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Thursday, July 6, 2023

Ironworks

From Wikipedia, the free encyclopedia
The Iron Rolling Mill (Eisenwalzwerk), 1870s, by Adolph Menzel.
 
Casting at an iron foundry: From Fra Burmeister og Wain's Iron Foundry, 1885 by Peder Severin Krøyer

An ironworks or iron works is an industrial plant where iron is smelted and where heavy iron and steel products are made. The term is both singular and plural, i.e. the singular of ironworks is ironworks.

Ironworks succeeded bloomeries when blast furnaces replaced former methods. An integrated ironworks in the 19th century usually included one or more blast furnaces and a number of puddling furnaces or a foundry with or without other kinds of ironworks. After the invention of the Bessemer process, converters became widespread, and the appellation steelworks replaced ironworks.

The processes carried at ironworks are usually described as ferrous metallurgy, but the term siderurgy is also occasionally used. This is derived from the Greek words sideros - iron and ergon or ergos - work. This is an unusual term in English, and it is best regarded as an anglicisation of a term used in French, Spanish, and other Romance languages.

Historically, it is common that a community was built around the ironworks where the people living there were dependent on the ironworks to provide jobs and housing. As the ironworks closed down (or was industrialised) these villages quite often went into decline and experienced negative economic growth. 

Varieties of ironworks

Primary ironmaking

A South Wales iron mill in 1798
 
Blast furnaces of Třinec Iron and Steel Works.
 
Toronto rolling mills

Ironworks is used as an omnibus term covering works undertaking one or more iron-producing processes. Such processes or species of ironworks where they were undertaken include the following:

  • Blast furnaces — which made pig iron (or sometimes finished cast iron goods) from iron ore;
  • Bloomeries — where bar iron was produced from iron ore by direct reduction;
  • Electrolytic smelting — Employs a chromium/iron anode that can survive a 2,850 °F (1,570 °C) to produce decarbonized iron and 2/3 of a ton of industrial-quality oxygen per ton of iron. A thin film of metal oxide forms on the anode in the intense heat. The oxide forms a protective layer that prevents excess consumption of the base metal.
  • Finery forges — which fined pig iron to produce bar iron, using charcoal as fuel in a finery (hearth) and coal or charcoal in a chafery (hearth);
  • Foundries — where pig iron was remelted in an air furnace or in a foundry cupola to produce cast iron goods;
  • Potting and stamping forges with melting fineries using the first process in which bar iron was made from pig iron with mineral coal or coke, without the use of charcoal;
  • Puddling furnaces — a later process for the same purpose, again with coke as fuel. It was usually necessary for there to be a preliminary refining process in a coke refinery (also called running out furnace). After puddling, the puddled ball needed shingling and then to be drawn out into bar iron in a rolling mill.

Modern steelmaking

The ironworks of Dalsbruk in Kimitoön, Finland

From the 1850s, pig iron might be partly decarburised to produce mild steel using one of the following:

The mills operating converters of any type are better called steelworks, ironworks referring to former processes, like puddling.

Further processing

After bar iron had been produced in a finery forge or in the forge train of a rolling mill, it might undergo further processes in one of the following:

Manufacture

Most of these processes did not produce finished goods. Further processes were often manual, including

In the context of the iron industry, the term manufacture is best reserved for this final stage.

Notable ironworks

Coat of arms of Eisenhüttenstadt ("city of ironworks"), Germany
 

The notable ironworks of the world are described here by country. See above for the largest producers and the notable ironworks in the alphabetical order.

Africa

South Africa

  • Cape Town Iron and Steel Works in Kuilsrivier, Western Cape
  • Mittal Steel South Africa

  • Americas

    United States

    Asia

    China

    India

    Japan

    The largest Japanese steel companies' main works are as follows:

    Korea

    Vietnam

    Europe

    Czech Republic

    Germany

    Great Britain

    Italy

    • Cogne acciai speciali, Aosta (example of a mountain steel meel)
    • Ferreira di Servola, Trieste (operating since 1896)
    • Acciaieria di Piombino
    • Società Italiana Acciaierie Cornigliano di Cornigliano, Genova
    • Acciai speciali Termi, now ThyssenKrupp Terni
    • Acciaieria di Bagnoli, Napoli
    • Acciaieria di Taranto (biggest Integrated steel mill in Europe)

    Sweden

    Russia

    Spain

    Historical

    Zero-sum game

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