History of Iron

Perhaps during the period 4000 to 1500 B.C. begun the history of iron.This wide span of time is a result of considering meteoric iron from actualsmelting iron.The meteoric iron contains 5 to 26 % Ni and smelted iron contains only traces of Nickel.

Some evidence of Iron history was found:

• Meteoric iron beads from Gerzeh (3500 B. C.)
• A dagger from Ur (3000 B.C.)
• The Great Pyramid of Gizeh built circa 2900 B.C. in an Egyptian tomb
• The Phoenicians may have known about iron as early as 2500 B.C. using a tooth of iron
• The production of iron by humans began probably sometime after 2000 BC in south-west or south-central Asia, perhaps in the Caucasus region. Thus began the Iron Age, when iron replaced bronze in implements and weapons.
• A Phoenician gold and iron ring dating to 1825 B.C. was found in the city of Byblos

It is often said that the technique of iron production was developed from observation made during copper extraction. According to present knowledge, iron was first smelted in eastern Asia Minor and northern Mesopotamia around 2000 -1500 B.S. and in the plains north of the Caucasus as well. Chinese produced the first high –carbon, high phosphorus (up to 7 %) at an early date around 500 B.C.,after which,the knowledge of iron winning spread through Asia Minor to North Africa, parts of Asia, and all of Europe.

At first, the iron was smelted in a bloomer fire .The bloomer was the earliest form of smelter iron. A bloomer's product is a porous mass of iron and slag called bloom. The development of iron making can be traced back on the basis of the different furnaces used thorough the ages for smelting the iron ore. The historical trail up to the present time could be described by the follow:

• bloomery hearth ("Renn") furnaces
• bloomery furnaces
• flowing furnaces and charcoal blast furnaces
• coke blast furnaces
• direct reduction facilities
• smelting reduction facilities

Bloomery hearth furnaces were made from clay, and/or stone . Cleaned ores mixed with charcoal were reduced into Iron in the furnace. The production was solid form of iron and slag. An example is Iron making in the bloomer hearth 2500 years ago in the Siegerland region of Germany. The produced metal blooms were crushed and manually forged and formed into utility items. There was little change to this process until the middle Ages. Around 10^th century the waterwheel technology revolutionized the iron making technology. Larger furnaces could be built due to high air pressure generated by waterwheels. It produced lumps (blooms) weighting up to 100 kg which contained iron and residual slag. The lumps could be also processed with large hammers. By about the 12^th century A.D. the availability of high temperature and the fact of carbon solubility in iron paved the way of iron ore semelting. The facilities in which the hot metal was produced were initially called "flowing furnaces". As they increased in size, the term "blast furnace" came into general usage. These were beginning of the blast furnace.By about the 18^th century blast furnace was operated with charcoal. Commercial production of pig iron in blast furnace started about 14^th century. In 1784 Henry Cort in Britain developed the pudding process for the refining pig iron using air but the real refining process developed in 1856 by Henry Bessemer and 1879 by Thomas in England using converter with blowing air through the molten pig iron. Around 1865, another efficient process for steelmaking was developed in Germany called Siemens –Martin process in the form regeneratively heated as heated-type furnaces for melting Scrap.