XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1735
Analysis
Ta, Nb, Ca, Fe and Mn concentrations in the aqueous phase
were assayed by ICP-AES (Varian Liberty 100), whereas
those in the organic phase were calculated based on the
difference in metal concentration inside the aqueous phase
before and after extraction. The distribution coefficient and
the extraction efficiency were then determined as follows:
D
eq
org =
6M@eq
6M@aq (1)
%E
V
V
D100
O
A
=
+
^
^
cD
h
m
h (2)
where D represent the coefficient distribution, M@eq
org 6 and
M@eq
aq 6 represent the metal concentration in organic and
aqueous phase respectively, VO and VA are the volumes of
organic and aqueous phases.
FT- IR spectroscopy (Nicolet iS5 FTIR spectrometer)
was used in the wavenumber range of 400–4000 cm−1 to
observe the structure of the loaded organic phase. To obtain
a Ta/Nb-loaded organic phase of high concentration (more
than 5g/L) for FT-IR analysis, 5 mL of organic phase was
contacted with 40 mL of aqueous phase.
RESULTS AND DISCUSSION
Effect of the Aliquat® 336 Concentration
The effect of the concentration of Aliquat ® 336 on the
extraction of Ta and Nb was studied at room temperature
using an O/A ratio of 1, a contact time of 15 minutes and
the agitation speed of 400 rpm. Aliquat ® 336 concentra-
tions ranging from 3–14% were investigated. The results
are shown in Figure 1.
The relationships seen in Figure suggest that the con-
centration of Aliquat ® 336 has a pronounced effect on the
distribution coefficient and the extraction efficiencies of Ta
and Nb. The increase of the Aliquat ® 336 concentration
leads to raise in the distribution coefficient, as well as in the
extraction efficiencies of both metals. High extraction effi-
ciency and distribution coefficients of Nb (78% and 3.6)
and Ta (42% and 0.73) were reached using Aliquat ® 336
concentration of 14%.
However, given the chemical composition of the initial
aqueous phase, the Ta and Nb distribution coefficients using
O/A ratio of 1 came significatively lower than expected and
hence need to be improved. Therefore, the O/A ratio was
increased to 2, with the respective results being displayed in
Figure 2 where the coefficients distribution and extraction
efficiencies of about 39.63 (98.75%)—Nb and 109.33
(99.54%) – Ta were reached. These results indicate that
the solvent extraction mechanism of Ta and Nb by amines
occurs via anion exchange (Deblonde et al., 2019a). An
increased concentration of Aliquat ® 336 logically leads to
a large amount of anions likely to be released and complex
further with the Ta and Nb oxalate complexes.
The slope method can be applied to process the data
generated using the O/A ratio of 1 in order to investigate
the extraction mechanism of Ta and Nb oxalate complexes
2 4 6 8 10 12 14
0
10
20
30
40
50
60
70
80 E
Nb E
Ta
D
Nb D
Ta
Aliquat
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Figure 1. Effect of the Aliquat® 336 concentration on the
extraction of Ta and Nb using O/A ratio of 1
2 4 6 8 10 12 14
0
20
40
60
80
100 E
Nb E
Ta
D
Nb D
Ta
Aliquat (%)
0
20
40
60
80
100
120
Figure 2. Effect of the Aliquat® 336 concentration on the
extraction of Ta and Nb using O/A ratio of 2
Extracti
on%
,
Distributi
coefficient
(D)
Extracti
,
%
Distributi
cefficietn
(
Analysis
Ta, Nb, Ca, Fe and Mn concentrations in the aqueous phase
were assayed by ICP-AES (Varian Liberty 100), whereas
those in the organic phase were calculated based on the
difference in metal concentration inside the aqueous phase
before and after extraction. The distribution coefficient and
the extraction efficiency were then determined as follows:
D
eq
org =
6M@eq
6M@aq (1)
%E
V
V
D100
O
A
=
+
^
^
cD
h
m
h (2)
where D represent the coefficient distribution, M@eq
org 6 and
M@eq
aq 6 represent the metal concentration in organic and
aqueous phase respectively, VO and VA are the volumes of
organic and aqueous phases.
FT- IR spectroscopy (Nicolet iS5 FTIR spectrometer)
was used in the wavenumber range of 400–4000 cm−1 to
observe the structure of the loaded organic phase. To obtain
a Ta/Nb-loaded organic phase of high concentration (more
than 5g/L) for FT-IR analysis, 5 mL of organic phase was
contacted with 40 mL of aqueous phase.
RESULTS AND DISCUSSION
Effect of the Aliquat® 336 Concentration
The effect of the concentration of Aliquat ® 336 on the
extraction of Ta and Nb was studied at room temperature
using an O/A ratio of 1, a contact time of 15 minutes and
the agitation speed of 400 rpm. Aliquat ® 336 concentra-
tions ranging from 3–14% were investigated. The results
are shown in Figure 1.
The relationships seen in Figure suggest that the con-
centration of Aliquat ® 336 has a pronounced effect on the
distribution coefficient and the extraction efficiencies of Ta
and Nb. The increase of the Aliquat ® 336 concentration
leads to raise in the distribution coefficient, as well as in the
extraction efficiencies of both metals. High extraction effi-
ciency and distribution coefficients of Nb (78% and 3.6)
and Ta (42% and 0.73) were reached using Aliquat ® 336
concentration of 14%.
However, given the chemical composition of the initial
aqueous phase, the Ta and Nb distribution coefficients using
O/A ratio of 1 came significatively lower than expected and
hence need to be improved. Therefore, the O/A ratio was
increased to 2, with the respective results being displayed in
Figure 2 where the coefficients distribution and extraction
efficiencies of about 39.63 (98.75%)—Nb and 109.33
(99.54%) – Ta were reached. These results indicate that
the solvent extraction mechanism of Ta and Nb by amines
occurs via anion exchange (Deblonde et al., 2019a). An
increased concentration of Aliquat ® 336 logically leads to
a large amount of anions likely to be released and complex
further with the Ta and Nb oxalate complexes.
The slope method can be applied to process the data
generated using the O/A ratio of 1 in order to investigate
the extraction mechanism of Ta and Nb oxalate complexes
2 4 6 8 10 12 14
0
10
20
30
40
50
60
70
80 E
Nb E
Ta
D
Nb D
Ta
Aliquat
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
Figure 1. Effect of the Aliquat® 336 concentration on the
extraction of Ta and Nb using O/A ratio of 1
2 4 6 8 10 12 14
0
20
40
60
80
100 E
Nb E
Ta
D
Nb D
Ta
Aliquat (%)
0
20
40
60
80
100
120
Figure 2. Effect of the Aliquat® 336 concentration on the
extraction of Ta and Nb using O/A ratio of 2
Extracti
on%
,
Distributi
coefficient
(D)
Extracti
,
%
Distributi
cefficietn
(