MEMBRANE RECYCLING IN THE LIQUID SURFACTANT MEMBRANE PROCESS

A study has been conducted to investigate the influence of membrane recycling on the kinetics of metal permeation and emulsion stability in the liquid surfactant membrane process. The analogous stages of the industrial process, i.e., emulsification, permeation, settling, and splitting, have been reproduced, however, so far on a laboratory scale. It has been revealed that after two cycles of the membrane circulation, the kinetics of metals extraction and emulsion stability have been drastically affected. Chemical and instrumental analysis of the membrane have shown considerable losses in the surfactant (Span 80) during cobalt extraction, while the carrier bis(2-ethylhexyl)phosphoric acid (D2EHPA) has not been affected. This fact has been mainly attributed to the surfactant chemical instability during exploitation and particularly in acidic media.