Application and characterization of new polymer dust suppression foam in coal mine and tunnel construction space

Abstract

Severe dust pollution is common in tunnel, coal mine, and other construction sites. Dust suppression foam is a feasible method for dust suppression, but its single function makes it difficult to adapt to complex construction sites. Driving by reconstructing the molecular structure of ecological raw materials and strengthening the network function, a new method of SPI based gel foam dust suppression was proposed in this study. This method was realized through improving the performance of soy protein isolate (SPI) gel by glycosylation and further enhancing the fluidity and foaming performance of SPI by enzymatic hydrolysis. Afterwards, its reaction mechanism and dust suppression mechanism were analyzed. It was found that after the glycosylation of 0.4% SPI with 0.2% xanthan gum (XG) and the subsequent addition of 0.15% transglutaminase (TGase), a relatively stable double reinforcement network structure was generated. This structure was confirmed by Fourier transform infrared spectroscopy and other experiments; to be specific, its viscosity was reduced to 28.3mPa·s, and the foaming multiple was improved by 16.8% than SPI. The particle size of foam was observed to reduce to 20-60μm through a three-dimensional microscope, which is more conducive to wetting and capturing coal dust. Then, the prepared solution was compounded with 1.0% dodecyl dimethyl Amine oxide (OA-12) to develop a dust suppression gel foam and it was sprayed on the coal dust. Through experiments on the mine airflow-dust environment simulation platform, the dust suppression gel foam reached a PM10 suppression efficiency of 98.42%, and remained a total dust suppression efficiency of above 98% after 75 days. Moreover, the validity of the molecular model was confirmed by X-ray photoelectron spectroscopy. The molecular dynamics simulation showed that coal molecules with negative potential attract positively charged OA-12 molecules, and the tail group of OA-12 contacts the hydrophobic sites of the coal at an inclined angle, allowing water molecules to fully contact the coal molecules and improving the wettability; while gel molecules are adsorbed on the surface of coal molecules to play the role of bonding and filling. This research provides a theoretical support for the application of SPI based gel in the field of dust suppression, and develops an environmentally friendly and efficient feasible scheme for dust control in the construction site.