![Dannemora Elias Martin 1700](https://upload.wikimedia.org/wikipedia/commons/3/35/Dannemora_Elias_Martin_1700.jpg)
The Dannemora mine (''Dannemora gruvor'') at
Dannemora in
Uppsala County
Uppsala County ( sv, Uppsala län) is a county or ''län'' on the eastern coast of Sweden, whose capital is the city of Uppsala. It borders the counties of Dalarna, Stockholm, Södermanland, Västmanland, Gävleborg, and the Baltic Sea.
Prov ...
, Sweden was once one of the most important
iron ore
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 fo ...
mines in Sweden. The mine was closed by its owners
SSAB
SSAB AB, earlier ''Svenskt Stål AB'' (English: Swedish Steel), () is a Swedish company, formed in 1978, that specialises in processing raw material to produce steel. The largest shareholders are Aktiebolag Industrivärden and the Government of ...
in 1992. It may have been open since the 13th century, but the first documentary reference was in 1481.
The mine has a depth of 640 metres and supplied
oregrounds iron
Oregrounds iron was a grade of iron that was regarded as the best grade available in 18th century England. The term was derived from the small Swedish city of Öregrund, the port from which the bar iron was shipped. It was produced using the Wal ...
by the
Walloon process
A Walloon forge (or Walloon process) is a type of finery forge that decarbonizes pig iron into wrought iron.
The process was conceived in the Liège region, and from there extended to France, then England around the end of the 15th century. ...
(''Vallonsmide'') using a
blast furnace and
finery forge
A finery forge is a forge used to produce wrought iron from pig iron by decarburization in a process called "fining" which involved liquifying cast iron in a fining hearth and removing carbon from the molten cast iron through oxidation. Finery ...
. Ironworks making sites included
Österbybruk
Österbybruk is a locality situated in Östhammar Municipality, Uppsala County, Sweden with 2,272 inhabitants in 2010.
Ironworks
The Österby works was one of a number mostly in Roslagen, where there were Walloon forges, producing high quality ore ...
and
Lövstabruk
Lövstabruk is a village on a common in the parish of Österlövsta, Tierp Municipality, Uppsala County, Sweden. In 2010 it had a population of 96, compared to some 1300 at its height during the 18th century. The word ''lövsta'' is derived from ...
). Their products were particularly pure
iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
, due to the
manganese
Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...
content of the iron ore. This made it the best material for conversion to
blister steel
The cementation process is an obsolete technology for making steel by carburization of iron. Unlike modern steelmaking, it increased the amount of carbon in the iron. It was apparently developed before the 17th century. Derwentcote Steel Furn ...
, the main variety of
steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...
made in
Great Britain
Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It is ...
between the 1610s and the 1850s.
History
Joachim Piper renewed the mining privileges at Dannemora in 1532 and devoted substantial resources to the mine, mainly producing iron but also other minerals. the ownership structure changed in 1545, and a dozen wealthy individuals entered as the owners, so that a number of Germans and even King
Gustav Vasa
Gustav I, born Gustav Eriksson of the Vasa noble family and later known as Gustav Vasa (12 May 1496 – 29 September 1560), was King of Sweden from 1523 until his death in 1560, previously self-recognised Protector of the Realm ('' Riksför ...
took part. The Germans were most interested in the export of pig iron but the king persuaded them to start production of wrought iron. It lasted only a few years and following a related bankruptcy, the king took over the operation fully.
Under 17th century, Dannemora iron had an uncontestedly high status among Swedish iron localities, especially in England where it was used in the steel raw material for tools, weapons, springs and other special purposes. A large part went to
Sheffield
Sheffield is a city status in the United Kingdom, city in South Yorkshire, England, whose name derives from the River Sheaf which runs through it. The city serves as the administrative centre of the City of Sheffield. It is Historic counties o ...
, England. Thus Dannemora contributed to Sheffield's worldwide reputation as a steel city.
Around 1700 there were about sixty workers at Dannemora residents of the neighbourhoods around the mine. The number of workers who obtained their support from the mine is likely to be several hundred. In each mine large quantities of wood would be used, a method not abandoned until the 1730s. The reason for this was partly because gunpowder would be more expensive than wood, but also for danger's sake.
