Kiruna iron ore mine
| Kiruna iron ore mine | |||
|---|---|---|---|
| General information about the mine | |||
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| Mining technology | Underground mining | ||
| Information about the mining company | |||
| Operating company | LKAB | ||
| Employees | 2250 | ||
| Start of operation | 1900 | ||
| Funded raw materials | |||
| Degradation of | Iron ore | ||
| Iron ore | |||
| Kiirunavaara | |||
| Greatest depth | -625 m above sea level | ||
| Luossavaara | |||
| Geographical location | |||
| Coordinates | 67 ° 51 '1 " N , 20 ° 11' 33.7" E | ||
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| Location | Kiruna | ||
| local community | Kiruna | ||
| province | Norrbotten County | ||
| Country | Sweden | ||
| District | Kiruna | ||
The Kiruna iron ore mine is located southwest of the homonymous city of Kiruna in Sweden . It is the most important mine of LKAB (Luossavaara-Kiirunavaara Aktiebolag) and is considered the world's largest iron ore - mine . The mine wins in Teilsohlenbruchbau from the Erzberg Kiirunavaara quality phosphorus-containing magnetite .
Geography and geology
Geographical location
The Kiruna mining area is located north of the Arctic Circle in the province of Norrbotten County . Apart from the two deposits Kiirunavaara and Luossavaara the deposits Rektorn, Per Geijer seam, Henry seam belong Haukivaara , Nukutusvaara and Tuolluvaara to the station. The mining of the Luossavaara has been suspended since 1985.
Every year, 26 million tons of raw ore are extracted from the pit, with the expansion of the new main floor to −1365 meters, it should be possible to increase production to 33 million tons of raw ore from 2013. 19 million tons of finished products are made from the raw ore, the majority of which is shipped as pellets . For transportation to the ports of Narvik and Luleå is Swedish Erzbahn used.
geology
Due to its high magnetite content, the Kiruna seam represents the second strongest magnetic anomaly on earth. The maximum of 70,000 nT measured on the earth's surface is about as strong as the normal magnetic field . At an altitude of 400 km, the ESA satellite SWARM could still detect 10 nT. The seam is about four kilometers long and an average of eighty meters thick. The thickness increases in depth and to the north to 150 to 180 meters. It falls 50 to 60 degrees and is trending northeast. The final depth of the deposit is unknown, but it certainly reaches up to two kilometers.
The deposit was formed about 1.6 billion years ago through the precipitation of iron-rich solutions on a syenite - porphyry bedrock after intense volcanism. The seam was covered by further volcanic deposits of rhyolite and sediments before it was tipped into its current position. The deposit consists almost entirely of magnetite and apatite . The rock contains up to 60% iron and an average of 0.9% phosphorus. The phosphorus content comes from the partially enclosed apatite. The number of inclusions increases towards the bedrock and towards the south.
Originally the seam stored around 1.8 billion tons of ore, of which around one billion tons have already been mined. In 2011, the operator LKAB estimated that there are still 590 million tonnes of safe stocks above the newly developed main production level 1365 m, and another 76 million tonnes are considered probable stocks. The iron content of these supplies is over 47%. 328 million tons of ore are suspected below the new level. The iron content tends to decrease with depth, but the amount of phosphorus also decreases.
Ore and ore refining
Magnetite is extracted in the Kiruna mine . After mining, the iron ore is crushed to a grain size of around ten centimeters. The iron content is concentrated to around 62% by magnetic separation of the ore from the dead rock . The material is then ground in mills to a grain size of about 0.05 mm. The resulting thin sludge is floated to remove the phosphorus and has an iron content of approx. 68%. The fine ore produced after drying is partially delivered to ironworks in this form, but mostly processed into more easily transportable pellets with a diameter of around ten millimeters.
For the production, the thin sludge is mixed with additives such as dolomite , olivine , limestone and quartzite , which are necessary as binders and for use as a moler in the blast furnace . Bentonite is used as a binding agent . After the sludge has dried to around 9% moisture, the pellets are produced in rotating drums. They are then dried, preheated and fired at 1250 ° C. During the firing process, the magnetite of the ore is converted into hematite and loses its magnetism.
