31
37
CHAPTER
5 MINERAL RESOURCES
Introduction
We live during an age of high consumption rates of matter and energy resources. Modern industrial nations depend on aluminium, chromium, iron, copper, lead, mercury, zinc, tin and other metals; on materials such as sand, gravel, stone and clay; and on coal, oil, natural gas, uranium and other energy resources.
The exploitation of mineral resources depends on their occurrence as concentrations, which render them economically viable. Such concentrations refl ect both crustal and denudation processes that promote the segregation (fractionation) of materials involved in geochemical cycles. Mineral resources are formed via diff erent processes.
Ores
An ore is a rock containing a suffi cient proportion of metal to make its extraction an economic proposition. For an ore to be mined, it must be economically profi table to do so. However, it is important to note that a metalliferous rock that is valueless as a source of a metal at one time, may be worthwhile mining some other time.
Origin of Mineral Deposits
In order for a deposit to form, some process or combination of processes must bring about a localized enrichment of one or more minerals. A convenient way to classify mineral deposits is through the principal concentrating process. Minerals become concentrated in fi ve ways:
Concentration by magmatic processes within a body of igneous rock to form magmatic mineral deposits.
Concentration by hot, aqueous solutions fl owing through fractures and pore spaces in crustal rock to form hydrothermal mineral deposits.
Concentration by precipitation from lake water or seawater to form sedimentary mineral deposits.
Concentration by fl owing surface water in streams or along the shore to form placer or detrital mineral deposits.
Concentration by weathering processes from residual mineral deposits.
38
Extraction of Minerals
As per the mineral to be extracted and pervading conditions, surface mining, open cut mining and underground mining are the methods. The mineral resources are extracted in variety of ways:Quarrying : The simplest mining is called as quarrying. A quarry is a type of open-pit mine from which rock or minerals are extracted. Quarries are generally used for extracting building materials, such as dimension stone, sand, and gravel.
Techniques for mining a Coal SeamIt is only after the Earth’s surface has been excavated, and the minerals exposed at the surface have been exhausted, that man abandons open-cast mining to work underground. And as demand for raw materials has increased, underground mines or shaft mines were developed; so subterranean workings have become even deeper and more extensive.Most solid mineral resources can be mined by fairly simple techniques. Shafts and tunnels are constructed, and extracted as the material is conveyed to the surface. The most important underground mining methods are-Room and Pillar that is a characteristic coal mining method in which mining commences from the bottom of the shaft and advances outwards into the deposit. The whole of the seam is mined out with the exception of pillars of coal, which are left to support the roof. An improvement over this method is longwall where as the mining face advances, the roof is allowed to collapse behind into the worked out area. Sub-level Stopping and Cut and Fill are the other variants.
Types of Mining: Underground, Open Pit and Strip MiningFracking : For liquid or gaseous resources, however, more complex methods are employed. Petroleum is obtained by drilling, whereby a circular cutter bores through the overlying rocks. The trapped oil then gushes out naturally (as a result of pressure) or is pumped to the surface. A new mining technique has developed to mine oil Shale. This is called horizontal mining and is called fracking.There are three mining methods for surface Mining and Placer Mining.Hydraulicking : Hydraulicking is used for large, unconsolidated heavy mineral deposits, such as gold bearing gravels, which may be worked by loosening the gravels with high pressure water jets, dredging is used for placer gold and tin deposits and Sluicing that is actually used to recover the sought after minerals and do not play any signifi cant part in the actual extraction of the ore bearing material.
39
Types of MineralsNormally two types of minerals are recognised:
Metallic Minerals -These minerals contain metal. Iron ore, copper, manganese, nickel, etc. are important examples of metallic minerals. Metallic minerals are further sub-divided into ferrous and non-ferrous minerals.
Ferrous Minerals- These minerals have iron content. Iron-ore, manganese, chromite, pyrites, tungsten, nickel, cobalt, etc. are important examples of ferrous minerals.
Non-ferrous Minerals -These minerals do not have iron content. Gold, silver, copper, lead, bauxite, tin, magnesium, etc. are important examples of non-ferrous minerals.
40
Non-metallic Minerals . These minerals do not contain metal. Limestone, nitrate, potash, dolomite, mica, gypsum, etc. are important examples of non-metallic minerals. Coal and petroleum are also non-metallic minerals. They are used as fuel and are also known as mineral fuels.
Other Classifi cation of MineralsThe wide varieties of minerals that have been explored by man for general and commercial purposes to satisfy his needs are classifi ed in to the following groups:
Industrial metallic minerals: Iron Ore Ferroalloy metallic minerals: Manganese, Chromium, Cobalt, Molybdenum Vanadium, Nickel. Precious metallic minerals: Gold (Au), Silver (Ag) and Platinum (Pt). Non-metallic minerals: Salt, and Tin, Potash, Asbestos, and Sulphur. Power Minerals (Mineral fuels): Coal, Petroleum and Natural Gas which arenon-metallic minerals derived from vegetable remains Other: Uranium
Mineralised Regions
The injection of metalliferous and other minerals into the earth’s crust is intimately associated with the movement of the plates or slabs of continental rock of which the crust is composed. Many of the concentrations of metalliferous ores are thus found in close association either with areas of ancient rock or with areas of recent tectonic movement in the course of which magma rose to the Surface.
Continental EuropeContinental Europe was formerly endowed with many deposits of the metalliferous minerals, but many are now exhausted and abandoned. Most lay in the belt of ancient rock, which extends from the Meseta (plateau) of Spain, through France and Germany to Czechoslovakia and Poland. Lead, zinc and copper remain of some importance. A second highly mineralized region is the ‘shield’ of very old rock, which makes up much of Finland and northern Sweden. Many metalliferous ores are obtained here, but the most important is the high- grade Swedish iron ore. Europe also contains extensive deposits of low-grade bedded iron ores. The most extensive and important are those of Lorraine in eastern France and of the Harz region in West Germany.
CISThe Ukrainian plateau Ural Mountains and the rocks of the Siberian ‘shield’ are highly mineralized, and the CIS has very large reserves of iron ore and of some non-ferrous metals.
AsiaMetalliferous resources in Asia, outside the Soviet Union, do not appear to be very extensive. China has large reserves of tin and tungsten, Malaya of tin and India of iron ore, but Japan, the most industrialized Asian country, is also one of the least well endowed.
Africa and AustraliaThese two landmasses are both made up largely of massifs or shields of hard, ancient rocks, intruded by numerous lodes or ore bodies. Africa, especially south of the Sahara Desert, is richly endowed.
41
Among its most important resources are the copper of Zambia and Zaire, the gold and diamonds of South Africa and the tin of Nigeria. But there are also important reserves of chrome, zinc, manganese, cobalt, the radioactive minerals and of bauxite-the ore of aluminium.Australia has a number of rich sources of lead-zinc-silver. Its gold mines are no longer of great importance, but Australia is now one of the world’s leading sources of iron ore, much of which is mined in Western Australia and shipped to Japan.
