MATHEMATICAL MODELING FOR THE EXTRACTION OF URANIUM AND MOLYBDENUM WITH EMULSION LIQUID MEMBRANE, INCLUDING INDUSTRIAL APPLICATION AND COST EVALUATION OF THE URANIUM RECOVERY

MATHEMATICAL MODELING FOR THE EXTRACTION OF URANIUM AND
MOLYBDENUM WITH EMULSION LIQUID MEMBRANE, INCLUDING
INDUSTRIAL APPLICATION AND COST EVALUATION OF THE URANIUM
RECOVERY. Emulsion liquid membrane systems are double emulsion drops. Two
immiscible phases are separated by a third phase which is immiscible with the other two
phases. The liquid membrane systems were classified into two types: (1) carrier mediated
mass transfer, (2) mass transfer without any reaction involved. Uranium extraction,
molybdenum extraction and solvent extraction were used as purposed elements for each
type of the membrane systems in the derivation of their mathematical models. Mass
transfer in emulsion liquid membrane (ELM) systems has been modeled by several
differential and algebraic equations. The models take into account the following : mass
transfer of the solute from the bulk external phase to the external phase-membrane
interface; an equilibrium reaction between the solute and the carrier to form the solutecarrier
complex at the interface; mass transfer by diffusion of the solute-carrier complex
in the membrane phase to the membrane-internal phase interface; another equilibrium
reaction of the solute-carrier complex to release the solute at the membrane-internal phase
interface into the internal phase. Models with or without the consideration of film
resistances were developed and compared. The models developed in this study can predict
the extraction rate through emulsion liquid membranes theoretically. All parameters
required in the models can be determined before an experimental extraction run.
Experimental data from literature (uranium extraction) and (molybdenum extraction and
solvent extraction) were used to test the models. The agreements between the theoretical
predictions and the experimental data were very good. The advantages of emulsion liquid
membrane systems over traditional methods were discussed. The models developed in this
research can be used directly for the design of emulsion liquid membrane systems. The
results of this study represent a very significant step toward the practical applications of
the emulsion liquid membrane technology.
Keywords : emulsion liquid membrane, uranium, molybdenum, mathematical modeling,
D2EHPA, mass transfer, span 80, batch process, recovery, cost