2278 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
60%. However, benzoyl hydroxamate exhibited a prefer-
ence for the heavy rare earth elements (HREEs), while the
other collectors showed inferior performance. Moreover,
there was a significant increase in all recoveries for tests
conducted at higher temperatures (Suslavich et al., 2024
Galt 2017).
EXPERIMENTAL WORK
The surfaces of pure oxide, carbonate, phosphate, and sili-
cate powders of three REEs were examined and character-
ized for the adsorption kinetics of SHA: La, Nd, and Dy.
Most of these materials were used as synthetic REMs and
were acquired from Alfa Aesar and Sigma Aldrich with puri-
ties of 99.9%. Additionally, other chemicals not limited to
SHA, SiO2, Na2SiO3, Na4SiO4, NaOH, ferric perchlorate,
ethanol, and perchloric acid were also obtained from these
suppliers. Various methodologies and software applications
were employed to determine the adsorption characteristics
on the surfaces of each REM. In the case of RESs, they were
synthesized at MT Tech.
Synthesis and Characterization of RESs
In contrast to the RECs, REPs and REOs, the RESs were
not readily available for purchase in the market. Instead,
the laboratories used by Metallurgical and Materials
Engineering (M&ME) and Center for Advanced Materials
Processing (CAMP) at MT Tech were actively involved in
synthesizing various types of RESs. The characterization
of these RESs was accomplished with X-ray Diffraction
(XRD) analysis. The RESs were synthesized using a dry
thermal method. The various rare earth oxides (REOs) were
stoichiometrically and homogeneously mixed with SiO2,
Na2SiO3, and Na4SiO4 and subjected to high temperatures
ranging from 900 to 1200 °C in a furnace. Figure 1 displays
an XRD graph representing one of the synthesized silicates
while, Table 1 provides a list of the synthesized silicates
together with their corresponding percentages indicating
their purity.
Kinetic Studies
Equilibrium tests were conducted at ambient temperature.
The tests utilized powdered forms of SHA and REMs, spe-
cifically lanthanum, neodymium, and dysprosium in the
form of REOs, RECs, REPs, and RESs. The experiments
Table1. XRD results of synthesized RESs
Silicate Wt% Wt% (SiO2)
La
4.67 (SiO
4 )
3 O 74.9 25.1
La
2 Si
2 O
7 64.3 35.7
Nd4.67(SiO4)3O 77.6 22.4
Nd2Si2O7 60 40
Dy
4.67 (SiO
4 )
3 O 70.9 29.1
Dy
2 Si
2 O
7 61 39
Figure1. XRD results of lanthanum silicate La
2 Si
2 O
7
60%. However, benzoyl hydroxamate exhibited a prefer-
ence for the heavy rare earth elements (HREEs), while the
other collectors showed inferior performance. Moreover,
there was a significant increase in all recoveries for tests
conducted at higher temperatures (Suslavich et al., 2024
Galt 2017).
EXPERIMENTAL WORK
The surfaces of pure oxide, carbonate, phosphate, and sili-
cate powders of three REEs were examined and character-
ized for the adsorption kinetics of SHA: La, Nd, and Dy.
Most of these materials were used as synthetic REMs and
were acquired from Alfa Aesar and Sigma Aldrich with puri-
ties of 99.9%. Additionally, other chemicals not limited to
SHA, SiO2, Na2SiO3, Na4SiO4, NaOH, ferric perchlorate,
ethanol, and perchloric acid were also obtained from these
suppliers. Various methodologies and software applications
were employed to determine the adsorption characteristics
on the surfaces of each REM. In the case of RESs, they were
synthesized at MT Tech.
Synthesis and Characterization of RESs
In contrast to the RECs, REPs and REOs, the RESs were
not readily available for purchase in the market. Instead,
the laboratories used by Metallurgical and Materials
Engineering (M&ME) and Center for Advanced Materials
Processing (CAMP) at MT Tech were actively involved in
synthesizing various types of RESs. The characterization
of these RESs was accomplished with X-ray Diffraction
(XRD) analysis. The RESs were synthesized using a dry
thermal method. The various rare earth oxides (REOs) were
stoichiometrically and homogeneously mixed with SiO2,
Na2SiO3, and Na4SiO4 and subjected to high temperatures
ranging from 900 to 1200 °C in a furnace. Figure 1 displays
an XRD graph representing one of the synthesized silicates
while, Table 1 provides a list of the synthesized silicates
together with their corresponding percentages indicating
their purity.
Kinetic Studies
Equilibrium tests were conducted at ambient temperature.
The tests utilized powdered forms of SHA and REMs, spe-
cifically lanthanum, neodymium, and dysprosium in the
form of REOs, RECs, REPs, and RESs. The experiments
Table1. XRD results of synthesized RESs
Silicate Wt% Wt% (SiO2)
La
4.67 (SiO
4 )
3 O 74.9 25.1
La
2 Si
2 O
7 64.3 35.7
Nd4.67(SiO4)3O 77.6 22.4
Nd2Si2O7 60 40
Dy
4.67 (SiO
4 )
3 O 70.9 29.1
Dy
2 Si
2 O
7 61 39
Figure1. XRD results of lanthanum silicate La
2 Si
2 O
7