复合抑尘剂强化润湿作用机理及应用效果研究OA

In order to improve the effect of low-permeability coal bed water injection wetting and dust suppression,the compound dust suppressant material of"surfactant+inorganic salt additives+acid corrosive agent"was selected through the experiments of settlement of coal samples,contact angle test and acid etching rate test.The optimal mass fractions are 0.8%sodium dodecyl sulfate(SDS),0.2%coconut oil fatty acid diethanolamide,0.8%sodium chloride(NaCl),and 4.0%hydrochloric acid(HCl).The infrared spectroscopy experiment and impact dust production experiment were carried out to clarify the changes of coal functional groups and the characteristics of broken dust production under the effect of compound dust suppressant.Based on the existing research and field layout,the physical and chemical synergistic liquid wetting and dust suppression system of"dynamic and static pressure water injec-tion+compound dust suppressant"was constructed and applied in Duerping Mine.The results show that the compound dust sup-pressant can reduce the contact angle of coal samples by more than 50%compared with that of clear water,the settling time is only 47 s,and the dissolution rate of coal body reaches 3.26%.The dust suppressant can significantly change the structures of aromatic hydrocarbons,oxygen-containing functional groups,aliphatic hydrocarbon and hydrocarbon groups in coal,making the structure of the coal body more loose and thus promoting the penetration of water,and adjusting the distribution of the charge on the surface of the coal body at the same time,enhancing the attraction to water molecules,and all-roundedly enhancing the wetting performance of the coal body.After the action of compound dust suppressant,the coal samples are easier to combine the dust during crushing,and fall off in the form of dust with large particle size,and the percentage of dust below 74 μm drops by 54%compared with that of coal samples wetted with water.The molecules of the compound dust suppressant are able to penetrate into the tiny pores inside the coal body,change the physicochemical properties of the surface of the coal body,enhance the combining force inside the coal body,and inhibit the dispersion of small particles during the process of crushing.After adopting the physical and chemical synergistic liquid in-jection wetting and dust suppression technology,the amount of water injected into the single hole of the coal seam at the site in-creased by 1.37 times compared with the hydrostatic injection,the incremental water content was improved by 1.4 times,the wetting radius was enlarged by 50%,and the concentration of dust during the back-mining was reduced by more than 50%,so that the operat-ing environment of the site was significantly improved.