North AmericaThis is probably the most richly endowed of all the continents, and in none have mineral resources been exploited more actively during the past century. There is today very little active mining in the eastern half of the United States, but there are large reserves of copper, lead, zinc and the alloy metals in the mountainous west. In Canada copper, nickel and iron are being worked in the old rocks of the Laurentian Shield,
Latin AmericaGold and silver, which attracted the early explorers, are today of little Importance except in Mexico. Far more important are the copper of Chile, the tin of Bolivia, the bauxite of Guyana, Surinam and some of the West Indian islands, and the iron ores of Venezuela and Brazil.
Industrial Metallic Mineral
Iron Ores (Fe)
Magnetite (Fe 3O4):Iron content up to 72.4%. It is a black mineral formed in igneous or metamorphic rocks in veins or lodes. It has excellent magnetic qualities.
Uses: Magnetite iron is used as natural magnets and in electrical industry.
Haematite (Fe 2O3):Iron content is 70% It is most important iron ore. They are red ores derived from sedimentary rocks and occur in crystalline or in powdery forms.
Uses:Iron is most important for the purpose of industrial use.
Limonite (2Fe 2O3H2O):Iron content is 60% This is brown ore occurring in thick beds in sedimentary rock sequence or in swamps or lakes, (lake or bog iron).
Siderite (Fe Co 3): Iron content up to 48% This is ash-grey in colour and is found interbedded with other sedimentary rocks. It is basically used for making steel.
42
Distribution
U.S.A.
Lake Superior Region—( Mainly haematite ores) Mesabi Range, Vermilion, Cuyuna, Gogebic, Menominee and Marquette Ranges.
North-eastern Region—( Mainly Magnetite ores) Adirondacks region of New York and Cornwall area of Pennsylvania.
South-western Region—( Both haematite and limonite ores) Birmingham and Alabama.
Western Region— Utah (magnetite), Nevada, Wyoming (haematite) and California.
Canada— Lake Superior Region, Labrador and Quebec (Haematite), the main centres being Scheff erville and Wabush city. Newfoundland, British Columbia.
CIS — Near Moscow and at Krivoi Rog in the Ukraine (haematite ore); Siberia and the Urals region near Magnitogorsk; Kuzbas at Kustanay. Kursk Magnetic Anomaly—Lipetsk and Donbass.
Sweden— Kiruna and Gallivare (Magnetite ores); Central Sweden—Dannemora and Grangeborg; Southern Sweden—Kopparberg.
France— Lorraine (Siderite ores); Normandy in Pyrenees; and central Massif.
Britain— Scunthorpe (Siderite ores) and Frodingham.
Germany— Siegerland.
Spain— Bilbao, Santander and Oviedo (haematite).
Norway— Kirkenes.
Finland— Jussaro in the Ekenas Archipelago.
Austria— Erzberg (siderite) and Huttenburg in Karnten.
ErstwhileYugoslavia— North of Sarajevo and Zagreb and Banjalanka.
Japan
China— Manchurian deposits at Anshan, Yangtze valley and in Hopei.
India— Jharkhand and Orissa.
South Africa— Postmasburg in Griqualand and Thabazimbi in the Transvaal (haematite).
Liberia— BomiHtlls and Mt. Nimba.
Mauritania— Zouerate.
Australia— Western -Australia at Mt. Goldsworthy, Mt. Whaleback, Mt. Bruce, Mt. Tom Price and Yampi Sound; South Australia at Iron Knob.
Brazil— Itabira and near Belo Horizonte in Minas Gerais.
Venezuela— Guiana highlands at Cerro Bolivar and El Pau.
Chile— Algarrobo in Central Chile.
Peru— Nazca-Marcona area.
43
Chromium (Cr)
Characteristics Nature: It is a hard, silvery metal with a bluish tinge and a metallic lustre.
Uses: Increases the hardenability of steel if mixed along with nickel.
Distribution of Chromium
44
It is used for making stainless steel which is widely used in manufacture of machinery where steam, water, moist air or acids would corrode ordinary steels quickly.
Larger amounts, 12-15% increase high temperature strength and corrosion resistance, as well as resistance to wear. Therefore, kitchen utensils, cutlery, oil burner components and bearings are made.
Chromite ore is also used as a refractory material in basic brick linings of various metallurgical furnaces—chromite or chrome magnesite brick.
Chromium, used in making nickel-chromium alloys (nichrome), is highly resistant to electric current and is thus used as a safety measure in electric wires, toasters and other electrical appliances.
Chromium salts and compounds (chromates) are used in the manufacture of paint pigments, chemical industry, for leather tanning, metal and Wood to prevent rotting.
Distribution Common Wealth of Independent States (CIS)— Sarany, north of Sverdlovsk and Chromtay in Urals; Balkan countries—Kukas in Albania; Finland; Philippines—Zambales in northern Luzon; Turkey—Fethiye and Guleman; India; S. Africa—Selukwe; Zimbabwe—Kildonan; Brazil
Manganese (Mn)
Manganese (Mn)
Characteristics Uses Distribution
A silvery metal exploited as
ores and also as nodules on the deep sea fl oor.
It is used as a ferro-alloy.
Percentage of manganese up to 14% give steel a hard surface but tough core, needed in rock crushers and railroad switches.
Mexico.
CIS— Nikopol and Tokmak the Ukrains; Chiaturejr Georgia; Ulu-Teljak in th§ Urals; Usa in Kuzbassanq Jashno-Chingan near River Amur.
Two types of commercially
exploited manganese ores are: Pyrolusite and
Psilomelane.
Manganese is also used in the manufacture of bricks, glazed pottery, plastics, fl oor tile, glass, varnish and dry-cell batteries.
Manganese compounds are used in making disinfecting liquids; as a decolouuriser in glass making; and for the manufacture of bleaching powder, used in the textile industry.
Mangnese is mixed with copper to produce manganese-bronze, and with nickel to produce ‘manganin’ which is highly resistant to corrosion.
India— Balaghat, Singhbhum, Goa and Vishakhapatnam.
S. Africa Postmasburg and Kuruman, West of Kinberley.
Gabon— Mouanda near Franceville,
Ghana— Nsuta.
Zaire— Kisenga and Kasekelesa.
Brazil— Near Mecapa in Amapa, Minas Gerais, and Urucum near Corumba in western Mato Grosso.
Others— Deposits as nodules especially in the Pacifi c Ocean.
45
World’s Manganese Distribution
Other Metallic Minerals
Nickel (Ni)Characteristics Uses Distribution
It is a hard, silvery metal. It is one of the hardest, most malleable and least fusible metals known.The ore of nickel is called Pent laud i te (mix ture of nickel, iron and sulphur).Often found in association with copper.
It gives strength to iron and other base metals. For heat and Corrosion uses, nickel has no substitute. Therefore, it is used in jet engines, gas turbines and rockets. Along with Chromium it is used in making stainless steel.
