There has been a steady increase in the consumption and global demand of minerals. Annual rise in the use of steel making minerals is 3-5 percent, of fertilizer production material is 3 percent, of phosphate rock 5.2 percent, and of aluminum 43 percent. The demand of non-fuel mineral will further by the development of less developed countries.
Most of the minerals reach sedimentary layers of the oceans and their takes a very long time. So these minerals remain out of the mineral cycles. Minerals are exhaustible non-renewable resources. Their limited stock earth once exhausted cannot be replenished. There is danger of depletion all known and easily available deposits of minerals within a few decades.
Moreover, geographical distribution of mineral deposits is not uniform. It is likely that some countries may monopolise deposits of certain essential minerals.
However, the crisis can be met by adopting measures such as:
(i) Development of technology for efficient extraction of minerals from ores.
(ii) Exploitation of untapped deposits.
(iii) Obtaining sedimentary minerals by deep sea mining.
(iv) Judicious use of minerals.
(v) Finding new uses for plastics, glass, ceramics and synthetic fibers.
(vi) Sharing of advancement in the field of mining, extraction and use substitute substances in place of exhaustible minerals.
(vii) Designing small equipments, pumps and engines with high efficiency.
Minerals include all materials derived from the earth by mining. Such materials may be of organic origin like coal or petroleum or inorganic in origin. Inorganic substances include both metallic and non-metallic materials. Minerals are dug out from the earth either from the surface or at varying depths.
Though minerals occur widely in rocks, they can be mined economically only at places where their concentration is high. A rock in which a particular metallic mineral occurs in a concentrated form is called an ore. Therefore, mining is limited to sites where ores occur. Though iron and aluminum may be found in most of the rocks, they are mined in those localities where they occur as ores.
Many metallic minerals like gold, silver, lead and zinc occur as ores in the form of narrow lodes or veins in igneous or metamorphic rocks. Coal and lignite occur as seams of layers between sedimentary rocks. Petroleum and natural gas occur in the pore space in sedimentary rocks. Some minerals like tin, gold and diamonds occur in gravel, sand and other alluvial deposits on the river beds. Denudation of rocks in the upper reaches of river basin has removed them from their original sites. They have been transported by rivers and deposited in the lower reaches. Such deposits are called placer deposits.
The occurrence of rich mineral deposit in an area may remain unexploited if physical and economic conditions are unfavourable. For example, mineral deposits in Tropical forests or deserts remain unexploited due to harsh living conditions.
Generally high grade are located near urban centers or ports are the first to be minded. When they get exhausted or mining conditions become difficult, distant deposits are opened up or imports are made from other countries. When prices increase, it becomes economical to mine low grade ores also. Price increase also boosts exploration and discovery of new deposits even in areas which were considered unfavourable. Continuous exploration of new resources is necessary to ensure supply of minerals as old mines get exhausted in a few years. Mineral ores contain a number of substances along with the mineral.
The percentage of mineral occurring in the ore varies from place to place. Minerals have to be processed to remove impurities and obtain pure mineral. Processing of iron ore to obtain iron involves establishment of a large manufacturing unit at great cost. Petroleum cannot be used in its crude form. It has be refined into petrol, diesel oil, kerosene etc.
IRON: India is exceptionally rich in both quantity and quality of its iron ore deposits. The ores mainly consist of hematite and magnetite.
The iron content of the ore is as high as 60 to 70 percent. This explains the big international demand for our iron ore. The official estimates of the proven reserves are 17,570 million tonnes. These estimates are on the Conservative side. Half of these deposits are confined to the districts of Singhbhum in Bihar and adjoining districts of Keonjhar Bonai and Mayurbhanj in Orissa. It is perhaps the world’s largest and richest iron ore field. Iron ore is also mined in Hazaribagh and Sbahabad districts of Bihar.
Bihar-Orissa iron fields further extend into Raipur, Durg and Bastar in Madhya Pradesh. The mines in Bailadila in Bastar have been lately developed to step up exports to countries like Japan. Madhya Pradesh ranks now next only to Bihar and Orissa in mining iron ore.
