1318 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
Unfortunately, the low scandium concentration in the
ore does not allow for the operation of units downstream
of the scandium extraction circuit nor of the scandium
scavenging recycle loop. Constraints on the demonstration
unit design at low flow forced L3 to operate the scandium
extraction circuit in non-steady state. The scandium extrac-
tion circuit uses a 20%v mixture of D2EHPA in kerosene.
The circuit operates using 25 mL per minute of HCl-PLS
and 5 mL per minute of organic for an operating O:A of
1:5. A 20 mL per minute internal recirculation to each cell
is also included in the circuit. Organic is circulated in a
closed loop from a buffer tank to the extraction battery and
back to the buffer tank. Periodically, a sample of loaded
organic is taken from the buffer tank and replaced by fresh
organic. Scrubbing and stripping experiments will be per-
formed manually using the loaded organic taken from the
extraction circuit. The scrubbing and stripping process has
been described by Verbaan et al. (Verbaan et al., 2017)
Figure 11 presents the key operating data for this extraction
circuit while Figure 12 presents the evolution of the organic
metal distribution during that period.
Thorium Recovery Circuit
The thorium recovery unit (ThE) is comprised of four
stages of extraction and four stages of stripping. The tho-
rium extraction circuit uses a 20%v mixture of D2EHPA
in kerosene. The demonstration circuit has the same con-
figuration as the commercial circuit and operates in series
on the raffinate of the scandium recovery circuit. It utilizes
5 mL per minute of organic for an approximate operating
O:A of 1:5. A 20 mL per minute internal recirculation to
each cell is also included in the extraction portion of the
circuit. The stripping circuit uses 25 mL per minute of a
2.5M sulfuric acid and 3%v of hydrogen peroxide solution
as a strip solution. Table 2 presents the key operating data
for this circuit.
In the commercial circuit, a bleed from the thorium cir-
cuit to the scandium circuit will also be operated for the
scavenging of any scandium not extracted in the scandium
circuit. Elemental deportation in the thorium extraction
demonstration circuit per product stream is presented as
Figure 13. The ThE circuit is not yet operating at steady
Figure 10. Primary solvent extraction block flow diagram
Unfortunately, the low scandium concentration in the
ore does not allow for the operation of units downstream
of the scandium extraction circuit nor of the scandium
scavenging recycle loop. Constraints on the demonstration
unit design at low flow forced L3 to operate the scandium
extraction circuit in non-steady state. The scandium extrac-
tion circuit uses a 20%v mixture of D2EHPA in kerosene.
The circuit operates using 25 mL per minute of HCl-PLS
and 5 mL per minute of organic for an operating O:A of
1:5. A 20 mL per minute internal recirculation to each cell
is also included in the circuit. Organic is circulated in a
closed loop from a buffer tank to the extraction battery and
back to the buffer tank. Periodically, a sample of loaded
organic is taken from the buffer tank and replaced by fresh
organic. Scrubbing and stripping experiments will be per-
formed manually using the loaded organic taken from the
extraction circuit. The scrubbing and stripping process has
been described by Verbaan et al. (Verbaan et al., 2017)
Figure 11 presents the key operating data for this extraction
circuit while Figure 12 presents the evolution of the organic
metal distribution during that period.
Thorium Recovery Circuit
The thorium recovery unit (ThE) is comprised of four
stages of extraction and four stages of stripping. The tho-
rium extraction circuit uses a 20%v mixture of D2EHPA
in kerosene. The demonstration circuit has the same con-
figuration as the commercial circuit and operates in series
on the raffinate of the scandium recovery circuit. It utilizes
5 mL per minute of organic for an approximate operating
O:A of 1:5. A 20 mL per minute internal recirculation to
each cell is also included in the extraction portion of the
circuit. The stripping circuit uses 25 mL per minute of a
2.5M sulfuric acid and 3%v of hydrogen peroxide solution
as a strip solution. Table 2 presents the key operating data
for this circuit.
In the commercial circuit, a bleed from the thorium cir-
cuit to the scandium circuit will also be operated for the
scavenging of any scandium not extracted in the scandium
circuit. Elemental deportation in the thorium extraction
demonstration circuit per product stream is presented as
Figure 13. The ThE circuit is not yet operating at steady
Figure 10. Primary solvent extraction block flow diagram