Influence Of Amine Collectors On The Hydration State And Wettability Of Muscovite Basal Surface

Amine collector is an important surfactant in silicate minerals flotation.In this study we choose muscovite as a typical silicate minerals,and Dodecylamine(DDA),dodecyl trimethyl ammonium bromide(DATB)and hexadecyl trimethyl ammonium Bromide(CTAB)as surfactants,studied how primary amine collector and quaternary amine collector effect on muscovite surface hydration by experiment and molecular dynamics simulation.(1)Experimental part,After being immersed in DDA,DTAB and CTAB solution,the collector solution concentration starts from 1�10-5mol�L-1 to 2�10-4mol�L-1,We measured contact angle on muscovite surface.It was found that with the concentration increasing,the hydrophilicity of muscovite surface has been weakened.At the same concentration,primary amine collector can weaken the hydrophilicity of muscovite surface much more efficient,and it also found that the longer carbon chain is,the weaker hydrophilicity of muscovite surface is.We observed the DDA,DTAB and CTAB adsorption structure on muscovite surface,it shows that DDA are much more easily adsorbed on muscovite surface.(2)Molecular dynamics simulation part,The hydration on muscovite(001)surface after adsorbed different amount of DDA,DTAB and CTAB have been performed by using materials studio 6.1 with PCFF_phyllosilicates force field.It was observed with the collector coverage increasing,the height of water molecular adsorbed structure increasing accordingly.It indicates the hydrophilicity of muscovite surface is weakening.It was discovered by analyzing the H-bonds relative concentration,that primary amine collector head groups can be adsorbed in six-member ring cavities forming H-bonds with bridging oxygen atoms on muscovite(001)surface.For quaternary amine collector,the ability of forming H-bonds is relatively weak.Primary amine collector adsorbed on muscovite(001)surface can be much steadier which shows a better ability to reduce the interaction between water molecular and muscovite(001)surface than quaternary amine collector.It means primary amine collector can weaken the hydrophilicity of muscovite surface much efficient.Analyzing hydration result with alky amines with different chain lengths,it suggests that with the chain lengths increase the ability to weaken the hydrophilicity of muscovite surface becomes better.