Dannemora mine
| Dannemora mine | |||
|---|---|---|---|
| General information about the mine | |||
 |
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| other names | Dannemora Gruvor | ||
| Mining technology | Civil engineering | ||
| Funding / year | 2,662,000 t | ||
| Rare minerals | Dannemora garnet | ||
| Information about the mining company | |||
| Operating company | Dannemora Mineral AB | ||
| Employees | 100 | ||
| Start of operation | 13th Century | ||
| Funded raw materials | |||
| Degradation of | Iron ore / silver / lead / copper | ||
| Raw material content | 40-50% | ||
| Greatest depth | 560 | ||
| Degradation of | silver | ||
| Degradation of | lead | ||
| Degradation of | copper | ||
| Geographical location | |||
| Coordinates | 60 ° 12 '10 " N , 17 ° 51' 45" E | ||
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| Location | Dannemora | ||
| local community | Osthammar | ||
| province | Uppsala län | ||
| Country | Sweden | ||
| District | Upland | ||
The Dannemora mine (formerly Danne More, Swedish Dannemora Gruvor ) is an iron ore mine in Dannemora , in the municipality of Östhammar and the Swedish province of Uppsala County . Until the beginning of the 20th century it was the most important iron ore mine in Sweden.
Geography and geology
The mine is located about 50 km northeast of the provincial capital Uppsala and 110 km north of Stockholm.
The Dannemora deposit consists of metamorphically shaped sedimentary rocks that are around 1.9 billion years old. The main components are limes, iron ores and volcanic rocks. The deposit body was heavily stressed tectonically and drops steeply at about 70 ° to 55 ° to the NW. It strikes about 30 ° NE, the extension in the direction of strike is about three kilometers. The thickness is between a few meters and up to 100 meters. The body of the deposit consists of many individual ore lenses .
The iron ore from Dannemora has a high iron content of 40–50% Fe and a low phosphorus content with a high proportion of lime and manganese . It is magnetic iron (Fe 3 O 4 ).
history
In the first documentary mention of 1481, the deposit is described as a silver , lead and copper deposit . For a short time, silver was mined. However, the iron ore reserves became more important. The ore could usually be smelted into high-quality iron and later steel without further additives on charcoal and cast into bars.
The German Joachim Piper had modernized the mine in 1532 after the contract extension of his mining rights in Dannemora. In 1545 a German-Swedish union was founded, to which 12 to 13 unions belonged. There were 86 shares , of which King Gustav Wasa claimed 8 for himself.
The German trades wanted to export pig iron to Germany, but the king was able to prevail with his request to export wrought iron if possible . After a few years, the union filed for bankruptcy and the Swedish king took over all the shares. Wrought iron production continued for a few decades.
The Dannemora iron bars were the basis of the steel industry in the historic Uppland province during the industrialization period . Most of the bars were exported to England.
Due to the lakes near the mine, there was a risk of water ingress since the mine was in operation. Overburden dumped into one of the lakes damaged its basic seal, causing water to get into the binge . At the beginning of the 17th century, a granite wall with pozzolana cement was built to seal it off. At that time the mines were being drained by wind and water power.
In 1728 Mårten Triewald was able to convince the trades to try dewatering with a Newcomens steam engine . Although he was able to demonstrate the function, there were no machinists who could operate the steam engine permanently.
The spring floods of 1795 caused the dam to burst, which drowned the mine . Only with a new Watt steam engine with an output of 10 HP could the pit be completely swamped again in 1815 . This was the first Wattscher type steam engine on Swedish soil.
The deposit was initially built on by around 80 individual mines, of which, however, as a result of plant closings and consolidations in 1879, only 14 were in operation, around 1900 only 10 and in 1918 only 6. Due to a lengthy strike in 1927 the production was stopped and due to the economic depression it was not started again in the following years. It was not until 1935 that dismantling was fully resumed.
In 1937, Dannemora Gruvor GmbH was founded by Fagersta AB , Stora Kopparberg AB , Iggesunds Bruk AB and Hargs Bruk AB . Gradually, shareholders withdrew, so that in 1974 Stora Kopparberg AB was the only partner.
In 1978, Svenskt Stål AB (SSAB) was founded, the shareholders of which were the Swedish state, Stora Kopparberg AB and Gränges AB . Dannemora Gruvor was part of the mining division of the group together with the Grängesberg and Stråssa mines.
