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Line 177: − + − + − + − + − + − + − + − + − + − + − + − + − + − + − + − + − + − + − Rasajalanidhi,<ref name=":8" /> describes the Doshas of iron as follows − − लौहस्य स्वाभाविकदोषाः । − − गुरुता दृढ़ता क्लेदः कश्मलं दाहकारिता । अश्मदोषो मलग्रहो दोषाः सप्तायसस्य तु ॥ − − शोधितव्यमतस्तद्धि मारणीयं यथाविधि । अशोधितममारितं लौहं ज्ञेयं महाविषम् ॥ − − The following are the seven blemishes of iron :- heaviness, hardness, mixture with foreign matters, power of causing hysteria, power of causing inflammation, evil characteristics of stone, and power of causing constipation. Iron should be properly purified and incinerated, if not done so it is equal to great poison.<ref name=":8" /> − − द्रुष्टलौहसेवनस्य फलम् । − − षण्डत्वकुष्ठामयमृत्युदं भवेद् हृदरोगशूलौ कुरुतेऽश्मरीञ्च । − − नानारुजानाञ्च तथा प्रकोपं करोति हृल्लास मवैधलोहम् ॥ − − Evil effects of taking impure iron: Iron, not properly purified and incinerated, gives rise to the following :-impotency, leprosy, death, heart disease, colic, stone disease, hiccough, and even augmentation of many of the diseases the patient has already been suffering from.<ref name=":8" /> − Line 222:
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no edit summary
Iron, called as Ayas (Samskrit: अयस्) heralded a new era in the history of mankind. Iron technology has a special place among the ancient technologies that accelerated the pace of progress and brought prosperity in society. In human history Iron Age succeeded Copper-Bronze Age as iron required a different kind of skill and a higher level of metallurgical expertise. The craftsmen who were adept in working with copper and its alloys and other glittering metals like gold, silver etc., that could be used in their native form at a much lower temperature could not smelt iron with the same technique. India has rich iron ore deposit. The ore is not only widely distributed but also easily accessible in the form of nodules scattered on the earth's surface. This must have facilitated easy hand picking of rich ore nodules by the early or primitive metal workers. However, wide distribution and easy access to the ore were insufficient to produce metallic iron and required skilled metal workers possessing sufficient metallurgical know-how. Archeological researches and archival accounts including foreign records by travelers or historians of ancient India bear that Indian iron and steel had gained significant recognition in the ancient world.<ref name=":0">Vibha Tripathi, ''Aspects of Iron Technology in India'' in Propagation, vol 3-1, 2012</ref> India abounded with vast deposits of many minerals and precious stones, thus [[Mineralogy (धातुशास्त्रम्)|mineralogy]] was an important topic dealt with even in texts such as Rigveda that helped develop and sustain many metal and alloy industries.
[[File:Properties of Iron Element.png|thumb|334x334px|Courtesy: Encyclopaedia Britannica Inc,]]
Iron, called as Ayas (Samskrit: अयस्) heralded a new era in the history of mankind. Iron (Fe), chemical element, metal of Group 8 (VIIIb) of the periodic table, is the most-used and cheapest metal found in the earth's crust.<ref name=":9">Britannica, T. Editors of Encyclopaedia. "iron." Encyclopedia Britannica, September 20, 2024. <nowiki>https://www.britannica.com/science/iron-chemical-element</nowiki>.</ref>
Iron technology has a special place among the ancient technologies that accelerated the pace of progress and brought prosperity in society. In human history Iron Age succeeded Copper-Bronze Age as iron required a different kind of skill and a higher level of metallurgical expertise. The craftsmen who were adept in working with copper and its alloys and other glittering metals like gold, silver etc., that could be used in their native form at a much lower temperature could not smelt iron with the same technique. India has rich iron ore deposit. The ore is not only widely distributed but also easily accessible in the form of nodules scattered on the earth's surface. This must have facilitated easy hand picking of rich ore nodules by the early or primitive metal workers. However, wide distribution and easy access to the ore were insufficient to produce metallic iron and required skilled metal workers possessing sufficient metallurgical know-how. Archeological researches and archival accounts including foreign records by travelers or historians of ancient India bear that Indian iron and steel had gained significant recognition in the ancient world.<ref name=":0">Vibha Tripathi, ''Aspects of Iron Technology in India'' in Propagation, vol 3-1, 2012</ref> India abounded with vast deposits of many minerals and precious stones, thus [[Mineralogy (धातुशास्त्रम्)|mineralogy]] was an important topic dealt with even in texts such as Rigveda that helped develop and sustain many metal and alloy industries.
