Interaction Free Energy Studies on Floe Foam Flotation

Abstract

The Gouy-Chapman theory of the electric double layer is applied to the calculation of interaction free energy of a charged surface film and a solid surface of opposite charge immersed in a solution of electrolyte. The interaction energies calculated with a constant surface charge density model and a constant surface potential model are compared. A constant surface charge density model for floe foam flotation is found to result in less effective binding energy than the constant surface potential model. The constant surface potential model can be found to account for the decrease in efficiency of floe foam flotation which is observed experimentally when ionic strength is increased. However, studying the binding energy at various ionic strengths with the constant surface charge density model gives results that are contradictory to the experimental results. We can thus conclude that the floe foam flotation system is better analyzed with a constant surface potential model.