Canada—Sudbury, Lynn Lake and Thompson in Nn. Manitoba.CubaPhilippines.CIS—Sverdlovsk and Orsk in the Urals; Kola Peninsula at Pechenga; and at Norilsk in Siberia.Myannmar
Monel metal (nickel-copper-alloys) is highly corrosion resistant to salt water and so it is used in pumps, propellers and mine screens.Invar (iron-nickel alloy) has the property of minimum expansion at high temperatures. It is used in making accurate measuring tapes, chronometer parts and railway lines.Permalloy (alloy of iron-nickel) is an alloy which is easily magnetized and demagnetized and is used electromagnets.Alnico (Al-Ni-Co-Fe alloy) is used for making strong permanent magnets.
Indonesia(Sulawesi/Celebes)S. AfricaNew Caledonia in thePacifi c.Australia—Queensland and KalgoorlieBrazilVenezuela
46
Cobalt (Co)
It is a hard, blue metal. Cobalt, when mixed with steel increases its hardness and high temperature strength. Therefore cobalt alloys are used for cutting tools in lathes, for components in jet engines and atomic energy reactors. It is also used in heating coils in electric radiators and for making permanent magnets.Cobalt is also used in paints, invisible ink, and medicines; staining window glass, pottery and bottles.The radioactive isotope can be used in radiotherapy.
Canada—Sudbury. CubaFinland—Outukumpu. CISZaire—Katanga district.Zambia—Kilemba.Morocco—BouAzzerAustralia, New Coledonia.
Copper (Cu)
Characteristics
Copper (Latin: Cyprium—metal from Cyprus) is a soft brown metal found almost solely in igneous and metamorphic rocks.
Uses Because of its high conductivity it is used in electrical engineering industry for making wires, parts in electric motors, transformers, generators, radio, T.V. and other electrical appliances. Its high ductility and malleability it is used for the manufacture of wires, cables, fi ttings and parts of automobile, armament and machinery.Copper is alloyable with other metals and is used to produce new compounds— tin with copper—bronze, copper with zinc—brass, copper with nickel & zinc— nickel silver used for making coins.Because of its resistance to corrosion it is used for roofi ng, for making tubes, pumps, radiators, boilers.It is a valuable metal for domestic utensils and ornamental uses.
Distribution U.S.A— Arizona—Morenci, Globe, Miami, Bisbee and Ajo; Utah—Bingham; Montana—Butte; Nevada; New Mexico.Canada— Sudbury region of Ontario, Noranda—Rouyn district of Quebec and FlinFlon, Sheridon, Lynn Lake and coppermine.CIS— Degtyarsk in Sverdlovsk area; Kazakhstan; and at Dzegkazgan; Kounradskiy north of lake Balkash.Sweden— Falun mine.Germany— Mansfi eld.Spain— Rio Tinto mines in Huelva.Norway— Sulitjelma.Erstwhile Yugoslavia— Bor fi eld and Zajecar.Mongolia— Ulan Bator and Erdenet.Zaire— Katanga Province.
47
Zambia— Nechanga, Kitwe and Mufulira.Australia— at Mt. Isa, Mt. Morgan and Mt. Lyell.Papua-New Guinea— Bongainville.Chile— Copper mountain of Chuquicamata, El Teniente, Rio Blanco, Braden, Potrerillos, Sierra Gorda near Antafagasta.Peru—Cerro de Pasco, Toquepala, Morococha and Casapalca
Aluminium (Al)
Characteristics Uses Distribution
Its main ore is bauxite from which alumina is extracted and later aluminium is obtained. It is light, cheap, tough metal with h i g h conductivity of electricity and great malleability. It has a very high resistance to corrosion.
It is used aircraft, wagons, machinery for manufacturing automobiles, rail coaches, ships, and domestic appliances; Electric Cables and other uses in electrical industry.
U.S.A—Arkansas, Alabama and Georgia.CIS—Krasnaya-Shapochka, Kamensk Ural’-Skiy in the Urals and Turgay.F r a n c e — B r i g n o l e s , northeast of Toulon.Erstwhile Yugoslavia, Hungary.India—Bihar, Guinea
It is also used for fabrication of doors, windows and screens and aluminium paint, aluminium foil, headlight refl ectors and mirrors. It is alloyable with other metals—duralumin: aluminium with copper and magnesium for hardening; silicon with aluminium is highly ductile and shock resistant.
A u s t r a l i a — W e i p a i n NorthWestern Australian and Cape York Peninsula.Jamaica, Guyana, Surinam.
48
Zinc (Zn)
Characteristics Uses Distribution
Zinc is mainly obtained from zinc sulphide and Calamine.
It is very resistant to corrosion.
It is used for coating iron or steel (galvanization) as aprotective sheath for metals.It is alloyable; copper with Zinc— brass, is used for kitchen utensils, ornamental wares, buttons etc.A zinc based alloy— mazak are used as die-casting alloys and used in automobile and locomotive industries.
U.S.A.— Missouri, Oklahoma and Kansas, New Jersey and the western mountain states.Canada—Sullivan mine at Kimberley, British Columbia, Mattagami area near Qntario-Quebec border—Kidd Creek mine and Cadmum mine; south of Bathurst in northern New Brunswick. Zinc is obtained as by product from FlinFlon region of Manitoba-Saskatchewan.
Zinc is also used for manufacture of paints, collapsible tubes, dry batteries, mouth-organ plates, boiler plates, cartridges, hardware, brake-linings, etc.
CIS—Kazakhstan, Leninogorsk and other mines in Altay region; Chimkent in the Tien Shan mountains; Tetyukhe, northeast of Vladivostok and Ordzhonikidze in the Caucasus.
Poland, Italy, Spain, Greece, Germany Sweden, Finland.Japan—Monshu and MokkaidoZambia—Kipushi mines. Morocco Namibia.Australia—Broken Hill, Mt. Isa and Tasmania.Mexico—Zacatecas and Chihuahua.Peru—Cerro de Pasco.
49
Non-metallic Minerals
Tin (Sn, stannum)
Tin has a low melting point. It is malleable and ductile and alloys easily, resists corrosion, is non-toxic and makes excellent solder. The main ore of tin is Cassiterite.
It is used in most electric and electronic equipment, as coating for steel, tin plate, soldering and also for making tincans.Important tin alloys are; copper with tin- Bronze, tin with lead—soft solder, copper, zinc, arsenic, antimony with tin-babbit metal and lead, antimony with tin-type metal.
CIS—Transbaikalia deposits near Verkhoyansk and Pevek.Malaysia—Kinta Valley, Larut Plain, Kelang Valley, Jelebu Valley of Negri Sembilan, Jemaluang and Kota Tinggi in southern Johore and Sungei, Lembing in Pahang.Thailand—Kra Peninsula and off shore island of Phuket.China—Yunnam, at Gejui (Kochin); Tauchinand He Xian in southeast China; andNanling Shan of Central China.Indonesia—Bangka, Billiton and Singkep of Sumatra. Some deposits are found in thestrait of Malacca.Nigeria—Bauchi Plateau and Jos Plateauand Zaria.Zaire—Monomo and Maniema.Australia—Cornwall.Bolivia—Catavi, Colquiriand Huanuni, Brazil, Argentina.
