Experimental Study on Wetting and Dissolution of Coal under Surfactant-assisted Acidification Conditions
Coal body wetting-acidification represents a promising chemical modification meth-od for coal dust control and gas prevention.To further understand the internal transformation mechanism of coal body wetting-dissolution,contact angle tests and low-temperature nitrogen ad-sorption experiments were employed to investigate changes in coal body wetting characteristics and pore structure before and after treatment with acid solution and surfactant composite rea-gents.The results showed that under surfactant-assisted acidification,the contact angle was re-duced by approximately 60％,greatly improving coal wettability.After treatment with composite reagents,chemical reactions within the coal body altered its pore structure,increasing total pore volume and average pore diameter by 2.0 and 1.5 times,respectively.In combination with the fractal theory,fractal dimensions D1 and D2 decreased by 24.1％and 10.3％compared to raw coal,indicating reduced surface roughness and enhanced pore connectivity.The addition of[BMIM]BF4 ionic liquid inhibited surfactant activity,leading to increased contact angles and weakened coal wettability,consequently reducing average pore diameter.A positive correlation existed between coal body wettability and dissolution;as wettability increases,it promoted the dissolution of more mineral impurities by acid solution,resulting in the increase of total pore vol-ume and average pore diameter.
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维普
