Effect of sodium hexametaphosphate modification on dispersion stability of natural brucite in aqueous media

Abstract

Natural brucite is unstable in aqueous media, was modified with sodium hexametaphosphate(SHMP) as a surface treatment. In order to explore the effect of sodium hexametaphosphate on the surface of brucite were studied by using relative sedimentation measurement, scanning electron microscopy (SEM), Zeta potential, infrared spectroscopy (FT-IR) and extend DLVO theoretical calculation. The sedimentation experiments show that the sodium hexametaphosphate modification have a positive effect on the dispersion of brucite in aqueous media. The sodium hexametaphosphate changes the potential of the burburite particles, which leads to the increase of electrostatic double layer energy between particles. Infrared spectrum analysis shows that sodium hexametaphosphate can form a hydrophilic complex with magnesium ions on the surface of brucite. DLVO extend theoretical calculation shows that the total energy between brucite particles turned from unfavorable to favorable with the increasing particles distance, and the steric hindrance interaction energy plays a dominant role. The results show that sodium hexametaphosphate have a positive effect on the stability of natural brucite suspension.