Study On The Wetting And Dust Reduction Mechanism Of Different Surfactants On Jincheng Anthracite

The hydrophilicity of the coal surface is a decisive factor affecting its effective wetting.By adding surfactants to change the properties of the solution,the surface of the anthracite can be covered by the hydrophobic groups of the surfactant molecules to improve the wettability of the solution to the anthracite with strong hydrophobicity.The wetting effect of coal is related to the conformation of the adsorption layer formed by surfactant molecules on the coal surface,and the structure of the adsorption layer mainly depends on the structure and composition of the surfactant solution molecules.Traditional experimental methods can only draw empirical conclusions about the wetting of anthracite by surfactants,while molecular dynamics can explain the mechanism of surfactant solution wetting anthracite from the micro-molecular level.Therefore,this paper uses improved sedimentation experiments,sonic atomization dust reduction experiments,dynamic surface tension and dynamic contact angle experiments,combined with molecular dynamics simulation to study the molecular structure and composition of different types of surfactants on the properties of surfactant solutions and the wetting of Jincheng anthracite.The impact of sex.(1)By studying the sonic atomization and dust reduction effects of fatty alcohol polyoxyethylene ether(AEO₉),sodium lauryl sulfate SDS and dodecyl trimethyl ammonium bromide(DTAB)on Jincheng anthracite at different concentrations.The wettability experiment found that the surfactant solution has a better dust reduction and wetting effect above the critical micelle concentration(CMC).The improved sedimentation experiment to achieve the best sedimentation rate will have a minimum concentration,which are AEO₉(0.4%),SDS(0.6%)and DTAB(1.0%).When the mass concentration of the three surfactants is 0.8%,the dust reduction efficiency of respirable dust is AEO₉(70.99%),SDS(67.17%)and DTAB(65.62%).(2)Dynamic surface tension and dynamic contact angle experiments show that when the AEO₉ surfactant solution is greater than the critical micelle concentration(CMC),it has the best effect on improving the surface tension of the solution and the fastest spreading speed on the surface of anthracite;combined with the interface system The simulation study with micellar system shows that the equilibrium surface tension value of the surfactant solution at the CMC concentration is consistent with the interaction of the surfactant adsorption layer on the water surface with water molecules.The stronger the interaction,the greater the equilibrium surface tension value;In addition,the easier the micelles are to dissociate,the faster the surfactant can be replenished from the water phase to the gas-liquid interface,and the faster the surfactant solution spreads on the anthracite surface.(3)Studying the adsorption behavior of surfactant solution on the surface of Jincheng anthracite by molecular dynamics simulation shows that the strong interaction between surfactant molecules will prevent the surfactant molecules from adsorbing on the coal surface in a flat conformation.At the critical micelle concentration,the interaction energies of the three surfactant interfacial adsorption layers with anthracite are AEO₉(-2054.03Kcal/mol),SDS(-1740.13Kcal/mol)and DTAB(-2022.90Kcal/mol).(4)Through the simulation study of the interface system,micellar system and the adsorption behavior of the fatty alcohol polyoxyethylene ethers AEO₇,AEO₉ and AEO₁₂ with different ethoxy groups and hydrophilic groups under CMC concentration,as well as the adsorption behavior on the surface of anthracite:the more EO number,The stronger the interaction between micelles and water,the stronger the interaction between the adsorption layer of the surfactant on the water surface and the water.The interaction energies between surfactants and Jincheng anthracite at the critical micelle concentration are AEO₇(-2551.79Kcal/mol),AEO₉(-2054.03Kcal/mol)and AEO₁₂(-2034.89Kcal/mol),and the micelles of AEO₇ are the lowest.It is easy to dissociate,so AEO₇ has the best wettability for Jincheng anthracite.