In February 1987, SSAB announced the closure of Dannemora Gruvor due to falling demand and low iron prices. The ore mining was finally stopped in 1992.
Resumption of funding
A new ore mining was started on a test basis in early 2009 by Dannemora Mineral AB , which was founded in March 2005. On June 13, 2012, the Dannemora mine was opened by Carl XVI. Gustaf , whereby a five-year contract for 300,000 tons of iron ore was concluded with Salzgitter AG . The ore railway to Hargshamn harbor has been modernized.
The known ore reserves in 2012 were 34 million tons.
| year | around 1550 | 1650 | Beginning of the 18th century | 1800-1870 | 1879 | 1890 | 1891-95 | 1900 | 1927-1934 | 1935 | 1955 | 1970 | 2012 | 2013 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Annual funding ( t ) | 15th | 10,000 | 18,000 | 15,000 to 20,000 | 48,000 | 60,000 | 55,440 | 50,000 | - | ? | 600,000 | <1,000,000 | 939,000 | 2,662,000 |
Processing
The extracted magnetite ore is broken up over days and separated dry using magnetic separators.
Bankruptcy and re-closure
In March 2015, Dannemora Mineral AB went bankrupt after attempts to restructure failed. After the last potential prospect had jumped out, the bankruptcy administrator announced the closure and liquidation of the mine on June 16, 2015.
literature
- Gabriel Jars : Metallurgical journeys to examine and observe the finest iron, steel, sheet metal and hard coal works in Germany, Sweden, Norway, England, and Scotland, from 1757 to 1769 (translation of Voyages Métallurgiques, ou Recherches et Observations sur les Mines, & Forges de fer, la Fabrication de l'acier, celle du fer-blanc, & plusieurs mines de charbon de terre, faites depuis l'année 1757 jusques & compris 1769, en Allemangne, Suéde, Norway, Angleterre, & Ecosse [ archive.org ] by Carl Abraham Gerhard). First volume. Christian Friedrich Himburg, Berlin 1777, pp. 205-214 ( archive.org ).
- Sven Rydberg: Dannemora genom 500 år. Fagersta bruks AB, Dannemora 1981, OCLC 187176878 .
- Ingemar Lager: The geology of the Palaeoproterozoic limestone-hosted Dannemora iron deposit, Sweden. Rapporter och meddelanden. Volume 107, Sveriges Geologiska Undersökning, Uppsala 2001 ( resource.sgu.se PDF; 25 MB).
Web links
- Dannemora mine, Dannemora, Östhammar, Uppland, Sweden. In: Mineral Database. Retrieved October 9, 2014 .
Individual evidence
- ↑ a b c About us. Dannemora Mineral AB, archived from the original on October 9, 2014 ; accessed on February 13, 2016 .
- ↑ Héron de Villefosse : on the mineral wealth. Considerations about the mining, smelting and salt works of different countries, both with regard to their production and administration as well as the current state of mining and metallurgy . Second volume. Bernhard Friedrich Voigt, Sondershausen 1822, The iron mines at Dannemora in Sweden, p. 392–398 ( Google Books [accessed October 10, 2014]).
- ↑ Richard Beck: Doctrine of the ore deposits . tape 1 . Borntraeger, Berlin 1901, I. Sedimentary iron ore deposits, p. 74-75 ( Google books [accessed October 9, 2014]).
- ↑ Dannemora's iron ore. Dannemora Mineral AB, archived from the original on October 9, 2014 ; accessed on February 13, 2016 .
- ↑ a b c Operations. Dannemora Mineral AB, archived from the original on October 9, 2014 ; accessed on February 13, 2016 .
- ↑ authors: Dannemora . In: Meyers Großes Konversations-Lexikon . 4th edition. 4th volume. Publishing house of the bibliographical institute, Leipzig / Vienna 1886, OCLC 312424626 , p. 528 ( RetroBib [accessed October 9, 2014]).
- ↑ a b c d History. Dannemora Mineral AB, archived from the original on October 9, 2014 ; accessed on February 13, 2016 .
- ↑ Christian Overhoff: Sweden's mining industry massively increases equipment purchases. Germany trade & invest, December 15, 2011, archived from the original on November 13, 2012 ; Retrieved October 9, 2014 .
- ↑ Dannemoragruvan avvecklas. In: UNT.SE. June 16, 2015, accessed June 16, 2015 (Swedish).