficient method for separating micrometer-sized particles.

Bioaccessibility and Distribution of Heavy Metals in Particles from a Dust Storm in Iraq

The issue of dust storms in Iraq is one of the issues that has caused Iraq to suffer economic and health losses and requires immediate attention. Nine of Iraq’s most important cities provided the collected samples. Atomic spectrometry was used to analyze dust samples for heavy metals such as lead, zinc, cadmium, nickel, copper, and chromium. The analysis was based on the particle size of the dust samples. The SBET was utilized for the goal of determining the scope of the threat posed by all of these elements of the dust storm and the impact they have on the health of humans. The results showed that Basra had the highest value of relative bioaccessibility of zinc (73.87%) in dust particle size (200 μm), whereas Samawah had the lowest value for cadmium (0.90%). Both values were based on the dust particle size. The relative bioaccessibility of cadmium was found to be at its highest in Najaf (85.80%) in dust particle 63 μm, whereas the relative bioaccessibility of lead was found to be at its lowest in Diwaniyah (0.28%). In addition, the findings demonstrated that the relative bioaccessibility of zinc was maximum in Amarah at a particle size of 75 μm (89.56%). The value distributions were sorted where there was high contamination of heavy metals during a dust storm from dark blue to yellow. With Kirkuk city having the highest concentration of Cr in size particle 75, the spatial distribution of Cu was notably distinct from other areas in Baghdad and Basra, where it was highest in particle sizes 63 and 200 μm. This study is important in order to determine the amount of human health damage and to control dust storms in Iraq.

Numerical simulation of dual-layer granular bed filtration based on particle collision rebound effect

This article established a dual-layer granular bed filtration model based on the dust collision rebound effect and investigated the influence of dust properties and filtration air velocity on the collision rebound effect and grade efficiencies of the filter layers. The results indicated that the characteristics of dust particle size, density, and effective Young's modulus had a significant impact on the critical adhesion velocity and collision rebound effect. Large dust particle size, density, and small effective Young's modulus resulted in a larger collision rebound effect. The collision rebound effect led to a decrease in grade efficiencies of each filter layer and the dual-layer granular bed with an increase in filtration velocity. To reveal the impact of the collision rebound effect on the movement of dust in the filter material layer, the trajectory and velocity changes of dust in the granule layer were simulated and calculated. The results show that the collision rebound effect caused the dust to repeatedly collide and rebound within the granular bed, penetrating deeper into the granular bed and increasing dust escape.

Research on Dust Migration and Dust Deposition Rules of Breathing Zone in Fully Mechanized Mining Face.

The dust in the breathing zone of the fully mechanized mining face poses a serious threat to the lives and health of the workers, and clarifying the distribution and settlement pattern of the dust in the breathing zone is an important foundation for reducing dust concentrations in the breathing zone and improving the workers' working environment. The dust concentration distribution at the mining face and the settlement results of different dust particle sizes along the breathing zone were analyzed in detail using a combination of computational fluid dynamics simulation and downhole measurements by establishing a highly simulated 3D solid model of the 2302 fully mechanized mining face at the Xinqiao coal mine. The study's findings reveal that dust from advanced support and coal-cutting processes converge within 20-60 m of the coal mining region, generating a high-concentration pollution zone at the height of the sidewalk breathing zone. The particle size of dust in the breathing zone is primarily concentrated between 1 and 40 μm, and the fully mechanized mining face is split into a rapid settling area, a medium settling area, and a slow settling area based on particle size settling speed. Eddy currents in the return airway lead to an increase in dust particles of 20-40 μm in the breathing zone area. The results of the study can provide a theoretical basis for dust management at the fully mechanized mining face for the breathing zone area.

