3330 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
Effects of NaOL/DAA Ratio on the Recovery of Lithium
In reverse flotation, a combination of cationic and anionic
collectors effectively floats gangue minerals, leaving spodu-
mene as tailings due to its high surface adsorption capacity.
The ratio of the mixed collectors has been found to be a
crucial criterion in the flotation test, thus the flotation per-
formances of the mixed 1000 g/t NaOL/DAA with various
ratios have been investigated at pH 10 and 25 °C to deter-
mine the optimum mixture dosage in the low-grade spodu-
mene ore. Lithium recovery trends, observed in Figure 8,
show an initial increase and slight decrease with rising
DAA dosage. The optimum lithium recovery of 35.94%
and a lithium grade of about 1.0% Li2O are achieved at
a NaOL to DAA ratio of 1:5. The lithium grade remains
relatively constant between mixture ratios of 1:5 and 1:9.
Consequently, the ratio of 1:5 is selected for subsequent
flotation studies, indicating a separation window using
mixed collectors at 1:3 and 1:5 NaOL/DAA ratios. This
underscores the importance of fine-tuning collector ratios
to optimize lithium recovery and grade in spodumene
flotation.
Effect of Collector Dosage
To optimize the mixed collector dosage of NaOL/DAA
at a 1:5 ratio for lithium flotation, tests were conducted
to observe changes in recovery and grade. The results of
reverse flotation, showed in Figure 9, revealed that increas-
ing the NaOL/DAA dosage from 100 to 3000 g/t resulted
in a decrease in lithium recovery from 37.5% to 3.0%. The
lithium grade peaked at 1% Li2O with a 1000 g/t dosage,
then declined with further increases in collector dosage.
Consequently, the dosage of 1000 g/t was identified as the
most effective for flotation performance, balancing recov-
ery and grade. This finding emphasizes the importance of
precise collector dosage in enhancing flotation efficiency
and underscores the need for careful optimization in the
flotation process for effective lithium extraction from spod-
umene ore. However, the highest recovery for spodumene
flotation is still less than 40%.
Effect of Depressant
Figure 10 displays the effect of two depressants on reverse
flotation recoveries of lithium at pH 10 with 1000 g/t
NaOL/DAA. As is well known, silicate minerals cannot
be efficiently separated using traditional anionic/cationic
collectors due to their similar physicochemical proper-
ties, unless a suitable depressant is used (Shu et al., 2020).
The results indicate that increasing the starch dosage from
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0
10
20
30
40
50
60
1:4 1:5 1:6 1:9 1:12
NaOL /DAA ratio
Recovery
Grade
Figure 8. The effect of the ratio of NaOL to DAA on
flotation recovery of lithium (pH 10, NaOL/DAA of
1000 g/t)
0.00
0.20
0.40
0.60(L
0.80
1.00
1.20
0
10
20
30
40
50
60
100 1000 2000 3000
NaOL/DAA dossage, g/t
Recovery
Grade
Figure 9. The effect of NaOL/DAA dosage
on flotation recovery of lithium (pH =10, ratio of 1:5)
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
0
10
20
30
40
50
60
0 2000 3000 4000
Dossage, g/t
Recovery (Starch) Recovery (Dextrin)
Grade (Starch) Grade (Dextrin)
Figure 10. The effect of starch and dextrin dosage
on flotation recovery of lithium (pH =10, NaOL/DAA of
1000 g/t)
Grade
(LiO,
2
%)
LiO
2
Recovery,
%
Grade
iO),
2
%
LiO 2
Recovery,
%
Grade
(LiO),
2
%
Recovery
(LiO),
2
%
Effects of NaOL/DAA Ratio on the Recovery of Lithium
In reverse flotation, a combination of cationic and anionic
collectors effectively floats gangue minerals, leaving spodu-
mene as tailings due to its high surface adsorption capacity.
The ratio of the mixed collectors has been found to be a
crucial criterion in the flotation test, thus the flotation per-
formances of the mixed 1000 g/t NaOL/DAA with various
ratios have been investigated at pH 10 and 25 °C to deter-
mine the optimum mixture dosage in the low-grade spodu-
mene ore. Lithium recovery trends, observed in Figure 8,
show an initial increase and slight decrease with rising
DAA dosage. The optimum lithium recovery of 35.94%
and a lithium grade of about 1.0% Li2O are achieved at
a NaOL to DAA ratio of 1:5. The lithium grade remains
relatively constant between mixture ratios of 1:5 and 1:9.
Consequently, the ratio of 1:5 is selected for subsequent
flotation studies, indicating a separation window using
mixed collectors at 1:3 and 1:5 NaOL/DAA ratios. This
underscores the importance of fine-tuning collector ratios
to optimize lithium recovery and grade in spodumene
flotation.
Effect of Collector Dosage
To optimize the mixed collector dosage of NaOL/DAA
at a 1:5 ratio for lithium flotation, tests were conducted
to observe changes in recovery and grade. The results of
reverse flotation, showed in Figure 9, revealed that increas-
ing the NaOL/DAA dosage from 100 to 3000 g/t resulted
in a decrease in lithium recovery from 37.5% to 3.0%. The
lithium grade peaked at 1% Li2O with a 1000 g/t dosage,
then declined with further increases in collector dosage.
Consequently, the dosage of 1000 g/t was identified as the
most effective for flotation performance, balancing recov-
ery and grade. This finding emphasizes the importance of
precise collector dosage in enhancing flotation efficiency
and underscores the need for careful optimization in the
flotation process for effective lithium extraction from spod-
umene ore. However, the highest recovery for spodumene
flotation is still less than 40%.
Effect of Depressant
Figure 10 displays the effect of two depressants on reverse
flotation recoveries of lithium at pH 10 with 1000 g/t
NaOL/DAA. As is well known, silicate minerals cannot
be efficiently separated using traditional anionic/cationic
collectors due to their similar physicochemical proper-
ties, unless a suitable depressant is used (Shu et al., 2020).
The results indicate that increasing the starch dosage from
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0
10
20
30
40
50
60
1:4 1:5 1:6 1:9 1:12
NaOL /DAA ratio
Recovery
Grade
Figure 8. The effect of the ratio of NaOL to DAA on
flotation recovery of lithium (pH 10, NaOL/DAA of
1000 g/t)
0.00
0.20
0.40
0.60(L
0.80
1.00
1.20
0
10
20
30
40
50
60
100 1000 2000 3000
NaOL/DAA dossage, g/t
Recovery
Grade
Figure 9. The effect of NaOL/DAA dosage
on flotation recovery of lithium (pH =10, ratio of 1:5)
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
0
10
20
30
40
50
60
0 2000 3000 4000
Dossage, g/t
Recovery (Starch) Recovery (Dextrin)
Grade (Starch) Grade (Dextrin)
Figure 10. The effect of starch and dextrin dosage
on flotation recovery of lithium (pH =10, NaOL/DAA of
1000 g/t)
Grade
(LiO,
2
%)
LiO
2
Recovery,
%
Grade
iO),
2
%
LiO 2
Recovery,
%
Grade
(LiO),
2
%
Recovery
(LiO),
2
%