低阶煤表面润湿性调控对油类捕收剂铺展的影响OACSTPCD

To elucidate the effects of the changes of low-rank coal surface wettability on the spreading performance of oil collector,the coal from Haerwusu was selected as the research material,three kinds of surfactants,namely dodecyl trimethyl ammonium bromide(DTAB,cat-ionic),sodium dodecyl sulfate(SDS,anionic)and dodecyl alcohol polyoxyethylene ether(AEO-4,non-ionic)were used to modify the surface wettability of low-rank coal.The thickness of ke-rosene oil film was measured by AFM directly,and the corresponding mechanism was investiga-ted.The results show that the spreading performance of nonpolar collector on coal surface is closely associated with the hydrophobic degree of coal surface.After SDS,AEO-4 and DTAB treatment,the thickness of oil film on the surface of low-rank coal is 17.86 nm,18.06 nm and 19.85 nm,respectively.DTAB exhibits superior performance compared to SDS and AEO-4,en-hancing the spreading of nonpolar collector on coal surface.The oil film with stable ordered layer and transition layer structure are formed on the coal surface treated with DTAB,measuring 19.85 nm in thickness.The thickness of oil film increases from 10.89 nm to 19.85 nm due to the increase of the AEO-4 mass fraction from 0.5%to 2.0%,indicating that increasing the mass fraction of surfactant can enhance the interaction between collector and low-rank coal surface.Meanwhile,a better flotation effect of low-rank coal is observed,with an increase in the yield of clean coal from 68.96%to 70.91%and an increase in the recovery of combustible material from 83.92%to 85.82%.