Determining Characteristics of a Model of Molecular Sorption, Based on an Example of the Separation of Components of Extractional Phosphoric Acid via “Retardation” on Ionites

Abstract

A dynamic model of the transfer and molecular sorption processes inside a sorption column is considered, based on the acid retardation of a gel anion exchanger. A three-layer model of a space filled with a solution is used to describe the process of keeping solution components inside nanosized pores in a multicomponent system. Allowance is made for the heterogeneity of the concentrations of molecules in the pores of the sorbent, caused by the forces acting on polar molecules from the sorption centers. The model allows calculation of changes in the concentrations of components over time inside the sorption column and, based on output concentration curves obtained experimentally, to determine characteristics of the process of holding molecules inside nanosized pores. Results from modeling are compared to experimental data on the purification of industrial extractive phosphoric acid.