Dispersion of ultrafine alumina suspension is examined by using particle size analyzer. The zeta potential and contact angle measurements were used to discuss the electrokinetic behavior and surface wettability of alu...Dispersion of ultrafine alumina suspension is examined by using particle size analyzer. The zeta potential and contact angle measurements were used to discuss the electrokinetic behavior and surface wettability of alumina in modifier solution, and to calculate the electrostatic interaction forces and interfacial interaction forces between alumina particles. The aggregation of ultrafine alumina occurs near its PZC. Addition of modifier increases the zeta potential of alumina and its surface hydrophilicity, resulting in increase of electrostatic and hydration repulsion. It makes the suspension of ultrafine alumina completely dispersed. The average particle size of the suspension is decreased from 1.73 μm in absence of modifier to 0.8 μm in the presence of tripolyphosphate. According to polar interfacial interaction approach, the hydration forces responsible for the stability of alumina suspension in the presence of modifier have also been obtained. The extended DLVO theory is successful to describe the dispersion behavior of ultrafine alumina in modifier solution.展开更多
The aggregation/dispersion of ultrafine particles is of interest for both fundamental and practical perspective. These behaviors of ultrafine silica in flotagent solution and the heter coagulation of silica and alumin...The aggregation/dispersion of ultrafine particles is of interest for both fundamental and practical perspective. These behaviors of ultrafine silica in flotagent solution and the heter coagulation of silica and alumina were examined using particle size analyzer, electrokinetic potential, contact angle measurements. The flotation reagents have a pronounced effect on the aggregation or dispersion behaviors of ultrafine silica suspensions. Collector dodecylamine chloride renders silica surfaces hydrophobic and the aggregation between silica particles takes place. Modifier tripolyphosphate makes the silica surface completely hydrophilic and enhances the stability of silica suspension. These experimental results can be explained based on the extended DLVO theory by considering polar interfacial interaction between particle surfaces.展开更多
文摘Dispersion of ultrafine alumina suspension is examined by using particle size analyzer. The zeta potential and contact angle measurements were used to discuss the electrokinetic behavior and surface wettability of alumina in modifier solution, and to calculate the electrostatic interaction forces and interfacial interaction forces between alumina particles. The aggregation of ultrafine alumina occurs near its PZC. Addition of modifier increases the zeta potential of alumina and its surface hydrophilicity, resulting in increase of electrostatic and hydration repulsion. It makes the suspension of ultrafine alumina completely dispersed. The average particle size of the suspension is decreased from 1.73 μm in absence of modifier to 0.8 μm in the presence of tripolyphosphate. According to polar interfacial interaction approach, the hydration forces responsible for the stability of alumina suspension in the presence of modifier have also been obtained. The extended DLVO theory is successful to describe the dispersion behavior of ultrafine alumina in modifier solution.
文摘The aggregation/dispersion of ultrafine particles is of interest for both fundamental and practical perspective. These behaviors of ultrafine silica in flotagent solution and the heter coagulation of silica and alumina were examined using particle size analyzer, electrokinetic potential, contact angle measurements. The flotation reagents have a pronounced effect on the aggregation or dispersion behaviors of ultrafine silica suspensions. Collector dodecylamine chloride renders silica surfaces hydrophobic and the aggregation between silica particles takes place. Modifier tripolyphosphate makes the silica surface completely hydrophilic and enhances the stability of silica suspension. These experimental results can be explained based on the extended DLVO theory by considering polar interfacial interaction between particle surfaces.
