Foaming agents

FOAMING AGENTS, FOAMERS (EN: foaming agent; DE: Schaumer, Schaumbildner; FR: reactifs moussants, ES: reactivos espumosos; RU: вспениватели) are the reagents, which are imparting to the liquid the ability for the forming of the foam. They use these reagents for the processes of the flotational beneficiation of the useful minerals, and also within the composition of the foamer liquids for the dust suppression and extinguishing of the fires. The typical foaming agents, which are used for the flotation, are the organic surfactants, which are possessing the ability to be adsorbed spontaneously onto the liquid-gas surface, and which are assisting to the increase of the dispersivity of the bubbles of the gas, and to the stability of the foam.

The foaming agents also possess the collecting properties. The molecules of the foaming agent have the heteropolar structure, that is, they contain the apolar (hydrophobic) and polar (hydrophilic) groups of the atoms. The apolar group includes one or several aliphatic or cyclic hydrocarbon radicals. There may be the polar group of the foaming agent the hydroxyl (-OH), carboxyl (-COOH), carbonyl (-CO), amino group (-NH2), and sulfo group (-SO3N). Depending on the character of the influence from the hydrogen indicator (pH), they distinguish the basic, acidic, and neutral foaming agents. The basic foaming agents possess the maximal foam-forming properties within the alkaline environment. For the flotation of the ores of the non-ferrous metals, there has the practical usage the heavy pyridine. The acidic foaming agents decrease the foam-forming properties with the increasing of the alkalinity of the solution. There belong to these agents the phenolic reagents (cr esol, xylenol, phenol-containing wooden oils, and so on), and also the alkylarylsulfonates (detergents, azolates). There compose the most significant group the neutral foaming agents, which are sub-divided into the aromatic and alicyclic alcohols (terpineol-containing substances, cyclohexanol, dimethyl-phenyl-carbinol), aliphatic alcohols (for example, the tertiary hexanol), and the neutral reagents, which are containing the substances with the ester bonds.