|
The effect of HNO3 in the extraction U
(IV) from buffered aqueous solution using a chloroform solution of
the ligand 1-phenyl-3-methyl-4-trichloroacetyl pyrazolone-5 (HTCP)
was studied. This was carried out using solvent-solvent extraction,
with 0.001 M, 0.005 M, 0.01 M, 0.05 M, 0.1 M, and 0.5 M aqueous
phases of HNO3. The working concentration was 200 mg/L. The
extraction was carried out using a chloroform solution of 0.05 M (HTCP).
The solution was agitated with an equilibration time of 30 min,
after which the phases were allowed to settle, and then, the aqueous
raffinate was withdrawn and analyzed by difference colorimetrically
using 1,10-phenanthroline. Distribution ratios (D) and percentage
extractions (% E) were calculated by difference. The results
obtained showed that the interference of nitrate ions was more
pronounced as nitric acid concentration got >0.01 M HNO3. U(VI) was
completely masked at concentrations greater than 0.01 M, indicating
that HNO3 is only a good extraction medium for the extraction of
U(VI) at lower concentrations. There was optimum % extraction of
95.59 %, 78.41%, and 33.92 % at molar concentrations 0.001 M, 0.01
M, and 1 M, respectively. An adduct complex of the metal
characterized as UO2 (NO3) was extracted. Complete recovery of U(VI)
will require two or three batches of extraction using the acid at
concentration 0.001 M where U(VI) was best extracted.
|
