The presentation covers in depth details of #IronOre Metallurgy, Formation, #genesis and #distribution of #Iron #Ore in India.

1. Iron Ore Deposits
(Mineralogy, Geology, Ore
Genesis, Occurance)

2. Introduction  Iron ore occurs in different geological
formations in India. But the most
important economically important
deposits belongs to pre-Cambrian
age.
 The iron ore deposits began forming
when the first organisms capable of
photosynthesis began releasing oxygen
into the waters. This oxygen
immediately combined with the
abundant dissolved iron to produce
hematite or magnetite
 Earth's most important iron ore deposits
are found in sedimentary rocks. They
formed from chemical reactions that
combined iron and oxygen in marine
and fresh waters.
 Iron ores are rocks and minerals from
which metallic iron can be economically
extracted. The ores are usually rich
in iron oxides and vary in color from
dark grey, bright yellow, or deep purple
to rusty red. The iron is usually found in
the form of magnetite,
hematite, goethite, limonite or siderite.
The primary use of iron ore is in the production of
iron. Most of the iron produced is then used to
make steel. Steel is used to make automobiles,
locomotives, ships, beams used in buildings,
furniture, paper clips, tools, reinforcing rods for
concrete, bicycles, and thousands of other items.
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3. Mineralogy of Iron Ore
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 Iron ore is regarded as naturally occurring mineral that is used for extraction of
metallic iron under existing economical and technological conditions.
 Iron, an abundant element, occurs in variable amounts in many minerals.
However few of them contain appreciable amount of iron, from which iron can
be economically obtained.
 Iron forms a large variety of mineral oxides, hydrated oxides, carbonates,
Sulphides, silicates, etc.
 Amongst many iron bearing minerals, most common are Haematite and
magnetite. Followed by goethite and limonite.
 These iron bearing minerals form principle constituents of Iron ores along with
silica, alumina, lime And magnesia minerals present in large quantities.

4. Brief
Mineralogy
Mineral Classification
Oxide
Chemical Formula
Fe2O3, α-Fe2O3
(hematite), Fe3+2O4
(magnetite).
Streak
red (hematite), black
(magnetite)
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Hardness
5.5–6.5 in Mohr’s Scale of
Hardness
Lustre
Metallic
Crystal System
Trigonal (hematite),
Isometric (magnetite)

5. Mineralogy of Fundamental Iron Ore Minerals
Composition Iron Content (in %)
Colour,
Hardness and
Specific Gravity
Haematite Fe2O3 69.9
Steel grey to red,
6.5,
4.9-5.3
Magnetite Fe3O4 72.4
Black, blue or brown
black,
5.5-6.5,
5.17
Siderite FeCO3 48.2
Ash grey to brown,
3.5-4,
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6. List of
Iron Bearing Minerals
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7. “
It’s the most abundant iron ore minerals.
It’s the red oxide crystallising in
hexagonal system. The coarse grained
Haematite is called specularite and may
form blocky or platy crysals with a strong
micasious parting.
Haematite is feebly magnetic, but one of
its verieities, Maghemite, has magnetitic
properties akin to magnetite.
The iron content of th ore varies
regionally.
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8. “ The name Martite is commonly used for
haematite that’s ”pseudomorphous” .
 It’s usually iron-black with a sub metallic
lustre ranging fro red to brownish red. It
may occure in large powdery masses,
and may be metamorphosed to
haematite.
 It’s feebly magnetic due to residual
magnetic inclusions and occure in many
environments.
 Its chemical comp. is Fe2O3 . (that of haematite)
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9. “
 It’s the second most important iron-bearing
mineral of economic importance. It’s black
magnetic oxide of iron crystallising in the
isometric system and has hardness of 5.5-6.5. It
occures as fine or coarse grained massesor in
octahedral or less commonly as dodecahedral
crystals.
 It occures as veins or stringers in igneous rocks
and has lenses in crystalline schists.
 Large deposits are due to magnetic
segregation and its low grade deposits occure
as disseminations in metamorphic & igneous
rocks.
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10. “
These minerals are hydrated oxides of
iron. Their colour is brown to ochour
yellow but may be black or dark brown
to reddish brown and they are often
called “Brown Iron Ores”.
These are secondary minerals, being
the product of alteration.
Occure as thcik capping formed by
weathering and hydration of underlying
orebody. When silica is leached, Iron
content is improved by 10-15 %
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11. “These are also called as ’Spathic Ore’ and is a
carbonate of iron. It’s colour is ash grey to
brown with yellow an red stains resulting from
oxidation and hydration.
The SG is 3.8 and hardness varies from 3.5-4. It
crystallises under rhombohedral division of the
hexagonal system.
“It occurs as Sedimentary or replacement
deposits.”
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12. “It’s a sulfide of iron with golden yellow colour
having metallic lustre.
It crystallise in cubic system.
It’s spefic gravity is 5.1 and hardness of 6-6.5
It can be used as an iron ore after the sulfur
has been removed by calcination
However, it’s not much favoured as an iron
ore at present.
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13. “Greenalite, chamocite, taconite, etc, are
iron silicates of varying composition.
Lately, taconites have been identified
as iron ore of economic importance.
Taconite is hard and fine grained
sedimentary rocks containing 25-30% of
Iron as silicates.
The principle gangue mineral is silica, in
which iron minerals are disseminated.
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14. Geology
“Everything has its limit -
Iron ore cannot be
educated into gold”.
@Mark_Twain
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15. Pre-Cambrian
Most important iron ore deposits are those associated with banded haematite
Jasper/Quartzite of Dharwarian formations of South India and their equivalents
of iron ore found in north India.
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The ores are derived from the enrichment of banded ferruginous rocks by
the removal of silica. The ore body usually forms on the top of ridges
which are often of greater magnitude.
Most of them contain high grade ore near the surface, with an iron
content of 60% and are associated with even lower quantities of low
grade ores.
Where metamorphosed regionally or by igneous intrusive, these
BHJ have been converted into Banded-Quartzite-Magnetite rocks
which also attain considerable importance in some areas in TN
and Southern Karnataka.

