XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1439
flotation test works on magnetic concentrates are assumed
to be necessary, magnetic separation is conducted with the
Blue Ribbon as it yields higher magnetic material output
compared to DT.
PROCESS MINERALOGY AT THE
FOREFRONT OF NEW PRODUCTS
Even though LKAB has operated iron ore mines for over a
century, the main products originate almost entirely from
magnetite ore. Small amounts of hematite fines from the
Malmberget western field orebodies are additionally pro-
duced. Based on the changing characters of the deposits
other targets emerge that could be exploited as potential by-
products. Among them is hematite, present in large quanti-
ties in the Per Geijer and Gruvberget deposits, and apatite.
Apatite is of special interest as it hosts both phosphorus
(P) and rare earth elements (REE’s). Both are needed as
fertilizer in agriculture and for the energy transition, espe-
cially in the form of permanent magnets used in electrical
vehicles. Of special interest is the Per Geijer deposit as the
modal abundance of apatite exceeds all other LKAB iron
ore deposits by 8 to 10 times. This results in the large ton-
nages of P and REE making it the largest deposit of REE
in Europe.
The process mineralogy team works closely with the
field exploration team to decipher the nature and affilia-
tion of apatite in the deposit. A specifically designed PhD
study will elaborate on the phosphates and their charac-
teristics to aid further exploration and mineral processing
activities. At the same time, LKAB and its subsidiary LKAB
Minerals investigate the potential of apatite (and other
phosphates) in the Malmberget and Kiruna deposits as part
of the REEMap project. Tailings are subject to processing
and metallurgical test works to firstly achieve a high qual-
ity apatite concentrate that is then subsequently treated by
hydrometallurgical processes to extract P and REE. Process
Mineralogy helps analyze the quality of the concentrate
by determining the modal mineralogy and liberation of
particles by SEMQEMSCAN. This approach of in-situ
characterisation and process mineralogical investigation of
subproducts are extended to other auspicious deposits with
elevated P content such as Gruvberget.
Besides investigating critical metal by-products, the
potential of hematite ore as pellet feed or fines product is
further elaborated. The Per Geijer and Gruvberget deposits
inherit significant resources in hematite. Current internal
projects focus on both in-situ hematite ore characteristics
and its amenability to the current beneficiation process.
Due to the paramagnetic physical properties of hematite,
adaptation to the existing magnetite process is needed.
Therefore, new processing workflows are currently being
developed with external collaboration partners. Preliminary
results suggest a combined density separation and high-gra-
dient magnetic separation process. Since LKAB does not
host suitable laboratory testing equipment for hematite
processing, investigation is ongoing aiming to evaluate the
most suitable instruments. Subsequent method develop-
ment will be conducted in LKAB’s research sites in Kiruna
and Malmberget led by a combined consortium of process
mineralogists and mineral processing engineers.
CONCLUSIONS AND IMPLICATIONS FOR
THE FUTURE OF PROCESS MINERALOGY
Process Mineralogy is not an entirely new field for min-
ing companies including LKAB. However, a need for more
detailed characterisation of ore and side rock is identified.
The main reasons are decreasing ore grades, more com-
plex mineralogy and stricter environmental regulations.
Therefore, process mineralogical investigations are ideally
conducted from an early exploration stage. It has become
salient that the integration of geological and mineralogi-
cal knowledge to processing is crucial to understand an
ores behaviour during beneficiation steps and to aid most
suitable flow sheet designs. It is highly beneficial for pro-
cess mineralogists to understand mineral properties and
geological processes, commonly resulting in geoscientists
filling these positions. Nevertheless, detailed knowledge
of the entire beneficiation chain is necessary in order to
transfer the obtained knowledge to the process or plant
engineers/operators. This bridging discipline will evolve
further in the future. But even though the need is evident,
it requires implementation of new techniques and method
development.
It has been observed that particle properties and libera-
tion can be studied with more precision when using 3D
methods such as computed tomography illuminating on
the true dimensions of particles.
Implementation of instruments allowing for three
dimensional investigations will aid future processing
especially when considering finetuning retention times
in the mills and better energy demand balancing. For
LKAB process mineralogists, a greater suite of analyti-
cal methods is already present. Recent replacement of the
SEM-QEMSCAN system with a combined SEM-TIMA
instrument coupled with a Raman system allows for
more detailed characterisation of ore and waste material.