Precious Metallic Minerals: Gold (Au), Silver (Ag)
Gold (Au)
Characteristics Distribution
Nature: A precious metal having high metallic lustre and attractive yellow reddish colour.
Canada—yellow knife in the Northwest Territories, Red lake in western Ontario, Timmins, Kirkland and Larder Lake.
Distribution of Zinc
50
It occurs in alluvial or placer deposits or as reefs or lodes underground.Uses: It has uses as an international reserve asset and in industry as jewellery, and also as gold tooth fi llings, gold leaf, gold paints for crockery, fountain pen nibs of and gold plating.
U.S.A—Homestake mine in the Black Hills of South Dakota; Bingham mine of Utah; and Nevada—Carlin and Cortez. California and Alaska (alluvial and placer deposits)CIS—Yakutsk region of Northeastern Siberia in the valleys of Aldan, Indigirka and Kolyma rivers (as placer deposits); Lake Bajkal (as lodes).JapanSouth Africa—Witwatersrand, Odendalrus and Lydenburg (gold occurs as reefs or lodes).
Zimbabwe, Ghana.Australia—Kalgoorlie and CoolgardiePhilippines, Papua New Guinea
Silver (Ag, argentum)
Characteristics Uses Distribution
Silver is a lustrous white metal. It has resistance to corrosion.
It is used as jewellery and fi ne house-furnishings, in photography and for coating German silver.Also used in commemorative coins and medals.
U.S.A.—Idaho, Arizona, Utah, and Montana. Canada—Timmins district in the Ontario Quebec border,
But it tarnishes when it comes into contact with sulphur of sulphurous ‘fumes, traces of which are always found in the air. It is very resistant to acetic acid.Its main ore is argentite.
It is ductile and malleable and has wide industrial applications.Silver is used in electro-plating, soldering- for the manufacture of silver lined steel tanks and peer vats.It has high thermal and electrical conductivity and is used as a substitute of copper in the electrical industry. It is also used as an electrical conductor in the electrolytic reduction of aluminium.Silver nitrate is used as an antiseptic and silver iodide for cloud seeding.
Yukon area and at Port Radium at Kimberley and FlinFlon. CIS—Kazakhstan and western Siberia.MexicoPeru—Cerro de Pasco.Bolivia.
Mineral Resources: India
India is endowed with a rich variety of minerals. It has been estimated that nearly 100 minerals are known to be produced or worked in India, of which nearly 30 may be considered more important including several which although comparatively unimportant in quantity today are capable of material development in future with expansion of industries.
The country has fairly abundant reserves of coal, iron and mica, adequate supplies of manganese ore, titanium and Aluminum, raw materials for refractories and limestone; but there is a defi ciency in ores of copper, lead and zinc.
There are workable deposits of tin and nickel.” India earns a lot of foreign exchange by exporting a large variety of minerals such as iron ore, titanium, manganese, bauxite, granite and a host of other minerals.
At the same time India has to depend upon imports to meet her requirements of some other minerals such as copper, silver, nickel, cobalt, zinc, lead, tin, mercury, limestone, platinum, graphite and so many other minerals.
51
Metallic Minerals
Metallic minerals form an important section of mining activity in India and provide solid base to metallurgical industries in the country.
52
Iron OreIron is a metal of universal use. It is the backbone of modem civilization. It is the foundation of our basic industry and is used all over the world. The standard of living of the people of a country is judged by the consumption of iron. Following four varieties of iron ore are generally recognized:
Haematite This is the best quality of iron ore with about 70 per cent metallic content and occurs as massive, hard compact and bumpy ore having reddish or coral red colour.
53
Most of the haematite ores are found in Dharwad and Cuddapah rock systems of the peninsular India. Over 80 per cent of the hematite ores are concentrated in eastern parts of India comprising of important iron ore producing states of Odisha, Jharkhand, Chhattisgarh and Andhra Pradesh. In the western section, the major concentration is in Karnataka, Maharashtra and Goa.
Magnetite Also known as ‘black ore’, due to blackish colour, this is the second best ore, next only to haematite with metallic content varying from 60 to 70 per cent. Like hematite, magnetite ores occur in the Dharward and Cuddapah systems of the peninsular India. Magnetite ores have magnetic quality as a result of which they are known as magnetite ores. Most of the reserves are found in Karnataka, Andhra Pradesh, Rajasthan, Tamil Nadu and Kerala.
Limonite Limonites are inferior ores, yellowish in colour, which contain 40 to 60 per cent iron metal. These are found in Damuda series in Raniganj coal fi eld, Garhwal in Uttarakhand, Mirzapur in Uttar Pradesh and Kangra valley of Himachal Pradesh.Though poor in quality, these have the advantage of easy and cheap mining.
Siderite Also known as ‘iron carbonate’ this type of iron ore is of inferior quality and contains less than 40 per cent iron. It also contains many impurities and its mining is not economically viable. However, it is self-fl uxing due to presence of lime.
Reserves Hematite and magnetite are the two most important iron ores in India. According to United Nations Framework Classifi cation (2015), the total reserves of hematite ore are estimated at 22,487 million tonnes. About 92 per cent of magnetic ore deposits occur in the eastern sector. Major sources of hematite ore located in Odisha, 7,559 million tonnes (34%), Jharkhand 5,286 million tonnes (24%), Chhattisgarh 4,858 million tonnes (22%), Karnataka 2,467 million tonnes (11%), and Goa, 1189 million tonnes (5%).The balance resources are spread in Andhra Pradesh, Assam, Bihar, Maharashtra, Madhya Pradesh, Meghalaya, Rajasthan and Uttar Pradesh.The total reserves of magnetite ore as per United Nations Framework Classifi cation (UNFC) of 2015, are estimated at 10,789 million tonnes. About 96 per cent of magnetite ore resources are located in just four states namely, Karnataka 7,802 million tonnes (72%), Andhra Pradesh 1,392 million tonnes (13%), Rajasthan 617 million tonnes (6%) and Tamil Nadu (5%). The remaining about 4 per cent are found in Assam, Bihar, Goa, Jharkhand, Kerala, Maharashtra, Meghalaya and Nagaland.
Important Producers
Odisha Odisha produces over 40 per cent iron ore of India. The most important deposits occur in Sundargarh, Mayurbhanj, Cuttack, Sambalpur, Keonjhar and Koraput districts. India’s richest haematite deposits are located in Barabil-Koira valley.
54
Chhattisgarh
Chhattisgarh has about 18 per cent of the total iron ore reserves of India. This state produced about 18 per cent of the total iron ore production of the country in 201 1-12.
