The major deposits of iron ore are located in Jharkhand, Orissa, Chhattisgarh, Karnataka and Goa States. The iron ore deposits of the Eastern, Central and Southern zone do not contain much overburden material except laterite and some low grade ferruginous shales and BHQ patches.
Haematite and magnetite are the most prominent of the iron ores found in India. About 60% of haematite ore deposits are found in the Eastern sector and about 80% magnetite ore deposits occur in the Southern sector, specially in Karnataka.
Hematite is considered to be superior because of its high grade. Indian deposits of hematite belong to the pre-Cambrian iron ore series and the ore is within banded iron ore formations occurring as massive, laminated, friable and also in powder form. India possesses hematite resources of 14,630 million tonnes of which 7,004 million tonnes are reserves and 7,626 million tonnes are remaining resources. Major hematite resources are located mainly in Jharkhand-4036 million tonnes (28%), Orissa-4761 million tonnes (33%), Chattisgarh-2731 million tonnes (19%), Karnataka-1676 million tonnes (11%) and Goa-713 million tonnes (5%). The balance resources are spread over in the state of Maharashtra, Madhya Pradesh, Andhra Pradesh, Rajasthan, Uttar Pradesh and Assam together contain around 4% of hematite.
Magnetite is the other principal iron ore occurring in the form of oxide which is either of igneous or metamorphoses banded magnetite silica formation, possibly of sedimentary origin.
The magnetite resources are placed at 10,619 million tonnes of which only 207 million tonnes constitute reserves located mainly in Karnataka and Goa. The balance 10,413 million tonnes constitute remaining resources. A major share of magnetite resources is located in Karnataka-7812 million tonnes (74%), Andhra Pradesh-1464 million tonnes (14%), Rajasthan-527 million tonnes & Tamil Nadu-482 million tonnes (5% each), and Goa-214 million tonnes (2%). Assam, Jharkhand, Nagaland, Bihar, Madhya Pradesh and Maharashtra together account for a meager share of magnetite resources. The most important magnetite deposits are located in Babubadan, Kudremukh, Bellary, Anadurga and Bangarkal areas of Karnataka, Goa region, Ongole and Guntur districts of Andhra Pradesh etc. Other deposits are also located in Jharkhand, Bihar, Tamilnadu, Kerala and Assam etc. However, reserves of high grade ore may be a cause of concern. The total iron ore resources are estimated at 25.25 billion tonnes, of which Hematite ore resources stands to the order of 14.63 billion tonnes and the remaining 10.61 billion tonnes are magnetite as on 1.4.2005.
World resources of Iron Ore are estimated to exceed 800 billion tonnes of crude ore containing more than 230 billion tonnes of iron. World iron ore production has touched 1690 million tonnes during 2006. Although iron ore is mined in more than 50 countries, the bulk of world production comes from just a few countries. The five largest producers, in decreasing order of production of gross weight of ore, were Brazil, China, Australia, India & Russia. Brazil was the largest producer in gross weight of ore produced. Open cast mines in China, CIS countries are now working at greater depths (sometimes more than 300m below ground level). This has necessitated adopting in-pit crushing with conveying system of ore transportation. Sweden is the only country where all its iron production (24Mt) comes from under ground iron ore mines. Under ground iron ore mining are also being practiced to an extent of 10 to 15% of total production in China and CIS countries.