Chemisorption and Physisorption of Collector and Composition of Collectors in Froth Flotation
S. A. Kondrat’ev
Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Flotation, collector, composition of collectors, chemisorption and physisorption, hydrolysis, dissociation, flotation activation, synergetic effect
Abstract
Flotation involves two forms of sorption using both a collector or a composition of collectors. Effect of the two forms of sorption of a collector can be assumed as a synergy of two reagents-collectors. In this case, flotation runs under conditions of hydrolysis of the reagent or its dissociation. Selection of a reagent mode means creation of condition for the two forms of sorption on a mineral surface. Activation of flotation by cations of metals, catalytic oxidation of xanthate form a sorption layer represented by the chemically or physically adsorbed reagents or by their derivatives. Each form of sorption plays a part in particle-bubble attachment. The first form of sorption aims at enhancement of hydrophobic properties of a mineral to be recovered, and the second form removes the kinetic constraint in the particle-bubble attachment. The strategy of selecting combinations of collectors to reach their synergetic effect in flotation is developed and proposed. Each collector performs its function in the particle-bubble attachment. Enhancement of hydrophobic properties of a mineral, or increase in the density of adsorption of a reagent at its surface results from the fulfilled condition of either chemisorption or physisorption of a reagent or a composition of reagents. It is shown that the properties of the second form of sorption are determined from the mechanism of work of a physically adsorbed collector.
|
