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| Anthracite: Highest Quality Coal/Image Source: Jakec |
What is a mineral?
A mineral can be defined as the naturally occurring substance with a definable internal structure. For example, common salt, coal and limestone.
As of now, more than 3800 mineral rocks have been identified, but only less than a hundred rocks are economically viable to extract. These economically viable and extractable mineral rocks are known as ores. For example, iron ore, manganese ore and bauxite (aluminium ore).
Mode of Occurrence of Minerals
Minerals generally occur in the following ways:
1. In igneous and metamorphic rocks
Here minerals occur the cracks, crevices, faults or joints. The smaller occurrences are known as veins and larger ones are called lodes. They are the result of cooled down magma. For example tin, copper, zinc and lead.
2. In sedimentary rocks
Here, a number of minerals appear in beds or layers. They are formed as a result of millions of years of deposition in horizontal strata. For example coal, iron, gypsum, potash salt and sodium salt.
3. In surface rocks
Here, minerals occur due to the decomposition of surface rocks and removal of soluble components, leaving a residual mass of material. For example bauxite.
4. In river valleys
Here, minerals are found in alluvial deposits of the river. These deposits are also known as placer deposits and contain minerals which do not get corroded by water such as gold, silver, tin and platinum.
5. In ocean beds
Here, minerals are found on the surface of oceans which do not get affected by saline water of ocean such as common salt, magnesium and bromine, and also under the ocean surface such as crude oil.
Classification of Minerals
- Minerals can be classified into three broad categories: 1. metallic, 2. non-metallic and 3. energy minerals.
- Metallic minerals can be further subdivided into 1. ferrous, 2. non-ferrous and 3. precious minerals.
Earlier, precious minerals used to be classified under non-ferrous mineral and energy minerals used to be classified under non-metallic minerals. But, due to their economic value, they have been given a separate category.
Ferrous Minerals
They account for three-fourths of overall metallic mineral production. India is known for its iron, manganese, copper and aluminium.
Iron Ore
- India is known for the production of both high quality (magnetite) and medium quality (hematite) iron ores.
- Magnetite is known for iron content up to 70% and Hematite is known for slightly lower iron content between 50-60%.
- Major iron belts in India are Odisha-Jharkhand belt, Durg-Bastar-Chandrapur Belt (Chattisgarh and Maharashtra), Bellari-Chitradurga-Chikkamagaluru-Tumakuru (Karnataka) and Maharashtra-Goa belt.
Manganese
- Manganese is a major component of steel and alloy industry. It is also used in making bleaching powder, insecticides and paints.
- Odisha is the largest manganese producer of India. It accounts for one-third of total manganese production.
Non-ferrous Minerals
In terms of non-ferrous minerals, India is known for copper, bauxite, lead, zinc and gold. These are used in a number of industries.
Copper
- Copper is mainly used in electrical cables, electronics and chemical industry.
- Madhya Pradesh, Rajasthan and Jharkhand are the leading copper producing states of India.
- India does not have large reserves of copper and it has to import copper to meet its requirement.
Bauxite
- Aluminium is extracted from bauxite. It is a clay-like substance rich in aluminium silicate.
- It is mostly found in Amarkantak plateau, Maikal hills and Bilaspur-Katni region (Chattisgarh and Madhya Pradesh) and Koraput district (Odisha).
- Odisha is the largest bauxite producing state of India.
Non-metallic minerals
Mica
- Mica is made up of thin sheets and found in a variety of colour such as opaque white, black, green, red, yellow, and brown.
- It is mainly used in the electronics industry and mostly found in Rajasthan and Jharkhand (Chota Nagpur plateau).
Limestone
- It is a sedimentary rock composed of calcium and magnesium carbonate.
- It is mostly used in the iron and cement industry.
Mineral Conservation
Why Do We Need To Conserve Minerals?
- Minerals are present in only minuscule amount, only one per cent of earth's crust.
- Minerals are formed at a very slow rate in comparison to present consumption rate. Therefore, we can say, minerals are non-renewable.
- Continued extraction has led to depletion of minerals from earth crust and increased the cost to extract them from depth.
How Can We Conserve Minerals?
- Adoption of modern technology to reduce wastage.
- Finding a solution to lower the cost of extraction from lower quality ores.
- Recycling of metals from old scrap materials.
Energy Resources
Energy is one of the essential requirements of modern life.
