The Formation and Stabilization of Oily Collector Emulsions – A Critical Review
Liang Cao, Xumeng Chen, Yongjun Peng
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.