1436 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
control in current operations are of increasing importance
in the researchers and engineer’s daily work. Main reasons
are heterogenous ores at deeper mining levels with more
complex mineralogy and mineral associations. At the end
of the LOM cycle, mine closures are inevitable. However,
LKAB’s mines are currently not subject to mine closure.
Therefore, process mineralogical assessments are rather
related to characterisation of waste material in the form of
dams and tailings.
Even though process mineralogical assessments are
conducted over the entire LOM, 90% of the current work
assignments are related to exploration activities. This is based
on the fact that LKAB has significantly increased explora-
tion activities for all its assets from Kiruna to Malmberget
to cope for decreasing resources and related challenges of
deep underground mining operations.
The practical work can best be described as process ori-
ented deposit/orebody characterisation and includes two
major foundations as can be seen in Table 1. Those include
in-situ ore/orebody characterisation and process-mineral-
ogical test works. Both are separately described in greater
detail further below.
IN-SITU ORE/OREBODY
CHARACTERISATION
Studies on in-situ ore/orebody characterisation are com-
monly carried out by process mineralogists in close collabo-
ration with the exploration and/or geology departments
at LKAB. It includes macro- to microscale investigations
using multiple analytical methods such as MINALIZE
drill core scanners, handheld X-ray fluorescence (p-XRF)
spectrometers, geochemical assays of bulk samples, optical
microscopy (OM), X-ray diffraction (XRD), and scanning
electron microscopy (SEM)-based materials characteri-
sation instruments such as QEMSCAN or TIMA. All of
the beforementioned equipment are available internally at
LKAB and the latter system has recently been purchased
and installed at LKAB’s research centers in Malmberget
and Luleå. One SEM-TIMA system includes an inte-
grated Raman spectroscope for better characterisation of
iron oxides and minerals of similar or identical mineral
chemistry. For detailed mineral chemical analysis, chemical
distribution in minerals and trace elemental investigation
of minerals of particular interest, LKAB collaborates with
research institutions such as universities or surveys, host-
ing respective infrastructure. In a recent project, it has been
shown that using bulk chemical assays by XRF for deter-
mining the grade of a deposit alone provides a somewhat
erratic result since the element/s of interest often occur in
more than just the target mineral(s). Therefore, the chemi-
cal composition of individual minerals was obtained by
using a Bruker M4 Tornado µ-XRF instrument at Luleå
University of Technology (LTU) on LKAB exploration drill
cores visualizing the distribution of elements in particu-
lar minerals. This highlighted that the extraction process
can thereby be adapted to process all minerals of interest
to get the best possible recovery (Månbro et al. 2023).
In-situ spot analysis for mineral chemistry are commonly
conducted by electron probe micro analysis (EPMA) or
laser ablation inductively coupled plasma mass spectrom-
etry (LA-ICP-MS). These micro-analytical tools allow for
quantitative determination of the major, minor and trace
elemental composition of target minerals, e.g., magne-
tite, hematite, apatite. The most important element con-
centrations to be measured are V, Cr, Ti, Ni, Co, Si, K,
Na, Mg, S and P. Thereby, it needs to be specified what
the state of the elements are incorporated in the miner-
als crystal lattice or present as inclusions, exsolutions or in
individual minerals other than the targeted. Therefore, it
is crucial to obtain elemental deportment information by
SEM-materials characterisation software which is usually
conducted prior to in-situ mineral chemical analyses. Such
studies in combination with detailed characterisation of
mineral textures and associations are commonly conducted
Table 1. Scheme of the two foundations of process mineralogy aiding process-oriented characterisation of
LKAB’s deposits
ln-Situ Orebody Characterisation Process Mineralogical Test Work
• Ore Mineralogy
• Gangue Mineralogy
• Ore textures
• Mineral association/lntergrowths
• Geochemistry
• Mineral chemistry
Comminution
(Crushing and Grinding)
Separation (Magnetic Separation
and Flotation)
• Modal Mineralogy
• Liberation
• Particle Size Distribution (PSD)
• Energy consumption
• Chemical composition of size
fractions
• Elemental recovery
• Mass recovery
• Chemical composition
• Waste material characteristics
Undisturbed Natural State Ore Behavior Product Characteristics
control in current operations are of increasing importance
in the researchers and engineer’s daily work. Main reasons
are heterogenous ores at deeper mining levels with more
complex mineralogy and mineral associations. At the end
of the LOM cycle, mine closures are inevitable. However,
LKAB’s mines are currently not subject to mine closure.
