Kiruna mine

Last updated
Kiruna mine
Kiruna iron mine ISS.jpg
Kiruna Mine and townsite from Landsat, 2016
Location
Sweden location map.svg
Schlaegel und Eisen nach DIN 21800.svg
Kiruna mine
Location in Sweden
Location Kiruna
Municipality Lapland
Country Sweden
Coordinates 67°51′01″N020°11′34″E / 67.85028°N 20.19278°E / 67.85028; 20.19278
Production
Products Iron ore
Production26.9 million tonnes
Financial year2018
History
Opened1898
Owner
Company Luossavaara-Kiirunavaara AB

The Kiruna mine is the largest and most modern underground iron ore mine in the world. [1] [ unreliable source? ] The mine is located in Kiruna in Norrbotten County, Lapland, Sweden. [1] The mine is owned by Luossavaara-Kiirunavaara AB (LKAB), a large Swedish mining company. In 2018 the mine produced 26.9 million tonnes of iron ore. [2] The Kiruna mine has an ore body which is 4 km (2.5 mi) long, 80 metres (260 ft) to 120 metres (390 ft) thick and reaching a depth of up to 2 km (1.2 mi). Since mining began at the site in 1898, the mine has produced over 950 million tonnes of ore. [1] As of 2020, the main haulage level is 1,365 m below the ore outcrop at Kiirunavaara that existed prior to mining. [3]

Contents

In 2004, it was decided that the present centre of the city would need to be relocated to accommodate mining-related subsidence. The relocation would be made gradually over decades. [4]

On May 18, 2020 an earthquake of approximate 4.9 Mw was triggered in the footwall of the mine. [5] The earthquake was not natural but induced by the mining activity. [5]

Geology

The ore deposit at Kiruna is part of a larger iron ore province stretching west-east from Kiruna to the Finnish border. [6] This province includes thus also the ores at Svappavaara and Pajala. [6] Malmberget is a large notable southward outlier of this province. [6] The largest ore bodies in the province are of iron oxide-apatite type, yet skarn iron deposits exists at Masugnsbyn and Hindersön. [7] The iron ores that lie closest to the Kiirunavaara are Loussavaara, Henry, Nakutus, Rektorn and Lappmalmen. [8]

The ore

The ore is predominately magnetite and disseminated interstitial apatite, with an average of 0.9% phosphorus. [9] [10] [11] The ore body has the form of a large sheet inclined about 60° to the east. [12] At surface this sheet was before mining about 4 km long and averages 90 m in width. [13] From geophysical studies it has been inferred that the ore continues as a coherent sheet at least 1500 m below the surface. [13] In many places the ore transitions to apparently disorganised ore veins in the country rock. [14] Apatite is by far the main gangue mineral while other gangue minerals are tremolite-actinolite and calcite. [11] Apatite is at places evenly distributed in the magnetite ore, but occurs also as veins and bands. [11] Diopside and biotite are also common gangue minerals but occur only in very small amounts. [11] For reasons related to ore processing the ore in Kiruna Mine is divided into two quality types based on chemistry, phosphorus-poor B-ore and phosphorus-rich D-ore, the latter being more common closer to the surface. [11]

Within the orebody, there is a volume of hematite ore with the same strike (direction) as the main orebody. [15] The thickness of this seemingly coherent hematite body is mostly within the range of decimeters but at one location it reaches 25 m. [15]

The largest deposit of rare earth metals discovered in Europe was announced by LKAB in January 2023 to be at Kiruna. The rare earth elements have been known about at this location for over 100 years and studied in detail before. [16] [17]

Origin

The origin of the Kiruna ore has been the matter of a protracted scientific debate, with the main point of contention being whether the ore is solidified magma or not. [3]

The Kiruna mineral deposit was formed following intense volcanic activity. [18] One theory holds that the ores are the result of magmatic differentiation. [14] Iron-rich solutions precipitated the iron on to a syenite porphyry footwall. [9] Then the ore bed was covered by further volcanic deposits, quartz porphyry, and sedimentary rocks. Later the whole body was tilted to its current dip of 50 to 60°. [9] [10] [ verification needed ]

The hematite bodies of Kiruna are considered by R. Frietsch to be "hydrothermal impregnations". [19]

The geology of the Kiruna ore has many parallels to that of the iron ore of El Laco volcano in Chile, leading to the claim they were both formed by volcanic activity. [20]

