Analysis of backmixing and mass transfer in solvent extraction columns

A critical survey of the published literature concerning modelling of liquid-liquid extraction columns, mass transfer studies in extraction towers and the influence of backmixing on concentration profiles, extraction efficiency and the number of transfer units has been made to determine the most accurate correlations for computing the true number of transfer units or the true overall mass transfer coefficients in backmixed solvent extraction columns. These parameters are of great significance and are very useful in the design and performance evaluation of solvent extraction columns. Several approximate correlations of these parameters as a function of column geometry, operating conditions, and physical properties of the liquid systems involved have been developed and it is possible to use mathematical models in the interpretation and analysis of experimental data to determine which correlations appear to be most accurate and easiest to use. The results of the data analysis, together with the best possible estimate of the extraction efficiency were applied to a differential backmixing model to obtain concentration profiles in an extraction column