Oregrounds iron
Encyclopedia
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
. The term was derived from the small Swedish city of Öregrund
Öregrund
Öregrund is a locality situated in Östhammar Municipality, Uppsala County, Sweden with 1,555 inhabitants in 2010. It is located by the coast of the Baltic Sea. Öregrund is, despite its small population, for historical reasons often still referred to as a city.- History :The town was granted a royal...
. The process to create it is known as the Walloon method.
Oregrounds iron is the equivalent of the Swedish vallonjärn, which literally translates as Walloon iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
. The Swedish name derives from the iron being produced by the Walloon version of the finery forge
Finery forge
Iron tapped from the blast furnace is pig iron, and contains significant amounts of carbon and silicon. To produce malleable wrought iron, it needs to undergo a further process. In the early modern period, this was carried out in a finery forge....
process, the Walloon method as opposed the German method, which was more common in Sweden. Actually, the term is more specialised, as all the Swedish Walloon forges made iron from ore ultimately derived from the Dannemora mine
Dannemora mine
The Dannemora mine at Dannemora, Sweden was one of the most important iron ore mines in Sweden. The mine was closed by its owners SSAB in 1992. It may have been open since the 13th century, but the first documentary reference was in 1481...
. It was made in about 20 forges mainly in Uppland
Uppland
Uppland is a historical province or landskap on the eastern coast of Sweden, just north of Stockholm, the capital. It borders Södermanland, Västmanland and Gästrikland. It is also bounded by lake Mälaren and the Baltic sea...
.
Many of the ironworks were founded by Louis de Geer
Louis De Geer (1587-1652)
Louis De Geer was a Walloon/Dutch merchant and industrialist. He is considered the father of Swedish industry for introducing Walloon blast furnaces in Sweden...
and other Dutch entrepreneurs who set up ironworks in Sweden in the 1610s and 1620s, with blast furnace
Blast furnace
A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally iron.In a blast furnace, fuel and ore and flux are continuously supplied through the top of the furnace, while air is blown into the bottom of the chamber, so that the chemical reactions...
s and finery forge
Finery forge
Iron tapped from the blast furnace is pig iron, and contains significant amounts of carbon and silicon. To produce malleable wrought iron, it needs to undergo a further process. In the early modern period, this was carried out in a finery forge....
s. Most of the early forgemen were also from Wallonia.
Origins in Wallonia
The technique was developed in Wallonia in present-day BelgiumBelgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
during the Middle Ages
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...
. The Walloon method consisted of making pig iron
Pig iron
Pig iron is the intermediate product of smelting iron ore with a high-carbon fuel such as coke, usually with limestone as a flux. Charcoal and anthracite have also been used as fuel...
in a blast furnace
Blast furnace
A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally iron.In a blast furnace, fuel and ore and flux are continuously supplied through the top of the furnace, while air is blown into the bottom of the chamber, so that the chemical reactions...
, followed by refining it in a finery forge
Finery forge
Iron tapped from the blast furnace is pig iron, and contains significant amounts of carbon and silicon. To produce malleable wrought iron, it needs to undergo a further process. In the early modern period, this was carried out in a finery forge....
. The process was devised in the Liège
Liège
Liège is a major city and municipality of Belgium located in the province of Liège, of which it is the economic capital, in Wallonia, the French-speaking region of Belgium....
region, and spread into France and thence from the Pays de Bray
Pays de Bray
The Pays de Bray is a small natural region of France situated to the north-east of Rouen, straddling the French départements of the Seine-Maritime and Oise...
to England before the end of the 15th century. Louis de Geer
Louis De Geer
Louis De Geer may refer to:People:*Louis De Geer , industrial entrepreneur of Walloon origin*Louis De Geer , industrial entrepreneur*Louis Gerhard De Geer , baron, Prime Minister of Sweden 1876–80...
took it to Roslagen
Roslagen
Roslagen is the name of the coastal areas of Uppland province in Sweden, which also constitutes the northern part of the Stockholm archipelago....
in Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
in the early 17th century, where he employed Walloon ironmakers. Iron made there by this method was known in England as oregrounds iron.