In 1973 Tibor Parák pointed out a series of problems with the magmatic origin theory and proposed instead that the ore originated as a sediment in a volcanic environment. [21] In 1975 Párak listed various arguments against a magmatic origin for the ore. The existence of "abundant fragments and balls" of ore found in the hanging wall of the Kiruna Ore and the nearby Loussavaara Ore are deemed by Párak to be contrary to a magmatic origin for the ore. [22] The grading of massive ore into quartz-banded ores at the nearby Per Geijer Ore is also deemed by Parák to be contrary to magmatic origin. [22] Parák also argued that the form of the orebodies as tilted sheets is also indicative of them being sedimentary units. Parák further argues that the "ore breccia" at Loussavaara Ore is due to its chemistry and texture not equivalent to the main ore bodies. [22]

Footwall

The waste rock at the footwall of the ore is syenite porphyry. [9] At places this syenite porphyry has nodules variously filled with actinolite, apatite, titanite and magnetite. [23] At some locations next to the ore what is thought to be beds of meta tuff has been found, these beds vary in thickness with the thickest ones being up to 2 metres (6.6 ft) thick. [23]

In some rare cases nodules are filled with zircon. [23] To the west the syenite porphyry borders the Kurravaara conglomerate which underlies it stratigraphically. [24]

Hanging wall

The hanging wall of the Kiruna ore is made up of quartz porphyry. [15]

History

Miners at work, circa 1940-1959 Miners in the Kirunavaara mine, Kiruna, Lappland, Sweden (10456674053).jpg
Miners at work, circa 1940–1959

In 1902 the Kiruna Narvik Railway was completed, allowing the shipment of ore through the ice-free port of Narvik. [25]

In the beginning, surface mining was used, but the mine has been mined with the sublevel caving mining method since the 1960s. In 1985 reserves for the Kiruna Mine were 1,800 million tonnes grading 60–65% iron and 0.2% phosphorus. [26] [1] As of 2018 the Kiruna Mine had Proven and Probable Reserves of 683 million tonnes grading 43.8% iron. [27]

Until 1999 the deepest level of the mine reached 775 metres (2,543 ft), but after 1999 mining went deeper, reaching a depth of 1,045 metres (3,428 ft). [1] The 1,045 metres (3,428 ft) level could support iron ore production until 2018. On October 28, 2008 LKAB decided to go even deeper, with the mine reaching a depth of 1,365 metres (4,478 ft) by 2012 at a cost of US$1.7 billion. [1]

Cross section of Kiruna iron ore mine Kiruna mine English.svg
Cross section of Kiruna iron ore mine

Moving the town

The re-development of Kiruna is a reconstruction project, as the Kirunavaara mine, run by LKAB, undermines the current town center. The town center is to be moved 3 km (1.9 mi) to the east. 21 of the most important buildings are to be moved. [28]

In 2004, it was decided that the city center would need to be relocated to accommodate mining-related subsidence. The relocation was to be made gradually over the coming decade. In January 2007 a new location was proposed, to the northwest at the foot of Luossavaara mountain, by Lake Luossajärvi. [29]

The first physical work moving the town commenced in November 2007, when work on the new main sewer pipe started. [30]

In the same week, first sketches for the layout of the new part of the town became available. [31] The sketches include a travel center, the new locations for the city hall and the church, an artificial lake and an extension of the Luossavaara hill into the city. [32] The location of the new section of the E10 is still uncertain, as is the location of the railway and the railway station. A more official sketch was published early in the spring of 2008, which was then discussed with various interest groups before a further version was to be produced.

In June 2010 the city council decided that the town would be moved eastwards (to 67°51′1″N20°18′2″E / 67.85028°N 20.30056°E / 67.85028; 20.30056 ), in the direction of Tuolluvaara, instead of the proposed northwestern location. [33] The town move was started in 2014 in a process that will continue to 2040, with the center-most part of the town re-established by 2022. [34] [35] White Arkitekter AB based in Stockholm and Ghilardi + Hellsten Arkitekter based in Oslo together with researchers from Luleå and Delft universities won the contract to design the new city, which envisages a denser city center with a greater focus on sustainability, green and blue infrastructure, pedestrians and public transport rather than automobiles. [36]

See also

Related Research Articles

<span class="mw-page-title-main">Kiruna</span> Mining city in northern Sweden

Kiruna is the northernmost city in Sweden, situated in the province of Lapland. It had 17,002 inhabitants in 2016 and is the seat of Kiruna Municipality in Norrbotten County. The city was originally built in the 1890s to serve the Kiruna Mine.

<span class="mw-page-title-main">Iron ore</span> Ore rich in iron or the element Fe

Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron is usually found in the form of magnetite (Fe
3O
4, 72.4% Fe), hematite (Fe
2O
3, 69.9% Fe), goethite (FeO(OH), 62.9% Fe), limonite (FeO(OH)·n(H2O), 55% Fe), or siderite (FeCO3, 48.2% Fe).

