XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 783
Metallurgical Performance of Flotation Tests
from DDCT
Flotation Tests Using 100% RDW as
Freshwater Makeup
Environmental constraints require the gradual change of
water usage, from continental water (CW) resources to sea-
water or desalinated seawater. In this aim, to evaluate the
effect of the Life of Mine (LOM) minerals dissolution on
the process water quality and the impact on the final min-
eral recovery, a first series of DDCT was developed. For this
purpose, 100% RDW was used as makeup water, to quan-
tify the individual effect of dissolving LOM minerals at the
same water quality. Table 4 shows the incremental changes
in flotation recovery of Cu, Mo, Fe, and mass, due to the
LOM minerals dissolution, for years 2024 to 2028. It can
be observed that the minerals dissolution increases the pro-
cess water conductivity around 2–3 (mS/cm) after reaching
the equilibrium of the DDCT. Additionally, the change in
the water quality (ionic strength) affects the minerals and
mass recovery differently, depending on the type of LOM
minerals. In terms of metallurgical results, the flotation
tests showed a consistent increase in copper recovery (0.1%
to 2.8%) and a decrease in molybdenite recovery (–0.4#
to –6.8%), except in 2028, were the molybdenite recov-
ery increases (3,1%) with minor effect in copper recovery.
These results show the effect of changing LOM minerals
with the same makeup water (reference).
Flotation Tests for the Future Freshwater Makeup
(FWM) Consisting of Mixtures of (RDW) and
Continental Water (CW)
A second series of DDCT was developed to quantify the
effect of the future process water quality, and the LOM
minerals dissolution on the mineral recovery for years
2024 to 2028. For this purpose, future freshwater makeups
consisting of mixtures of 50% RDW and 50% continental
water CW (50/50), and mixtures of 65% RDW and 35%
CW (65/35), allowed to quantify the effect of the makeup
water quality and dissolution of LOM minerals on the flo-
tation recovery.
Flotation tests were developed at the beginning of the
DDCT using the freshwater makeup (FWM), and at the
end of the DDCT using the water of the last cycle (11), to
evaluate the combined effect of the mineral and the fresh-
water makeup. According to the continental water (CW)
constraints for the next years (2024–2028), the year 2024
considers actual process water (PW) for the initial flotation,
while freshwater makeup with RDW/CW (50/50) was used
for the initial flotation and makeup water in years 2025 to
2027. Finally, for year 2028 the RWD/CW was (65/35) for
the initial flotation and for the freshwater makeup.
Table 5 shows the incremental changes in flota-
tion recovery of Cu, Mo, Fe, and mass, for years 2024 to
2028. Only in 2024, the final conductivity of the DDCT
(12.0 mS/cm) was lower than the initial condition using
PW, because the ionic strength of the freshwater makeup
(50/50) was lower than the initial process water inventory
in the plant, and the effect of minerals dissolution was
less significant than the dilution due to the new freshwa-
ter makeup. In years 2025, 2026 and 2027, the final con-
ductivity increased up to 11.5–12.1 mS/cm, after reaching
the equilibrium in the DDCT, due to the mineral dissolu-
tion. For 2028, the conductivity reached a final value of
10.6 mS/cm, because the water makeup has a larger con-
tent of RDW (65/35), with lower conductivity (8.5 mS/
cm), which increases the water dilution effect. Additionally,
the changes in the water quality (ionic strength) affect the
minerals and mass recovery differently, depending on the
type of LOM minerals. In terms of metallurgical results,
there was an increment of copper recovery in all cases
Table 4. Effect of minerals dissolution on the incremental recovery, using remineralized desalinated water (RDW) as makeup water
LOM
Mineral Water type
DDCT Conductivity
(mS/cm)
Incremental Recovery, %
ΔCu, %ΔFe, %ΔMo, %Δmass, %
2024 Initial: RDW Initial 0.6 2.8 –1.6 –5.5 0.1
Makeup: RDW Final 2.6
2025 Initial: RDW Initial 0.7 0.1 –1.1 –4.8 –0.4
Makeup: RDW Final 3.3
2026 Initial: RDW Initial 0.6 2.0 –0.9 –6.8 0.8
Makeup: RDW Final 2.3
2027 Initial: RDW Initial 0.6 0.4 5.7 –0.4 0.9
Makeup: RDW Final 4.3
2028 Initial: RDW Initial 0.6 0.1 4.7 3.1 1.1
Makeup: RDW Final 3.6
Metallurgical Performance of Flotation Tests
from DDCT
Flotation Tests Using 100% RDW as
Freshwater Makeup
Environmental constraints require the gradual change of
water usage, from continental water (CW) resources to sea-
water or desalinated seawater. In this aim, to evaluate the
effect of the Life of Mine (LOM) minerals dissolution on
the process water quality and the impact on the final min-
eral recovery, a first series of DDCT was developed. For this
purpose, 100% RDW was used as makeup water, to quan-
tify the individual effect of dissolving LOM minerals at the
same water quality. Table 4 shows the incremental changes
in flotation recovery of Cu, Mo, Fe, and mass, due to the
LOM minerals dissolution, for years 2024 to 2028. It can
be observed that the minerals dissolution increases the pro-
cess water conductivity around 2–3 (mS/cm) after reaching
the equilibrium of the DDCT. Additionally, the change in
the water quality (ionic strength) affects the minerals and
mass recovery differently, depending on the type of LOM
minerals. In terms of metallurgical results, the flotation
tests showed a consistent increase in copper recovery (0.1%
to 2.8%) and a decrease in molybdenite recovery (–0.4#
to –6.8%), except in 2028, were the molybdenite recov-
ery increases (3,1%) with minor effect in copper recovery.