== Introduction ==
== Introduction ==
== Pyrometallurgy ==
== Pyrometallurgy ==
The extraction of iron is pyrometallurgy. It is the extractive metallurgy which consists of the thermal treatment given to minerals or ores to recover the metal. The process involves chemical reactions at elevated temperature. The process of extraction of iron is fundamentally very simple as it consists essentially of the reduction of iron oxide by carbon. But as molten iron dissolves carbon and other impurities, iron obtained is impure and is known as pig iron or cast iron. The ore (red haematite or hydrated oxide or carbonate) is calcined in shallow kilns to remove moisture, carbon dioxide etc. The ore thereby becomes porous and is then more easily reduced in the blast furnace.<ref name=":3">[https://prog.lmu.edu.ng/colleges_CMS/document/books/MCE329%20-%20Metallurgy%20of%20Iron(329).pdf Metallurgy of Iron] </ref>
The extraction of iron is pyrometallurgy. It is the extractive metallurgy which consists of the thermal treatment given to minerals or ores to recover the metal. The process involves chemical reactions at elevated temperature. The process of extraction of iron is fundamentally very simple as it consists essentially of the reduction of iron oxide by carbon. But as molten iron dissolves carbon and other impurities, iron obtained is impure and is known as pig iron or cast iron. The ore (red haematite or hydrated oxide or carbonate) is calcined in shallow kilns to remove moisture, carbon dioxide etc. The ore thereby becomes porous and is then more easily reduced in the blast furnace.<ref name=":3">[https://prog.lmu.edu.ng/colleges_CMS/document/books/MCE329%20-%20Metallurgy%20of%20Iron(329).pdf Metallurgy of Iron] </ref>
{| class="wikitable"
|+Elemental Properties of Iron<ref name=":9" />
|'''Atomic number'''
|26
|-
|'''Atomic mass'''
|55.85 g.mol -1
|-
|'''Electronegativity according to Pauling'''
|1.8
|-
|'''Density'''
|7.8 g.cm-3 at 20°C
|-
|'''Melting point'''
|1536 °C
|-
|'''Boiling point'''
|2861 °C
|-
|'''Specific gravity'''
|7.86 (20 °C)
|-
|'''Isotopes'''
|8
|-
|'''Electronic Configuration'''
|[ Ar ] 3d6 4s2
|-
|'''Discovered by'''
|The ancients
|}
==== Iron Ores ====
==== Iron Ores ====
== Ferrous Materials - Types and Characteristics ==
== Ferrous Materials - Types and Characteristics ==
The Rasaratnasamucchaya describes three types of ferrous materials.<ref name=":6" />
The Rasaratnasamucchaya<ref name=":6" /> and Rasa-jala-nidhi<ref name=":8" /> describe three types of ferrous materials with their characteristics.<blockquote>मुण्डं तीक्ष्णं तथा कान्तं । मुण्डात् तीक्ष्णं ततः कान्तं प्रशस्तं ज्ञायते बुधैः ॥</blockquote>Iron is of three different kinds, namely Munda, Tikshna and Kanta. The second is better than the first and the third is better than the second.
मुण्डम् (पूतिलौहम्) ।<blockquote>मृदु कुण्ठं कड़ारञ्च त्रिविधं मुण्डमुच्यते । द्रुतद्रावमविस्फोटं चिक्कणं मृदु तच्छुभम् ॥
हतं यत् प्रसरेद् दुःखात् तत् कुण्ठं मध्यमं स्मृतम् । यद्धतं भज्यते कृष्णां हीनं स्यात्तत् कड़ारकम् ॥</blockquote>(a) Munda or ordinary iron.
Munda or ordinary iron is of three different kinds, viz. mridu (soft), kuntha/kadara (obdurate), and karara (brittle). Mridu or soft is that which melts quickly and has a smooth and glossy surface. Kuntha or obdurate is that which can be expanded with much difficulty by hammering. Karara or brittle iron is that which breaks easily. Of these, the first is comparatively commendable, the second is of moderate efficacy and the third is the least efficacious for medicinal purposes.<ref name=":8" />
तीक्ष्णम् ।<blockquote>खरं सारञ्च हृन्नालं तारापट्टञ्च वज्रकम् । काललौहाभिधानञ्च षड्विधं तीक्ष्णमुच्यते ॥</blockquote>(b) Tikshna iron.
There are six different kinds of tikshna iron, viz. (1) khara (2) sara, (3) hrinnala (4) tarapatta (5) vajraka and (6) kala. Each of them is further described.
# Khara iron - is that which is coarse, inflexible, and devoid of carved lines on its surface. This iron when broken into pieces, presents sectional surfaces as glazy as mercury.
# Sara iron - this kind of tikshna iron which breaks into pieces, when hammered, has pogara or carved lines on its surface. It is obtained from ores of yellowish colour.
# Hrinnala - this is yellowish black in color. It has on its surfaces, pogara or carved lines in the shape of bird's beaks. It presents very coarse sectional surfaces at the places where it is cut into pieces.