The energy resources can be classified as
Conventional resources: firewood, cattle dung cake, coal, petroleum, and natural gas
Non-conventional resources: solar, wind, tidal, geothermal, biogas and atomic energy
Conventional Sources of Energy
Coal
Coal is formed due to the compression of plant remains over a million years. Depending on factors like the degree of compression, depth and time of burial, there are four major types of coal formed during coalification. These are
1. Lignite: It is a low-grade brown coal, high in moisture and low in carbon content. Principally found in Tamil Nadu.
2. Sub-bituminous: It is medium grade coal, low in moisture and high in carbon content. Commercially used for power generation.
3. Bituminous: It is also known as metallurgical coal and used in metallurgy.
4. Anthracite: It is the highest quality of coal, very low in moisture and very high in carbon content.
Peat is a pre-coal substance that is formed due to the incomplete decomposition of plants.
Metallurgical coal is mostly found in Jharkhand, Odisha, West Bengal, Chhattisgarh, and Madhya Pradesh. It is also known as Gondwana coal in India as it formed in Gondwana age. The coal is found in Meghalaya, Assam, Arunachal Pradesh and Nagaland is known as tertiary coal.
Petroleum
- Petroleum is the second most important energy mineral after coal. Petroleum refineries act as a nodal industry for several other industries.
- Mumbai High produces more than 63% of total Indian oil. Next 18% comes from Gujarat and 16% comes from Assam.
- Assam is the oldest oil-producing state of India. Digboi, Naharkatiya and Moran-Hugrijan are important oil fields in Assam.
Natural Gas
- It is a much cleaner form of energy as it produces a low amount of carbon dioxide in comparison to coal and petroleum.
- It is found with or without petroleum and used for both domestic and industrial purpose.
- Natural gas in India is discovered in Krishna-Godavari basin, Mumbai High, Gulf of Cambay and Andaman and Nicobar Islands.
Electricity
- Electricity in India is mainly generated in two ways: 1. by the action of running water to generate hydroelectricity and 2. by the action of burning fuels such as coal, petrol, natural gas to generate thermal energy.
- Bhakra-Nangal, Damodar Valley Project and Kopili Hydel Project are a few examples of hydro-electricity plants whereas there are more than 310 thermal power plants running at present in India.
Non-conventional source of Energy
The pollution associated with coal and petrol energy has caused serious environmental problems. This problem is aggravated by rising fuel prices and diminishing resources. Hence, there is a shift toward cheaper, cleaner and unconventional forms of energy which can help our nation to grow.
Nuclear Energy
- It is generated by altering the atom structure. Hence, it is also known as atomic energy.
- Uranium and Thorium are two major sources of nuclear energy. They are available in Jharkhand and Rajasthan. Monazite salt of Kerala is also being explored for thorium.
- As of now, there are seven major nuclear power stations in India.
Solar Energy
- India has a tremendous opportunity for tapping solar energy due to its geographical location.
- Photovoltaic cells are mainly used for tapping solar energy and fast becoming popular in rural and remote areas.
- It is also tapped with the help of solar cookers, solar water heaters and other solar devices.
Wind Energy
- India has enormous possibilities to tap wind energy.
- Wind farm clusters can be spotted in Tamil Nadu, Andhra Pradesh, Karnataka, Gujarat, Kerala, Maharashtra and Lakshadweep.
Biogas
- Biogas is produced by the decomposition of plant, farm, animal and human wastes. It has higher thermal efficiency than kerosene, dung cake and charcoal.
- In rural India, mostly cow dung is used for producing biogas, therefore biogas plants are also known as gobar gas plants.
- It also provides high-quality manure as a by-product.
Tidal Energy
- The energy produced with the help of tidal waves is known as tidal energy.
- Gulf of Khambhat, Gulf of Kuchchh, Sunderbans provide ideal sites for producing tidal energy in India.
Geothermal Energy
- It refers to the energy produced by using the heat produced from the earth's interior. It is mainly captured through hot springs.
- Mankam (Parvati Valley), Himachal Pradesh and Puga Valley, Ladakh are two major projects running in India to capture the geothermal energy.
Conservation of Energy Resources
- The energy resources are limited and energy demand is increasing day by day. Therefore, it becomes necessary to develop a sustainable energy development plan.
- The energy plan has two major components: 1. promotion of energy conservation and 2. increased use of renewable energy sources.
Some ways to conserve energy
1. Using public transport system
2. Judicial use of electricity
3. Using high quality and power saving devices
4. Switching to non-conventional sources of energy