Dissolution Property of Serpentine Surface and the Effect on Particle–Particle Interaction Behavior in Solution

Abstract

The dissolution property of serpentine and its effect on the interaction between particles are reported here. Dissolution experiments showed that magnesium ions and hydroxyl were removed from the surface after mechanically stirring in solution, leading to the incongruent dissolution of ions. SEM, XPS, and Zeta potential analysis uncovered a significant change in serpentine surface potential and elements distribution after dissolution. Meanwhile, dramatic morphology changes on the surface were observed. A settlement test was carried out to explore the effect of dissolution on particle interaction. The results indicated that the settlement rate rises with increasing pH, but the fine particles had a lower settlement rate, showing the close connection between dissolution and particle interaction. AFM analysis revealed that the interparticle force could be changed because of surface properties at different pH values, leading to different interaction behaviors in the solution. In general, the adhesion force gradually increased and even changed from repulsive to attractive as pH ranged from 4 to 11, reflecting the adhesion behavior among particles in water. Moreover, compared to −45 + 38 μm samples, −38 μm particles are more likely to be kept repulsive in acid solution.