Throughout the mine's history, it had problems with water being situated by a lake. A pile-dam was built during the 17th century, and water- and wind-powered pumps were used. In 1728, at the initiative of
Mårten Triewald
Mårten Triewald FRS (18 November 1691 – 8 August 1747), sometimes referred to as Mårten Triewald the Younger, was a Swedish merchant, engineer and amateur physicist.
Mårten Triewald was the son of Mårten Triewald the Elder, a farrier ...
(1691–1747), a steam-driven pump was installed, a
Newcomen atmospheric engine
The atmospheric engine was invented by Thomas Newcomen in 1712, and is often referred to as the Newcomen fire engine (see below) or simply as a Newcomen engine. The engine was operated by condensing steam drawn into the cylinder, thereby creati ...
, the first in Sweden, but it was never a success. The failure was probably due to the technology, which worked flawlessly in England, being new to Sweden and was run by inexperienced staff. During blasting to remove two waterfalls in the 1750s, water swept away a blast furnace, a mill and two sawmills. Despite a newly built dam, the mines were flooded in the spring flood of 1795 and it took until 1815 before the situation became normal. In 1805 a new steam engine of 10 horsepower was installed.
During the century 1770–1870, production was between 15,000 and 20,000 tonnes. In the 1870s, it rose to 40,000 tonnes and exports of pig iron from the Österby ironworks became significant. In order to facilitate shipments of ore Dannemora Hargs Railway (''Dannemora–Hargs Järnväg'') was built between Dannemora mines and
Hargshamn
Hargshamn is a locality situated in Östhammar Municipality, Uppsala County
Uppsala County ( sv, Uppsala län) is a county or ''län'' on the eastern coast of Sweden, whose capital is the city of Uppsala. It borders the counties of Dalarna, S ...
in 1878. During the 20th century, production was 50,000 tonnes, but a strike in 1927 stopped operations entirely. Only in 1935 was it resumed. 1955 a new facility, with sorting plant and concentrator was finished and the annual production reached 600,000 tons. During the latter part of the 1970s, output decreased but still amounted to about one million tonnes of crude ore, of which the bulk was exported.
Shareholders of Dannemora mines had declined since the late 19th century through closures and mergers. In 1937 the four remaining owners (Fagersta Bruk, Iggesunds Bruk, Hargs Bruk and Stora Kopparbergs Berglag) formed AB Dannemora Mines. In 1974 Stora Kopparberg became the sole owner of the Dannemora mine. Only four years later, during the crisis that hit the Swedish steel industry in the late 1970s, however, the state-owned SSAB was forced to take over the mine.
Current Status
The current owner is Dannemora Mineral AB, which was listed May 25, 2007. The initial stock placement was heavily oversubscribed.
In 2008, preparations began to resume mining of iron ore as well as other more precious metals. The mine was emptied of water and a new sorting mill and loading terminal was built. The railroad to the port at Hargshamn was refurbished. An opening ceremony featuring H M
King Carl XVI Gustaf
Carl XVI Gustaf (Carl Gustaf Folke Hubertus; born 30 April 1946) is King of Sweden. He ascended the throne on the death of his grandfather, Gustaf VI Adolf, on 15 September 1973.
He is the youngest child and only son of Prince Gustaf Adolf, D ...
was held on 13 June 2012. The company went bankrupt in 2015 due to a decrease in iron price by 70 %.
The main access ramp is being extended down to the 350 m level, and a new ore elevator is being put in.
The estimated ore reserves have been revised up to 35 million tonnes, sufficient for at least 14 years production.
References
This article is based mainly on the
Swedish Wikipedia article, whose sources are given as:
*B. Boethius: ''Gruvornas, hyttornas och hamnarnas folk'' (1951)
*J. O. Carlberg: ''Historiskt sammandrag om svenska bergverkens uppkomst och utveckling'' (1879)
*Svante Lindqvist: The impact of the Introduction of Steam Engine Technology on the Society of Dannemora Mines (in Svensson, Nils Eric, Strandh, Sigvard: ''Tekniska Museet Symposium on the History of Technology'', No. 1 (1977)
*K. C. Barraclough, 'Swedish iron and Sheffield steel' History of Technology 12 (1990), 1-39 - originally published in Swedish in A Attman et al., ''Forsmark och vallonjärnet''
orsmark and Walloon iron(Sweden 1987)
External links
Dannemora Mineral AB website
{{DEFAULTSORT:Dannemora Mine
Iron mines in Sweden
Former mines in Sweden
Uppland