Direct measurements of particle–bubble interactions

The essence of mineral flotation is the formation of strong particle–bubble aggregates. Hydrodynamics and DLVO forces hinder the particle–bubble approach, however the presence of a hydrophobic surface results in hydrophobic attraction and strong aggregate formation. In this article we review literature where the colloid probe technique has been used to investigate flotation, primarily particle–bubble interactions in aqueous solution. In some instance particles–bubble interactions have used to quantify the hydrophobic force, whilst hydrophobic forces are crucial for particle–bubble attachment, studies of hydrophobic forces are not the main focus of this article.