Intergrowth characteristics can be studied at nanometre
scale and chemically similar iron oxide minerals, e.g., mag-
netite, hematite, maghemite distinguished more easily.
flotation test works on magnetic concentrates are assumed
to be necessary, magnetic separation is conducted with the
Blue Ribbon as it yields higher magnetic material output
compared to DT.
PROCESS MINERALOGY AT THE
FOREFRONT OF NEW PRODUCTS
Even though LKAB has operated iron ore mines for over a
century, the main products originate almost entirely from
magnetite ore. Small amounts of hematite fines from the
Malmberget western field orebodies are additionally pro-
duced. Based on the changing characters of the deposits
other targets emerge that could be exploited as potential by-
products. Among them is hematite, present in large quanti-
ties in the Per Geijer and Gruvberget deposits, and apatite.
Apatite is of special interest as it hosts both phosphorus
(P) and rare earth elements (REE’s). Both are needed as
fertilizer in agriculture and for the energy transition, espe-
cially in the form of permanent magnets used in electrical
vehicles. Of special interest is the Per Geijer deposit as the
modal abundance of apatite exceeds all other LKAB iron
ore deposits by 8 to 10 times. This results in the large ton-
nages of P and REE making it the largest deposit of REE
in Europe.
The process mineralogy team works closely with the
field exploration team to decipher the nature and affilia-
tion of apatite in the deposit. A specifically designed PhD
study will elaborate on the phosphates and their charac-
teristics to aid further exploration and mineral processing
activities. At the same time, LKAB and its subsidiary LKAB
Minerals investigate the potential of apatite (and other
phosphates) in the Malmberget and Kiruna deposits as part
of the REEMap project. Tailings are subject to processing
and metallurgical test works to firstly achieve a high qual-
ity apatite concentrate that is then subsequently treated by
hydrometallurgical processes to extract P and REE. Process
Mineralogy helps analyze the quality of the concentrate
by determining the modal mineralogy and liberation of
particles by SEMQEMSCAN. This approach of in-situ
characterisation and process mineralogical investigation of
subproducts are extended to other auspicious deposits with
elevated P content such as Gruvberget.
Besides investigating critical metal by-products, the
potential of hematite ore as pellet feed or fines product is
further elaborated. The Per Geijer and Gruvberget deposits
inherit significant resources in hematite. Current internal
projects focus on both in-situ hematite ore characteristics
and its amenability to the current beneficiation process.
Due to the paramagnetic physical properties of hematite,
adaptation to the existing magnetite process is needed.
Therefore, new processing workflows are currently being
developed with external collaboration partners. Preliminary
results suggest a combined density separation and high-gra-
dient magnetic separation process. Since LKAB does not
host suitable laboratory testing equipment for hematite
processing, investigation is ongoing aiming to evaluate the
most suitable instruments. Subsequent method develop-
ment will be conducted in LKAB’s research sites in Kiruna
and Malmberget led by a combined consortium of process
mineralogists and mineral processing engineers.
CONCLUSIONS AND IMPLICATIONS FOR
THE FUTURE OF PROCESS MINERALOGY
Process Mineralogy is not an entirely new field for min-
ing companies including LKAB. However, a need for more
detailed characterisation of ore and side rock is identified.
The main reasons are decreasing ore grades, more com-
plex mineralogy and stricter environmental regulations.
Therefore, process mineralogical investigations are ideally
conducted from an early exploration stage. It has become
salient that the integration of geological and mineralogi-
cal knowledge to processing is crucial to understand an
ores behaviour during beneficiation steps and to aid most
suitable flow sheet designs. It is highly beneficial for pro-
cess mineralogists to understand mineral properties and
geological processes, commonly resulting in geoscientists
filling these positions. Nevertheless, detailed knowledge
of the entire beneficiation chain is necessary in order to
transfer the obtained knowledge to the process or plant
engineers/operators. This bridging discipline will evolve
further in the future. But even though the need is evident,
it requires implementation of new techniques and method
development.
It has been observed that particle properties and libera-
tion can be studied with more precision when using 3D
methods such as computed tomography illuminating on
the true dimensions of particles.
Implementation of instruments allowing for three
dimensional investigations will aid future processing
especially when considering finetuning retention times
in the mills and better energy demand balancing. For
LKAB process mineralogists, a greater suite of analyti-
cal methods is already present. Recent replacement of the
SEM-QEMSCAN system with a combined SEM-TIMA
instrument coupled with a Raman system allows for
more detailed characterisation of ore and waste material.
Intergrowth characteristics can be studied at nanometre
scale and chemically similar iron oxide minerals, e.g., mag-
netite, hematite, maghemite distinguished more easily.