Effects of Surfactants on Flotation Separation Performance

Flotation is a continuous, efficient, inexpensive, and well-developed commercial process. It has been widely applied in a variety of industrial processes, including mineral processing, and oily water treatment. Gas bubbles are generated within a solid-liquid or liquid-liquid suspension during flotation process. Based on the hydrophobicity of the surface, hydrophobic particles/immiscible droplets attach easily to gas bubbles and rise to the froth layer on top of the liquid surface. Finally, the floated solid particles, or immiscible liquid droplets, are skimmed off to achieve the separation.

In this study, we have investigated the effects of surfactants on the enrichment of rare earth elements (REEs) from coal and coal by-products, and the cleanup of oily sea water. The effectiveness of surfactants, i.e., frother, depressant, and collector, can strongly influence the flotation process. Different types of frothers and collectors were studied at varying flotation conditions. The properties of particle size, temperature, and pH were also studied. The discussion will focus on the performance of these surfactants and the efficiency of separation at those operating conditions.