Froth flotation is a physicochemical process that is used to separate fine mineral particles from aqueous suspensions by selective attachment of some types of minerals to air bubbles. Froth flotation is the most important mineral processing technology for the production of valuable mineral concentrates from which metals and minerals are obtained. Practically all metals in use today were recovered, at some point in their production cycle, by froth flotation from ground ores. This article focuses on the surface properties of minerals relevant to froth flotation: wetting of mineral surfaces by water and surface charge characteristics of minerals in aqueous suspension. Interactions between mineral surfaces and flotation surfactants are discussed, starting from simple physical/electrostatic interactions to complex electrochemical reactions. The effect of surfactant adsorption on the froth flotation behavior of minerals is analyzed. Functions of other reagents used in froth flotation are summarized. Adsorption of surfactants at the gas–liquid interface in relation to gas dispersion and frothing phenomena is also discussed. Selected examples of industrial separation of minerals are given to highlight how the presented fundamentals are applied on an industrial scale. The froth flotation process is generally presented as an example of applied interfacial chemistry. This material should serve as an introduction to the subject at the undergraduate and graduate levels.
标签: