Abstract
Efficient recovery of uranium from productive leaching solutions requires a clear under-standing of hydrodynamic and mass-transfer processes in ion-exchange sorption col-umns. In this study, a coupled hydrodynamic and mass-transfer model is developed to investigate uranium sorption in a packed ion-exchange column equipped with a conical flow distributor. Fluid flow in the porous resin bed is described by the Forchheimer filtra-tion law combined with the mass conservation equation, while transport of dissolved uranium species is modeled using a convective–dispersion equation coupled with a sorp-tion kinetics equation based on the linear driving force approximation. Numerical simu-lations are performed using the fictitious domain method to represent the complex geom-etry of the column. The pressure field is determined using the Ritz variational method, and the transport equation is solved with the Crank–Nicolson scheme. The results show that uranium distribution between liquid and solid phases forms a ring-shaped region in-side the column, indicating uneven utilization of the sorbent bed. It is also found that the conical flow distributor does not fully eliminate radial flow non-uniformity. Doubling the solution flow rate increases the width of the mass-transfer zone by about 1.5 times due to enhanced longitudinal dispersion. The proposed approach can be used to analyze and optimize industrial sorption columns for uranium recovery.