Croatica Chemica Acta, Vol. 39 No. 2, 1967.
Original scientific paper
Solvent Extraction and Separation of Niobium and Tantalum by Monooctylester of Anilinobenzylphosphonic Acid
M. M. Herak
; Institute »Ruder Boskovic«, Zagreb, Croatia, Yugoslavia
V. Jagodić
; Institute »Ruder Boskovic«, Zagreb, Croatia, Yugoslavia
M. J . Herak
; Institute »Ruder Boskovic«, Zagreb, Croatia, Yugoslavia
Abstract
The extraction of niobium and tantalum from aqueous solutions
of their oxalato and fluoro complexes h as been studied, using
the monooctylester of anilinobenzylphosphonic acid (MOABP) as
extractant. The dependence of the extraction of niobium a nd tantalum
upon th e hydrochloric, sulphuric, nitric, perchloric, phosphoric,
hydrofluoric and oxalic acid concentration is described. A procedure
for the separation of niobium from tantalum has been established.
The back-extraction of niobium and tantalum from the organic
phase was carried out with hydrofluoric, phosphoric a nd oxalic acid.
The dependence of the extraction of niobium upon the MOABP
concentration in the organic phase, and oxalic or hydrofluoric acid
in the aqueous phase was also· studied. It was found that the distribution
coefficients for niobium from oxalate solution were proportional
to the second power of the MOABP concentration. The loga rithmic
de p endence of the distribution coefficients for niobium from
fluoride solution vs. the MOABP concentration gave a curve whose
slope was 1.5. The extraction of niobium from oxalate solution is
linearly proportional to the oxalic acid conce ntration, while the
extraction of niobium from fluoride solution depends upon the second
power of the hydrofluoric acid concentration. Similar experiments
with tantalum were not made because of its very low extraction
under the same conditions. The radionuclides 95Nb and 1s2Ta
were used for the dete rmination of the distribution coefficients of
niobium and tantalum in all of the experiments described.
Keywords
Hrčak ID:
208094
URI
Publication date:
10.8.1967.
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