Therefore, process mineralogical assessments are rather
related to characterisation of waste material in the form of
dams and tailings.
Even though process mineralogical assessments are
conducted over the entire LOM, 90% of the current work
assignments are related to exploration activities. This is based
on the fact that LKAB has significantly increased explora-
tion activities for all its assets from Kiruna to Malmberget
to cope for decreasing resources and related challenges of
deep underground mining operations.
The practical work can best be described as process ori-
ented deposit/orebody characterisation and includes two
major foundations as can be seen in Table 1. Those include
in-situ ore/orebody characterisation and process-mineral-
ogical test works. Both are separately described in greater
detail further below.
IN-SITU ORE/OREBODY
CHARACTERISATION
Studies on in-situ ore/orebody characterisation are com-
monly carried out by process mineralogists in close collabo-
ration with the exploration and/or geology departments
at LKAB. It includes macro- to microscale investigations
using multiple analytical methods such as MINALIZE
drill core scanners, handheld X-ray fluorescence (p-XRF)
spectrometers, geochemical assays of bulk samples, optical
microscopy (OM), X-ray diffraction (XRD), and scanning
electron microscopy (SEM)-based materials characteri-
sation instruments such as QEMSCAN or TIMA. All of
the beforementioned equipment are available internally at
LKAB and the latter system has recently been purchased
and installed at LKAB’s research centers in Malmberget
and Luleå. One SEM-TIMA system includes an inte-
grated Raman spectroscope for better characterisation of
iron oxides and minerals of similar or identical mineral
chemistry. For detailed mineral chemical analysis, chemical
distribution in minerals and trace elemental investigation
of minerals of particular interest, LKAB collaborates with
research institutions such as universities or surveys, host-
ing respective infrastructure. In a recent project, it has been
shown that using bulk chemical assays by XRF for deter-
mining the grade of a deposit alone provides a somewhat
erratic result since the element/s of interest often occur in
more than just the target mineral(s). Therefore, the chemi-
cal composition of individual minerals was obtained by
using a Bruker M4 Tornado µ-XRF instrument at Luleå
University of Technology (LTU) on LKAB exploration drill
cores visualizing the distribution of elements in particu-
lar minerals. This highlighted that the extraction process
can thereby be adapted to process all minerals of interest
to get the best possible recovery (Månbro et al. 2023).
In-situ spot analysis for mineral chemistry are commonly
conducted by electron probe micro analysis (EPMA) or
laser ablation inductively coupled plasma mass spectrom-
etry (LA-ICP-MS). These micro-analytical tools allow for
quantitative determination of the major, minor and trace
elemental composition of target minerals, e.g., magne-
tite, hematite, apatite. The most important element con-
centrations to be measured are V, Cr, Ti, Ni, Co, Si, K,
Na, Mg, S and P. Thereby, it needs to be specified what
the state of the elements are incorporated in the miner-
als crystal lattice or present as inclusions, exsolutions or in
individual minerals other than the targeted. Therefore, it
is crucial to obtain elemental deportment information by
SEM-materials characterisation software which is usually
conducted prior to in-situ mineral chemical analyses. Such
studies in combination with detailed characterisation of
mineral textures and associations are commonly conducted
Table 1. Scheme of the two foundations of process mineralogy aiding process-oriented characterisation of
LKAB’s deposits
ln-Situ Orebody Characterisation Process Mineralogical Test Work
• Ore Mineralogy
• Gangue Mineralogy
• Ore textures
• Mineral association/lntergrowths
• Geochemistry
• Mineral chemistry
Comminution
(Crushing and Grinding)
Separation (Magnetic Separation
and Flotation)
• Modal Mineralogy
• Liberation
• Particle Size Distribution (PSD)
• Energy consumption
• Chemical composition of size
fractions
• Elemental recovery
• Mass recovery
• Chemical composition
• Waste material characteristics
Undisturbed Natural State Ore Behavior Product Characteristics