Wettability Of Dust Research Articles

High-Efficient Dust Trapping Performance of AES/Polyacrylamide Strengthen Foam Based on the Structure Stability and Dust Wettability.

The atmospheric dust has a great negative impact on the societal harmonious development that starves for an efficient dust suppressant. This paper proposes a novel AES/polyacrylamide strengthen foam (APSF) to improve the dust trapping effectiveness. The APSF structure property and dust suppression capacity are studied and evaluated through the molecular dynamics simulation and experimental tests. The results express that APSF exhibits the stronger structure stability, superior water retention, and slower drainage performance than the traditional water-based foam (WBF). APSF dynamic simulation is studied by the relative concentration, radial distribution function, head group orientation, and mean square displacement. Research shows that APSF introduces water to thicken the hydration layer. The interaction strength between water and surfactant head groups is enhanced by 22.62 and 31.37% in the first and second hydrated water shells. APSF improves the sodium fatty alcohol ether sulfate (AES) orientation and weakens the diffusion of water molecules, which favors the foam stability. APSF exerts a better wettability on the coal dust through the wet settlement and contact angle tests. The APSF liquid film thickness reduces to 58.05 from 64.80 μm that is 3.14 times of WBF according to the foam liquid film decay experiment. Fourier transform infrared (FTIR) spectroscopy analysis indicates that there is an evident reinforcement on the coal surface absorption peak intensity of hydroxyl- and oxygen-containing functional groups treated by APSF. FTIR results are further determined by energy-dispersion spectrum analysis.

Influence of particle diameter on the wettability of coal dust and the dust suppression efficiency via spraying

Spraying is a main technique means for the prevention and control of coal dust in coal mines. The dust suppression efficiency by spraying is highly correlated with the wettability of coal dust. There are many influencing factors for the wettability of coal dust, among which the particle diameter of dust is one of the most significant factors. In order to analyze the influence of particle diameter on the wettability of coal dusts and the dust suppression efficiency via spraying, 18 different samples with 3 different types of coal samples and 6 different particle diameters were selected in this study. A series of experiments were designed and performed to evaluate the micro-properties, the wettability, and the dust suppression performance via spraying of coal dust. According to experimental results on the micro-properties, the amount of hydrophilic oxygen-containing functional groups gradually dropped with the decrease of the particle diameter. As the particle diameter decreased, the specific surface area of coal dust gradually increased while the average diameter of the internal pores decreased. Based on the experimental results on the wettability of coal dust, the wettability of the dust with the same property dropped with the decrease of particle diameter. Finally, based on the experimental results on the dust suppression efficiency via spraying, the dust suppression efficiency via spraying was determined by both the wettability of coal dusts and the value of △D50 (the absolute value of the difference between the droplet diameter and the dust particle diameter). As the particle diameter of coal dust increased, the dust suppression efficiency via spraying first increased and then decreased.

Surface physical properties and its effects on the wetting behaviors of respirable coal mine dust

In the present research work, coal dust physical properties as well as its wetting behaviors were analyzed systemically. The influences of different surfactants on coal dust's wetting behaviors were also investigated and compared with deionized water . Research results show that the finer the coal particle sizes, the more complex the coal particle micro structures are, which may cause the poor wetting abilities. Among the three different coal dust samples, the wetting performance is poor for the coal with higher volatile content due to the easier release of volatile matter and the easier formation of gas film around the particle. The fractal dimension and contact angles are presenting perfect correlations. With the increase of the fractal dimension, the contact angle would increase correspondingly, which indicates a poor wetting performance. The wetting behaviors of coal dust could be greatly improved by adding surfactant in the deionized water. However, the species of surfactant and its contents in the solvent are the two important factors for dust wetting abilities enhancement. For the two selected surfactants, sodium dodecyl sulfate (SDS) may be a better choice and 0.2% concentrations are recommended during coal dust suppression applications. Based on the experimental results, a wetting dynamic model was built to simulate coal dust wetting process. The calculated values agreed well with the experimental results. In the present paper, coal dust physical properties and its wetting behaviors were analyzed. The influences of different surfactants on coal dust’s wetting behaviors were investigated and compared with deionized water. The fractal dimension and contact angles were correlated with each other. Based on the experimental results, a wetting dynamic model was built to simulate coal dusts’ wetting process. ► Particle size and its micro structure have great effects on dust's wettability. ► Volatile content of coal is another important factor on its wetting behavior. ► The fractal dimension and contact angles are presenting perfect correlations. ► Using surfactants reasonably is important for dust wettability enhancement.