Study On The Interface Assembly Mechanism For Flotation Separation Of Mica And Quartz By Mixed Collectors

High-quality quartz sand,an important mineral,is widely used in numerous high-tech industries.Inferior quality quartz is a potential raw material for producing high-quality quartz.Quartz is often associated with mica,and the deep removal of mica is the premise of subsequent treatment of quartz ores.Flotation is well known as the most valid separation method used to beneficiate quartz from gangue minerals.Mixed collectors have shown excellent flotation performance.This study researches the flotation separation mechanism of different mixed anionic/cationic collectors on the flotation separation of quartz and mica by means of experiments and molecular dynamics simulation.The main results of this paper are shown as follows:1.Effective flotation separation of mica and quartz can be achieved using mixed anionic/cationic collector(SDS/DDA)during a wide range of molar ratios,and the flotation performance of muscovite is better than that of biotite.The mixed collectors show superior flotation performance on the separation of muscovite and quartz with the molar ratio of 5:1 at the whole p H range.2.The results of large-scale molecular dynamics simulation show that collectors spontaneously form spherical aggregates in aqueous phase with polar group outside and nonpolar group inside.The collectors randomly distributed in liquid phase move to interface with head group immersed in water and tail chains stretched towards to air.In mixed collector systems,the electrostatic repulsion is reduced between collectors with opposite charge and the counterions distribute in aqueous solution.Additionally,the CMC value of mixed collector is lower by one or two orders of magnitude compared with single collector,and the foam produced by mixed collector is more suitable for mineral flotation.3.The adsorption of DDA occupies dominant position in mixed collectors.Chemical adsorption such as hydrogen bonding also exists in addition to physical adsorption caused by electrostatic interaction.SDS adsorbs on the mineral surface through electrostatic attraction with the head group of DDA and metal ions on muscovite surface,as well as the hydrophobic interaction with the tail chains of DDA.