Search

This study aims to develop eco-friendly composite dust suppressants to mitigate the adverse impact of coal mine dust on worker health and the environment. An environmentally friendly dust suppressant with bonding and wetting effects was prepared by combining modified pectin as a binder and a non-toxic surfactant as a wetting agent. Optimal ratios of sodium carboxylate ethoxylate sulfate (LMES), isomeric alcohol ethoxylate (XL-70), and modified pectin were determined through experiments. The modified pectin exhibited stronger wetting properties on coal powder due to its increased hydrophilicity. Wetting performance tests confirmed its excellent performance. Film-forming and scanning electron microscope tests demonstrated the dust suppressant's ability to bond with coal dust, resulting in a smooth surface and closely connected particles. Environmental tests showed its non-toxicity and degradability. Spraying dust reduction tests revealed a significant average increase of 40.51 % in dust reduction rate compared to water spraying, effectively lowering dust concentration. These findings have practical implications for the development of eco-friendly composite dust suppressants and controlling underground dust in coal mines, benefiting worker health and environmental sustainability. • A dust suppressant was developed using modified pectin and a non-toxic, non-corrosive surfactant, demonstrating its environmentally friendly nature. • The dust suppressant exhibited outstanding wetting capabilities, effectively penetrating and covering coal dust particles. • The dust suppressant effectively bonded with coal dust, resulting in a smooth surface and tightly connected particles. • The dust suppressant proved to be non-toxic to plants and readily degradable, with minimal impact on the environment. • The dust suppressant outperformed water spraying in dust reduction tests, significantly reducing coal dust concentration in underground coal mines. [ABSTRACT FROM AUTHOR]

Injecting surfactants into coal seams is an effective means to improve coal wettability. Previous studies have shown that nanofluids provided excellent drag reduction and wetting. Therefore, this manuscript investigates the synergies of AOS (Sodium alpha-olefin sulfonate)-modified SiO 2 nanofluid on the wettability of coal. Contact angle experiments were performed to examine the effects of deionized water on the wettability of coal treated with different solutions. The results demonstrated that 0.01 wt% nanofluid containing with 0.2 wt% AOS as the significantly increased the wettability. At the micro level, molecular dynamics simulations were employed to analyze the relative concentration distribution and MSD (mean square displacement) of water molecules in different systems. The simulation outcomes revealed that water molecules formed the thickest adsorption layer, and the diffusion range was more expansive, in the H 2 O/AOS-modified SiO 2 /Coal system. This was attributed to the amphiphilic structure of AOS-modified SiO 2 , which bent and folded on the coal surface, where hydrophobic sites were masked and hydrophilic sites were increased. Therefore, water molecules were attracted to the coal, the potential for collision was increased, and the wettability of the coal was enhanced. These findings provide a crucial foundation for modifying nanoparticles with surfactants and using them in coal seam water injection. • Experimental and simulation research methods were used to explain wetting effects. • Constructed the H 2 O/AOS-modified SiO 2 /Coal simulation system. • The effect of AOS-modified SiO 2 on the wettability of coal was studied. • Provide ideas for the application of nanofluids in coal seam water injection. [ABSTRACT FROM AUTHOR]