Sweden

Malmberget/Gallivare Mine

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Overview

Mine TypeUnderground
StatusActive
Commodities
  • Iron Ore
  • REE
  • Phosphorus
Mining Method
  • Sub-level caving
Backfill type ... Lock
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Mine Life... Lock
SnapshotMalmberget is one of the world's largest underground mines for iron ore production.

Malmberget/Gallivare’s underground mine consists of around 20 orebodies, of which around 10 are currently mined. The ore is processed above ground in two concentrating and pelletising plants.

In May 2023 LKAB submitted an application for environmental permits for continued and expanded operations in Gällivare including facilities for direct reduction of iron ore using hydrogen and a plant for extracting apatite.

In December 2023 it was announced that LKAB has been granted support from The Industrial Leap (Industriklivet), the Swedish Energy Agency’s programme to support Swedish industry’s transition to becoming fossil free. A total of SEK 3.1 billion has been allocated for the establishment of a first demonstration plant in Gällivare for the production of fossil-free sponge iron on an industrial scale.

Owners

SourceSource
CompanyInterestOwnership
Luossavaara-Kiirunavaara AB (LKAB) 100 % Indirect
LKAB is a limited liability company wholly owned by the Swedish state. The Iron Ore business operations include mines and processing plants in Kiruna, Svappavaara and Malmberget in Gällivare.

Contractors

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Deposit type

  • Kiruna-type
  • Metamorphic

Summary:

Deposit Geology
The host rocks to the Malmberget mineralisation comprises a package of mafic to felsic, mildly alkaline, volcanoclastic to sub-volcanic metavolcanic rocks. The ore bodies and the metavolcanic rocks have been intruded by dolerite dikes, as well as, several generations of pegmatitic and aplitic dikes, and granitic bodies (Lund, 2013). U-Pb dating of oscillatory zoned zircons from the metavolcanic rock yields magmatic ages between 1.89 and 1.87 Ga and metamorphic ages between 1.80 and 1.77 Ga (Sarlus et al., 2020).

Amphibolite facies metamorphism, deformation and several phases of hydrothermal alteration have transpositioned primary bedding, and partly to completely destroyed the primary features of the ore and the volcanic rocks (Skiöld and Cliff, 1984; Bauer et al., 2018). The high metamorphic grades have significantlly coarsened the grainsize of the Malmberget rocks.

Alteration typically consists of pervasive K-feldspar and albite alteration, and patchy to disseminated amphibole-, biotite-, hematite- and magnetite-alteration. High temperature metamorphism is more prevalent in the western part of the deposit, proximal to the large Lina type granitic intrusion, typically evident as sillimanite- and muscovite-bearing gneisses. Massive biotite zones (i.e., biotite schist) occur in the proximity of the ore-zones and are interpreted to be mylonites that were formed as a result of strain partitioning between the metavolcanic host rock and the massive ore during deformation (SRK, 2012; Bauer et al., 2018).

Apatite Iron Ores
The Malmberget deposit is considered an amphibolite facies equivalent of the Kiirunavaara deposit. The origin of IOA deposits have been subject to a long-going scientific debate and several different modes of formation have historically been proposed, namely, hydrothermal exhalative, hydrothermal replacement, and high-temperature magmatic (Geijer, 1910; Parák, 1973; Hildebrand, 1986). Recent evidence predominantly supports a high-temperature origin, either by magmatically derived fluids, or by direct crystallisation from an iron-rich magma (Jonsson et al., 2013; Knipping et al., 2015; Tornos et al., 2017; Troll et al., 2019). Fe-O isotope thermometry on massive magnetite samples from the Fabian and Viri ore bodies in Malmberget indicates magmatic formation temperatures at = 800 °C (Henriksson et al., 2022). U-Pb dating of zircons from the Kiirunavaara ore suggest formation of the IOA mineralisation between 1.88 and 1.87 Ga (Westhues et al., 2016).

