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.