<span class="mw-page-title-main">Skarn</span> Hard, coarse-grained, hydrothermally altered metamorphic rocks

Skarns or tactites are coarse-grained metamorphic rocks that form by replacement of carbonate-bearing rocks during regional or contact metamorphism and metasomatism. Skarns may form by metamorphic recrystallization of impure carbonate protoliths, bimetasomatic reaction of different lithologies, and infiltration metasomatism by magmatic-hydrothermal fluids. Skarns tend to be rich in calcium-magnesium-iron-manganese-aluminium silicate minerals, which are also referred to as calc-silicate minerals. These minerals form as a result of alteration which occurs when hydrothermal fluids interact with a protolith of either igneous or sedimentary origin. In many cases, skarns are associated with the intrusion of a granitic pluton found in and around faults or shear zones that commonly intrude into a carbonate layer composed of either dolomite or limestone. Skarns can form by regional or contact metamorphism and therefore form in relatively high temperature environments. The hydrothermal fluids associated with the metasomatic processes can originate from a variety of sources; magmatic, metamorphic, meteoric, marine, or even a mix of these. The resulting skarn may consist of a variety of different minerals which are highly dependent on both the original composition of the hydrothermal fluid and the original composition of the protolith.

Luossavaara-Kiirunavaara Aktiebolag (LKAB) is a state-owned Swedish mining company. The company mines iron ore at Kiruna and at Malmberget in northern Sweden. The company was established in 1890, and has been 100% state-owned since the 1950s. The iron ore is processed to pellets and sinter fines, which are transported by Iore trains (Malmbanan) to the harbours at Narvik and Luleå and to the steel mill at Luleå (SSAB). Their production is sold throughout much of the world, with the principal markets being European steel mills, as well as North Africa, the Middle East and Southeast Asia. LKAB's mines supply at least 80% of Europe's iron ore.

<span class="mw-page-title-main">Ore genesis</span> How the various types of mineral deposits form within the Earths crust

Various theories of ore genesis explain how the various types of mineral deposits form within Earth's crust. Ore-genesis theories vary depending on the mineral or commodity examined.

The Emily Ann and Maggie Hays nickel deposits are situated 117 km west of the town of Norseman, Western Australia, within the Lake Johnston Greenstone Belt.

<span class="mw-page-title-main">Broken Hill ore deposit</span>

The Broken Hill Ore Deposit is located underneath Broken Hill in western New South Wales, Australia, and is the namesake for the town. It is arguably the world's richest and largest zinc-lead ore deposit.

<span class="mw-page-title-main">Svappavaara</span> Place in Lapland, Sweden

Svappavaara is a locality situated in Kiruna Municipality, Norrbotten County, Sweden with 417 inhabitants in 2010. It is a mining village. Mining was started around 1650. Large scale iron mining started in 1965. The mine was closed in 1983, but enrichment of iron ore from the mine at Kiruna is still going on. The mine is owned by LKAB, and there is an ongoing project to open it again for production around year 2015.

<span class="mw-page-title-main">Kiirunavaara</span> Mountain in Norrbotten, Sweden

Kiirunavaara is a mountain situated in Kiruna Municipality in Norrbotten County, Sweden. It contains one of the largest and richest bodies of iron ore in the world.

<span class="mw-page-title-main">Hjalmar Lundbohm</span> Swedish geologist and chemist

Johan Olof Hjalmar Lundbohm was a Swedish geologist and chemist and the first managing director of LKAB in Kiruna. He made a strong contribution to the design of the new community of Kiruna in Lapland.

Iron oxide copper gold ore deposits (IOCG) are important and highly valuable concentrations of copper, gold and uranium ores hosted within iron oxide dominant gangue assemblages which share a common genetic origin.

The Malmberget mine is one of the largest iron ore mines in the world. The mine is located in Malmberget in Norrbotten County, Lapland, it is owned by Luossavaara-Kiirunavaara AB (LKAB). The mine has an annual production capacity of over 5 million tonnes of iron ore and has reserves amounting to 350 million tonnes of ore grading 43.8% iron, resulting 153.3 million tonnes of iron. In 2009, the mine produced 4.3 million tonnes of iron.

<span class="mw-page-title-main">Atacama Fault</span> System of geological faults in northern Chile

The Atacama Fault Zone (AFZ) is an extensive system of faults cutting across the Chilean Coastal Cordillera in Northern Chile between the Andean Mountain range and the Pacific Ocean. The fault system is north–south striking and runs for more than 1100 km North and up to 50 km in width through the Andean forearc region. The zone is a direct result of the ongoing subduction of the Eastward moving Nazca plate beneath the South American plate and is believed to have formed in the Early Jurassic during the beginnings of the Andean orogeny. The zone can be split into 3 regions: the North, Central and South.