# Tarapatta iron - is obtained from iron ores by a class of smiths who are specialists in the science of ores. This iron is black, smooth, glazy, and has fine pogara on its surface. This is prepared in the shape of a spoon (minus the handle). It is a kind of iron which never rusts, even if it is exposed to the sun, rains, and wind. This is most probably the iron out of which the Iron Pillar of Delhi, the iron beams in the ruins of Konark temple, the cannons of Vishnupur etc., were prepared. The art of preparing this iron is now totally lost.
# Vajra iron - is that which has on its surface plenty of fine and deep seated lines; straight and carved pogara. It is of the appearance of an electric flash and is of a glossy black color.
# Kala iron - is heavy and of a deep blue black color. Its surface is glossy, heavy and bright. It can not be broken into pieces by being hammered upon by means of another piece of iron.<ref name=":8" />
कान्तलौहम् । तस्य लक्षणम् ।<blockquote>पात्रे यस्मिन् प्रसरति जले तैलबिन्दुर्नलिप्तं गन्धं हिंगु त्यजति च तथा तिक्ततां निम्बकल्कः ।
पाके दुग्धं व्रजति शिखराकारतां नैति भूमिं कृष्णाङ्ग स्यात् सजलचणकः कान्तलौहं तदुक्तम् ॥</blockquote>Kanta iron (an oxide of iron) having the magnetic power of attracting iron. It is of such nature that a drop of oil thrown into water contained in a pot of this iron does not spread over the surface of the water; neither does the oil stick to the inner surface of the pot. Hingu (asafoetida) kept in a pot of this iron loses its smell in course of time. Bark of nimba tree (neem) pestled with water, loses its bitterness if kept for sometime in a pot of this iron. Milk boiled in a pot of this iron will not overflow the borders of this pot.
Kanta iron is softer than silver, coarse and black in color. It is directly obtained from the mines. Water boiled in a pot made of this iron smells of hingu. Kanta iron of superior quality is generally found to be in the form of ores covered with silver. Such iron can cure all sorts of diseases, including leprosy. It is of five kinds.
# Bhramaka iron is that which makes a piece of ordinary iron revolve around it.
# Chumbaka kanta iron (loadstone) is that which can cling to pieces of ordinary iron.
# Karshaka kanta iron is that which can attract to it pieces of ordinary iron.
# Dravaka kanta iron is that at touch of which ordinary iron melts (without any heat being applied).
# Romakanta is that which causes the growth of fresh hair at that part of the skin which is lightly pierced through by it.
Of these, Bhramaka is the least efficacious while Dravaka is the most efficacious of all. The kanta iron which has only one or magnetic point is the Ekamukh, and is least efficacious, while that having two (dvimukh) or three (trimukh) points is of moderate efficacy, while that with several points (sarvatomukha) is the most efficacious.
{| class="wikitable"
{| class="wikitable"
|+Classification of iron and its properties as given in Rasa Ratna Samucchaya<ref name=":6">Prakash, B. ''Ancient Iron Making in India'' in Iron & Steel Heritage of India Ed. S. Ranganathan, ATM 97, Jamshedpur</ref><ref name=":8">Mookerjee, Bhudeb. (1984 Second Edition) ''Rasa-Jala-Nidhi or Ocean of Indian Chemistry, Medicine and Alchemy'', ''Vol. 3'' Varanasi: Srigokul Mudranalaya</ref>
|+Indian Classification of iron and its properties <ref name=":6">Prakash, B. ''Ancient Iron Making in India'' in Iron & Steel Heritage of India Ed. S. Ranganathan, ATM 97, Jamshedpur</ref><ref name=":8">Mookerjee, Bhudeb. (1984 Second Edition) ''Rasa-Jala-Nidhi or Ocean of Indian Chemistry, Medicine and Alchemy'', ''Vol. 3'' Varanasi: Srigokul Mudranalaya</ref>
!Kinds of Iron
!Kinds of Iron
(Loha)
(Loha)
!Properties
!Properties
|-
|-
| rowspan="5" |Kanta Loha (Soft Iron)
| rowspan="5" |कान्तम् ॥ Kanta Loha (Soft Iron)
|Bhramaka
|भ्रामक (Bhramaka)
|Very soft magnetic iron
|Very soft magnetic iron
|-
|-
|Chumbaka
|चुम्बक (Chumbaka)
|Mildly magnetic, sticks to iron pieces
|Mildly magnetic, sticks to iron pieces
|-
|-
|Karsaka
|कर्षक (Karsaka)
|It can attract iron objects
|It can attract iron objects
|-
|-
|Dravaka
|द्रावक (Dravaka)
|Very strong magnetic iron
|Very strong magnetic iron
|-
|-
|Romaka
|रोमकान्तम् (Romakanta)
|Permanent magnet, develops strong magnetic field around it. Itmay be Ekmukh or sarva mukh
|A permanent magnet develops a strong magnetic field around it. It may be Ekmukh, dvi or trimukh. Sarvatomukham is the best.
