1720 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
CONCLUSIONS
Antisolvent crystallization has been proven to be an alterna-
tive candidate to produce a crucial vanadium intermediate
product from Bayer liquor under ambient conditions. At
the higher O/A ratio (0.75), a faster attainment of desirable
yields (≥ 97%) was realized. This yield came with an early
onset of acicular crystal formation along with more impu-
rity incorporation into the solid phase, although this was
less pronounced in cases where dilute acetone was used. It
is anticipated that coupling dilute antisolvent with seeding
could induce closer supersaturation control of the impure
system and lead to attainment of the desired purity and
yield. The value proposition would be retrofitting plants
using the Bayer process to include addition of antisolvent
crystallization or removing one calcining stage in the con-
ventional vanadium extraction flowsheet.
1 h 2 h 4 h 6 h
Pure
AS: 100 %
Impure
AS: 100 %
Impure
AS: 90 %
Impure
AS: 80 %
Figure 5. Changes in crystal habit at [V5+] =30 g/L and O/A =0.75 for pure and impure system
Figure 6. SEM images for impure system at [V5+] =
30 g/L and O/A =0.75
CONCLUSIONS
Antisolvent crystallization has been proven to be an alterna-
tive candidate to produce a crucial vanadium intermediate
product from Bayer liquor under ambient conditions. At
the higher O/A ratio (0.75), a faster attainment of desirable
yields (≥ 97%) was realized. This yield came with an early
onset of acicular crystal formation along with more impu-
rity incorporation into the solid phase, although this was
less pronounced in cases where dilute acetone was used. It
is anticipated that coupling dilute antisolvent with seeding
could induce closer supersaturation control of the impure
system and lead to attainment of the desired purity and
yield. The value proposition would be retrofitting plants
using the Bayer process to include addition of antisolvent
crystallization or removing one calcining stage in the con-
ventional vanadium extraction flowsheet.
1 h 2 h 4 h 6 h
Pure
AS: 100 %
Impure
AS: 100 %
Impure
AS: 90 %
Impure
AS: 80 %
Figure 5. Changes in crystal habit at [V5+] =30 g/L and O/A =0.75 for pure and impure system
Figure 6. SEM images for impure system at [V5+] =
30 g/L and O/A =0.75