<span class="mw-page-title-main">El Laco</span> Volcanic complex in the Antofagasta Region, Chile

El Laco is a volcanic complex in the Antofagasta Region of Chile. It is directly south of the Cordón de Puntas Negras volcanic chain. Part of the Central Volcanic Zone of the Andes, it is a group of seven stratovolcanoes and a caldera. It is about two million years old. The main summit of the volcano is a lava dome called Pico Laco, which is variously reported to be 5,325 metres (17,470 ft) or 5,472 metres (17,953 ft) high. The edifice has been affected by glaciation, and some reports indicate that it is still fumarolically active.

<span class="mw-page-title-main">Primary mineral</span>

A primary mineral is any mineral formed during the original crystallization of the host igneous primary rock and includes the essential mineral(s) used to classify the rock along with any accessory minerals. In ore deposit geology, hypogene processes occur deep below the Earth's surface, and tend to form deposits of primary minerals, as opposed to supergene processes that occur at or near the surface, and tend to form secondary minerals.

<span class="mw-page-title-main">Mining in Sweden</span> Mining industry in Sweden

The mining industry in Sweden has a history dating back 6,000 years.

The Chilean Iron Belt is a geological province rich in iron ore deposits in northern Chile. It extends as a north-south beld along the western part of the Chilean regions of Coquimbo and Atacama, chiefly between the cities of La Serena and Taltal. The belt follows much of the Atacama Fault System and is about 600 km long and 25 km broad.

Kiruna porphyry is a group of igneous rocks found near Kiruna in northernmost Sweden. The Kiruna Porphyry formed 1,880 to 1,900 million years ago during the Paleoproterozoic Era in connection to the Svecofennian orogeny.

Tibor Parák was a Hungarian geologist known for his mineral explorations and academic contributions to economic geology. Parák arrived in Sweden from Soviet-occupied Hungary as a refugee in 1956.

The Mertainen is an iron ore deposit and mine in Lapland, Sweden, Sweden. It is located about 30 km southeast of the town of Kiruna. In December 2016 Luossavaara-Kiirunavaara AB closed the mine for indefinite time. Re-opening the mine remains a possibility according to LKAB executive Magnus Arnkvist.