Mountain damage
Although pings are visible on the surface of the mine , the city of Kiruna was hardly affected by mining for a long time. Only the district of Ön, located south of Lake Luossajärvi, was given up in the 1960s and 1970s and fenced in as company premises. With the planned expansion of mining to the north, it was decided in June 2010 to relocate the city five kilometers to the east. The southern part of Lake Luossajärvi had to be drained as early as June 2007 . The dismantling below began about six months later. On August 31, 2012, the line of the Swedish Ore Railway , now running west of Kiirunavaara , went into operation. By 2013 the European route and the historic buildings Bolagshotellet and Hjalmar Lundbohmsgården will also be affected by mining damage .
history
The Kiirunavaara was first mentioned in writing in 1696, but ore mining was not worthwhile for a long time despite the rich occurrence. The site was too remote in an inhospitable environment and the phosphorus-containing ore could not be processed with the technologies available at the time. The ore deposit only became interesting with the invention of the Thomas process in the 1870s, because it was also possible to process ores containing phosphorus. After the Swedish ore railway was completed, industrial-style mining began in 1900.
Mining technology
The extraction was carried out until 1957 exclusively in the open pit , then was gradually underground mining introduced until the reduction is set entirely over days 1,962th Underground ridge joint construction and pillar construction were used in part , and later only partial bottom fracture construction was used.
The ore is extracted in eight different mining areas. The routes are 28.5 meters apart and 25 meters next to each other. The triggered respectively after midnight blast triggers about 8,500 tons of debris that with driving loaders to role groups is brought crashed and classified in this rough. On the main floor, the material is taken over by mine railways and brought to crushers . The raw ore, crushed to a grain size of approx. 10 cm , is thrown into skips from the rollers below the crusher and conveyed to the day.
The pit is about five spiral paths opened up and with ten ventilation shafts bewettert .
Shaft hoisting system
The ore is unearthed using several skip conveyors supplied by ABB . The extraction takes place in two stages, with the ore being reloaded on the −775 m level.
The carriers exchange the lower stage is at -740 m and houses the equipment for four Skip conveyor which promote the ore from the -1045 m level. A fifth plant has been producing raw ore from the new −1365 m level since 2012. The upper level comprises seven skip conveyor systems, the machines of which are housed in the winding tower built in 1954 on the Kiirunavaara. The conveyor baskets reach speeds of up to 17 meters per second.
Processing plants
The raw ore from the pit is processed by a screening plant , two concentrators and two pelletizing plants. The KK4 rotary grate kiln pellet system that went into operation on June 17, 2008 is the largest of its kind in the world. It can produce up to 6 million tons of pellets per year. The finished products of the pit are fine sinter and pellets.
Some of the raw ore is transported to Svappavaara by freight trains and processed into pellets there.
Main soles
The soles of the Kiruna ore mine are named after their height in relation to the current peak of the Kiirunavaara. The mountain peak is labeled 0 m, the shaft head of the elevator system is at the −142 m level, the entrance to the pit at the −230 m level. The Kiirunavaara was originally higher, but the former mountain top was made of iron ore and was therefore mined as early as 1910. Over the years, the distance between the main soles increases. The main levels of the mine are at −275 m, −320 m, −420 m, −540 m, −775 m, −1045 m and −1365 m.
−345 m
The first main floor was laid on the floor of the old open-cast mine in the lying rock, so that a mine train could bring the excavated debris to the newly built ski conveyor . The first underground canteen and workshop was also built on this main floor. Until 1999, the sole also housed the visitor mine. From 1953 to 1961 a standard-gauge tram for the staff, called Kiruna Under Jord (KUJ, English: Kiruna-U-Bahn) in Swedish , also ran on this floor .
−540 m level
In the 1960s, the second main level was set up and all production facilities were moved here from the −345 m level. Since the company's facilities were moved to the lower main level, some empty stretches have been used to grow shiitake mushrooms. Today's LKAB InfoMine visitor mine is also located at the −540 m level .
−775 m level
In 1979 the next new main floor was installed. For the first time, driverless mine railways and loaders are used. The device operators sit in a control room and guide their vehicles with the help of joysticks and video monitors. One worker can operate up to three loaders at the same time because they automatically drive the route between the cross passages and the roller holes and automatically tip the material into them. The pile is picked up manually.
−1045 m level
The main lift level of 1045 m has been in operation since 1999 and is to be used until 2018. Seven trains run on the level, which is 300 meters below sea level, which are controlled by the control room on the −775 m level and each transport 500 tons of debris to the four crushing systems.
−1365 m level
On October 28, 2008 LKAB decided to build another main floor. This sole is scheduled to go into operation in 2012 and will remain in operation until around 2030, with an investment cost of 1.7 billion US dollars. This will enlarge the pit and increase the annual production. The two main levels −1045 m and −1365 m are operated in parallel for about seven to eight years.