These results show the effect of changing LOM minerals
with the same makeup water (reference).
Flotation Tests for the Future Freshwater Makeup
(FWM) Consisting of Mixtures of (RDW) and
Continental Water (CW)
A second series of DDCT was developed to quantify the
effect of the future process water quality, and the LOM
minerals dissolution on the mineral recovery for years
2024 to 2028. For this purpose, future freshwater makeups
consisting of mixtures of 50% RDW and 50% continental
water CW (50/50), and mixtures of 65% RDW and 35%
CW (65/35), allowed to quantify the effect of the makeup
water quality and dissolution of LOM minerals on the flo-
tation recovery.
Flotation tests were developed at the beginning of the
DDCT using the freshwater makeup (FWM), and at the
end of the DDCT using the water of the last cycle (11), to
evaluate the combined effect of the mineral and the fresh-
water makeup. According to the continental water (CW)
constraints for the next years (2024–2028), the year 2024
considers actual process water (PW) for the initial flotation,
while freshwater makeup with RDW/CW (50/50) was used
for the initial flotation and makeup water in years 2025 to
2027. Finally, for year 2028 the RWD/CW was (65/35) for
the initial flotation and for the freshwater makeup.
Table 5 shows the incremental changes in flota-
tion recovery of Cu, Mo, Fe, and mass, for years 2024 to
2028. Only in 2024, the final conductivity of the DDCT
(12.0 mS/cm) was lower than the initial condition using
PW, because the ionic strength of the freshwater makeup
(50/50) was lower than the initial process water inventory
in the plant, and the effect of minerals dissolution was
less significant than the dilution due to the new freshwa-
ter makeup. In years 2025, 2026 and 2027, the final con-
ductivity increased up to 11.5–12.1 mS/cm, after reaching
the equilibrium in the DDCT, due to the mineral dissolu-
tion. For 2028, the conductivity reached a final value of
10.6 mS/cm, because the water makeup has a larger con-
tent of RDW (65/35), with lower conductivity (8.5 mS/
cm), which increases the water dilution effect. Additionally,
the changes in the water quality (ionic strength) affect the
minerals and mass recovery differently, depending on the
type of LOM minerals. In terms of metallurgical results,
there was an increment of copper recovery in all cases
Table 4. Effect of minerals dissolution on the incremental recovery, using remineralized desalinated water (RDW) as makeup water
LOM
Mineral Water type
DDCT Conductivity
(mS/cm)
Incremental Recovery, %
ΔCu, %ΔFe, %ΔMo, %Δmass, %
2024 Initial: RDW Initial 0.6 2.8 –1.6 –5.5 0.1
Makeup: RDW Final 2.6
2025 Initial: RDW Initial 0.7 0.1 –1.1 –4.8 –0.4
Makeup: RDW Final 3.3
2026 Initial: RDW Initial 0.6 2.0 –0.9 –6.8 0.8
Makeup: RDW Final 2.3
2027 Initial: RDW Initial 0.6 0.4 5.7 –0.4 0.9
Makeup: RDW Final 4.3
2028 Initial: RDW Initial 0.6 0.1 4.7 3.1 1.1
Makeup: RDW Final 3.6