Equilibrium Calculation in the System: Uranyl Nitrate, Nitric Acid, Water, Tbp, and Kerosene Diluent Using the Oracle Digital Computer

Abstract

S. H. Jury and M. E, Whatley ABSTOACT A set of eqxiations was written which allowed the calculation of equilibritim concentrations in the solvent phase of nitric acid and uranyl nitrate, given the initial TBP concentration in the solvent and the aqueous phase concentrations of acid and uranium. An ORACLE subroutine was written based on these equations which will calcxolate a set of equilibrium values in about 55 milliseconds. The subroutine was incorporated into a short program to calculate equilibrium points. A set of calcTilated points are presented in graphical form for 5, 20, 50, kO, ahd 100^ TBP for nitric acid concentrations up to 7 M and uranyl nitrate concentrations iip to 0.6 M in the aqueous pha¥e. Since these calculations were based on limited data, it is the purpose of this memo to invite comment on their accuracy. The equations were reworked from a Russian paper by A. M. Rozen and L. P. Khorkhorina, using en^terical polynomial fits for some poorly defined paramsters, and were based principally on data from J. W. Codding. This project was undertaken to provide a subroutine to calculate equilibria in a general purpose (BACLE program to calculate the performance of multistage compound extraction cascades with more than one significant solute. NOTICEThis document contains information of a preliminary nature and was prepared primarily for internal use at the Oak Ridge National Laboratory. It is subject to revision or correction and therefore does not represent a final report. The Information is not to be abstracted, reprinted or otherwise given public dissemination without the approval of the ORNL patent branch. Legal and Information Control Department.

Solvent Extraction of Inorganic Species.

“…Rozen and Khorkhorina (330) presented a detailed thermodynamic analysis, particularly of the case where considerable amounts of uranium and nitric acid are coextracted. Jury and Whatley utilized this treatment, together with empirical functions connecting the activity coefficients with the TBP concentration and the ionic strength, to correlate experimental extraction data (182). A similar treatment was used by Codding (62) to explain quantitatively the extraction from an acid-deficient aluminum nitrate medium.…”