The iron ores are widely distributed, the prominent deposits being those of Bastar and Durg districts.
These reserves are of high grade ore, containing over 65 per cent iron. Bailadila in Dakshin Bastar, Dantewada and Bijapur district, and Dalli Rajhara in Durg district are important producers.
Jharkhand
Jharkhand accounts for 25 per cent of reserves and over 11 per cent of the total iron ore production of the country.
Iron ore of Singhbhum district is of highest quality and will last for hundreds of years. The main iron bearing belt forms a range about 50 km long extending from near Gua to near Pantha in Bonai (Odisha).
The other deposits in Singhbhum include those of Budhu Buru, Kotamati Buru and Rajori Buru. The well-known Noamandi mines are situated at Kotamati Buru. Magnetite ores occur near Daltenganj in Palamu district. Less important magnetite deposits have been found in Santhal Parganas, Hazaribagh, Dhanbad and Ranchi districts.
Karnataka
Karnataka is the fi fth largest producer and accounts for nearly 8 per cent of the total iron ore produced in India.
Iron ores are widely distributed in the state, but high grade ore deposits are those of Kemmangundi in Bababudan hills of Chikmagalur district and Sandur and Hospet in Bellary district.
Most of the ores are high grade haematite and magnetite. The other important producing districts are Chitradurga, Uttar Kannad, Shimoga, Dharwar and Tumkur.
ManganeseIt is an important mineral which is used for making iron and steel and it acts as a basic raw material for manufacturing alloy. Nearly 6 kilograms of manganese is required for manufacturing one tonnes of steel.
It is also used for the manufacture of bleaching powder, insecticides, paints, and batteries.
Production and Distribution India has the second largest manganese ore reserves in the world after Zimbabwe. The total reserves of manganese ore as in 2015 are 496 million tonnes.
The main concentration is in Odisha (44%), Karnataka (22%), Madhya Pradesh (12%), Goa and Maharashtra (7% each), Andhra Pradesh (4%), Jharkhand (2%). Rajasthan. Gujarat and West Bengal together share the remaining 2 per cent resources.
55
India is the world’s fi fth largest producer of manganese ore after Brazil, Gabon, South Africa and Australia. Production of manganese ore in India remains more or less static with slight variations from
56
State Production in tonnes Percentage of all India Production
1. Maharashtra 6,49,898 27.66
2. Madhya Pradesh 6,48,283 27.59
3. Odisha 5,65,662 24.08
4. Andhra Pradesh 3,22,087 13.71
5. Karnataka 1,36,072 5.79
6. Jharkhand 18,265 0.78
7. Rajasthan 7,483 0.32
8. Others 1,550 0.07
Total 23,49,300 100.00
Maharashtra - The main belt is in Nagpur and Bhandara districts. High grade ore is found in Ratnagiri district also.Madhya Pradesh- Maharashtra is closely followed by Madhya Pradesh. The state produced only 11 per cent of India’s manganese ore just two decades ago. The main belt extends in Balaghat and Chhindwara districts. It is just an extension of the Nagpur- Bhandara belt of Maharashtra.Odisha. It is obtained from Gondite deposits in Sundargarh district and Kodurite and Khondolite deposits in Kalahandi and Koraput Districts. Manganese is also mined from the lateritic deposits in Bolangir and Sambalpur districts.Andhra Pradesh - The main belt is found between Srikakulam and Vishakhapatnam districts. Srikakulam district has the distinction of being the earliest producer (1892) of manganese ore in India. Cuddapah, Vijayanagaram and Guntur are other producing districts.Karnataka- The main deposits occur in Uttara Kannada, Shimoga, Bellary, Chitradurg and Tumkur districts.
Other producers- Jharkhand, Rajasthan, Goa, Panchmahals and Vadodara in Gujarat, Udaipur and Banswara in Rajasthan and Singhbhum and Dhanbad districts in Jharkhand are other producers of manganese.
ChromiteChromite is an oxide of iron and chromium. It is widely used in metallurgical, refractories and chemical industries. Over 93 per cent of the resources are in Odisha, mostly in the Sukinda valley in Cuttack and Jajapur districts. Minor deposits are scattered over Manipur, Nagaland, Karnataka, Jharkhand, Maharashtra, Tamil Nadu and Andhra Pradesh.
CopperAs a metal, copper came in use of man much earlier than iron. Copper has been used for making utensils and coins since long. Being a good conductor of electricity and ductile, it is extensively used in a vast variety of electrical machinery, wires and cables. It is also an important metal used by automobile and defence industries. Further, it is alloyed with iron and nickel to make stainless steel, with nickel to make ‘monel metal’ and with aluminium to make ‘duralumin’. When alloyed with zinc it is known as ‘brass’ and with tin as ‘bronze’.
57
Copper ore is found in ancient as well as in younger rock formations and occurs as veins, as dis-semination and as bedded deposits. Mining for copper is a costly and a tedious aff air because most of the copper ores contain a small percentage of the metal. Against the international average of metal content (in the ore) of 2.5 per cent, Indian ore grade averages less than one per cent.
Production and Distribution The total reserves of copper in the country are estimated at 1511.50 million tonnes with about 12.16 million tonnes of copper metal (2015). Rajasthan has 813.13 million tonnes ore (54%) containing 4.48 million tonnes of copper metal.
This is followed by Madhya Pradesh 283.43 million tonnes (19%) containing 3.42 million tonnes of copper metal and Jharkhand 295.39 million tonnes ore (20%) containing 3.28 million tonnes of copper metal.
The rest 7 per cent of reserves are accounted for by Andhra Pradesh, Gujarat, Haryana, Karnataka, Maharashtra, Meghalaya, Nagaland, Odisha, Sikkim, Tamil Nadu, Telangana, Uttarakhand and West Bengal.
The entire copper of India is produced by three states namely Madhya Pradesh, Rajasthan and Jharkhand.
Madhya Pradesh Madhya Pradesh has become the largest producer of copper in India surpassing Karnataka, Rajasthan and Jharkhand in succession. In the year 2011-12 the state produced 59.85 per cent of the total copper production of the country.
The state is blessed with a fairly large belt in Taregaon area, in Malanjkhand belt of Balaghat district. This district has recoverable reserve of 84.83 million tonnes of copper ore having 1,006 thousand tonnes of metal.
Reserves of moderate size are also found in Kherlibazar-Bargaon area of BetuI district. Some other areas are also reported to have copper ore reserves.
Rajasthan Rajasthan has also progressed a lot with respect to production of copper and is now the second largest producing state in India accounting for over 28 per cent of the total production of the country.
Most of the copper reserves are found along the Aravali range, spread over the districts of Ajmer, Alwar, Bhilwara, Chittaurgarh, Dungarpur, Jaipur, Jhunjhunu, Pali, Sikar, Sirohi and Udaipur.
