3582 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
StackCell, Staged flotation reactor (SFR), Direct flotation
reactor (DFR), etc. Both HIP and HIM flotation cells are
energy efficient and produce fine bubbles suitable for the
recovery of fine particles (Hassanzadeh et al, 2020). Several
studies have demonstrated that both HIP and HIM flota-
tion cells outperform mechanical cells in terms of metallur-
gical performance at pilot and industrial scales, especially
in fines flotation (Hassanzadeh et al, 2020). In the iron ore
context, both HIP and HIM flotation technologies may
be able to recover fine-grained hematite resources through
direct flotation (DF). They may also recover fine-grained
silica through the RCF process. Furthermore, most of the
HIP and HIM flotation cells have froth washing systems
which may reduce the entrainment of Fe-bearing miner-
als during RCF. Froth washing is important, considering
that there is a push towards the product of high-quality DR
concentrates.
Coarse Particle Processing Opportunities
Mining companies are under pressure to decarbonize their
operations and one of the strategies to achieve this goal is
coarse particle processing (CPP). Conventional iron pro-
cessing flowsheets which involve fine grinding of 25–44 µm
are energy intensive as the finer the ore, the higher the
energy consumption rate (Mwale et al, 2005). CPP may be
employed to recover coarse-grained hematite from stock-
piles. Emerging coarse comminution technologies include
high pressure grinding roll (HPGR), vertical stirred mills,
etc. Currently, only 2 mining operations in Minnesota uti-
lise HPGR for tertiary crushing duty. Emerging coarse par-
ticle flotation technologies include the Eriez’ HydroFloat
(HF), Jord International’s NovaCell, FLSmidth’s Reflux
Flotation Cell (RFC). Both NovaCell and RFC are still
under development. According to Kohmuench et al (2013),
Mankosa et al (2016) and Taguta et al, (2023), the Eriez’
HF technology offers the following benefits:
i. Increase in global recoveries.
ii. 10–20% reduction in energy consumption as the HF
has very low liberation requirements.
iii. 25% water savings.
iv. 20–25% increase in plant throughput due to rejec-
tion of coarse liberated gangue.
v. Safer and easier handling of coarse tailings.
vi. Improved filtration efficiency of the coarse
concentrates.
Although the Eriez HF technology has been successfully
commercialized in the coarse flotation of precious metals
(Taguta et al, 2023), base metals (Kohmuench et al, 2023
Mankosa et al, 2016), and industrial minerals, it is still to
be evaluated in the iron ore industry. Several studies have
demonstrated that the Eriez HF outperforms the conven-
tional Denver mechanical flotation cell across multiple
commodities (Paiva &Rubio, 2016 Taguta, et al, 2023).
The technology has potential to revolutionize the US iron
ore industry, with direct coarse flotation of iron bearing ores
or reverse coarse flotation (silica flotation) being potential
process routes.
It is perceived that the transformative mineral process-
ing flowsheet of the future will include coarse and fine par-
ticle technologies to maximise valuable mineral recovery.
Dry Processing
Only one mining operation in Minnesota utilizes in-situ
dry processing of run of mine (ROM) magnetic taconite
for the rejection of coarse liberated silica gangue. The pro-
cess involves crushing and coarse cobbing of ROM using
a mobile crusher and a mobile magnetic belt separator,
respectively, within the open pit mine. Coarse gangue rejec-
tion results in energy savings and increase in throughput in
downstream unit operations.
Dry processing of iron ore is suitable for processing
direct shipping ores (DSO). However, dry processing may
not be optimal for fine liberating taconite due to loss of
efficiency as the ore becomes finer. Few researchers have
recently attempted to understand the amenability of low-
grade iron ore to dry beneficiation using advanced technol-
ogies such as air classifiers for desliming (Nunna et al 2019
Nunna et al 2019a) as well as microwave roasting followed
by magnetic separation (Nunna, et al. 2022).
Fluidized Bed Separators
Fluidized bed-based separators are gaining popularity in
coal processing. Dry jigging is one of the promising unit
operations for separating coal from maceral. In the early
2000s, dry jigging which works completely dry with air only
in the coal industry was introduced by allair ®, Germany.
Since then, there are many allair ® that have been supplied
for coal preparation plants in the U.S., India, Colombia,
Spain, and Ukraine. However, its application in the mineral
and iron ore industry is limited and needs to be investi-
gated. He et al (2017), investigated the application of a dry
density-based fluidized bed separator to beneficiate coarse
hematite fines based on density difference. In this study,
atomized iron powder and zircon sand with size fractions
were mixed and used as a dense media for separating hema-
tite particles from gangue. A theoretical separation density
of 3.5–4.0 g/cm3 was established for efficient density-based
separation. However, scale-up studies in this area have not
been reported.
