1242 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
concentration of 0.5 mol/L was used. Samples were taken
frequently throughout the experiment.
It was expected that the REE would precipitate as REE
oxalates with the introduction of fresh oxalic acid. However,
the REE dissolution stayed constant throughout. This sug-
gests that the reaction needs a higher concentration of oxalic
acid as this would allow for additional free oxalate for the
REE to precipitate as REE oxalate. Therefore, further test
work is to be done with a greater concentration of oxalic
acid, which will be used throughout the experiment.
Leaching experiments for ACL tails were conducted at
different concentrations of oxalic acid to understand the
reactivity and see if the reaction was as rapid as 0.57 or
0.8 mol/L. The results obtained are presented in Figure 8.
It was observed that the dissolution of these elements
at different concentrations was linear till 0.57 mol/L. After
0
10
20
30
40
50
60
70
80
90
100
0 5 10 15 20 25
Time (h)
P Fe T-REE
Figure 6. Elemental dissolution of ACL tailings in 0.8 mol/L
oxalic acid (S/L ratio =1:10, 250 rpm, 0.3 mol/L oxalic acid
added after 24 h)
0
10
20
30
40
50
60
70
80
90
100
0 0.5 1 1.5 2 2.5 3
Time (h)
P Fe REE
Figure 7. Elemental dissolution of ACL tailings in 0.5 mol/L
oxalic acid (S/L ratio =1:10, 250 rpm, 0.1 mol/L oxalic acid
added every hour)
y =204.36x -28.799
R² =0.9958
y =177.26x -13.177
R² =0.9964
y =144.51x -28.798
R² =0.8811
0
10
20
30
40
50
60
70
80
90
100
0 0.1 0.2 0.3 0.4 0.5 0.6
P Fe T-REE
0
10
20
30
40
50
60
70
80
90
100
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
P Fe T-REE
Figure 8. Effect of oxalic acid concentration on the elemental dissolution of ACL tailings (25°C, 1 hour, S/L ratio =1:10,
250 rpm)
Disolton(
)Disolton(
)
Disolton(
)Disolton(
)
concentration of 0.5 mol/L was used. Samples were taken
frequently throughout the experiment.
It was expected that the REE would precipitate as REE
oxalates with the introduction of fresh oxalic acid. However,
the REE dissolution stayed constant throughout. This sug-
gests that the reaction needs a higher concentration of oxalic
acid as this would allow for additional free oxalate for the
REE to precipitate as REE oxalate. Therefore, further test
work is to be done with a greater concentration of oxalic
acid, which will be used throughout the experiment.
Leaching experiments for ACL tails were conducted at
different concentrations of oxalic acid to understand the
reactivity and see if the reaction was as rapid as 0.57 or
0.8 mol/L. The results obtained are presented in Figure 8.
It was observed that the dissolution of these elements
at different concentrations was linear till 0.57 mol/L. After
0
10
20
30
40
50
60
70
80
90
100
0 5 10 15 20 25
Time (h)
P Fe T-REE
Figure 6. Elemental dissolution of ACL tailings in 0.8 mol/L
oxalic acid (S/L ratio =1:10, 250 rpm, 0.3 mol/L oxalic acid
added after 24 h)
0
10
20
30
40
50
60
70
80
90
100
0 0.5 1 1.5 2 2.5 3
Time (h)
P Fe REE
Figure 7. Elemental dissolution of ACL tailings in 0.5 mol/L
oxalic acid (S/L ratio =1:10, 250 rpm, 0.1 mol/L oxalic acid
added every hour)
y =204.36x -28.799
R² =0.9958
y =177.26x -13.177
R² =0.9964
y =144.51x -28.798
R² =0.8811
0
10
20
30
40
50
60
70
80
90
100
0 0.1 0.2 0.3 0.4 0.5 0.6
P Fe T-REE
0
10
20
30
40
50
60
70
80
90
100
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
P Fe T-REE
Figure 8. Effect of oxalic acid concentration on the elemental dissolution of ACL tailings (25°C, 1 hour, S/L ratio =1:10,
250 rpm)
Disolton(
)Disolton(
)
Disolton(
)Disolton(
)