Influence mechanism of dispersion and agglomeration characteristics of micron/nano carbon dust on its combustion kinetics and explosion process

Due to the widespread use of lithium-ion batteries, evaluations of the flammability and explosive characteristics of carbon dust materials as anodes require attention. Carbon dust often reaches the micron/nano scale, and dust particle state and explosion risk generated in different industrial scenarios are different, which is in urgent need of research. Nanoscale dust has relatively static coagulation properties and shows characteristics of dispersion and reagglomeration under a certain airflow. The particle size characteristics affect its thermodynamic characteristics and various consequence parameters of dust explosion. The oxidation and combustion characteristics are mainly affected by dust particle size distribution characteristics. The apparent activation energy is mainly affected by the proportion of small and medium-sized particles and pre-exponential index factor is mainly affected by the dust overall average particle size and specific surface area. The explosion consequence parameters are affected by the thermodynamic parameters, by the disturbance state, particle distribution degree of dust cloud and other factors, which affect the heat radiation and heat transfer process to some extent resulting in different explosion consequence parameters. Due to the agglomeration characteristics of nano-level dust, the minimum ignition energy and minimum ignition temperature of nano-level dust are generally smaller than that of micron level dust.

Cometary dust collected by MIDAS on board Rosetta

Context. The MIDAS (Micro-Imaging Dust Analysis System) atomic force microscope on board the Rosetta comet orbiter investigated and measured the 3D topography of a few hundred of nm to tens of μm sized dust particles of 67P/Churyumov-Gerasimenko with resolutions down to a few nanometers, giving insights into the physical processes of our early Solar System. Aims. We analyze the shapes of the cometary dust particles collected by MIDAS on the basis of a recently updated particle catalog with the aim to determine which structural properties remained pristine. Methods. We develop a set of shape descriptors and metrics such as aspect ratio, elongation, circularity, convexity, and particle surface and volume distribution, which can be used to describe the distribution of particle shapes. Furthermore, we compare the structure of the MIDAS dust particles and the clusters in which the particles were deposited to those found in previous laboratory experiments and by Rosetta/COSIMA. Finally, we combine our findings to calculate a pristineness score for MIDAS particles and determine the most pristine particles and their properties. Results. We find that the morphological properties of all cometary dust particles at the micrometer scale are surprisingly homogeneous despite originating from diverse cometary environments (e.g., different collection targets that are associated with cometary activities/source regions and collection velocities/periods). There is only a weak trend between shape descriptors and particle characteristics such as size, collection targets, and cluster morphology. We next find that the types of clusters found by MIDAS show good agreement with those defined by previous laboratory experiments, however, there are some differences to those found by Rosetta/COSIMA. Furthermore, our pristineness score shows that almost half of MIDAS particles suffered severe alteration by impact, which indicates structural modification by impact (e.g., flattening and/or fragmentation) is inevitable despite the very low collection speeds (i.e., ~3–7 m s−1). Based on our result, we rate 19 out of 1082 MIDAS particles at least moderately pristine that is they are not substantially flattened by impact, not fragmented, and/or not part of a fragmentation cluster.

Interactions between fluorocarbon surfactant and coal dust at macro, meso and molecular scales and their applications in coal dust control

Surfactants play an important role in the field of coal dust prevention, among which fluorocarbon surfactants have the advantages of low surface tension and have the potential to become mine dust suppressants. In this study, the wettability of fluorocarbon surfactant (OBS) on coal dust was studied from macro experiments, meso dust mist coupling and micro molecular simulation. The results showed that the surface tension of 0.06% OBS was as low as 17.6 mN/m, and the median particle size of coal dust reached 60.25 μm after wetting coal dust. Coal dust particles are easier to bond with each other into large particles, thus promoting settlement; During the meso collision between droplets and coal dust particles, OBS droplets showed excellent wetting and spreading effect, and the droplet state was stable, and the optimal spraying velocity was determined to be 20–30 m/s; At the molecular level, the diffusion coefficient of water molecules in the OBS system is minimally 0.46 Å2/ps, indicating a strong ability to constrain water molecules. The strength and energy of the hydrogen bonds formed with water molecules were greater than those of hydrocarbon surfactants, resulting in the best adsorption of water molecules. Additionally, it was found that the law of attractive and competitive adsorption of different surfactants in wetting coal dust is based on the difference in positive and negative electrostatic potential, where the greater the difference, the stronger the interaction. This provides a theoretical reference for judging the wetting performance of different surfactants at the molecular level.