DIMENSIONLESS OVERALL DRIVING FORCE AND A POTENTIAL PLANE IN EXTRACTIVE MASS TRANSPORT BETWEEN NITRIC ACID AND 30-PERCENT TBP DILUTED IN N-DODECANE

摘要

The variations of solute concentrations in aqueous solutions and extractants of 30% TBP-dodecane were traced experimentally during forward and reverse transport of U(VI), Re(VIT) and HNO3. Besides, a theoretical attempt was made to describe the transient mass transport between two liquid solutions. The states of a solute during mass transport have been represented in an implicit form of time using new state functions A and A*, which are defined by the bulk concentrations of a solute. and the derivatives of A* with respect to a. The simultaneous transport fluxes of solutes in the forward and reverse directions have been confirmed to be an almost linear function of the first derivative, except for HNO3 accompanying simultaneous transport of a. macro amount of U(VI). The first derivative is regarded as a dimensionless overall driving force for mass transport irrespective of transport direction; since the first derivative is expressed by the liquid volume and bulk concentrations of a transferring solute, and also as a function of conventional linear driving force. Furthermore, the driving farce has been obtained as the gradient of a transport potential cur ie with respect to A where the curve is on a plane in three-dimensional space. [References: 20]