The iron ore deposits are also found in several districts of Andhra Pradesh. The State of Goa has also iron ore deposits, although of not very high quality. They are largely exported. Ratnagiri and Chanda districts of Maharashtra have some iron ore deposits. The production of iron ore has been steadily rising. Unfortunately major portion is mined for export rather than manufacture of iron and steel in our own country. The ports specializing in the export of iron are Visakhpatnam (for Bailadila mines). Manna Goa, Paradip and Calcutta, Manglore is likely to emerge as an iron ore exporting port, as Kundremukh mines have been developed for this purpose.
Ferro alloys are mixed metals with iron as the base are prized for their strength, and as such they have become very Important in the age of powerful giant machines. Manganese is used for this purpose and hence its growing importance.
The mines of manganese are located in Mayurganj and Keonjhar in e State of Orissa. In karnantaka, the deposits are located in Chitredurga, lumukur, Shimoga, Chikmaglur, Belgaum, Dharwar and North Kanara districts.
The other States in which manganese is found are Bihar (Singhbhum), Andhra Pradesh Pradesh (Nizamabad and Visakthapatnam) and in Rajasthan (Banswara Udaipur). The total production in 1987 was 13 million tonnes as against the Dnservative estimates of 135 million tonnes of total reserves. Of these at least 50 million tonnes are of high quality.
Bauxite: Bauxite ore has gained an importance because aluminum: a very light but highly useful metal, is produced from it. It is a must for aircraft industry. It is also now being increasingly used in electrical industry rand also in everyday life. But the manufacture of alumina and aluminium depends largely on the availability of cheap and abundant supply of electricity.
The bauxite deposits in India are widely distributed. Traditionally Bihar, Gujrat and Madhya Pradesh have been the major producers. Maharashtra has also high grade deposits in Koihapur district. Recently deposits in Orissa have been developed and the largest plant of its kind in Asia has been set up to produce aluminia and aluminium. It annual capacity is 800,000 tonnes of alumina and 225,000 tonnes of aluminium. It uses the latest French technology which economizes on the use of electricity. Ore is exported to Japan and European countries.
In 1987 the output of bauxite was 2.6 million tonnes. The country’s reserves are estimated at 270 million tonnes, of which 73 million tonnes are of high quality.
Mica: India produces nearly 90 percent of the world’s mica. It is a basic ingredient of the electrical industry. India accounts for two-thirds of the world’s mica entering into international trade. Annual production is about 30,000 tonnes. Half of it comes from Hazaribagh, Gaya and Munger districts of Bihar. These districts lie on the northern edge of Chotanagpur plateau. The remaining half is equally shared by Nellore district in Andhra Pradesh and Bhilwara District in Rajasthan. India faces competition from Brazil. It has been noticed that our way of mining mica are rather wasteful.
Copper : Copper was widely used for making household utensils. In fact before the discovery of iron, copper held its way symbolizing march of civilization. But today it is valued as the best conductor of electricity. Currently, most of the ore is mined in the districts of Singhbhum (Bihar), Balaghat (M.P.) and Jhunjhuni and Alwar (Rajasthan). The minor producers are Khamman district of Andhra Pradesh, Chitradurga and Hassan district of Karnataka and also Sikkim. The total reserves are estimated at about 570 million tonnes with only 6.3 million of copper content. The annual output of the ore in 1987 was nearly 5 million tonnes.
Gold : India is very poorly placed in regard to the reserves of gold ore. Currently, gold is mined at Kolar mines, the world’s deepest, and Hutti mines (Raichur District), both in Karnataka. The other two mines in Anantpur and Chiltoor districts of Andhra Pradesh have lately started functioning. The known reserves are placed at only 81,000kg of gold content.
Conservation of Minerals : The limited stock of minerals on once exhausted cannot be replenished. Therefore, consumption of minerals needs immediate attention. Following measures can be adopted to conserve the mineral resources—
- The wasteful and injudicious consumption of minerals should be checked by recycling and devising more efficient techniques.
- Untapped mineral deposits should be exploited. Deep sea mining can yield more minerals.
- Designing smaller equipments, using some alternative new raw material can also minimise the excessive use of minerals.
- Using proper substitutes of minerals and finding more uses of glass, plastic, synthetic fibres and ceramics.