Mineralisation
Currently 15 of the historically defined ore bodies in the Malmberget deposit are mined. The IOA mineralisation predominantly consists of massive magnetite, but breccia-style and disseminated mineralisation also occur in the proximity of the massive ore bodies. Density plots of the Zr/Al2O3 vs Al2O3/TiO2 data reveal that the mineralisation in Malmberget is mainly hosted in dacitic to basaltic rocks. The ore bodies in the Malmberget deposit can be divided into the Western Field (Välkomman, Baron, Johannes, Josefina, Hens, Tingvallskulle), Printzsköld-Alliansen, the Eastern Field (Dennewitz, Parta, Viri, Östergruvan) and FabianKapten. The Western Field and Printzsköld-Alliansen form two continuous, openly folded ore-zones with moderate dips towards the south-southwest, whereas the Fabian-Kapten and Eastern Field ore bodies have tabular geometries and are elongated along the plunge of the ore body at ca. 40° to 50° towards the south-southwest (Geijer, 1930; Bergman et al., 2001; Martinsson and Virkunnen, 2004).

The ore mineralogy is dominated by magnetite, with subordinate amounts of hematite, fluorapatite, titanite, Cu-Fe sulphides, and REE-bearing phosphates. Gangue minerals include amphiboles, anhydrite, gypsum, and calcite. Massive hematite and mixed magnetite-hematite mineralisation mainly occurs in the Western Field and in the hinge of the Printzsköld-Alliansen fold structure. Apatite contents have a similar spatial distribution, with high concentrations (P2O5 > 3%) dominantly occuring in Printzsköld-Alliansen and in the Western Field. In general, the massive magnetite ore is medium- to coarse-grained with well-developed granoblastic textures. Lund (2013) described five different massive ore-types in the Malmberget deposit: fine-grained massive magnetite, coarse-grained massive magnetite, apatite-banded, fine-grained amphibole-rich, and coarse-grained amphibole-rich ore. The different ore-types are not exclusive to any particular ore body, but the massive fine-grained and coarse-grained magnetite is most common in the Fabian-Kapten and the Eastern Field ore bodies, whereas the apatitebanded ore type is most prevalent in Printzsköld-Alliansen, Fabian-Kapten, and the Western field. Amphibole-rich ore types occur in all ore bodies.

Further, the magnetite from the different ore bodies can be distinguished from each other based on chemical composition. The Western Field magentite is charaterised by low V- and high Ticontents, while the Eastern Field magnetite has moderate to high V- (0.1-0.3%) and high Ticontents (0.2-1.0%). Magnetite from the Printzsköld-Alliansen ore-zone has moderate V- (0.1- 0.18%) and low Ti-contents (0.05-0.3%). On the contrary, the magnetite from the FabianKapten ore body does not form a distinct cluster, but rather range from low to high V- and Ticontents. Lund (2013) attributes this wide range of the magnetite composition in the FabianKapten ore to reflect a primary variation within the ore body.

Mineralisation at Malmberget mine has historically been identified to comprise 30 orebody areas which are either active, inactive or mined-out. The orebodies are distributed over an area of about 5.0 km by 2.5 km and are grouped into Eastern Field and Western Field.

The average width of the orebodies ranges from 20 m to 100 m, and iron mineralisation is comprised around 90% magnetite and 10% hematite. The host rocks are metamorphosed volcanic rock such as gneisses and fine-grained feldspar-quartz rock called leptite. Granite veins often intrude into the ore zones.

Reserves

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Mining Methods

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Comminution

Crushers and Mills

Milling equipment has not been reported.

Processing

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Production

CommodityUnits20232022202120202019201820172016
Iron Ore Mt  ....  Subscribe  ....  Subscribe  ....  Subscribe  ....  Subscribe9.69.49.29
All production numbers are expressed as pellets & fines. * Combined production for Kiruna Mine, Malmberget/Gallivare Mine and Svappavaara (Leveaniemi) Mine

Operational metrics

Metrics2023202220212019201820172016
Ore tonnes mined  ....  Subscribe  ....  Subscribe  ....  Subscribe15.5 Mt13.5 Mt13.2 Mt16.4 Mt
Tonnes processed  ....  Subscribe  ....  Subscribe  ....  Subscribe

Production Costs

Commodity production costs have not been reported.

Heavy Mobile Equipment

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Personnel

Mine Management

Job TitleNameProfileRef. Date
....................... Subscription required ....................... Subscription required Subscription required Jun 7, 2024
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