Graphite flotation by β-cyclodextrin/kerosene Pickering emulsion as a novel collector

Abstract

• β-cyclodextrin/kerosene Pickering emulsion were prepared. • Effects of factors on the droplet size and stability of emulsion were investigated. • Response surface methodology was used to obtain optimal preparation conditions. • A proper β-cyclodextrin dosage used for emulsification promoted graphite flotation . • Mechanism of Pickering emulsion on graphite flotation was discussed. Pickering emulsions use nanoparticles to reduce the amount of emulsifiers and generate environmentally friendly reagents; this can be employed in different processes. However, there are no published reports on the application of Pickering emulsions in mineral beneficiation by flotation separation. Collector emulsification is an effective way to improve flotation performance. β-cyclodextrin is a granular emulsifier that has been widely considered in various investigations. As a comparative investigation, this study explored the application of the β-cyclodextrin/kerosene Pickering emulsion as a collector for the flotation beneficiation of a low-grade graphite ore. The response surface design was applied to investigate the influence of the water phase ratio, β-cyclodextrin weight, stirring time, stirring intensity, and the interaction of these factors on the emulsion droplet size and emulsion stability. The β-cyclodextrin weight optimization test showed that the Pickering emulsion reached its optimum flotation performance when the weight of β-cyclodextrin was 0.10 g. Surface analyses (zeta potential and contact angle measurements) indicated that the emulsion is stabilized by vesicles, which are self-assembled by inclusion compounds formed by kerosene and β-cyclodextrin. The developed Pickering emulsion could improve graphite recovery by 6%.