XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 1435
value (Bergman et al. 2001). Among them, the well-
known Kiirunavaara and Malmberget deposits host current
resources of 3 Gt.
The expression “Kiruna-type” has been justified by
the special character of the ores and earliest studies were
focused on Kiruna (e.g., Geijer 1910, 1931, Parak 1975,
Frietsch 1978). To date, over 40 orebodies are known in the
Norrbotten area. Most of the IOA deposits in the region
display almost pure magnetite ores with minor impuri-
ties in the form of gangue minerals such as apatite, quartz,
calcite, actinolite and pyrite (Parak 1975, Frietsch 1978,
Lund 2013, Aupers, 2014, Niiranen 2015, Martinsson et
al. 2016, Andersson et al. 2022). Recent exploration cam-
paigns revealed much greater complexity in deeper parts of
the orebodies, especially in the Gruvberget and Per Geijer
deposits located in the Svappavaara and Kiruna area. The
complexity is induced by large variations in texture, miner-
alogy and relation to wall rocks (Frietsch 1966, Lundberg
and Smellie 1979, Edfelt et al. 2005, Martinsson 2015,
Krolop et al. 2019). The host rocks to iron ore mineralisa-
tion are volcano-sedimentary in origin, belonging to the
Svecofennian bedrock. They were generated during sub-
duction and accretion of several volcanic arc complexes
(Weihed et al. 1992, Skiöld et al. 1993, Mellqvist et al.
1999, Lahtinen et al. 2003, 2005, 2011). These 1.9–1.8
Ga old complexes are subdivided into three units the
lower unit named Porphyrite Group, the middle unit called
Kiirunavaara Group and the upper Hauki Group. The iron
ore deposits are emplaced in the Kiirunavaara group com-
monly between volcanic horizons and/or intercalated with
them.
PROCESS MINERALOGICAL
ASSESSMENTS
Since the introduction of process mineralogy at LKAB in
the early 2000s, the discipline has been significantly devel-
oped with regard to internal workflows, cross-disciplinary
and innovative approaches as well as applied multi-method
analytics. The first process mineralogical studies were car-
ried out for the Kiirunavaara and Malmberget deposits
addressing specific product quality challenges related to the
crude ore (Lund 2013, Niiranen 2015). Today, it forms its
own technical note within the research and development
department in LKAB’s business area iron ore. However,
research is not solely on iron ore. It addresses all the rock
mass from economically feasible minerals to waste material
characterisation.
The intention is to integrate process mineralogy at dif-
ferent levels in the Life Of Mine (LOM) from the early
exploration stage until mine closure (Figure 1). Activities
connected to the exploration stage are related to all efforts
to report resources (and reserves) according to the Pan-
European Reserves and Resources Reporting Committee
(PERC) standards. This includes ore, gangue and wall rock
characterisation in its in-situ condition. Common proce-
dure at LKAB includes input from process mineralogy and
the information obtained in all deposit development activi-
ties. In a later stage of exploration, often connected to pre-
feasibility and feasibility studies, process mineralogy is part
of pilot and full-scale test work. The key challenge is link-
ing bench scale test work results with those from upscaling
tests that mimic active operations. Since process mineral-
ogy is a fairly new field at LKAB, quality issues and process
Figure 1. Connection of process mineralogy to different aspects in the life of a mine. Activities span
from early stage exploration to phases until production, process control and final mine closure
value (Bergman et al. 2001). Among them, the well-
known Kiirunavaara and Malmberget deposits host current
resources of 3 Gt.
The expression “Kiruna-type” has been justified by
the special character of the ores and earliest studies were
focused on Kiruna (e.g., Geijer 1910, 1931, Parak 1975,
Frietsch 1978). To date, over 40 orebodies are known in the
Norrbotten area. Most of the IOA deposits in the region
display almost pure magnetite ores with minor impuri-
ties in the form of gangue minerals such as apatite, quartz,
calcite, actinolite and pyrite (Parak 1975, Frietsch 1978,
Lund 2013, Aupers, 2014, Niiranen 2015, Martinsson et
al. 2016, Andersson et al. 2022). Recent exploration cam-
paigns revealed much greater complexity in deeper parts of
the orebodies, especially in the Gruvberget and Per Geijer
deposits located in the Svappavaara and Kiruna area. The
complexity is induced by large variations in texture, miner-
alogy and relation to wall rocks (Frietsch 1966, Lundberg
and Smellie 1979, Edfelt et al. 2005, Martinsson 2015,
Krolop et al. 2019). The host rocks to iron ore mineralisa-
tion are volcano-sedimentary in origin, belonging to the
Svecofennian bedrock. They were generated during sub-
duction and accretion of several volcanic arc complexes
(Weihed et al. 1992, Skiöld et al. 1993, Mellqvist et al.
1999, Lahtinen et al. 2003, 2005, 2011). These 1.9–1.8
Ga old complexes are subdivided into three units the
lower unit named Porphyrite Group, the middle unit called
Kiirunavaara Group and the upper Hauki Group. The iron
ore deposits are emplaced in the Kiirunavaara group com-
monly between volcanic horizons and/or intercalated with
them.
PROCESS MINERALOGICAL
ASSESSMENTS
Since the introduction of process mineralogy at LKAB in
the early 2000s, the discipline has been significantly devel-
oped with regard to internal workflows, cross-disciplinary
and innovative approaches as well as applied multi-method
analytics. The first process mineralogical studies were car-
ried out for the Kiirunavaara and Malmberget deposits
addressing specific product quality challenges related to the
crude ore (Lund 2013, Niiranen 2015). Today, it forms its
own technical note within the research and development
department in LKAB’s business area iron ore. However,
research is not solely on iron ore. It addresses all the rock
mass from economically feasible minerals to waste material
characterisation.
The intention is to integrate process mineralogy at dif-
ferent levels in the Life Of Mine (LOM) from the early
exploration stage until mine closure (Figure 1). Activities
connected to the exploration stage are related to all efforts
to report resources (and reserves) according to the Pan-
European Reserves and Resources Reporting Committee
(PERC) standards. This includes ore, gangue and wall rock
characterisation in its in-situ condition. Common proce-
dure at LKAB includes input from process mineralogy and
the information obtained in all deposit development activi-
ties. In a later stage of exploration, often connected to pre-
feasibility and feasibility studies, process mineralogy is part
of pilot and full-scale test work. The key challenge is link-
ing bench scale test work results with those from upscaling
tests that mimic active operations. Since process mineral-
ogy is a fairly new field at LKAB, quality issues and process
Figure 1. Connection of process mineralogy to different aspects in the life of a mine. Activities span
from early stage exploration to phases until production, process control and final mine closure