Quality, uses and marketing
Swedish law required bars of iron to have the forge's mark stamped into it for quality control reasons. In Britain, the iron was known by these 'marks', and the quality of each brand was well-known to the buyers in LondonLondon
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...
, Sheffield
Sheffield
Sheffield is a city and metropolitan borough of South Yorkshire, England. Its name derives from the River Sheaf, which runs through the city. Historically a part of the West Riding of Yorkshire, and with some of its southern suburbs annexed from Derbyshire, the city has grown from its largely...
, Birmingham
Birmingham
Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London, with a population of 1,036,900 , and lies at the heart of the West Midlands conurbation, the second most populous urban area in the United Kingdom with a...
and elsewhere. It was divided into two grades:
- 'First oregrounds' came from ÖsterbyÖsterbyÖsterby is a village in Noarootsi Parish, Lääne County, in western Estonia....
('double bullet'), Leufsta (now Lövsta - hoop L), and ÅkerbyÅkerbyÅkerby is a small Swedish village in the area of Småland, neighboring the small commynity of Lessebo. A famous place in Åkerby is Åkerby Vägskäl, where the first people gathered before emigrating to America in the 19 century. Wilhelm Moberg wrote about this in his book utvandrarna. It was briefly...
(PL crown). Later Gimo joined them. - 'Second oregrounds' came from the other forges, including ForsmarkForsmarkForsmark is a village with 59 inhabitants on the east coast of Uppland, Sweden. It is most known as the location of the Forsmark Nuclear Power Plant....
, Harg, VattholmaVattholmaVattholma is a locality situated in Uppsala Municipality, Uppsala County, Sweden with 1,413 inhabitants in 2005....
, and Ullfors.
Its special property was its purity. The manganese
Manganese
Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...
content of the Dannemora ore caused impurities, which would otherwise have remained in the iron, to react preferentially with the manganese and to be carried off into the slag
Slag
Slag is a partially vitreous by-product of smelting ore to separate the metal fraction from the unwanted fraction. It can usually be considered to be a mixture of metal oxides and silicon dioxide. However, slags can contain metal sulfides and metal atoms in the elemental form...
. This level of purity meant that the iron was particularly suitable for conversion to steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
by being re-carburized
Carburization
Carburizing, spelled carburising in the UK, is a heat treatment process in which iron or steel is heated in the presence of another material which liberates carbon as it decomposes. Depending on the amount of time and temperature, the affected area can vary in carbon content...
, using the cementation process
Cementation process
The cementation process is an obsolete technique 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 Furnace, built in 1720, is the earliest surviving example...
. This made it particularly suitable for making steel, oregrounds iron was an indispensable raw material for metal manufactures, particularly the Sheffield
Sheffield
Sheffield is a city and metropolitan borough of South Yorkshire, England. Its name derives from the River Sheaf, which runs through the city. Historically a part of the West Riding of Yorkshire, and with some of its southern suburbs annexed from Derbyshire, the city has grown from its largely...
cutlery
Cutlery
Cutlery refers to any hand implement used in preparing, serving, and especially eating food in the Western world. It is more usually known as silverware or flatware in the United States, where cutlery can have the more specific meaning of knives and other cutting instruments. This is probably the...
industry. Substantial quantities were also (until about 1808) bought for use by the British Navy
Royal Navy
The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...
.
This and other uses absorbed substantially the whole output of the industry. The trade in oregrounds iron was controlled from the 1730s to the 1850s by a cartel of merchants, of whom the longest enduring members were the Sykes family of Hull
Kingston upon Hull
Kingston upon Hull , usually referred to as Hull, is a city and unitary authority area in the ceremonial county of the East Riding of Yorkshire, England. It stands on the River Hull at its junction with the Humber estuary, 25 miles inland from the North Sea. Hull has a resident population of...
. Other participants were resident in (or controlling imports through) London and Bristol. These merchants advanced money to Swedish exporting houses, which in turn advanced it to the ironmasters, thus buying up the output of the forges several years in advance.