Accumulation and separation of surfactants in a foam

In the oil flotation process emulsion drops to which ore particles adhere are used instead of gas bubbles. In the case of film flotation the crushed ore is dumped on a continuously moving water surface. The easily wetted particles sink while the poorly wettable ones remain at the surface and are then collected with a special device. The theory of particle extraction by flotation have been further developed due to the detailed study of the elementary stages of particle adhesion and attachment to bubbles, accounting for the interaction forces of wetting films on solid substrate [e.g. 15-17]. 

A large number of studies on non-chromatographic methods of surface separation of dissolved substances (molecules and ions) and highly dispersed particles (colloids and other small particles) to which the principles of common flotation are inapplicable, have been 

It has been suggested the methods of separation involving adherence of particles of different dispersity on bubble surface as a result of adsorption or adhesion, to be named adsorptive-bubble (adsubble) methods [27,28]. The methods of surface separation are termed differently in the different publications in the case of surfactant extraction they are referred to as adsorption flotation, foam flotation, foam fractionation, foam separation or adsorptive accumulation in the case of ion extraction, they are called ion flotation, foam flotation of hydrophobic precipitates, etc. 

All these methods have many features in common but at the same time they bear noticeable differences. For example, in foam flotation of macroscopic particles (suspensions), 

The role of foams and foam films depends significantly on the flotation type. From all methods only the foam adsorptive accumulation of surfactants and their complexes with ions, is based entirely on the regularities of the process of substance accumulation by adsorption in the stable foam. That is why further on the main target will be the analysis of the regularities of the adsorptive accumulation and separation of surfactants in the polyhedral foam. 

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