Determination of activity/selectivity ratio in physical and chemical adsorption of a reagent

Resumo

Under discussion is the particle and bubble interaction in froth flotation. Water flow from an interlayer between a particle and a gas bubble under effect of hydrophobic component of wedging pressure is studied. It is assumed for a mineral to be extracted, that electrostatic interaction slightly influences the particle and bubble contingence and the liquid interlayer thinning. For this reason, particular attention is given to the effect exerted by mineral particle surface hydrophobicity on water flow rate from the interlayer. It is found that water flow rate under influence of hydrophobic component of wedging pressure is less than water flow rate under physical adsorption of a reagent. The authors hypothesize that hydrophobization creates areas on the mineral particle surface, where the reagent species active relative to gas–water interface attach in accordance with the polarity equalizing rule. Physically adsorbed reagent species pull out water from the interlayer after the interlayer rupture and, thus, remove the kinetic constraint of the particle–bubble attachment.