Dannemora mine
The mine is an iron mine in Dannemora Dannemora, in the municipality of Östhammar and the Swedish province of Uppsala County, 50 km northeast of the provincial capital of Uppsala. Until the early 20th century it was the most important iron mine in Sweden.
History
In the first mention of 1481 it is described as the deposit of silver, lead and copper. For a short time then silver was mined. However, large importance came to the iron deposits, which on the one hand by a high proportion of pig iron in the ore (40-50 %) are characterized, on the other hand have a low phosphorus content with a high calcium and Manganoxidanteil. Under this condition, it was melted in the control without any further additives on charcoal and made into ingots.
The iron bars of Dannemora were the times of the Industrial Revolution, the basis for high-quality iron and later steel. They formed the basis for the steel industry in the historic province of Uppland, but they were also an important export for Sweden: The majority of bullion was shipped to England.
The German Joachim Piper had modernized the mine after the contract extension of its mining rights in Dannemora 1532. In 1545 the rights of an individual to a consortium of 12 to 13 persons were converted. It was a German - Swedish consortium of solvent persons in which 86 shares were distributed among the members of the Swedish king Gustav Vasa claimed eight shares for themselves.
While the Germans interests existed in an export of pig iron to Germany, the king was a suggestion to export possible wrought iron, prevail. After a few years, the consortium had to file for bankruptcy and the Swedish king took over control of all shares. The production of wrought iron, however, was maintained only for a few decades.
Through the fantastic pit near lakes, there was the problem of flooding since operation of the mine. At the beginning of the 17th century a dam to control the water masses was built. At this time the mines were dewatered by wind and water power.
Mårten trie forest was able to convince the consortium members from trying drainage by means of a steam engine of Newcomen - type 1728. Although he was able to demonstrate the function, but there was no machinist who could keep the steam engine permanently in operation.
The spring floods of 1795 led to a dam break with flooding of the mine. Only through the installation of a new steam engine in 1815 the pit was completely drained again. Here, it was the first steam engine Watt's type on Swedish soil, they had a power of 10 hp.
The commercial mining areas were set in 1992 by the then owner, the SSAB Svenskt Stål AB. A new mining areas were tested as early 2009 by the Dannemora Mineral AB, which was founded in March 2005, started. On 13 June 2012, the Dannemora Mine by Carl XVI. Gustaf opened, with a 5 - year contract for 300 000 tonnes of iron ore with the German steel company Salzgitter AG has completed.
Geology
The Dannemora Mine consists of approximately 80 individual mines, of which, however, already in 1900, only 10 were used commercially. All mines are on a 2.1 km long, 150-210 m wide, open with Ping for a precipice of more than 160 m depth. Underground the mine has now a depth of 640 m.
Production
By 1550, the annual iron production was 15 tons. By 1650, annual production was 10,000 tonnes, to the turn of the century 18,000 tons. By 1870, production fluctuated 15-20000 tonnes per year. Thereafter, production jumped to 40,000 tons per year and continued until 1890 to 60,000 tons in 1900 to drop again to 50,000.
Through a longer strike the ore production was set in 1927 and not approached again due to the economic depression in the following years. Only in 1935 the ore production was resumed in full. 1955, the production of much ore mining rose to 600,000 tonnes by 1970 to less than one million tons.