Molecular Simulation Of Rock Dust Wettability Enhanced By Compound Surfactant

In view of the high dust concentration in the process of coal mining and the poor application effect of dust removal technology caused by the current dust removal agent’s weak targeting on dust types,theoretical analysis,laboratory experiment and molecular dynamics simulation are adopted to carry out research on the influence of the compound surfactant on the wettability of rock dust,so as to lay a theoretical foundation for the surfactant in mine dust control.It is of great significance to provide technical support for improving the effect of mine dust control.The main research achievements are as follows:Through the experimental study of wetting rock dust with a single surfactant,it is concluded that increasing the concentration of a single surfactant can effectively improve the wettability of the solution to rock dust,but when the concentration is too high,the improvement of the wettability of the solution to rock dust tends to be stable,and the critical micellar concentration of most surfactants is 0.06%.By analyzing the wetting experiment results,the wetting performance of eight surfactants on rock dust was ranked in order from best to worst:SDBS>SDS>AEO-7>DTAB>APG1214>BS-12>OA-12>CTAB.Anionic surfactant has the best wetting effect on rock dust.Through the molecular simulation of wetting rock dust with a single surfactant,it is concluded that the wetting process is dominated by electrostatic energy,and the looser the arrangement of hydrophilic head group on the interface,the more water molecules can be adsorbed around the polar head group,that is,the stronger the wettability.SDS,DTAB and AEO-7 solutions all show high wettability in kaolinite system,and only SDBS solution is more advantageous to improve the wettability of Muscovite system,and it is found that a single surfactant acting on the surface of kaolinite will produce a stronger wetting effect than quartz and Muscovite.Through the experimental study of the wetting of rock dust with complex surfactant,it is concluded that the addition of anionic surfactant can obviously improve the wetting ability of the complex solution,but the wetting ability of rock dust is weakened when there is cationic surfactant in the complex solution.The experimental results show that the anion/non-ionic surfactant solution has obvious additive and synergistic effects on the wetting effect of rock dust compared with other complex solutions,among which the 0.02%+0.04% AEO-7/SDS complex solution has the best wetting effect on rock dust.Through the molecular simulation study of the wetting of rock dust with complex surfactant,it is concluded that the complex surfactant can effectively reduce the critical micellar concentration of the solution and further improve the wetting ability of the solution.Through the analysis of the simulation parameters,it was found that when anionic surfactants existed in the system,the wetting ability of the solution was positively correlated with the number of molecules of anionic surfactants,and most of the complex systems had more advantages in the surface wettability of kaolinite and quartz,while it was difficult to improve the wetting effect of Muscovite system.