StackCell, Staged flotation reactor (SFR), Direct flotation
reactor (DFR), etc. Both HIP and HIM flotation cells are
energy efficient and produce fine bubbles suitable for the
recovery of fine particles (Hassanzadeh et al, 2020). Several
studies have demonstrated that both HIP and HIM flota-
tion cells outperform mechanical cells in terms of metallur-
gical performance at pilot and industrial scales, especially
in fines flotation (Hassanzadeh et al, 2020). In the iron ore
context, both HIP and HIM flotation technologies may
be able to recover fine-grained hematite resources through
direct flotation (DF). They may also recover fine-grained
silica through the RCF process. Furthermore, most of the
HIP and HIM flotation cells have froth washing systems
which may reduce the entrainment of Fe-bearing miner-
als during RCF. Froth washing is important, considering
that there is a push towards the product of high-quality DR
concentrates.
Coarse Particle Processing Opportunities
Mining companies are under pressure to decarbonize their
operations and one of the strategies to achieve this goal is
coarse particle processing (CPP). Conventional iron pro-
cessing flowsheets which involve fine grinding of 25–44 µm
are energy intensive as the finer the ore, the higher the
energy consumption rate (Mwale et al, 2005). CPP may be
employed to recover coarse-grained hematite from stock-
piles. Emerging coarse comminution technologies include
high pressure grinding roll (HPGR), vertical stirred mills,
etc. Currently, only 2 mining operations in Minnesota uti-
lise HPGR for tertiary crushing duty. Emerging coarse par-
ticle flotation technologies include the Eriez’ HydroFloat
(HF), Jord International’s NovaCell, FLSmidth’s Reflux
Flotation Cell (RFC). Both NovaCell and RFC are still
under development. According to Kohmuench et al (2013),
Mankosa et al (2016) and Taguta et al, (2023), the Eriez’
HF technology offers the following benefits:
i. Increase in global recoveries.
ii. 10–20% reduction in energy consumption as the HF
has very low liberation requirements.
iii. 25% water savings.
iv. 20–25% increase in plant throughput due to rejec-
tion of coarse liberated gangue.
v. Safer and easier handling of coarse tailings.
vi. Improved filtration efficiency of the coarse
concentrates.
Although the Eriez HF technology has been successfully
commercialized in the coarse flotation of precious metals
(Taguta et al, 2023), base metals (Kohmuench et al, 2023
Mankosa et al, 2016), and industrial minerals, it is still to
be evaluated in the iron ore industry. Several studies have
demonstrated that the Eriez HF outperforms the conven-
tional Denver mechanical flotation cell across multiple
commodities (Paiva &Rubio, 2016 Taguta, et al, 2023).
The technology has potential to revolutionize the US iron
ore industry, with direct coarse flotation of iron bearing ores
or reverse coarse flotation (silica flotation) being potential
process routes.
It is perceived that the transformative mineral process-
ing flowsheet of the future will include coarse and fine par-
ticle technologies to maximise valuable mineral recovery.
Dry Processing
Only one mining operation in Minnesota utilizes in-situ
dry processing of run of mine (ROM) magnetic taconite
for the rejection of coarse liberated silica gangue. The pro-
cess involves crushing and coarse cobbing of ROM using
a mobile crusher and a mobile magnetic belt separator,
respectively, within the open pit mine. Coarse gangue rejec-
tion results in energy savings and increase in throughput in
downstream unit operations.
Dry processing of iron ore is suitable for processing
direct shipping ores (DSO). However, dry processing may
not be optimal for fine liberating taconite due to loss of
efficiency as the ore becomes finer. Few researchers have
recently attempted to understand the amenability of low-
grade iron ore to dry beneficiation using advanced technol-
ogies such as air classifiers for desliming (Nunna et al 2019
Nunna et al 2019a) as well as microwave roasting followed
by magnetic separation (Nunna, et al. 2022).
Fluidized Bed Separators
Fluidized bed-based separators are gaining popularity in
coal processing. Dry jigging is one of the promising unit
operations for separating coal from maceral. In the early
2000s, dry jigging which works completely dry with air only
in the coal industry was introduced by allair ®, Germany.
Since then, there are many allair ® that have been supplied
for coal preparation plants in the U.S., India, Colombia,
Spain, and Ukraine. However, its application in the mineral
and iron ore industry is limited and needs to be investi-
gated. He et al (2017), investigated the application of a dry
density-based fluidized bed separator to beneficiate coarse
hematite fines based on density difference. In this study,
atomized iron powder and zircon sand with size fractions
were mixed and used as a dense media for separating hema-
tite particles from gangue. A theoretical separation density
of 3.5–4.0 g/cm3 was established for efficient density-based
separation. However, scale-up studies in this area have not
been reported.