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The precise manner in which man discovered iron is unknown and may have been accidental. Man must have come to know of iron through '''meteorites'''; they contain high percentage of nickel and is difficult to forge. The earliest recorded instances of the use of meteoric iron are from Egypt and Mesopotamia. It is more likely that iron was first found in ashes of a fire set up by chance near the outcrop of an iron rich mineral. A '''folklore of the `Bastar''' tribe of central India states that their forefathers first made iron accidentally in a hollow anthill. Meteoric iron did not offer scope for any techniques involved in iron working such as smelting and forging and thus may have hardly played any role in the development of Iron age. The intentional heating of iron mineral with charcoal and development of smelting process heralded the beginning of iron making and subsequently its fabrication into implements and weapons marks the emergence of iron age.<ref name=":1">A. K., Vaish, Biswas P. K., Goswami N. G., Krishnan C. S. S., and Ramachandra Rao P. “Historical Perspective of Iron in Ancient India.” ''Journal of Metallurgy and Materials Science'' 42, no. 1 (January 2000): 65–74.</ref>

The precise manner in which man discovered iron is unknown and may have been accidental. Man must have come to know of iron through '''meteorites'''; they contain high percentage of nickel and is difficult to forge. The earliest recorded instances of the use of meteoric iron are from Egypt and Mesopotamia. It is more likely that iron was first found in ashes of a fire set up by chance near the outcrop of an iron rich mineral. A '''folklore of the `Bastar''' tribe of central India states that their forefathers first made iron accidentally in a hollow anthill. Meteoric iron did not offer scope for any techniques involved in iron working such as smelting and forging and thus may have hardly played any role in the development of Iron age. The intentional heating of iron mineral with charcoal and development of smelting process heralded the beginning of iron making and subsequently its fabrication into implements and weapons marks the emergence of iron age.<ref name=":1">A. K., Vaish, Biswas P. K., Goswami N. G., Krishnan C. S. S., and Ramachandra Rao P. “Historical Perspective of Iron in Ancient India.” ''Journal of Metallurgy and Materials Science'' 42, no. 1 (January 2000): 65–74.</ref>

Greek historian, Herodotus, stated in his book that Indian soldiers fought with '''iron-tipped arrowheads''' in their battles. There are records stating that swords of '''Indian steel were gifted as a tribute to monarchs''' emphasizing their valuable nature and they were exported to different parts of the ancient world.<ref name=":0" /> In India, D.K. Chakrabarti states that Iron has entered as a productive system by 800 B.C. Many areas from Central and Southern India, show evidence of Iron ore and Iron smelting indicating the earliest use of Indian iron in India. The iron and steel produced in early days was also shaped into useful articles. The primacy of iron technology in the Indian subcontinent is well established and there are several published books<ref>Bag, A. K (1997) ed., ''History of Technology in India, Vol. 1, From Antiquity to c. 1200 A.D.'' New Delhi: Indian National Science Academy.</ref><ref>Bose, D. M, et al., (1971) ed., ''A Concise History of Science in India''. New Delhi: Indian National Science Academy</ref><ref>Rao, Ramachandra P. and Goswami, N.G. (2001) ''Metallurgy in India: A Retrospective'' New York: India International Publisher</ref> and articles on the state of ancient Indian iron technology. Sushruta, the medical science expert in ancient India described many surgical instruments in his book [[Sushruta Samhita (सुश्रुतसंहिता)|Sushruta Samhita]] (third or fourth century BCE).<ref>Iron and Steel Industry in Ancient India by Satyendra</ref> The present article includes the chronology of time as stated in particular authors mentioned in the references in some instances and are not the views of the author of this writeup.  

Greek historian, Herodotus, stated in his book that Indian soldiers fought with '''iron-tipped arrowheads''' in their battles. There are records stating that swords of '''Indian steel were gifted as a tribute to monarchs''' emphasizing their valuable nature and they were exported to different parts of the ancient world.<ref name=":0" /> In India, D.K. Chakrabarti states that Iron has entered as a productive system by 800 B.C. Many areas from Central and Southern India, show evidence of Iron ore and Iron smelting indicating the earliest use of Indian iron in India. The iron and steel produced in early days was also shaped into useful articles. The primacy of iron technology in the Indian subcontinent is well established and there are several published books<ref>Bag, A. K (1997) ed., ''History of Technology in India, Vol. 1, From Antiquity to c. 1200 A.D.'' New Delhi: Indian National Science Academy.</ref><ref>Bose, D. M, et al., (1971) ed., ''A Concise History of Science in India''. New Delhi: Indian National Science Academy</ref><ref name=":2">Prakash, B. "Ferrous Metallurgy in Ancient India" in ''Metallurgy in India: A Retrospective'' Ed. P. Ramachandra Rao, and N. G. Goswami. New York: India International Publisher (2001) 52-91</ref> and articles on the state of ancient Indian iron technology. Sushruta, the medical science expert in ancient India described many surgical instruments in his book [[Sushruta Samhita (सुश्रुतसंहिता)|Sushruta Samhita]] (third or fourth century BCE).<ref>Iron and Steel Industry in Ancient India by Satyendra</ref> The present article includes the chronology of time as stated in particular authors mentioned in the references in some instances and are not the views of the author of this writeup.  