16. Cuddapah
The Bijawar of Central India and the Pulivendla Quartzite of Cuddapah district in
AP contain workable deposits of rather small size. They seem to be the locally
enriched forms of ferruginous formations.
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17. Vindhyans
No useful deposits are known in these formations though some sandstones are
to some extent ferruginous. Occasional pockets and concretions of limonite are
associated.
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18. Gondwana
Barakar formations in rare instances contain concretionary masses of limonite. I
the Auranga coalfield in Bihar, clay ironstones are found in these formations.
Some of these have been derived from the original Carbonate ores by ocidation
and hydration
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The ironstone shale stage, particularly of Raniganj Coalfield, contains
considerable amounts of clay.
Ironstones derived from siderites are irregularly distributed as thin lenses
in the formations.

19. Jurassics
The inter-trappean beds of Rajmahal Hills contain thin beds and concretions of
ironstones which are formerly worked for smelting in small indigenous furnaces.
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20. Deccan Traps
The tropical weathering of Deccan Traps at and near the surface has given rise
to massive beds of laterite which at many places is fairly rich in Iron, perhaps
averaging 25 to 30 percent of the metal.
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21. Tertiary
 The Nahan Series of Siwaliks in Uttar Pradesh and Assam Himalayas, the
Tipam Series of Upper Assam and Rajahmundry, Cudallore and Varkala
sandstones of TN and Kerala- all contain fairly rich concretions of ironstone
which were formerly used as ore in the respective regions.
 They are of Miocene to Pliocene age
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22. Ore
Genesis
Iron ores are deposited under various
geological conditions. They occure in
basis of sedimentation, with eroded,
deep seated intrusive and where deep
tropical weathering prevails. Various
such processes are as follows:
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23. Igneous Magmatic
Segregation
╸ The igneous deposits are due to segregation of iron ore from cooling
of basic or acidic magma or rfom volcanic.
╸ The products of crystallisation form a magma segregate into lenses
or stratified sheets..
╸ The ore minerals are magnetite or titaniferous magnetite. They are
associated with acidic iigneous rocks, such as granodiorites and aslo
with anorthasites, niorite, pyroxinites, etc. (found in Scandinavia, SA,
Lapland,USA)
╸ In India, Titaniferous deposits in south-east of Singhbhum (Bihar) are
associated with ultrabsic rocks.
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In the neighbourhood of volcanic vents, crystalline haematite is formed which is believed to be
the result of interaction of gases containing iron chloride with steam

