Stage efficiency based on dispersed phase concentration in a mixer-settler extraction column

The stage efficiencies in a mixer-settler extraction column have been obtained for the extraction of iodine by heptane from the aqueous solution of I-2-KI. The results were compared with the values estimated from the volumetric overall mass transfer coefficient that was calculated with the interfacial area and the mass transfer coefficients of the dispersed and continuous phases. Good agreement between the observed and calculated stage efficiency was obtained. The stage efficiency based on the dispersed phase concentration increases with increasing agitation speed and decreases with increasing flow rates of the continuous phase and the dispersed phase or with increasing distribution ratio of solute.