On the floor, 1,600-ton trains are used on standard gauge tracks. They are pulled by contact wire locomotives. The four-axle, 106-ton locomotives are built by the Schalke ironworks .
literature
- Hans G. Roeschen: Kiirunavaara, the Swedish iron ore mountain . In: Expansion , issue 7/1957, pp. 389–398, Paul-Christiani-Verlag, Konstanz 1957
- Kjell Törmä: Kiruna 100-årsboken . 2000, ISBN 91-630-9371-5 .
Web links
- LKAB - Official website of the operator
Individual evidence
- ↑ Short facts. (No longer available online.) LKAB, archived from the original on January 25, 2013 ; Retrieved January 6, 2013 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ a b c d e f g Kiruna Iron Ore Mine, Sweden. Archived from the original ; accessed on December 5, 2010 (English).
- ↑ The even larger Kursk Magnetic Anomaly in southern Russia is mined in an open pit.
- ↑ Ines Kurmies: The magnetite-apatite ore of the Kiruna district, Northern Sweden . Ed .: Technical University Bergakademie Freiberg . ( tu-freiberg.de [PDF]).
- ↑ a b c d LKAB Kiruna's new haulage level - ABB mine hoist upgrade for production increase. (PDF; 807 kB) Retrieved January 6, 2012 (English, project description from ABB Sweden ).
- ↑ P. JANLE, G. SCHULZ: Space and time structure of the earth's magnetic field - an overview. (PDF) Retrieved May 21, 2016 .
- ^ The mission objectives of the ESA satellite SWARM. (PDF; 778 kB) Archived from the original on October 29, 2014 ; Retrieved January 26, 2011 .
- ^ Mineralienatlas Lexikon - Mineralienportät / Magnetit. (PDF) Retrieved on December 5, 2010 (lecture TU Freiberg).
- ↑ C. Quinteiro, M. Quinteiro, O. Hedstrom: Underground Iron Ore Mining at LKAB, Sweden . In: Society for Mining Metallurgy & Exploration (Ed.): WA Hustrulid: Underground mining methods: engineering fundamentals and international case studies . 2001, ISBN 978-0-87335-193-5 .
- ↑ Annual Report and Sustainability Report 2011. (PDF; 7.3 MB) (No longer available online.) LKAB, archived from the original on October 29, 2015 ; Retrieved January 6, 2013 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Various LKAB publications
- ↑ a b City in Transformation. Kiruna Parish, archived from the original on May 18, 2008 ; accessed on December 11, 2010 (English).
- ↑ Swedish city moves 5 km to the east. krone.at, June 21, 2010, accessed on June 21, 2010 .
- ↑ Dewatering of the southern part of Lake Luossajärvi, Kiruna. LKAB, July 29, 2007, accessed on July 29, 2007 (English, press release).
- ↑ Mariann Nordmark: Järnvägen. (No longer available online.) Kiruna Parish, October 18, 2012, archived from the original on May 21, 2016 ; Retrieved January 6, 2013 (Swedish). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ a b About LKAB / History 1920-1969. LKAB, accessed December 7, 2010 .
- ^ Howard L. Hartman: SME Mining Engineering Handbook . Society for Mining, Metallurgy, and Exploration, Littleton CO 1998, ISBN 0-87335-100-2 ( limited preview in Google Book Search).
- ↑ a b c d Kjell Törmä: Kiruna 100-årsboken . 2000, ISBN 91-630-9371-5 .
- ↑ L. Mukka, C. Blomgren: Extension of the main ventilation system at LKAB Kiruna mine for the new main haulage level 1365 m . In: 12th US / North American Mine Ventilation Symposium . Wallace 2008, ISBN 978-0-615-20009-5 (English, smenet.org ( Memento of December 16, 2010 in the Internet Archive ) [PDF]). Extension of the main ventilation system at LKABs Kiruna Mine for the new main haulage level 1365 m ( Memento of the original from December 16, 2010 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ J. Olsson, M. Hedqvist: Malmens Väg - Fordonen i gruvan. (No longer available online.) Archived from the original on September 7, 2014 ; Retrieved January 6, 2013 (Swedish). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Kiruna Mine Level. (No longer available online.) LKAB, archived from the original on April 28, 2013 ; Retrieved January 6, 2013 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Locomotives from Schalke soon also in Sweden. (No longer available online.) April 7, 2010, archived from the original on September 8, 2014 ; accessed on December 6, 2010 (notification from Schalke Eisenhütte). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Data sheet 108 t mine locomotive. (PDF) Archived from the original on September 8, 2014 ; accessed on September 7, 2014 (notification from Schalke Eisenhütte).