References

  1. 1 2 3 4 5 6 "Kiruna Iron Ore Mine, Sweden". mining-technology.com. 2010. Retrieved 2010-08-29.
  2. ↑ "Mining". LKAB. 2010. Retrieved 29 January 2020.
  3. 1 2 Andersson, Joel B.H.; Bauer, Tobias E.; Martinsson, Olof (December 2021). "Structural Evolution of the Central Kiruna Area, Northern Norrbotten, Sweden: Implications on the Geologic Setting Generating Iron Oxide-Apatite and Epigenetic Iron and Copper Sulfides". Economic Geology. 116 (8): 1981–2009. Bibcode:2021EcGeo.116.1981A. doi: 10.5382/econgeo.4844 . S2CID   244595358.
  4. ↑ Michael, Chris (2 December 2018). "'Will I have existed?' The unprecedented plan to move an Arctic city". The Guardian. London. Retrieved 29 January 2020.
  5. 1 2 Setså, Ronny (May 20, 2020). "Derfor ristet Kiruna". geoforskning.no (in Norwegian). Archived from the original on February 27, 2021. Retrieved June 15, 2020.
  6. 1 2 3 Grip & Frietsch 1973, p. 67
  7. ↑ Grip & Frietsch 1973, p. 77
  8. ↑ Grip & Frietsch 1973, p. 86
  9. 1 2 3 4 "Kiruna Iron Ore Mine". miningweekly.com. 2010. Retrieved 2010-08-29.
  10. 1 2 Pålsson, Bertil I.; Martinsson, Olof; Wanhainen, Christina; Fredriksson, Andreas (5 September 2014). Unlocking Rare Earth Elements From European Apatite-Iron Ores (PDF). ERES 2014 - 1st European Rare Earth Resources Conference. Milos, Greece. Retrieved 29 January 2020.
  11. 1 2 3 4 5 Grip & Frietsch 1973, p. 85
  12. ↑ Grip & Frietsch 1973, p. 80
  13. 1 2 Parák 1973, p. 28
  14. 1 2 Grip & Frietsch 1973, 78
  15. 1 2 3 Parák 1973, pp. 29
  16. ↑ Jonsson, Erik; Troll, Valentin R.; Högdahl, Karin; Harris, Chris; Weis, Franz; Nilsson, Katarina P.; Skelton, Alasdair (10 April 2013). "Magmatic origin of giant 'Kiruna-type' apatite-iron-oxide ores in Central Sweden". Scientific Reports. 3 (1): 1644. Bibcode:2013NatSR...3E1644J. doi:10.1038/srep01644. PMC   3622134 . PMID   23571605.
  17. ↑ "Mining firm: Europe's largest rare earths deposit found in Sweden". POLITICO. 2023-01-12.
  18. ↑ Troll, Valentin R.; Weis, Franz A.; Jonsson, Erik; Andersson, Ulf B.; Majidi, Seyed Afshin; Högdahl, Karin; Harris, Chris; Millet, Marc-Alban; Chinnasamy, Sakthi Saravanan; Kooijman, Ellen; Nilsson, Katarina P. (12 April 2019). "Global Fe–O isotope correlation reveals magmatic origin of Kiruna-type apatite-iron-oxide ores". Nature Communications. 10 (1): 1712. Bibcode:2019NatCo..10.1712T. doi:10.1038/s41467-019-09244-4. PMC   6461606 . PMID   30979878.
  19. ↑ Frietsch, R. (1978). "On the magmatic origin of iron ores of the Kiruna type". Economic Geology . 73 (4): 478–485. Bibcode:1978EcGeo..73..478F. doi:10.2113/gsecongeo.73.4.478.
  20. ↑ Nyström, Jan Olov; Henríquez, Fernando (1994). "Magmatic Features of Iron Ores of the Kiruna Type in Chile and Sweden: Ore Textures and Magnetite Geochemistry". Economic Geology . 89 (4): 820–839. Bibcode:1994EcGeo..89..820N. doi:10.2113/gsecongeo.89.4.820.
  21. ↑ Parák 1973, pp. I-II
  22. 1 2 3 Parák, Tibor (1975). "Kiruna iron ores are not "intrusive-magmatic ores of the Kiruna type"". Economic Geology . 70 (7): 1242–1258. Bibcode:1975EcGeo..70.1242P. doi:10.2113/gsecongeo.70.7.1242.
  23. 1 2 3 Parák 1973, p. 6
  24. ↑ Parák 1973, p. 5
  25. ↑ Liza Piper (2010). The Industrial Transformation of Subarctic Canada. UBC Press. p. 50. ISBN   978-0774858625 . Retrieved 29 January 2020.
  26. ↑ Lankford, William T. (1985). The Making, Shaping, and Treating of Steel. Association of Iron and Steel Engineers. p. 281.
  27. ↑ "Mineral reserves and mineral resources". LKAB. Luleå, Sweden. 20 June 2019. Retrieved 29 January 2020.
  28. ↑ "Kiruna: the town being moved 3km east so it doesn't fall into a mine". The Guardian. 22 October 2014. Retrieved 29 October 2017.
  29. ↑ TT (2007-01-08). "Klart med Kirunas flytt". Dagens Nyheter (in Swedish). Retrieved 2015-10-24.
  30. ↑ Jessica Rosengren (2007-11-23). "Kirunaflytten är igång". Norrländska Socialdemokraten (in Swedish). Retrieved 2015-10-24.
  31. ↑ Jessica Rosengren (2007-11-23). "Nu finns det skiss över nya Kiruna". Norrländska Socialdemokraten (in Swedish). Archived from the original on 2007-11-23. Retrieved 2007-11-25.
  32. ↑ Skissförslag nov.-07 Archived 2008-04-08 at the Wayback Machine
  33. ↑ "Framtida placeringen av Kiruna klar". Dagens Nyheter (in Swedish). 2010. Archived from the original on February 23, 2011.{{cite news}}: CS1 maint: bot: original URL status unknown (link)
  34. ↑ Anzilotti, Eillie (12 November 2018). "Saving this Swedish town from falling into a mine has big lessons about a post-climate change world". Fast Company. Retrieved 29 January 2020.
  35. ↑ "FAQ - Kiruna kommun". www.kiruna.se. Archived from the original on 2016-09-18. Retrieved 2016-08-21.
  36. ↑ "Kiruna: How to move a town two miles east". BBC News. 6 March 2014. Retrieved 2014-03-06.
Bibliography
View of Kiruna from the old mine (Luossavaara) to the new mine (Kiirunavaara) View on Kiruna from the old mine to the new mine.jpg
View of Kiruna from the old mine (Luossavaara) to the new mine (Kiirunavaara)
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.