Flotation-introduced nanobubbles were expected to be an efficient and economical method to recover fine muscovite. This study aimed to explore the mechanism of the change appearing in flotation after introducing nanobubbles through micro-flotation, particle vision and measurement, flotation kinetics, and induction time measurement. The results of micro-flotation, which respectively feed muscovite or muscovite pretreated with nanobubbles in different concentrations of dodecylamine (DDA), were fitted with four flotation kinetic models using Origin. Different methods were used to examine how the introduction of nanobubbles affected the flotation process. The results showed that nanobubbles improved both the flotation rate and recovery of muscovite. Nanobubbles played different roles in different stirring intensities. At low stirring intensity, nanobubbles did not perform well. In suitable stirring intensity, nanobubbles helped particles aggregate and improved the collision probability between bubbles and minerals. However, at high stirring intensity, shear forces caused by ultra-high fluid velocities could disrupt particle aggregation.
Biao Long,Daqiang Wang,Ruixia Niu,Hua Song,Yu Ma,Guangmiao Qu,Junyao He
The in situ activation of silica nanoparticles (NPs) by adsorption of an anionic surfactant, nonylphenol-substituted decylsulfonate (C10-NPAS), has been studied. The mechanism whereby such NPs stabilize foams has been elucidated. Traditional static foam tests were carried out, focusing on the influence of stirring intensity on the stability characteristics of the foams. A freezing method has been applied for the first time to fix aqueous foams, and an anticipated mechanism has been verified. It was found that higher stirring intensity results in a finer foam and thinner foam lamellae, and the distribution of NPs is inhomogeneous therein. The foam stabilizing effect of NPs is more noticeable for thinner foam films. The anticipated mechanism, whereby partial aggregation of nano-SiO2 is beneficial to foam stability, has been verified by observing SEM images. Due to the strong hydrogen bonds interactions, C10-NPAS has the ability to activate NPs in situ and to stabilize negative charge thereon, making it potentially applicable in oilfields. The obtained results may expedite the development of super-long-term stable foams and potential application of NPs in enhanced oil recovery technology.
危险品化学品经营许可证（带存储）