Category: Class 8th

Minerals :

• Minerals are non-living solid substances which are concentrated in a particular area or rock formations.
• These natural substances found in nature that have a definite chemical composition is called minerals.

Properties Of Mineral

• They are unevenly distributed over the earth’s surface.
• They are mixed up with a large variety of impurities.
• The mineral resources are exhaustible

Types of Mineral

On the basis of composition, minerals are broadly classified into metallic and non-metallic.

EXTRACTION OF MINERALS

• The method of taking out minerals from rocks buried under the earth’s surface is called mining.
• The method used for mining depends upon the depth at which the minerals are located.

1. Quarrying– Minerals present near the surface of the earth are simply dug out is called

1. Open Cast mining-. Minerals present at shallow depth can be taken out by removing the surface layer. It is one of the easiest and cheapest methods of extracting minerals.
2. Shaft Mining- To extract minerals which are present at great depths, a deep hole or shaft is dug. It is known as shaft mining.

1. Drilling- Deep wells are bored to obtain mineral oil like petroleum, and natural gas which occur far below the earth’s surface by the process called drilling.

Distribution of minerals in different continents

• Asia- The important minerals found are iron ore, tin, manganese, bauxite, nickel, copper, zinc, lead, antimony, mica and tungsten.

• China, India, Russia, Azerbaijan and southeast Asia have rich deposits of iron ore.
• India and Indonesia are the main producers of bauxite.
• Asia produces more than half of the world’s tin.
• The leading producers are China, Malaysia, Thailand, Vietnam, Philippines and Indonesia.
• India is the largest producer of mica in the world.
• China is the leading producer of lead, antimony and tungsten.
• Asia also has rich commercial deposits of manganese, nickel, copper, gold, silver and zinc.

Europe-

• The main producers of Iron is Ukraine, Russia, Spain, Germany, France. Sweden and UK.
• Germany, France, Norway, Austria, UK. Russia and Italy are main producers of Bauxite.
• Eastern Europe and Russia have deposits of copper, manganese and nickel.

North America

• USA is the second-largest producer of iron ore in the world
• The largest deposits of lead and zinc are found in British Columbia in Canada.
• Mexico is the largest producer of silver in the world.

South America

• Brazil is the largest producer of iron ore in the world
• Nitrates, used in the making of chemical fertilizers, are found in the Atacama desert
• Brazil and Bolivia are major producers of tin in the world

Africa

• Congo is the largest producer of cobalt.
• Diamonds are mostly found in Kimberley in South Africa
• Gold is mined in South Africa, Zimbabwe and Congo

Australia

• Australia is the largest producer of bauxite in the world.
• Rich deposits of gold, diamond, iron ore, tin and nickel are also mined.
• Gold deposits are mostly found in Kalgoorlie and Coolgardie.

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Antarctica

• Due to large deposits of ice cover it is very difficult to mine minerals in this region
• It is believed that there are reserves of coal, iron ore, copper, uranium, gold and silver.

Distribution of minerals in India

Metallic Minerals 

 

Non- Metallic Minerals 

CONSERVATION OF MINERALS

• Minerals are non-renewable resources.
• Their rate of formation is slow as compared to the rate at that they are getting used.
• it’s completely necessary to use these resources judiciously, with minimum wastage
• recycling of metals is another way of conserving our mineral resources

POWER RESOURCES

• Power is needed for the growth and development of agriculture, industry, transport and communication.
• Their distribution is highly uneven as some places have many resources and few are not.

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The power resources are of two types—

1. conventional and Non-Conventional Power Resources

• Conventional sources of energy are those which have been in common use for a long time.
• These are Usually exhaustible sources of energy.
• Exhaustible sources or non-renewable sources are the sources of energy which cannot be replenished in a shot\rt time and take millions of years.
• Example-Coal, petroleum and natural gas are formed from fossils and hence are called fossil fuels
• Hydel power is also a conventional source of energy, but it is non-exhaustible

1. Coal –

• Coal was the basis for the Industrial Revolution in Europe.
• It occurs in layers of varying thickness in sedimentary rocks.
• The four varieties of coal are peat, lignite, bituminous and anthracite.
• It is the major source for thermal electricity.

