1312 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
leach circuit for approximately 5 months in its initial con-
figuration and for three months in the later configuration.
The circuit processed approximately 1,500 kg of ammo-
nium chloride leach residue. The leach efficiency and HCl-
PLS composition for both scenarios is presented in Table 1.
The typical HCl-PLS composition for each scenario is
presented as Table 1. The low density leaching operation
aggregates data from approximately 1-month continuous
campaign while the high density operation aggregates data
from over a month of HCl-PLS fed to the solvent extrac-
tion process covering many leach campaigns. The elemental
analyses were performed using a combination of ICP-OES
(Agilent 5800), ICP-MS (Analytik Jena PlasmaQuant MS
Elite) and XRF (Rigaku ZSX Primus IV). XRF assays are
identified using a *and are elements that do not have a sig-
nificant impact in the solvent extraction circuit.
FLOWSHEET DEVELOPMENT FOR SC
AND REE RECOVERY
The primary objective of the process development effort
was to design a high recovery, low operating cost circuit for
the recovery of scandium and magnet rare earth elements.
It was understood that it implied a highly acidic solution
containing a large variety of metals ions and that hydro-
chloric acid regeneration would be required to support the
low operating cost requirements.
A review of the literature was conducted for the extrac-
tion potential of various extractants for REE across a range
of acidity. The main parameter of the scandium circuit raf-
finate governing the potential recovery of rare earth ele-
ments is the acidity of the stream. To a lesser extent the
chloride content of the stream also impacts the process,
but contrarily to the acidity, the high chloride content of
the stream has a positive impact on all extractants. The pH
operating range of various extractants were compared for
representative REEs such as lanthanum (La) for the lower
limit of extractability as it has the largest ionic radius typi-
cally translating in lower extraction extents. Neodymium
(Nd) and dysprosium (Dy) were selected because they are
the main targeted products. The summarized literature
reviewed for distribution ratios of Nd are presented as
Figure 4. It should be noted that smoothed lines between
the data points are presented as a support for ease of reading,
Figure 3. Carbonates elemental distribution
leach circuit for approximately 5 months in its initial con-
figuration and for three months in the later configuration.
The circuit processed approximately 1,500 kg of ammo-
nium chloride leach residue. The leach efficiency and HCl-
PLS composition for both scenarios is presented in Table 1.
The typical HCl-PLS composition for each scenario is
presented as Table 1. The low density leaching operation
aggregates data from approximately 1-month continuous
campaign while the high density operation aggregates data
from over a month of HCl-PLS fed to the solvent extrac-
tion process covering many leach campaigns. The elemental
analyses were performed using a combination of ICP-OES
(Agilent 5800), ICP-MS (Analytik Jena PlasmaQuant MS
Elite) and XRF (Rigaku ZSX Primus IV). XRF assays are
identified using a *and are elements that do not have a sig-
nificant impact in the solvent extraction circuit.
FLOWSHEET DEVELOPMENT FOR SC
AND REE RECOVERY
The primary objective of the process development effort
was to design a high recovery, low operating cost circuit for
the recovery of scandium and magnet rare earth elements.
It was understood that it implied a highly acidic solution
containing a large variety of metals ions and that hydro-
chloric acid regeneration would be required to support the
low operating cost requirements.
A review of the literature was conducted for the extrac-
tion potential of various extractants for REE across a range
of acidity. The main parameter of the scandium circuit raf-
finate governing the potential recovery of rare earth ele-
ments is the acidity of the stream. To a lesser extent the
chloride content of the stream also impacts the process,
but contrarily to the acidity, the high chloride content of
the stream has a positive impact on all extractants. The pH
operating range of various extractants were compared for
representative REEs such as lanthanum (La) for the lower
limit of extractability as it has the largest ionic radius typi-
cally translating in lower extraction extents. Neodymium
(Nd) and dysprosium (Dy) were selected because they are
the main targeted products. The summarized literature
reviewed for distribution ratios of Nd are presented as
Figure 4. It should be noted that smoothed lines between
the data points are presented as a support for ease of reading,
Figure 3. Carbonates elemental distribution