1214 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
diagrammatically in Figure 5. This flowsheet arrangement
achieved a final concentrate assaying 90% THM, with
assay grade of 0.4% CeO2, 39% TiO2 and 4.5% ZrO2.
Based on CeO2 distribution, the overall recovery of mona-
zite (and other REE-minerals) was determined to be 94.7%,
which was comparable to the recovery of zircon (95.2%)
and TiO2-minerals (93.4%).
Initial Conventional MSP
Initial concept for the mineral separation plant (MSP)
flowsheet utilized conventional dry mill techniques based
on the relative coarse size of the heavy minerals as well as
the elevated proportion of ilmenite in the feed. A stage of
mechanical attrition was included to remove staining from
the mineral surface with the aim of improving selectivity
through the dry circuit.
An overview of the circuit configuration is shown in
Figure 6 two stages of dry RED separation, one stage of dry
HTR and one stage of dry RER separation were required
to isolate the monazite and xenotime into a medium grade
raw concentrate with grade 11.5% CeO2 and 1.47% Y2O3.
Recovery of REE-minerals, based on CeO2 performance,
was 92.9% relative to the MSP feed. Final upgrading
required additional stages of HTR, wet gravity separation
by wet shaking table and dry magnetic separation. Final
grades of 23.0% CeO2 and 2.5% Y2O3 were achieved and
overall recovery relative to the MSP was calculated to be
77%.
The complexity of the circuit is consistent with over-
lapping physical properties of the mineral components in
the gravity concentrate. Minerals compete against each
other when processed through the series of electrostatic,
magnetic and gravity separation steps. For example, ilmen-
ite and monazite are both para-magnetic minerals, with
modest variance in magnetic susceptibility. Aluminum-
silicates, zircon and monazite are non-conductive minerals,
with modest difference in electrostatic response. Zircon and
monazite are also both relatively high specific gravity (SG)
minerals, thereby limiting the efficacy of gravity separation
techniques.
Discussion
Due to their high SG, monazite and xenotime co-report to
concentrate with other heavy minerals in the initial PCP.
C T
M
C T
M
M T
C
T M
C
M
C
Finisher Stage
PCP Feed
HMC
Rougher Stage
Scavenger
Stage
Cleaner stage
Recleaner
Stage
Figure 5. Ore-1 PCP circuit
diagrammatically in Figure 5. This flowsheet arrangement
achieved a final concentrate assaying 90% THM, with
assay grade of 0.4% CeO2, 39% TiO2 and 4.5% ZrO2.
Based on CeO2 distribution, the overall recovery of mona-
zite (and other REE-minerals) was determined to be 94.7%,
which was comparable to the recovery of zircon (95.2%)
and TiO2-minerals (93.4%).
Initial Conventional MSP
Initial concept for the mineral separation plant (MSP)
flowsheet utilized conventional dry mill techniques based
on the relative coarse size of the heavy minerals as well as
the elevated proportion of ilmenite in the feed. A stage of
mechanical attrition was included to remove staining from
the mineral surface with the aim of improving selectivity
through the dry circuit.
An overview of the circuit configuration is shown in
Figure 6 two stages of dry RED separation, one stage of dry
HTR and one stage of dry RER separation were required
to isolate the monazite and xenotime into a medium grade
raw concentrate with grade 11.5% CeO2 and 1.47% Y2O3.
Recovery of REE-minerals, based on CeO2 performance,
was 92.9% relative to the MSP feed. Final upgrading
required additional stages of HTR, wet gravity separation
by wet shaking table and dry magnetic separation. Final
grades of 23.0% CeO2 and 2.5% Y2O3 were achieved and
overall recovery relative to the MSP was calculated to be
77%.
The complexity of the circuit is consistent with over-
lapping physical properties of the mineral components in
the gravity concentrate. Minerals compete against each
other when processed through the series of electrostatic,
magnetic and gravity separation steps. For example, ilmen-
ite and monazite are both para-magnetic minerals, with
modest variance in magnetic susceptibility. Aluminum-
silicates, zircon and monazite are non-conductive minerals,
with modest difference in electrostatic response. Zircon and
monazite are also both relatively high specific gravity (SG)
minerals, thereby limiting the efficacy of gravity separation
techniques.
Discussion
Due to their high SG, monazite and xenotime co-report to
concentrate with other heavy minerals in the initial PCP.
C T
M
C T
M
M T
C
T M
C
M
C
Finisher Stage
PCP Feed
HMC
Rougher Stage
Scavenger
Stage
Cleaner stage
Recleaner
Stage
Figure 5. Ore-1 PCP circuit