6
circulating loads to the mills, thus reducing material over-
grinding and energy consumption. These designs will pre-
vent the generation of middlings through the flowsheet,
thus reducing the silica and impurity content in the final
iron concentrate.
Cleaner Circuit
The particle size distribution achieved by the second-
ary grinding circuit will be improved to accomplish high
enrichment and reject of impurities in LIMS hydrosepara-
tors and magnetic separators. These cleaning stages are effi-
cient because they remove a large amount of gangue from
the undersize of high-frequency screens.
Reverse Flotation, Regrinding and Magnetic Separation
Circuit Scavenger
Reverse flotation will allow the sulphur to be removed in
the final concentrate and to obtain high-grade iron con-
centrate with a low content of impurities. The scavenger
LIMS dewatering, grinding and magnetic separation stages
will allow the liberation and recovery of the iron associated
with the gangue (aluminosilicates), avoiding iron losses and
incorporating it into the final concentrate. With this con-
figuration, only a part of the cleaner concentrate (froth) is
ground to liberate magnetite that allows savings in energy
consumption.
CONCLUSION
The process flowsheet met the objective of achieving high
quality and recovery of the final iron concentrate while also
meeting the objective of saving energy and consumables in
its process design. Through the systematic application of
correct metallurgical principles during metallurgical tests
resulting in a modern flowsheet with the incorporation of
proven technologies in the industry. All this from low-grade
disseminated magnetite ore that is difficult to release.
The application of comminution processes in HPGR
equipment significantly aided in the performance of mag-
netic cobbing separation. Then, the classification by par-
ticle sizes in the primary and secondary grinding circuits
was essential to minimize the generation of particles called
“middlings”. Finally, the last part of the flowsheet made it
possible to achieve the high quality and iron production
targets.
ACKNOWLEDGMENTS
I extend a sincere thanks to all colleagues from the differ-
ent specialties of Andes Iron, NRRI Coleraine and Barr
Engineering for their contributions, expertise and high pro-
fessionalism that contributed to the realization of this work.
I would also like to give special thanks to my Heavenly
Father and to Fernando Porcile V., who rests in peace.
REFERENCES
[1] R. L. Bleifuss (1968), “The Mineralogy of Taconite
Products as Related to the Augmentation of
Magnetite Middlings,” 29th Annual mining sympo-
sium, Minnesota, pp. 131–138.
[2] J. Wheeler (2011), “Fine Sizing in Magnetite
Concentration,” Iron Ore Conference, Perth,
Australia.
circulating loads to the mills, thus reducing material over-
grinding and energy consumption. These designs will pre-
vent the generation of middlings through the flowsheet,
thus reducing the silica and impurity content in the final
iron concentrate.
Cleaner Circuit
The particle size distribution achieved by the second-
ary grinding circuit will be improved to accomplish high
enrichment and reject of impurities in LIMS hydrosepara-
tors and magnetic separators. These cleaning stages are effi-
cient because they remove a large amount of gangue from
the undersize of high-frequency screens.
Reverse Flotation, Regrinding and Magnetic Separation
Circuit Scavenger
Reverse flotation will allow the sulphur to be removed in
the final concentrate and to obtain high-grade iron con-
centrate with a low content of impurities. The scavenger
LIMS dewatering, grinding and magnetic separation stages
will allow the liberation and recovery of the iron associated
with the gangue (aluminosilicates), avoiding iron losses and
incorporating it into the final concentrate. With this con-
figuration, only a part of the cleaner concentrate (froth) is
ground to liberate magnetite that allows savings in energy
consumption.
CONCLUSION
The process flowsheet met the objective of achieving high
quality and recovery of the final iron concentrate while also
meeting the objective of saving energy and consumables in
its process design. Through the systematic application of
correct metallurgical principles during metallurgical tests
resulting in a modern flowsheet with the incorporation of
proven technologies in the industry. All this from low-grade
disseminated magnetite ore that is difficult to release.
The application of comminution processes in HPGR
equipment significantly aided in the performance of mag-
netic cobbing separation. Then, the classification by par-
ticle sizes in the primary and secondary grinding circuits
was essential to minimize the generation of particles called
“middlings”. Finally, the last part of the flowsheet made it
possible to achieve the high quality and iron production
targets.
ACKNOWLEDGMENTS
I extend a sincere thanks to all colleagues from the differ-
ent specialties of Andes Iron, NRRI Coleraine and Barr
Engineering for their contributions, expertise and high pro-
fessionalism that contributed to the realization of this work.
I would also like to give special thanks to my Heavenly
Father and to Fernando Porcile V., who rests in peace.
REFERENCES
[1] R. L. Bleifuss (1968), “The Mineralogy of Taconite
Products as Related to the Augmentation of
Magnetite Middlings,” 29th Annual mining sympo-
sium, Minnesota, pp. 131–138.
[2] J. Wheeler (2011), “Fine Sizing in Magnetite
Concentration,” Iron Ore Conference, Perth,
Australia.