Removal of metal ions from solution by foam fractionation methods

Foam separation is used as a method for separation of solute from liquid solutions. The physical chemistry of a foam-liquid system was investigated including studies of foam density, foam stability and foam drainage, and the counter-current flow of liquid and foam. The experimental results obtained were tested with models proposed for the counter-current liquid-foam flow. It was found that the pattern of flow is different at low -s liquid flow from that at high flow rates. The change is mainly in the degree of mixing between the solution flow with the foam and the solution flow counter-current to the foam. This was found to affect the efficiency of washing and of adsorption in the foam separation column. Reflux with control of dilute foamate was used to achieve foam at saturation concentration washed free from any undesired ions