1
25-062
Modern Process Design for Iron Ore
Milton Rojas
ANDES IRON, Stgo., Chile.
Boyd Eisenbraun
BARR ENGINEERING, MN, US.
Dennis Murr
BARR ENGINEERING, MN, US.
INTRODUCTION
Approximately since 1925, the phenomena of grinding and
classification of minerals with screens have been studied. In
the U.S. iron ore mining operations located in the so-called
“Mesabi Iron range,” magnetite processing plants have
made progress in the application of high-frequency screens
that have allowed them to process low-grade Taconite ores
and successfully achieve the economic benefit of these
minerals. In the particular case of magnetite minerals dis-
seminated in the siliceous matrix, the main objective is to
reduce the generation of particles called “middlings” with
high silica contents.
Commonly the primary challenge of the metallurgical
task is to achieve high recoveries and iron concentrates with
low impurities. To achieve this, several studies and indus-
trial applications have shown success in this regard and
not only in iron ores, but also in other minerals around
the world. The study described in this paper attempts to
describe some key aspects that helped develop an effective
solution and list the benefits associated with this modern
process design by using industry-proven technologies for
minerals in Chile that have similar characteristics to the
minerals of the iron belt in the United States.
ORE
The Dominga project deposit is made up of two IOCG
“Iron Oxide Copper Gold” mineralized bodies and its min-
eral resources are estimated at around one billion tons of
magnetite ore and is located in the fourth region of Chile
in the coastal mountain range belonging to the ferrous belt
of Chile.
Mineralogy
The mineralogical study indicates that the main minerals
of the deposit are albite, magnetite, quartz, mica, chlorite,
actinolite, pyrite, chalcopyrite and calcite, whose miner-
als with economic value are magnetite and chalcopyrite.
Additional studies also indicate that pyrite contains cobalt
contents, and studies are currently underway to evaluate its
production.
Figure 1. Photomicrographs typical sample of ore
(from HPGR under 3 mm), +53 µm (+270 Mesh).
Photomicrograph (500X) of liberated magnetite,
chalcopyrite and pyrite. Liberated magnetite with gangue
inclusions is also observed
25-062
Modern Process Design for Iron Ore
Milton Rojas
ANDES IRON, Stgo., Chile.
Boyd Eisenbraun
BARR ENGINEERING, MN, US.
Dennis Murr
BARR ENGINEERING, MN, US.
INTRODUCTION
Approximately since 1925, the phenomena of grinding and
classification of minerals with screens have been studied. In
the U.S. iron ore mining operations located in the so-called
“Mesabi Iron range,” magnetite processing plants have
made progress in the application of high-frequency screens
that have allowed them to process low-grade Taconite ores
and successfully achieve the economic benefit of these
minerals. In the particular case of magnetite minerals dis-
seminated in the siliceous matrix, the main objective is to
reduce the generation of particles called “middlings” with
high silica contents.
Commonly the primary challenge of the metallurgical
task is to achieve high recoveries and iron concentrates with
low impurities. To achieve this, several studies and indus-
trial applications have shown success in this regard and
not only in iron ores, but also in other minerals around
the world. The study described in this paper attempts to
describe some key aspects that helped develop an effective
solution and list the benefits associated with this modern
process design by using industry-proven technologies for
minerals in Chile that have similar characteristics to the
minerals of the iron belt in the United States.
ORE
The Dominga project deposit is made up of two IOCG
“Iron Oxide Copper Gold” mineralized bodies and its min-
eral resources are estimated at around one billion tons of
magnetite ore and is located in the fourth region of Chile
in the coastal mountain range belonging to the ferrous belt
of Chile.
Mineralogy
The mineralogical study indicates that the main minerals
of the deposit are albite, magnetite, quartz, mica, chlorite,
actinolite, pyrite, chalcopyrite and calcite, whose miner-
als with economic value are magnetite and chalcopyrite.
Additional studies also indicate that pyrite contains cobalt
contents, and studies are currently underway to evaluate its
production.
Figure 1. Photomicrographs typical sample of ore
(from HPGR under 3 mm), +53 µm (+270 Mesh).
Photomicrograph (500X) of liberated magnetite,
chalcopyrite and pyrite. Liberated magnetite with gangue
inclusions is also observed