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Effect of Makeup Water Quality and Future Minerals on
Flotation Plant Performance
P. Vallejos, J. Yianatos
Dept. of Chemical and Environmental Eng., Universidad Técnica Federico Santa María, Chile
C. Jara
Compañía Minera Doña Inés de Collahuasi (CMDIC), Chile
BHP Minerals Americas, Chile
F. Ruiz and D. Dragicevic
Compañía Minera Doña Inés de Collahuasi (CMDIC), Chile
ABSTRACT: The use of water in flotation plants is quite efficient, recovering about 80% of the process water
while the remaining 20% corresponds to fresh makeup water. Currently, due to environmental constraints,
including the shortage of freshwater resources, the use of seawater as alternative makeup water has been
considered, either as seawater or desalinated water. Changes in the makeup water quality will affect the process
water, having an impact on the plant metallurgical performance. At the same time, the new water resources will
cause changes in the future plant operation, which deserves study.
In this paper, a case study is presented, considering the use of remineralized desalinated water as a partial
replacement of the continental freshwater resources that are currently available. As a preliminary analysis, the
effect of water quality on the metallurgical performance was evaluated at batch scale, considering tap water, sea-
water, desalinated water, current process water, and mixtures of water with different salinity. Different minerals
with fast and slow floatability were included in the analysis. Then, the assessment of the future makeup water
changes on the process water quality and metallurgical performance showed a significant impact for the period
2024–2028, according to the type of future life-of-mine (LOM) minerals. Results showed lower mineral recov-
eries when desalinated water, tap water and seawater was tested. The best recoveries were obtained for the cur-
rent process water, and mixtures of water. Therefore, the minerals studied require a certain level of ionic strength
to reach an optimal recovery. Additionally, the water quality changes affect more strongly the low-floatability
minerals.
The quality of the future process water was estimated using a dissolution/dilution cycle test (DDCT) developed
for testing at laboratory scale. Results showed a decrease in the ionic strength of the process water, by dilution
of the recovered water, when the makeup water has a significant lower ions content (e.g., desalinated water). On
the other hand, it was found an increase in the ionic strength of the process water because of the mineral dis-
solution. Additionally, the future process water quality stabilizes at an ionic strength closer to the new makeup
water. Consequently, the plant metallurgical performance will depend on the future mineral characteristics and
the future makeup water quality.
Effect of Makeup Water Quality and Future Minerals on
Flotation Plant Performance
P. Vallejos, J. Yianatos
Dept. of Chemical and Environmental Eng., Universidad Técnica Federico Santa María, Chile
C. Jara
Compañía Minera Doña Inés de Collahuasi (CMDIC), Chile
BHP Minerals Americas, Chile
F. Ruiz and D. Dragicevic
Compañía Minera Doña Inés de Collahuasi (CMDIC), Chile
ABSTRACT: The use of water in flotation plants is quite efficient, recovering about 80% of the process water
while the remaining 20% corresponds to fresh makeup water. Currently, due to environmental constraints,
including the shortage of freshwater resources, the use of seawater as alternative makeup water has been
considered, either as seawater or desalinated water. Changes in the makeup water quality will affect the process
water, having an impact on the plant metallurgical performance. At the same time, the new water resources will
cause changes in the future plant operation, which deserves study.
In this paper, a case study is presented, considering the use of remineralized desalinated water as a partial
replacement of the continental freshwater resources that are currently available. As a preliminary analysis, the
effect of water quality on the metallurgical performance was evaluated at batch scale, considering tap water, sea-
water, desalinated water, current process water, and mixtures of water with different salinity. Different minerals
with fast and slow floatability were included in the analysis. Then, the assessment of the future makeup water
changes on the process water quality and metallurgical performance showed a significant impact for the period
2024–2028, according to the type of future life-of-mine (LOM) minerals. Results showed lower mineral recov-
eries when desalinated water, tap water and seawater was tested. The best recoveries were obtained for the cur-
rent process water, and mixtures of water. Therefore, the minerals studied require a certain level of ionic strength
to reach an optimal recovery. Additionally, the water quality changes affect more strongly the low-floatability
minerals.
The quality of the future process water was estimated using a dissolution/dilution cycle test (DDCT) developed
for testing at laboratory scale. Results showed a decrease in the ionic strength of the process water, by dilution
of the recovered water, when the makeup water has a significant lower ions content (e.g., desalinated water). On
the other hand, it was found an increase in the ionic strength of the process water because of the mineral dis-
solution. Additionally, the future process water quality stabilizes at an ionic strength closer to the new makeup
water. Consequently, the plant metallurgical performance will depend on the future mineral characteristics and
the future makeup water quality.