The Khetri-Singhana belt in Jhunjhunu district is the most important copper producing area. This belt runs in north-east to south-west direction over a distance of 80 km from Singhana to Raghunathgarh with average width varying from 3 to 5 km.
Jharkhand Jharkhand, used to be the largest producer of copper till early 1980s but it has lost much importance and has slipped to third position, partly due to fall in its own production and mainly due to increased production of other states.
The state’s share of copper ore production has fallen from 62 per cent of the nation’s total production in 1977-78 to a desperate 11 per cent in 2011-12. The main copper belt extends over a distance of 130 km.
Singhbhum is the most important copper producing district where Rakha, Kendadih, Surda, Dhobani, Mosabani and some other areas have proved reserves of 58.044 million tonnes from which 1,480.12 thousand tonnes of metal may be recovered.
Hasatu, Baraganda, Jaradih, Parasnath, Barkanath, etc. in Hazaribagh district; Bairakhi in SanthalParganas area and some parts of Palamu and Gaya districts are also reported to have some deposits of copper ore.
58
NickelNickel does not occur free in nature and is found in association with copper, uranium and other metals. It is used as an important alloying material. When alloyed with iron, rust proof stainless steel of superior quality is obtained, from which utensils are made.Because of its greater hardness and tensile strength nickel steel is used for manufacturing armored plates, motor cars, bullet jackets and in naval construction. When alloyed with copper or silver, it is used for making coins. Nickel-Aluminium alloys are used for manufacturing aeroplanes and internal combustion engines. Metallic nickel is used for making storage batteries and as a catalyst for hydrogenation or hardening of fats and oils intended for use in soap and foodstuff s and in making vanaspati.
Mines: Important occurrences of nickeliferous limonite are found in the Sukinda valley of Jajapur district, Odisha. Where it occurs as oxide. A suitable process is being developed for its utilization. Nickel also occurs in sulphide form along with copper mineralization in east Sighbhum district, Jharkhand. In addition, it is found associated with uranium deposits at Jaduguda, Jharkhand and process are being developed for its recovery. Other important occurrences of nickel are in Karnataka, Kerala and Rajasthan. Polymetallic sea nodules are another source of nickel. The total resources of nickel ore have been estimated at 189 millions tonnes in the country. About 92 per cent resources i.e., 175 million tonnes are in Odisha. The remaining 8 per cent resources are distributed in Jharkhand (9 million tonnes) and Nagaland (5 million). Nominal resources are reported from Karnataka (0.23 million tonnes).
Lead and ZincLead is a widely used metal due to its malleability softness, heaviness and bad conductivity of heat. The most important industrial use of lead is as a constituent in alloys such as type metal, bronzes and anti-friction metall. Lead oxide is used in lead sheeting, cable covers, ammunition, paints, glass and rubber industry. It is also made into tubes and pipes which are used in buildings, especially as sanitary fi ttings. It is now increasingly used in automobiles, Aeroplanes, and calculating machines. Lead nitrate is used in dyeing and printing.Lead does not occur free in nature, rather it occurs as a cubic sulphide known as galena. Galena is found in veins in limestones, calcareous slates and sandstones and occasionally in met amorphic rocks or in association with volcanic rocks.Zinc is a mixed ore containing lead and zinc and is found in veins in association with galena, chalcopyrites, iron pyrites and other sulphide ores. The total resources of lead and zinc ores are estimated at 749.46 million tonnes. Of these, 106.12 million tonnes (14 per cent) fall under ‘reserves’ while balance 643.34 million tonnes (86 per cent) are classifi ed as ‘remaining resources’. The total metal content in resources is 1 1.55 million tonnes lead and 36.66 million tonnes zinc. Besides, 18.45 thousand tonnes lead and zinc metal resources are available. In terms of reserves. 224 million tonnes of lead metal and 12.45 million tonnes of zinc metal are estimated. Rajasthan is endowed with the largest resources of lead-zinc ore amounting to 670 34 million tonnes (89.44 per cent), followed by Andhra Pradesh 22.69 million tonnes (3.02 per cent), Madhya Pradesh 14.84 per million tonnes (1.98 per cent), Bihar 1.43 million tonnes (1.52 per cent) and Maharashtra 9.27 million tonnes (1.24 per cent).
59
Resources are also established in Gujarat, Meghalaya, Odisha. Sikkim. Tamil Nadu, Uttarakhand and West Bengal.
BauxiteBauxite is an important ore which is used for making aluminium. It is an oxide of aluminium. It is not a specifi c mineral but a rock consisting mainly of hydrated aluminium oxides. It is a clay-like substance which is pinkish, whitish or reddish in colour depending on the amount of iron content.
60
Production and Distribution Odisha alone accounts for 52 percent of country’s resources of bauxite followed by Andhra Pradesh 18 percent, Gujarat 7 percent, Chattisgarh and Maharashtra 5 percent each and Madhya Pradesh and Jharkhand 4 percent. Major bauxite resources are concentrated in the east coast in Odisha and Andhra Pradesh.
Odisha, Gujarat, Jharkhand, Maharashtra, Chhattisgarh, Tamil Nadu and Madhya Pradesh are the main bauxite producing states in India.
Odisha Odisha is the largest bauxite producing state accounting for more than one-third of the total production of India. The main bauxite belt is in Kalahandi and Koraput districts and extends further into Andhra Pradesh. This 300 km long. 40 to 100 km wide and 950 to 1300 metre thick belt is the largest bauxite bearing region of the country. The main deposits occur in Kalahandi, Koraput, Sundargarh, Bolangir and Sambalpur districts. The important mining areas include Chandgiri, Baphalimoli Parbat, Kathakal, Manjimali, Pasenmali, Kunnumali, Kodingandi, Pottangi and Karalput in Kalahandi and Koraput districts.
Chhattisgarh Chhattisgarh is the second largest producer of bauxite in India and produces more than 18 per cent bauxite of India. The Maikala range in Bilaspur, Durg districts and the Amarkantak plateau regions of Surguja, Raigarh and Bilaspur are some of the areas having rich deposits of bauxite.
Maharashtra Maharashtra accounts for over 15 percent of the total bauxite produced in India. The total recoverable reserves in the state, have been estimated to be of the order of 87.7 million tonnes. The largest deposits occur in Kolhapur district capping the plateau basalts. Udgeri, Dhangarwadi, Radhanagari and Inderganj in Kolhapur district contain rich deposits with alumina content 52 to 89 percent. The other districts with considerable deposits are Thane, Ratnagiri, Satara and Pune.
Jharkhand Jharkhand is an important bauxite producing state of India accounting for over 14 per cent of the total production. The reserves of this state are found in extensive areas of Ranchi, Lohardaga, Palamu and Gumla districts. Some bauxite is also found in Dumka and Munger districts. High grade ore occurs in Lohardaga and adjoining areas.
GoldIt is a valuable metal which occurs in auriferous lodes and some of it is found in sands of several rivers. It is used for making ornaments and is known as international currency due to its universal use.
