2280 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
understood that SHA-REE interaction is maximum with
REE cations near this size ±0.1 Å (Trant 2018 Trant et al.,
2018 Sime 2018 Galt 2017) as illustrated by the yellow
band. However, this depends greatly on both lanthanide
contraction (LC) and coordination number (CN) as well
as the anion that the REE is bonded to. Thus, according
to Figure 2, SHA will adsorb strongly on HREE carbon-
ates (HRECs), MREE phosphates (MREPs), and LREE
oxides (LREOs). Likewise, it will adsorb weakly on LREE
carbonates (LRECs) and HREE oxides (HREOs). The goal
of this research is to determine if this phenomenon can be
ascribed to RESs (Mamudu 2024) by comparing the previ-
ous research findings on RECs, REPs and REOs.
Rare Earth Silicates (RESs)
Kinetic Studies
The solution depletion analysis was used to investigate SHA
adsorption on an array of RESs, namely Ln4.67(SiO4)3O
and Ln2Si2O7 where Ln represents lanthanum (La), neo-
dymium (Nd), and dysprosium (Dy) for this study. In
agreement with Figure 2, it is widely recognized that La
and Nd are LREEs whereas Dy belongs to the MREE clas-
sification. Solution depletion results for these six RESs are
Figure 2. Lanthanide contraction (LC) for REE3+ diameter to the head group size of SHA as a function of REM and
coordination number (CN) (Young 2023)
0
0.0001
0.0002
0.0003
0.0004
0.0005
0 50 100 150
Time (min)
pH 9 pH 10 pH 11
Figure 4. SHA solution depletion via La2Si2O7
0
0.0001
0.0002
0.0003
0.0004
0.0005
0 50 100 150
Time (min)
pH 9 pH 10 pH 11
Figure 3. SHA solution depletion via La4.67(SiO4)3O
Conc.
moles/L
Conc.
moles/L
understood that SHA-REE interaction is maximum with
REE cations near this size ±0.1 Å (Trant 2018 Trant et al.,
2018 Sime 2018 Galt 2017) as illustrated by the yellow
band. However, this depends greatly on both lanthanide
contraction (LC) and coordination number (CN) as well
as the anion that the REE is bonded to. Thus, according
to Figure 2, SHA will adsorb strongly on HREE carbon-
ates (HRECs), MREE phosphates (MREPs), and LREE
oxides (LREOs). Likewise, it will adsorb weakly on LREE
carbonates (LRECs) and HREE oxides (HREOs). The goal
of this research is to determine if this phenomenon can be
ascribed to RESs (Mamudu 2024) by comparing the previ-
ous research findings on RECs, REPs and REOs.
Rare Earth Silicates (RESs)
Kinetic Studies
The solution depletion analysis was used to investigate SHA
adsorption on an array of RESs, namely Ln4.67(SiO4)3O
and Ln2Si2O7 where Ln represents lanthanum (La), neo-
dymium (Nd), and dysprosium (Dy) for this study. In
agreement with Figure 2, it is widely recognized that La
and Nd are LREEs whereas Dy belongs to the MREE clas-
sification. Solution depletion results for these six RESs are
Figure 2. Lanthanide contraction (LC) for REE3+ diameter to the head group size of SHA as a function of REM and
coordination number (CN) (Young 2023)
0
0.0001
0.0002
0.0003
0.0004
0.0005
0 50 100 150
Time (min)
pH 9 pH 10 pH 11
Figure 4. SHA solution depletion via La2Si2O7
0
0.0001
0.0002
0.0003
0.0004
0.0005
0 50 100 150
Time (min)
pH 9 pH 10 pH 11
Figure 3. SHA solution depletion via La4.67(SiO4)3O
Conc.
moles/L
Conc.
moles/L