The Formation and Stabilization of Oily Collector Emulsions – A Critical Review

ABSTRACT

Oily collectors are widely used to enhance the surface hydrophobicity of target minerals in flotation. However, the application of oily collectors is challenging in mineral flotation owning to their low adsorption on mineral surfaces. The presence of surfactants, fine particles and electrolytes in flotation has the potential to disperse oily collectors. In this paper, a thorough review of emulsions induced by surfactants, solid particles and electrolytes is presented. It begins with the application of collector emulsification in flotation and the mechanisms responsible for the formation and stabilization of emulsions. It is followed by a review on how surfactants, solid particles and electrolytes affect the formation and stability of emulsions. It is demonstrated that the interfacial properties between oil and water can be modified by the adsorption of surfactants acting as emulsifiers. Likewise, the adsorption of solid particles at the interface can modify the interfacial properties based on their surface wettability and particle morphology. In addition, the presence of electrolytes can influence the surface charge of oil droplets and then modify the emulsification process. Based on the review, future research is proposed to understand the emulsification of oily collectors under the context of mineral flotation.

KEYWORDS:

• Oily collector
• flotation
• surfactant emulsion
• pickering emulsion
• electrolyte

Acknowledgments

The authors greatly appreciate financial support from Australian Coal Association Research Program (ACARP). The first author also thanks the scholarship provided by the University of Queensland and the second author would like to acknowledge the support from Queensland Government through Advance Queensland Research Fellowship funding scheme.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Australian Coal Industry’s Research Program [C26008].