Production and Distribution The total resources of gold ore in the country were estimated at 527.96 million tonnes in 2015. Out of these, 17.23 million tonnes were placed under reserves category and the remaining 510.73 million tones under remaining resources category. Total resources of gold (primary), in terms of metal, stood at 654.74 tonnes. Out of these, 70.09 tonnes were placed under reserves category and 584.65 tonnes under remaining resources category. The resources include place type gold ore in Kerala estimated at 26.12 million tonnes containing 5.86 tonnes gold metal. Among the states, the largest resources in terms of the metal ore (primary) are located in Bihar (44 per cent) followed by Rajasthan (25 per cent), Karnataka (21 per cent), West Bengal and Andhra Pradesh (3 per cent each), Telangana and Madhya Pradesh (2 per cent each).
61
There are three gold fi elds in the country, namely Kolar Gold Field, Kolar district, Hutti Gold Field Raichur district (both in Karnataka) and Ramgin Field in Anantpur district (Andhra Pradesh).Karnataka is the largest producer of gold in India. The main reserves are Kolar, Hassan and Raichur districts. Some gold reserves also reported from a number of scattered localities in Gulbarga, Belgaum, Bellary, Mysore, and Chikamagalur and Shimoga districts.
Alluvial GoldApart from the gold mines in the above mentioned areas, some gold is collected from the sands and gravels of several rivers. Gold is often liberated from the rocks by weathering and its particles get concentrated at certain places in the rivers. Such deposits are called placer deposits from which gold is recovered by panning. Although very small in quantity, this type of gold is widely spread in a large number of rivers.Jharkhand: Jharkhand is an important producer of gold in India. Jharkhand has both alluvial and native gold. Alluvial gold is obtained from the sands of the Subarnarekha (gold streak) river, as its name suggests, Sonanadi in Singhbhum district and the streams draining the Sonapat valley. Native gold is found near Lowa in Singhbhum district and in some other parts of Chota Nagpur plateau.Kerala : The river terraces along the Punna Puzha and the Chabiyar Puzha have tracts of gold. Alluvial gold is found in the Ambankadava Puzha, Chabiyar Puzha and in the rivers near Mannarkkat.
Silver Silver is another precious metal produced in India. It is valued next only to gold for making ornaments due to its softness and attractive white colour.It had been an important currency metal in several parts of the world. It is also used in the manufacture of chemicals, electroplating, photography and for colouring glass, etc.The chief ore minerals of silver are agentine, stephanite, pyrargyrite and proustite. It is found mixed with several other metals such as copper, lead, gold, zinc, etc.India is not a major producer of silver in the World. The main production comes from Zawar mines in Udaipur district of Rajasthan. Here, silver is obtained as a by-product during the concentration and smelting of galena ore in Hindustan Zinc Smelter.
Non-Metallic MineralsIndia also produces a large number of non-metallic minerals although only a few of them have assumed as much industrial and economic importance as is done by the metallic minerals. However, they are used in a large variety of industries; the major industries being cement, fertilizers, electricals, etc.
MicaMost important mica-bearing pegmatites occur in Andhra Pradesh, Bihar, Jharkhand, Maharashtra and Rajasthan. Occurrences of mica pegmatites are also reported from Gujarat, Haryana, Karnataka, Kerala, Odisha, Tamil Nadu and West Bengal. The total resources of mica in the country are estimated at 5,32,237 tonnes out of which 1,90,741 tonnes are placed under reserves category and 3,41,496 tonnes under remaining resources category. Andhra Pradesh leads with 41 per cent share in country’s total resources followed by Rajasthan (21 per cent), Odisha (20 per cent), Maharashtra (15 per cent), Bihar (2 per cent) and balance (less than 1 per cent) in Jharkhand.India has a near monopoly in the production of mica, producing about 60 per cent of world’s total production. About 95 per cent of India’s mica is found in just three states of Andhra Pradesh, Rajasthan and Jharkhand. Some mica is produced in Bihar also.
62
LimestoneLimestone is associated with rocks composed of either calcium carbonate, the double carbonate of calcium and magnesium, or mixture of these two constituents. In addition to the main constituents of calcium and magnesium carbonates, limestone also contains small quantities of silica, alumina, iron oxides, phosphorus and sulphur. Limestone deposits are of sedimentary origin and exist in almost all the geological sequences from pre-cambrian to recent except in Gondwana.The total resources of limestone of all categories and grades are estimated at 2,03,225 million tonnes in 2015. Karnataka is the leading state having 27 per cent of total resources followed by Andhra Pradesh and Rajasthan (12 per cent each), Gujarat (10 per cent), Meghalaya (9 per cent), Telangana (8 per cent) and Chhattisgarh (5 per cent). The total production of limestone was 293 million tonnes in 2014-15, an increase by 4% as compared to that of the previous year. As much as 87.22% of the total output in 2014-15 was contributed by eight principal states, viz., Rajasthan (21.02%), Madhya Pradesh (13.31%), Andhra Pradesh (12.10%), Gujarat (8.79%), Karnataka (8.21%), Telangana (8.18%), Chhattisgarh (8.03%) and Tamil Nadu (7.58%). The remaining 12.78% of the total production was shared by other limestone producing states.Limestone is used for a large variety of purposes. Of the total consumption, 75 per cent is used in cement industry, 16 per cent in iron and steel industry and 4 per cent in the chemical industries. Rest of the limestone is used in paper, sugar, fertilizers, glass, rubber and ferromanganese industries.
DolomiteLimestone with more than 10 per cent of magnesium is called dolomite; when the percentage rises to 45, it is true dolomite. The economic uses of dolomite are chiefl y metallurgical; as refractories, as blast furnace fl ux as a source of magnesium salts and in fertilizer and glass industries. Iron and Steel industry is the chief consumer of dolomite accounting for over 90 per cent consumption followed by fertilizer (4%), ferro-alloys and glass (2% each), alloy steel (1%) and others (1%). Dolomite is widely distributed in the all parts of the country.
AsbestosAsbestos has found great commercial value due to its fi brous structure, its capability to be readily separated into fi laments of high tensile strength and its great resistance to fi re. It is widely used for making fi re-proof cloth, rope, paper, millboard, sheeting, belt, paint, etc. and for manufacturing fi re proof safes, insulators, felts, etc. It is also used in making aprons, gloves, curtains, brake-linings in automobiles and insulating mats. Asbestos cement products like sheets, slates, pipes and tiles are used for building purposes. When asbestos is brittle, it is made into fi lter pads for fi ltering acids, organic liquids and other chemicals. Mixed with magnesia, it is used for making ‘magnesia bricks’ used for heat insulation.Important occurrences are known in Udaipur, Dungarpur, Alwar, Ajmer and Pali districts. In Andhra Pradesh, asbestos of fi ne quality occurs in Pulivendla taluk of Cuddapah district. There are several occurrences between Chitravati and Papaghani rivers. The 15 km long zone between Lopatanuthula and Brahamnapalle is most promising. In Karnataka, the main deposits occur in Hassan, Mandya, Shimoga, Mysore and Chikamaglur districts.
