Mechanism of hydrolyzable metal ions effect on the zeta potential of fine quartz particles

ABSTRACT

The effects of ion species, cation valence, ionic strength, and hydrated ionic radius on the zeta potential of quartz have been systematically studied through the measurement of zeta potential, sedimentation rate, and aggregation observation. The results show that the interaction between hydrolysis components and quartz particles results in three critical points – CR₁, CR₂, and CR₃. The results of sedimentation and aggregation observation are in good agreement with the changes of the zeta potential in 0.1 M MgCl₂, the maximum sedimentation rate being 99.26% at pH 10.85. When the pH is around 6.25 or 10.00, the sedimentation rate is relatively lower and the size of aggregation smaller. The adsorption of hydrolyzable multivalent metal ions on the quartz surface is a combination of three adsorption forms, namely electrostatic adsorption, hydroxyl complex adsorption, and hydroxide precipitation adsorption. Then the hydrolysis properties of metal ions and the surrounding environment determine the action of the hydrolysis components and the main form of adsorption.

GRAPHICAL ABSTRACT

KEYWORDS:

• Hydrolyzable metal ions
• quartz
• sedimentation rate
• zeta potential

Additional information

Funding

The financial supports for this work from the National Natural Science Foundation of China under the grant No. 51474011, the National Natural Science Foundation of China under the grant No. 51504011, and the Anhui Provincial Natural Science Foundation of China under the grant No. 1508085QE90 are gratefully acknowledged.