Petroleum

• Petroleum (in Latin petra means rock and oleum means oil) is also known as rock oil or crude oil.
• Petroleum or mineral oil is derived from organic materials trapped in the layers of sedimentary rocks
• Majority of world’s petroleum is found in Gulf countries
• The major petroleum rich countries are Saudi Arabia, Iran, Iraq, Kuwait, United Arab Emirates (UAE), Qatar and Bahrain
• In India oil is found in Digboi (Assam), Gujarat, off the coast of Mumbai and in Godavari and Krishna river basin.

Natural Gas –

• Natural gas can be found in association with petroleum, or it may occur alone.
• because of undeveloped technology in the past major natural gases were escaped or burnt without using it properly
• The main producing areas are Mumbai High, Gujarat, Assam, Tamil Nadu and Tripura.

Hydroelectric power-

• In hydro electric power electricity is produced using the potential energy of water falling from height by using dams.
• The falling water is channelized to enter a turbine and the moving blades turn the generator to produce electricity.
• The water coming out of the turbine is used for irrigation
• In India some of the major multi purpose dams are of them are Bhakra, Nangal, Hirakud, Damodar Valley Corporation, Nagarjuna Sagar, Kosi, Koyna, Rihand and Narmada valley.

Advantages	Disadvantages
it is renewable source of energy The generated electricity is cheap It causes limited pollution	Dams are expensive to build some time it becomes major reason for flooding and earth quake Electricity can’t be stored once produced

Nuclear Energy

• The use of this technology to produce electricity started in the 60s.
• Nuclear power is obtained by altering the structure of atoms.
• When such an alteration is made, energy is released in the form of heat.
• The heat energy is used to produce electricity.
• The main nuclear power generating stations are at Tarapur, Kalpakkam, Rawatbhata

Non-conventional Sources of Energy

• With increase in the demand for energy and fast depletion of conventional energy sources
• The non-conventional sources of energy are gaining importance.

Solar Energy

• The sun is the source of all energy on the earth.
• In the tropical region solar energy is widely available.
• But it has not been fully developed due to lack of available technology.
• Photovoltaic cells convert sunlight directly into electricity.
• The cost involved in installing and maintaining solar energy equipment is high.
• Also its use is limited by clouds and at night.

Wind Energy

• It is also an inexhaustible source of energy.
• The wind blows onto the wind turbines and rotates them
• Wind turbines can be most efficient in areas with high and regular wind speeds such as exposed coast or upland areas.
• Tamil Nadu, Maharashtra, Gujarat, Karnataka and Rajasthan are major produces of wind energy .

Advantages	Disadvantages
It is Non-Polluting After the Initial Expense ,Relative cost becomes less	Winds donot blow all the time so,production and storing is difficult WInd farms are noisy and disturb the TV and Radio reception

Geothermal Energy

• The energy derived from hot springs, emission of dry or wet steam from hot rocks at great depths is called geothermal energy.
• In India, the potential sites for generating geothermal energy are Puga Valley (Ladakh), Tatapani (Odisha), Tuwa (Gujarat) and Jalgaon, Unai (Maharashtra).

Tidal Energy

• The rise and fall of sea water in coastal areas are called tides
• Blades of turbine are turned by the tides to produce electricity.
• Gulf of Kutch in India has huge tidal barrages

Bio-gas

• Organic wastes, especially human and animal wastes, cow dung, dead plants and kitchen wastes are converted into gaseous fuel called Biogas
• India is the leader in the development of this technology.

Conservation of Mineral and Natural Resources

• The following steps are useful in conserving minerals and power resources.
• Efficient utilization of resources
• Improvement in the techniques of extraction and purification
• Recycling of resources
• Saving mines from collapsing
• Use of alternative energy resources
  Implementing above steps could  conservation of minerals and power resources will ensure a better economy for future generations.