MagnesiteThe total reserves/resources of magnesite are about 394 million tonnes. Substantial quantities of resources are established in Uttarakhand (59 per cent), followed by Rajasthan (14 per cent) and Tamil Nadu (12 per cent). Resources are also located in Andhra Pradesh, Himachal Pradesh, Jammu and Kashmir, Karnataka and Kerala. Occurrences of magnesite in Tamil Nadu are low in lime and high in silica whereas those of Uttarakhand are high in lime and low in silica.
63
Production of magnesite recorded more than four-fold increase in forty years from 1.19 lakh tonnes in 1951 to 5.28 lakh tonnes in 1990-91 after which production regularly declined and stood at 2.76 lakh tonnes in 2014-15.Tamil Nadu, Uttarakhand, Karnataka and Rajasthan produce almost the entire magnesite of India.
GypsumGypsum is a hydrated sulphate of calcium which occurs as white opaque or transparent mineral in beds or bands in sedimentary formations such as limestones, sandstones and shales. In some cases it occurs as transparent crystals associated with clays. It is mainly used in making ammonia sulphate fertilizer and in cement industry. It is an essential constituent of cement, though its proportion is only 4-5 percent. It is also used in making plaster of Paris, moulds in ceramic industry, nitrogen chalk, partition blocks, sheets, tiles, plastics, etc. It is conveniently applied as surface plaster in agriculture for conserving moisture in the soil and for aiding nitrogen absorption.The total resources of mineral gypsum in the country are estimated at 1,330 million tonnes (2015) of which 37 million tonnes have been placed under ‘reserve’ and 1,293 million tonnes under ‘remaining resources’ category. Of the total resources, fertilizer/pottery grade accounts for about 80 percent and cement/paint grade 13 percent.
DiamondsDiamonds have been highly valued and cherished throughout the ages because of their brilliance, adamantine, lustre, transparency and hardness. They are widely used for ornaments and for polishing the surface metals, minerals and gem cutting. The most important industrial use of diamonds is in cutting- edges of drills used for exploration and mining of minerals.The production of diamonds had increased from 1,674 carats valued at 5.34 lakh in 1950 to 18,489 carats valued at 19.8 crore in 2011-12. The main diamond bearing areas are Panna belt in Madhya Pradesh; Wajrakarur Kimberlite pipe in Anantapur district and the gravels of the Krishna river basin in Andhra Pradesh. Reserves have been estimated only in Panna belt and Krishna Gravels in Andhra Pradesh. The total in situ reserves are about 26,43,824 carats. There are conditional resources of 19,36,512 carat. The new kimberlite fi elds are discovered recently in Raichur-Gulbarga districts of Karnataka.Further investigations for diamonds are being carried out in Andhra Pradesh, Madhya Pradesh and Karnataka. Reserves of diamonds in India are not yet exhausted and modern methods are being applied for intensive prospecting and mining in Panna, Kumool, Bellary and some other selected places in central India. Indian diamonds are in great demand in the international market, especially for jewellery. Cutting and polishing of diamonds is done by modern techniques at important centres like Surat, Navasari, Ahmedabad. Palanpur, Bhavnagar and Mumbai. Khambhat, Jaipur, Trichur and Goa are comparatively new centres.
Atomic MineralsUranium and Thorium are the main atomic minerals to which many be added i.e., beryllium, lithium and zirconium. Uranium is perhaps the only chemical element that has been dominating the world strategic scene since the mid-twentieth century. Discovered more than 200 years ago in mineral known as pitchblende by a German chemist Martin Heinrich Klaproth, it derives its name from the planet Uranus, which was discovered only a few years earlier in 1781. Uranium occurs in the earth crust with average concentrations 2 to 4 ppm (parts per million) and in sea water with average concentration 0.003 ppm. It occurs with much higher concentration in certain minerals like uraninite, pitchblende, autunite and uranophane.
64
65
Australia is said to have largest deposits of uranium which amount to about 11,42,000 tonnes (about 30% of the world deposits). This is followed Kazakhstan, Canada. U.S.A., South Africa, Namibia, Brazil, Niger and Russia.
The world production of uranium at present is in the vicinity of forty thousand tonnes. Canada with 25% of the world production is at the top followed by Australia, Kazakhstan and some other countries.
The fi rst uranium deposit was discovered in 1951 at Jaduguda in Jharkhand and the mine was commissioned in 1967. Three more mines have been established in Jharkhand one each in Narwapahar (1995), Turamdih(2002) and Bagjata (2007).
The other major deposits have been found at Bodal in Chhattisgarh and Jajawal in Madhya Pradesh; Domiasiat (known to be one of the largest and richest), Wahkyn and Tyrani in Meghalaya and Lambapur-Peddagattu and Tummalapalle in Andhra Pradesh.
Favourable uranium mineralization has also been identifi ed at Gogi in Karnataka, Kuppam and Gandi in Andhra Pradesh, Rohil in Rajasthan, Bastar district in Chhattisgarh and many other places.
The mixed mineral ore is processed at uranium mills at Jaduguda, Batin and Narwapahar where it is converted into uranium oxide ,popularly known as “Yellow Cake”.
State Uranium reserves (metric tonnes)1. Jharkhand 46,7002. Andhra Pradesh 22,0003. Karnataka 21,0004. Meghalaya 16,4005. Rajasthan 2,9006. Chattisgarh 2,800
Total 1,17,800
RECENT DEVELOPMENTS
Massive reserves of mercury hidden in permafrost
Researchers have discovered permafrost in the northern hemisphere stores massive amounts of natural mercury, a fi nding with signifi cant implications for human health and ecosystems worldwide.
About:
Researchers from American Geophysical Union have discovered permafrost in the northern hemisphere which stores massive amounts of natural mercury.
The study revealed that northern permafrost soils are the largest reservoir of mercury on the planet, storing nearly twice as much mercury as all other soils, the ocean and the atmosphere combined.
Thawing of permafrost due to global warming can release mercury into ocean and can impact ecosystem in diff erent ways.
Mercury accumulates in aquatic and terrestrial food chains, and has harmful neurological and reproductive eff ects on animals.
66
Advantages:
If mercury reserve found in permafrost can be exploited, it can serve humanity. Mercury is the only metal which is in liquid state at room temperature and has high coeffi cient of expansion.Mercury is still used for the manufacture of industrial chemicals and for electrical and electronic applications.
Disadvantages:If the mercury is transported across waterways, it could be taken up by microorganisms and transformed into methylmercury.This form of mercury is a dangerous toxin that causes neurological eff ects in animals ranging from motor impairment to birth defects.This is called Minamata disease, or Chisso-Minamata disease, which is a neurological syndrome caused by severe mercury poisoning.
**********
