The effect of aliphatic alcohol frothers on the dispersion of oily collector

•Aliphatic alcohol frothers inhibited dodecane dispersion in de-ionised water.•Aliphatic alcohol frothers improved dodecane dispersion in NaCl solution.•These frothers decreased interfacial tension, promoting formation of dodecane droplets.•Adsorption of these frothers reduced stability of dodecane droplets in de-ionised water.•Adsorption of these frothers increased stability of dodecane droplets in NaCl solution. There has been perception that flotation frothers, a type of surfactants, can disperse oily collectors in water, promoting oil attachment on mineral particles. In this study, the effect of aliphatic alcohol frothers (including MIBC, 1-hexanol and diacetone) on the dispersion of dodecane in de-ionised water and NaCl solution was studied. It turned out that these frothers actually inhibited the dispersion of dodecane in de-ionised water, but promoted the dispersion in NaCl solution. The underpinning mechanism was then investigated to decouple the effect of these frothers on the subprocesses of dodecane dispersion, emulsion formation controlled by the interfacial tension between oil and water, and emulsion stabilisation controlled by zeta potential and rheology of oil droplets. It was found that these frothers could decrease the interfacial tension of dodecane/water interface to facilitate the formation of dodecane droplets in water, but they were unable to form stable protective coatings around dodecane droplets in de-ionised water, resulting in the coalescence of dodecane droplets. In NaCl solution, the presence of Na+ can improve the strength of protective coatings formed by frother molecules around dodecane droplets and therefore the stability of dodecane emulsion.