Steel has been part of the greatest achievements in history. It was the "iron horse" and steel rails that helped carve a nation out of the frontier. Steel is the backbone of bridges, the skeleton of skyscrapers and the framework of automobiles. Now in the 21st century, it is still revolutionizing the way we live. It is high strength frames for eyeglasses; it is a strong durable frame in housing and it's precise surgical instruments used in hospital operating rooms around the world.
Iron has been a vital material in technology for well over 3,000 years. But until the Industrial Revolution, its mining, smelting, and working were largely done by individuals and small groups. Known since ancient times, steel is made by alloying iron with carbon to produce a harder stronger metal.
Steel was very expensive to manufacture by the primitive methods available and was used largely for specialty items such as swords and precision instruments.
"Steel making (in the 18th century) was a laborious and time-consuming process." (1) Manufacturing of steel improved during the 19th century with Henry Bessemer's invention of using a blast furnace method for making steel.
During the 20th century, a basic oxygen-furnace process and the electric arc furnace produced steel. The electric arc method is the least costly method of making steel. This uses scrap metal as its base. Steel scrap from many sources such as old bridges, refrigerators and automobiles and other sources are placed in an electric arc furnace, where the intense heat produced by carbon electrodes melts the scrap, converting it into molten steel. Establishments that use this method of producing steel are called electric arc furnace (EAF) mills or minimills.
The small initial capital investment required to start and operate an EAF mill has helped drive the growth of the production...