XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1219
run-of-mine ore was comparable with CeO2 assay of 0.03%
only.
Detailed understanding of the samples’ particle size
distributions, specific gravity profiles, chemistry and miner-
alogy through simple metallurgical characterization allowed
the definition of tailored laboratory test work programs.
These led to the development of flowsheets specific to the
unique characteristics of the samples.
In both samples, rare-earth-bearing minerals were able
to be recovered and upgraded by conventional feed prepara-
tion and gravity separation techniques using spiral separa-
tors. Careful selection and control of the spiral separators
coupled with intermediate re-cleaner feed preparation per-
mitted the use of simple gravity spirals for the beneficiation
of the ore-2 despite its significantly finer average particle
size range of 85 µm compared to 220 µm for ore-1.
The study also showed that froth flotation of the rare-
earth minerals contained in the gravity heavy mineral
concentrate is highly selective and effective. The flotation
circuit offers advantages over the dry and wet conventional
processing methods because the rare-earth minerals which
are naturally radioactive are extracted from the circuit
upfront, using a wet-only process. The circuit configuration
therefore alleviates potential onerous occupational health
issues which are linked to the generation of radioactive dust
in conventional mineral sand operations. In addition, flota-
tion achieved both superior recovery and upgrade of the
rare-earth minerals compared to the conventional circuits,
thereby improving projects economics.
The paper demonstrated the value of considering the
varying beneficiation techniques as complementary pro-
cesses rather than competing technologies.
ACKNOWLEDGMENTS
The authors acknowledge the assistance of Tony Fallows,
Josh Hudson, and Graham Fairweather from Mineral
Technologies technical services for the execution of the test
work campaigns. The authors are also grateful to Mineral
Technologies for the support and permission to present the
results.
REFERENCES
Andrews, W. H., Collins, D. N., Hollick C. T. (1990).
The Flotation of Rare Earths—A Contribution to
Industrial Hygiene, The AusIMM Annual Conference.
The Australian Institute of Mining and Metallurgy,
Rotorua, New Zealand. pp. 243–252.
Baker, G. (1962). Detrital Heavy Minerals in Natural
Accumulates: with special reference to Australian
occurrences, Australasian Institute of Mining and
Metallurgy. Pp. 18,19, 82 &83.
Burt, R. (1999). The Role of Gravity Concentration in
Modern Processing Plants. Minerals Engineering, 12
(11), pp. 1291–1300.
Holland-Batt, A. B., Holtham, P.N. (1991). Particle and
fluid motion on spiral separators. Minerals Engineering,
4 (3–4), pp. 457–482.
Holland-Batt, A. B. (1995). Some design considerations
for spiral separator. Minerals Engineering, 8 (11),
pp. 1381–1395.
Mursky, G.A. and Thompson R. M. (1958). A specific
gravity index for mineral, Canadian Mineralogist, 6,
pp. 273–287.
Table 5. Ore-2 REE concentrate chemical composition
Description TiO
2 Fe
2 O
3 SiO
2 Al
2 O
3 ZrO
2 P
2 O
5 U Th CeO
2 Y
2 O
3
Unit %%%%%%%%,%%
Detection Limit 0.01 0.01 0.01 0.01 0.01 0.01 0.001 0.001 0.01 0.01
Conventional MSP 3.47 3.20 3.46 0.26 5.75 24.6 0.26 3.29 19.5 5.21
Hybrid MSP 0.90 0.98 3.53 2.34 1.12 26.7 0.31 3.84 21.3 6.89
run-of-mine ore was comparable with CeO2 assay of 0.03%
only.
Detailed understanding of the samples’ particle size
distributions, specific gravity profiles, chemistry and miner-
alogy through simple metallurgical characterization allowed
the definition of tailored laboratory test work programs.
These led to the development of flowsheets specific to the
unique characteristics of the samples.
In both samples, rare-earth-bearing minerals were able
to be recovered and upgraded by conventional feed prepara-
tion and gravity separation techniques using spiral separa-
tors. Careful selection and control of the spiral separators
coupled with intermediate re-cleaner feed preparation per-
mitted the use of simple gravity spirals for the beneficiation
of the ore-2 despite its significantly finer average particle
size range of 85 µm compared to 220 µm for ore-1.
The study also showed that froth flotation of the rare-
earth minerals contained in the gravity heavy mineral
concentrate is highly selective and effective. The flotation
circuit offers advantages over the dry and wet conventional
processing methods because the rare-earth minerals which
are naturally radioactive are extracted from the circuit
upfront, using a wet-only process. The circuit configuration
therefore alleviates potential onerous occupational health
issues which are linked to the generation of radioactive dust
in conventional mineral sand operations. In addition, flota-
tion achieved both superior recovery and upgrade of the
rare-earth minerals compared to the conventional circuits,
thereby improving projects economics.
The paper demonstrated the value of considering the
varying beneficiation techniques as complementary pro-
cesses rather than competing technologies.
ACKNOWLEDGMENTS
The authors acknowledge the assistance of Tony Fallows,
Josh Hudson, and Graham Fairweather from Mineral
Technologies technical services for the execution of the test
work campaigns. The authors are also grateful to Mineral
Technologies for the support and permission to present the
results.
REFERENCES
Andrews, W. H., Collins, D. N., Hollick C. T. (1990).
The Flotation of Rare Earths—A Contribution to
Industrial Hygiene, The AusIMM Annual Conference.
The Australian Institute of Mining and Metallurgy,
Rotorua, New Zealand. pp. 243–252.
Baker, G. (1962). Detrital Heavy Minerals in Natural
Accumulates: with special reference to Australian
occurrences, Australasian Institute of Mining and
Metallurgy. Pp. 18,19, 82 &83.
Burt, R. (1999). The Role of Gravity Concentration in
Modern Processing Plants. Minerals Engineering, 12
(11), pp. 1291–1300.
Holland-Batt, A. B., Holtham, P.N. (1991). Particle and
fluid motion on spiral separators. Minerals Engineering,
4 (3–4), pp. 457–482.
Holland-Batt, A. B. (1995). Some design considerations
for spiral separator. Minerals Engineering, 8 (11),
pp. 1381–1395.
Mursky, G.A. and Thompson R. M. (1958). A specific
gravity index for mineral, Canadian Mineralogist, 6,
pp. 273–287.
Table 5. Ore-2 REE concentrate chemical composition
Description TiO
2 Fe
2 O
3 SiO
2 Al
2 O
3 ZrO
2 P
2 O
5 U Th CeO
2 Y
2 O
3
Unit %%%%%%%%,%%
Detection Limit 0.01 0.01 0.01 0.01 0.01 0.01 0.001 0.001 0.01 0.01
Conventional MSP 3.47 3.20 3.46 0.26 5.75 24.6 0.26 3.29 19.5 5.21
Hybrid MSP 0.90 0.98 3.53 2.34 1.12 26.7 0.31 3.84 21.3 6.89