Effect of Al(III) as an Activator for Adsorbing Colloid Flotation

The effect of Al(III) on adsorbing colloid flotation using Fe(OH)3 as the coprecipitant and sodium lauryl sulfate as the collector was studied, and the results of foam separation were compared with the zeta potential of the floc before and after Al(III) being added to the solution. It was found that when Al(III) is used as an activator, the zeta potential of the floc is more positive, which presumbly gives the floc a stronger affinity for anionic surfactant adsorption, resulting in better separation efficiency. The working range of pH for an effective separation is extended and good separation efficiency can be achieved at pH values closer to neutral with the aid of Al(III). Furthermore, the separation efficiency is significantly improved for solutions containing interfering ions, such as sulfate, by using Al(III) as an activator.