== Does Ayas mean a metal or iron? ==

== Does Ayas mean a metal or iron? ==

Where Fe₂O₃(s) stands for Hematite ore (Ferrous Oxide, s = solid), C stands for Carbon (in the form of solid coke), Δ represents the energy requirement for the reaction to take place, Fe stands for Ferrum (elemental Iron, l = liquid) and CO stands for Carbon monoxide (g = gaseous state)

Where Fe₂O₃(s) stands for Hematite ore (Ferrous Oxide, s = solid), C stands for Carbon (in the form of solid coke), Δ represents the energy requirement for the reaction to take place, Fe stands for Ferrum (elemental Iron, l = liquid) and CO stands for Carbon monoxide (g = gaseous state)

Iron compounds in the ores could be reduced by carbon; and for a long time, charcoal was the form of carbon used in the reduction process. Charcoal was replaced by Coke, a form of carbon formed by heating coal in the absence of air to remove impurities, improving the reduction process. As seen in the equation above, the actual reductant is CO, which reduces Fe₂O₃ to give Fe(l) and CO₂(g).

Iron compounds in the ores could be reduced by carbon; and for a long time, charcoal was the form of carbon used in the reduction process. Charcoal was replaced by Coke, a form of carbon formed by heating coal in the absence of air to remove impurities, improving the reduction process. As seen in the equation above, the actual reductant is CO, which reduces Fe₂O₃ to give Fe(l) and CO₂(g).[[File:Blast furnace .png|right|frameless|325x325px|Blast Furnace for Converting Iron Oxides to Iron Metal. Courtesy: General Chemistry (Libre Texts)]]

 

==== Steps in the Extraction of Iron ====

==== Steps in the Extraction of Iron ====

The extraction of iron involves following steps.

The extraction of iron involves following steps.

# Reduction or smelting in a Blast Furnace  

# Reduction or smelting in a Blast Furnace  

=== Process in Ancient Times ===

== Extraction Process in Ancient Times ==

Iron ores were widely distributed in Indian subcontinent. However they were delayed to smelt Iron. The reason is that the primitive condition of furnace has produced temperature about 1100°C which is required for Copper smelting. But Iron needs a high temperature almost above 1500°C for the ore to smelt into a liquid. Little solid grains of Iron have obtained by low temperature as 800°C. Iron was a soft and spongy material which had to be admixed with carbon in proper proportion to obtain sufficient sharpness and hardness. It was obtained from ores at high temperature. Iron has more impurties than Copper. This impurity has to be removed by using a catalytic flux such as lime to produce the slag (Rao 1970:258). Iron produced by smelting is divided into 3 kinds:  

Iron ores were widely distributed in Indian subcontinent. However they were delayed to smelt Iron. The reason is that the primitive condition of furnace has produced temperature about 1100°C which is required for Copper smelting. But Iron needs a high temperature almost above 1500°C for the ore to smelt into a liquid. Little solid grains of Iron have obtained by low temperature as 800°C. Iron was a soft and spongy material which had to be admixed with carbon in proper proportion to obtain sufficient sharpness and hardness. It was obtained from ores at high temperature. Iron has more impurties than Copper. This impurity has to be removed by using a catalytic flux such as lime to produce the slag (Rao 1970:258). Iron produced by smelting is divided into 3 kinds:  

* carbon steel (Tikshna Loha)

* carbon steel (Tikshna Loha)

Quenching and tempering was also learned along with steeling of Iron. Quenching consists immersing the red hot metal into water. Metal would become harden by this process. Tempering consists of repeated heating of the metal and allowing it to cool slowly while it is hammered (Banerjee 1965:2).<ref>Saravanan, R. ''Iron:'' ''From Metal to Metallurgy'' Heritage: Journal of Multidisciplinary Studies in Archaeology 5 (2017): 514‐518</ref>

Quenching and tempering was also learned along with steeling of Iron. Quenching consists immersing the red hot metal into water. Metal would become harden by this process. Tempering consists of repeated heating of the metal and allowing it to cool slowly while it is hammered (Banerjee 1965:2).<ref>Saravanan, R. ''Iron:'' ''From Metal to Metallurgy'' Heritage: Journal of Multidisciplinary Studies in Archaeology 5 (2017): 514‐518</ref> Raw iron, wood and carbon are heated in earthen bowls at a temperature of 1535°C and then, slowly cooled over 24 hours. This gives high quality carbon rich steel. A sword made of this steel is so sharp and strong that it even cuts silk smoothly.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

== References ==

== References ==

[[Category:Shastras]]

[[Category:Shastras]]