Iron Industrial Revolution

November 24, 2020

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The Industrial Revolution Index

Chronology of the Iron and Steel Industry
1709 - 1879


Abraham Darby used coke to make pig iron at Coalbrookdale to make pig iron



Benjamin Huntsman "rediscovered" steel.



The first iron rolling mill (to make wrought iron) was opened at Foreham, Hampshire.



Darby laid an iron plateway


Matthew Boulton established an ironworks, using coke as the fuel, in Birmingham.


The iron industry was centred around Merthyr, in the heart of the Welsh coalfields.



Iron had replaced wood as the material for making industrial machines.


Wilkinson bored cylinders for Watt's engine


Abraham Darby III built the first iron bridge at Coalbrookdale.



Henry Cort invented a new and improved method to produce wrought iron. He also developed a new way of making wrought iron railings.



James Beaumont Neilson improved the blast furnace construction.



Henry Bessemer developed the "basic oxygen converter" to make steel.



Britain was producing 60 times as much pig iron as in 1800.


Percy Gilchrist and S.G. Thomas adapted Bessemer's process to suit phosphoric ores.


20th Century Iron and Steel Production

Iron is the fourth most common metal in the earth's crust. It makes up 5% of its weight. Iron occurs naturally in a variety of ores in sedimentary rocks:


Chemical Name

iron pyrites (or fool's gold)

iron II sulphide


iron III oxide

limonite or goetite ("bog ore")

hydrated iron oxide (same composition as rust)


iron II oxide and iron III oxide


iron II carbonate

Iron pyrites, or fool's gold, cannot be used to make iron because of its high sulphur content which makes the iron too brittle.

Although the early iron industry used "bog ore" to obtain iron, ironstone is the most common iron ore and it is extracted from open cast (surface) sites in England, from the River Humber to the River Severn.

To obtain iron from ironstone the ore is first roasted with coal. This process is called sintering. Sintering drives off impurities, such as water, carbon dioxide, sulphur dioxide and arsenic compounds. It leaves a sinter which is mainly granules of magnetite (an oxide of iron).

The magnetite is then reduced in the blast furnace. The sinter is mixed with high grade coke and limestone (calcium carbonate). Hot air at 2 atmospheres pressure, is blasted into the furnace, creating temperatures of up to 1900°C. The iron ore reacts with carbon monoxide in a reduction reaction producing iron and carbon dioxide. Any impurities fuse with the limestone to form a sludge which sinks to the bottom of the furnace. The molten iron, known as pig iron, lies on top of the sludge and can be run off. If the pig iron is re-melted and poured into moulds, it sets as cast iron.

Cast iron is brittle which makes it impractical for some uses. However, it does have a high compression strength and can be heated with air and hammered to produce wrought iron. Hammering cast iron into wrought iron was a long process.

To be converted into steel, the pig iron has to be melted in the presence of oxygen to remove any remaining impurities. Then an alloy of iron, manganese and carbon, is added. The result is a tremendous display of explosive sparks which shoot out of the converter. The carbon converts the iron into steel. High carbon steels are extremely strong and durable.

Production of pig iron in Britain during the 18th century.


Pig iron production (tons)






After 1770, iron (and later, steel), replaced wood as the material for making industrial machines and tools. In 1806, the annual production of pig iron had reached 272000 tons, which was a 200% increase over 18 years.


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The Industrial Revolution

Iron and Steel Manufacture

The development of the railway stimulated the economy in two important ways. First, the advent of cheap and efficient transport lowered the carriage cost of goods. This meant that goods were cheaper in the shops and this increased the demand. The increase in demand led to the expansion of factories which required more energy. The prime energy source at the time was coal. As the Industrial Revolution began to speed up, the need for coal grew because it provided power for the factory engines, steam powered ships and steam locomotives. Second, the demand for iron increased. Iron was needed to make the railway tracks, steam locomotives and the giant Watt steam engines that pumped the mines and provided energy to run factory machinery. At a later stage, iron was needed to construct the steamships.

The developers of the early steam engines and steam railways would never have been so successful without parallel developments taking place in the iron industry. Without the ironmasters' expertise in creating new methods of iron casting and working iron, it would have been impossible to have produced steam power in the first place. All of these developments which drove the Industrial Revolution were dependent on each other for their success. New inventions in one field led to advancements in another. These, in turn, stimulated further research and development.

John Wilkinson (1728-1808)

John Wilkinson played an important role in the development of James Watt's rotary steam engine. In 1774, he patented a precision cannon borer which he manufactured at his father's Beisham factory at Denbigh in Wales. This boring machine was essential for the manufacture of Watt's engines since it allowed for the detailed measurements needed in the steam engine's design. Wilkinson was then able to use Watt's steam engines to power the bellows at his own wrought iron furnace at Broseley in Shropshire.

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