|-
|-
| rowspan="6" |Tikshna Loha (Carbon steel)
| rowspan="6" |तीक्ष्ण ॥ Tikshna Loha (Carbon steel)
|Khara
|खरं (Khara)
|Develops good cutting edge, breaks on bending
|Develops good cutting edge, breaks on bending
|-
|-
|Sara
|सार (Sara)
|Softer iron and it has fibrous fracture
|Softer iron and it has fibrous fracture
|-
|-
|Hrnnala
|हृन्नाल (Hrnnala)
|Hard and tough having fibrous fracture
|Hard and tough having fibrous fracture
|-
|-
|Travaratta
|तारापट्ट (Tarapatta)
|Develops good cutting edge
|Develops good cutting edge
|-
|-
|Vajra
|वज्रकम् (Vajra)
|Has good hardening and tempering property, has bluish color and hard cutting edge
|Has good hardening and tempering property, has bluish color and hard cutting edge
|-
|-
|Kala
|काल (Kala)
|Develops hard cutting edge after blue tempering
|Develops hard cutting edge after blue tempering
|-
|-
| rowspan="3" |Munda Loha (Cast Iron)
| rowspan="3" |मुण्ड ॥ Munda Loha (Cast Iron)
|Mrdu
|मृदु (Mrdu)
|Soft brittle iron may be grey cast iron, has low melting point
|Soft brittle iron may be grey cast iron, has low melting point
|-
|-
|Kunda
|Kunda/कुण्ठ (Kuntha)
|Mottled grey iron
|Mottled grey iron
|-
|-
|Kadara
|कड़ार (Kandara)/Karara
|White cast iron
|White cast iron
|}
|}
== Extraction 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 is 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 impurities than Copper. This impurity is removed by using a catalytic flux such as lime to produce the slag. Iron produced by smelting is of 3 kinds based on its carbon content:
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 is 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 impurities than Copper. This impurity is removed by using a catalytic flux such as lime to produce the slag. Iron produced by smelting is of 3 kinds based on its carbon content:
== Iron In Ayurvedic References ==
== Iron In Ayurvedic References ==
'''Ayurvedic Properties''': Iron is sweet, astringent, and bitter in taste; cold, laxative; heavy, course, preventer of senile decay, improves eyesight, reduces fat, increaser of a little vayu in the system. It pacifies an excess of kapha (phlegm) and pitta (animal heat). It cures toxins, colic, swelling of the body, piles, spleen, anemia, obesity, spermatorrhoea and worms. Iron increases strength and longevity. It cures diseases and is an aphrodiasic. It is one of the best remedies for senility.<ref name=":8" />
'''Ayurvedic Properties''': Iron is sweet, astringent, and bitter in taste; cold, laxative; heavy, course, preventer of senile decay, improves eyesight, reduces fat, increaser of a little vayu in the system. It pacifies an excess of kapha (phlegm) and pitta (animal heat). It cures toxins, colic, swelling of the body, piles, spleen, anemia, obesity, spermatorrhoea and worms. Iron increases strength and longevity. It cures diseases and is an aphrodisiac. It is one of the best remedies for senility.<ref name=":8" />
Rasajalanidhi,<ref name=":8" /> describes the Doshas of iron as follows
लौहस्य स्वाभाविकदोषाः । natural blemishes of iron <blockquote>गुरुता दृढ़ता क्लेदः कश्मलं दाहकारिता । अश्मदोषो मलग्रहो दोषाः सप्तायसस्य तु ॥
शोधितव्यमतस्तद्धि मारणीयं यथाविधि । अशोधितममारितं लौहं ज्ञेयं महाविषम् ॥</blockquote>The following are the seven natural blemishes of iron :- heaviness, hardness, mixture with foreign matters, power of causing hysteria, power of causing inflammation, evil characteristics of stone, and power of causing constipation. Iron should be properly purified and incinerated, if not done so it is equal to great poison.
द्रुष्टलौहसेवनस्य फलम् । Evil effects of taking impure iron:<blockquote>षण्डत्वकुष्ठामयमृत्युदं भवेद् हृदरोगशूलौ कुरुतेऽश्मरीञ्च ।
नानारुजानाञ्च तथा प्रकोपं करोति हृल्लास मवैधलोहम् ॥</blockquote>Iron, not properly purified and incinerated, gives rise to the following :-impotency, leprosy, death, heart disease, colic, stone disease, hiccough, and even augmentation of many of the diseases the patient has already been suffering from.
#
#