This work is mainly concerned with the uranium
extraction from phosphoric acid commercially produced
by Abu Zaabal Fertilizers and Chemical Co., Egypt.
This target would realize a dual purpose where the phosphate
ore is considered as an alternative source of uranium
besides eliminating its environmental contamination. The
applied procedures are that of the new technology of
emulsion liquid membrane. Authors have indeed pointed
out that the variables explored still leave open to question
the roles of stripping at the internal interface as well as the
bulk transfer of uranium in the internal phase. For this
purpose, two reducing agents are studied as additives to
two organic solvent systems; namely the organophosphorous
synergistic mixture of D2EHPA/TOPO as well as the
tridodecyl amine. The relevant factors have first been
optimized upon synthetic uraniferous phosphoric acid
solution followed by the application upon the commercial
acid after purification. These factors include the concentration
of solvent system and the used emulsifier, acid
concentration of the external and internal phases besides
the nature and concentration of the reductant added to the
internal phase. In addition, the permeation time as well as
the oxidation state of the external phase was studied. All
these factors have indeed been studied under different
mixing speeds ranging from 300 up to 1,000 rpm. Ascorbic
acid concentration, 1 % as an additive to the internal
phosphoric acid phase (40 % P2O5) resulted in 95 % uranium
extraction efficiency at the lower speed of 600 rpm. |
