Solvent extraction as a method of promoting uranium enrichment by chemical exchange
Author(s)
Fathurrachman, {unknown}
Type
Thesis
Abstract
This thesis examines a chemical exchange process for uranium enrichment using solvent extraction. The system selected is the isotope exchange for uranium species in the form of uranous and uranyl chloride complexes. Solvent extraction has been studied before by French workers for this application but little was published on this. Much of this present work is therefore novel. The equilibrium data for the extraction of U(IV) as u4+ and U(VI) as uo22+ from hydrochloric media into an organic phase containing tri-n octylamine (TOA) in benzene is given. Benzene is used to prevent third phase formation. In 4 M HCl U(VI) was found to be very soluble in the organic phase but u(IV) was virtually insoluble. Most of the equilibrium data has been correlated by the Langmuir isotherm. This thesis also outlines the methodology that has to be used to design a plant based on this process. It involves the calculation of the number of stages and uses a finite difference formula for these calculations. Several different methods of introducing the feed are considered, as is the use of cascades. To operate the plant continuously, the product and the tailings would be treated in an electrolytic cell unit containing a cation exchange membrane where the U(VI) in the product changes to U(IV) in the cathode chamber and the U(IV) in the tailings changes to U(VI) in the anode side of the cell. The kinetics of this reaction have been studied experimentally. From the results of the work it is possible to specify all the cell operating variables. The enriched uranium cost obtained using mixer settlers as contactors for running the plant is much larger than the enriched uranium cost from gaseous diffusion plant.
Version
Open Access
Date Awarded
1995
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
White, D. A.
Sponsor
STAID programme of the Agency for Assessment and Application of Technology (BPPT)
Publisher Department
Department of Chemical Engineering
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)