24. Magnetite and Haematite are
sometimes developed at the
contacts of limestones or with
intermediate or basic igneous
rocks. They are generally
associated with typical contact
minerals like Garnet, pyroxene,
epidote, etc. Pyrites and
Chalcopyrites are also found.
Contact Metasomatic/
Contact Deposits
Such occurrences are
found in Pennsylvania and
the western states of the
USA and Japan.
Sources of those deposits
are now regarded as of
metasomatic (replacement)
origin.
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25. Lode Deposits
Lode deposits are formed due to formations of lodes in fracture zones
deposited from solution derived from igneous sources.
The haematite deposits of Elba (Itlay) are found as veins and lense in
limestones.
Lode of siderite in Siegsland (Germany) and in Czechoslavakiaare found in
sedminetary rocks not far from igneous masses.
The Veldurti Deposits in Kurnool (AP) occupies a fault zone in the rocks of
Cudappah age.
The lode deposits are however not much of importance.
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26. Replacemnet
Deposits
These deposits are formed due to the replacement of country rock by iron-
bearing solution at comparatively low temperatures.
Typical examples are the haematites of the Lakes district, England and
Bibao of Spain which occur as replacements in limestone.
These are generally low in phosphorus.
The pyrite deposits of Rio Tinto of Spain, are also considered as
replacement deposits.
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27. Sedimentary Iron
Ores
Banded Iron
formations of India,
Brazil, Venezuela, SA,
Lake Superior Region
etc.
Oolithic Haematites,
such as those of
Alabama (USA ) and
Carbonate Ores, such
as Minette Ores of
Lorraine.
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These includes several large deposits of the
world. They belong to one or the other of the
following classes
The sedimentary Iron Ores generally consists of Haematite, but they may be associated with varying
quantities of Hydrous iron silicates such as greenalite, chamosite, etc.
There are also beds of sideritic and limonitic ores such as those in the Ironstone shales of Raniganj
Coalfields of Indi and blackband ironstone of Scotland.
Bog Iron Ores are formed in Swamps and lakes in moist climate as ferrous carbonate or ferric hydroxid
In the formation of these ores, bacteria and decaying organic matter may play a key role

28. Residual and
Superficial Deposits
When rocks containing iron ore are weathered, iron goes into solution and is later
deposited more or less in situ. It may also become concentrated in at the surface by
being drawn up through capillary pore spaces in the rock.
Many deposits capping banded ironstones are really to be considered as residual
deposits. The ultrabasic have given rise to lateritic capping as a result of weathering
such as Mayari formations of Cuba, Phillipines, and Borneo.
Rocks containing magnetite and ilmenite, when they undergo weathering may yield
sands rich in heavy minerals. Such sands may be concentrated later into workable
deposits of by the action of river/sea waves along the coast.
Ilmenite deposits of this nature are found along certain parts of coastal India,
Malaysia, Brazil and also in Pleistocene and recent formation of Japan and Indonesia
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29. Impurities
Impurities in iron ore consists
of slag forming constituents
and other minerals like
Arsenic, Titanium, Vanadium,
Zinc, Tin, Chromium, Nickel,
Phosphorus, Sulphur, etc.
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30. Global Iron Ore Distribution
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Find more maps at slidescarnival.com/extra-free-resources-icons-and-maps

31. Top countries with
Iron Ore Reserves
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UKRAINE
CANADA
AUSTRALIA
RUSSIA
BRAZIL
CHAIN
48 Billion Tons
29 Billion Tons
25 Billion Tons
20 Billion Tons
6.5 Billion Tons
6 Billion Tons

32. 2,850,000,000 tons
of iron produced globally in 2019.
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33. Indian
Occurance
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╸ In India, major
economic deposits of iron ore are found
associated with volcano- sedimentary
Banded Iron Formation (BIF) of Pre-
Cambrian Age. The major "hematite"
type iron deposits are located in well
defined belts in the States of Orissa,
Jharkhand, Chhattisgarh, Maharashtra,
Goa and Karnataka

34. 220,000,000 metric tons
Produced in India in the year 2019
3.7%
Unsold iron ore
28,700,000 tons (~15% of the total)
Produced by Karnataka alone in 2019, second only to Chhattisgarh (35 Mn tons)
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35. Leading Producer
of Iron Ore in India
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42. Thanks!
You can find me at:
╸ @iamthesuraj
╸ surajbmofficial@gmail.com
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