The Effect of Ca2+ and Mg2+ on the Dispersion and Flocculation Behaviors of Muscovite Particles

Abstract

Abstract:The dispersion and flocculation behavior of muscovite suspensions in the presence of Ca 2+ and Mg 2+ are relevant for industrial processing of pre-concentrated muscovite from stone coal, a primary source of vanadium. In this study, the dispersion and flocculation behavior were investigated by means of sedimentation, zeta potential, and ion absorption experiments, as well as the force between particles and ion speciation calculations. The results indicated that the dispersion and flocculation behavior of muscovite particles without excess ions were in qualitative agreement with the classical DLVO theory. The muscovite particles aggregated mainly due to basal surface-edge interactions in acidic suspensions but were dispersed in alkaline suspension by electrostatic repulsion of the total particle surface. In acidic suspensions, the ability of muscovite to form dispersions of muscovite was increased with the decrease in the electrostatic attraction between the basal surface and the edge caused by the compression of the electric double layers withCa 2+ and Mg 2+ . In alkaline suspension, the main adsorption form of Ca 2+ and Mg 2+ on muscovite surface was the ion-hydroxy complexes. The flocculation behavior of muscovite was affected by the static bridge effect of the ion-hydroxy complexes.

Probing Silica-Kaolinite Interactions with Sum Frequency Generation Spectroscopy

“…[52][53][54] However, for like charged surfaces, multivalent cations have been reported to induce bridging, especially under highly alkaline conditions. [55][56][57][58] For example, calcium ions induced the adsorption of an anionic surfactant onto a negatively charged silica surface at pH 8 and above, 57 and promoted flocculation of muscovite particles in alkaline conditions. 58 Therefore, we attribute the binding of the kaolinite at pH 12 and above to overlapping electrical double layers for the two oxides and calcium-mediated binding, rather than just electrostatic interactions.…”

“…[55][56][57][58] For example, calcium ions induced the adsorption of an anionic surfactant onto a negatively charged silica surface at pH 8 and above, 57 and promoted flocculation of muscovite particles in alkaline conditions. 58 Therefore, we attribute the binding of the kaolinite at pH 12 and above to overlapping electrical double layers for the two oxides and calcium-mediated binding, rather than just electrostatic interactions. We note that the pH where this lack of water structure is observed (pH 12) correlates well with the optimal pH for dewatering of kaolinite-and silica-rich tailings using Ca(OH)2 and low pressure filtration.…”

Preparation of reactive nanoscale carbon black dispersion for pad coloration of cotton fabric

“…It is known that steric hindrance, electrostatic repulsion and van der Waals interactions are the main forces among colloidal particles in solution, and that the net interaction may be either repulsive or attractive depending on the balance of these forces. According to DLVO theory and Stokes’ equation , electrostatic repulsion and van der Waals interactions among particles gave the same value because the particles in the two dispersions almost had the same zeta potential and the mean particle size. Therefore, the observation that reactive nanoscale CB dispersion showed better stability than the comparative nanoscale CB dispersion may depend instead on steric hindrance.…”

Chloride Removal of Calcium Aluminate-Layered Double Hydroxide Phases: A Review

“… Variation of ( a ) carbonate, ( b ) calcium, and ( c ) aluminum species with pH [ 39 , 43 , 46 , 47 ]. …”