Study On Suspension Stability Of Graphite Aqueous Suspensions

In this thesis,the graphite aqueous suspension was prepared by mechanical stirring.The effects and action mechanism of inorganic and organic dispersants on the suspension stability and rheological behavior of artificial graphite and amorphous graphite were investigated by means of infrared absorption spectra(IR),Zeta potential,laser particle size and scanning electron microscopy(SEM).The main results were as follows:(1)The effect of inorganic dispersants on artificial graphite shows : Aluminum silicate can effectively improve the suspension stabilit y of the artificial graphite suspension system.When the amount of aluminum silicate is 15wt%,the settling time becomes 234 s,the absorbance of the upper layer solution is increased to 0.563.Aluminum oxide can effectively improve the rheological properties of artificial graphite suspension system.When the amount of aluminum oxide is 17wt%,the viscosity of the system is 24.8 pa·s.(2)The effect of inorganic dispersants on amorphous graphite shows : Aluminum silicate is effective for improving the suspens ion stability and the rheological property of the amorphous graphite.When the amount of aluminum silicate is 15wt%,the absorbance of the stable upper layer is increased to 0.476,the viscosity of the system is reduced to 61.5 pa·s.(3)The effect of inorganic dispersants on artificial graphite shows: PVP can effectively improve the rheological behavior of artificial graphite suspension system.When the amount of PVP is 2.0wt%,the viscosity of the artificial graphite suspension system is 3.4 pa·s;SA-Na is effective for improving the suspension stability of artificial graphite.When the dosage of SA-Na is 1.5wt%,the viscosity is 14.7 pa·s,the settling time becomes 3574 s,and the absorbance of the stable upper layer solution is increased to 1.190.(4)The effect of inorganic dispersants on amorphous graphite shows : PVP can effectively improve the rheology of the suspended graphite system.When the PVP dosage is 1.0wt%,the viscosity of the soil graphite suspension system is 4.4 pa·s.CMC is effective for improving the suspension stability of the soil like graphite.When the amount of CMC is 1.5 wt%,the viscosity is 12.0 pa·s,the settling time becomes 7752 s,and the absorbance of the stable upper layer solution is increased to 1.235.(5)The above inorganic dispersant improves the suspension stability and the rheological property of artificial graphite and amorphous graphite suspension,mainly due to its electrostatic repulsion force.By physical or chemical adsorption of artificial graphite and amorphous gr aphite,the above organic dispersant increases the electrostatic repulsion and the space resistance effect between graphite particles and make the suspension stability and rheology of graphite better.