Mineral & Power Resources Summary Class 8 NCERT Summary Chapter 1

Mineral

• A naturally occurring substance that has a definite chemical composition is a mineral.
• Minerals are not equally distributed over space.
• Minerals are formed in different types of geological environments, under varying conditions. 
• They are created by natural processes without any human interference.
• They can be identified on the basis of their physical properties such as colour, density, hardness and chemical property such as solubility.

Types of Minerals

• On the basis of composition, minerals are classified mainly as: 
  • Metallic
  • Non-metallic minerals
• Metallic minerals contain metal in raw form.
  • Examples: Iron ore, bauxite, manganese ore.
• Metallic minerals may be ferrous or non-ferrous.
  • Ferrous minerals contains iron. Examples are iron ore, manganese and chromites.
  • Non-ferrous mineral does not contain iron but may contain some other metal such as gold, silver, copper or lead.
• Non-metallic minerals do not contain metals.
  • Examples: Limestone, mica and gypsum and mineral fuels like coal and petroleum.

Extraction of Minerals

• Minerals can be extracted by mining, drilling or quarrying.
• The process of taking out minerals from rocks buried under the earth’s surface is called mining.
  • Minerals that lie at shallow depths are taken out by removing the surface layer; this is known as open-cast mining.
  • The mining in which deep bores, called shafts, have to be made to reach mineral deposits that lie at great depths is called is shaft mining.
• Deep wells are bored to take minerals out is called drilling. Petroleum and natural gas are extracted through drilling method.
• Minerals that lie near the surface are simply dug out, by the process known as quarrying.

Distribution of Minerals

• Minerals occur in different types of rocks such as igneous rocks, metamorphic rocks or sedimentary rocks.
  • Generally, metallic minerals are found in igneous and metamorphic rock formations that form large plateaus.
• Metamorphic examples: Iron-ore in north Sweden, copper and nickel deposits in Ontario, Canada, iron, nickel, chromites and platinum in South Africa.
• Sedimentary rock examples: Limestone deposits of Caucasus region of France, manganese deposits of Georgia and Ukraine and phosphate beds of Algeria

Asia

• China and India have large iron ore deposits.
• The continent produces more than half of the world’s tin.
  • China, Malaysia and Indonesia are among the world’s leading tin producers.
• China also leads in production of lead, antimony and tungsten.
• Asia also has deposits of manganese, bauxite, nickel, zinc and copper.

Europe

• It is the leading producer of iron-ore in the world.
  • Russia, Ukraine, Sweden and France have large deposits of iron ore.
• Minerals deposits of copper, lead, zinc, manganese and nickel are found in eastern Europe and European Russia.

North America

• Mineral deposits in North America are located in three zones:
  • The Canadian region north of the Great Lakes: Iron ore, nickel, gold, uranium and copper
  • The Appalachian region: Coal
  • The mountain ranges of the west: Copper, lead, zinc, gold and silver

South America

• Iron Ore: Brazil
• Copper: Chile and Peru
• Tin: Brazil and Bolivia
• Mineral Oil: Venezuela, Argentina, Chile, Peru and Columbia
• South America also has large deposits of gold, silver, zinc, chromium, manganese, bauxite, mica, platinum, asbestos and diamond.

Africa

• It is the world’s largest producer of diamonds, gold and platinum.
• Gold: South Africa, Zimbabwe and Zaire
• Oil: Nigeria, Libya and Angola.
• Other minerals found in Africa are copper, iron ore, chromium, uranium, cobalt and bauxite.

Australia

• It is the largest producer of bauxite in the world.
• It is a leading producer of gold, diamond, iron ore, tin and nickel.
• It is also rich in copper, lead, zinc and manganese.
• Kalgoorlie and Coolgardie areas of western Australia have the largest deposits of gold.

Antartica

• Deposits of coal in the Transantarctic Mountains and iron near the Prince Charles Mountains of East Antarctica is predicted
• Iron ore, gold, silver and oil are also present in commercial quantities.

Distribution in India

• Iron: Jharkhand, Odisha, Chhattisgarh, Madhya Pradesh, Goa, Maharashtra and Karnataka.
• Bauxite: Jharkhand, Odisha, Chhattisgarh, Madhya Pradesh, Gujarat, Maharashtra and Tamil Nadu.
• Mica: Jharkhand, Bihar, Andhra Pradesh and Rajasthan.
  • India is the largest producer and exporter of mica in the world.
• Copper: Rajasthan, Madhya Pradesh, Jharkhand, Karnataka and Andhra Pradesh.
• Manganese: Maharashtra,  Madhya  Pradesh, Chhattisgarh,  Odisha,  Karnataka  and Andhra Pradesh.
• Limestone: Bihar, Jharkhand, Odisha, Madhya Pradesh, Chhattisgarh, Rajasthan, Gujarat and Tamil Nadu.
• Gold:  Kolar in Karnataka has deposits of gold in India. These mines are among the deepest in the world which makes mining of this ore a very expensive process.
• Salt:  It is obtained from seas, lakes and rocks. India is one of the world’s leading producers and exporters of salt.

Uses of Minerals

• Minerals are used in many industries.
• Minerals used in various styles for jewellery.
• Copper is another metal used in everything from coins to pipes.
• Silicon, used in the computer industry is obtained from quartz.
• Aluminum obtained from its ore bauxite is  used in automobiles and airplanes, bottling industry, buildings and even in kitchen cookware.

Conservation of Minerals

Why to conserve minerals?

• Minerals are a non-renewable resource.
• It takes thousands of years for the formation and concentration of minerals.
• The rate of formation is much smaller than the rate at which the humans consume these minerals.

How to conserve minerals?

• By reducing wastage in the process of mining.
• Recycling of metals is another way in which the mineral resources can be conserved.

Power Resources

• Power or enrgy is necessary for industry, agriculture, transport, communication and defense.
• Power resources categorised as:
  • Conventional resources
  • Non-conventional resources

Conventional Sources of Energy

• Those sources which have been in common use for a long time are called Conventionals sources of energy.
• Firewood and fossil fuels are the two main conventional energy sources.

Firewood

• It is widely used for cooking and heating. 
• In India, more than fifty per cent of the energy used by villagers comes from fire wood.

Fossil Fuels

• Remains of plants and animals which were buried under the earth for millions of years got converted by the heat and pressure into fossil fuels.
• Coal, petroleum and natural gas are the fossils fuels which are the main sources of conventional energy.
• Fossile fuels are in limited quantities and the rate at which the growing world population is consuming them is far greater than the rate of their formation.

Coal

• Most abundantly found fossil fuel. 
• It is used as a domestic fuel, in industries such as iron and steel, steam engines and to generate electricity. 
  • Electricity from coal is called thermal power. 
• The giant ferns and swamps got buried under the layers of earth millions of years ago converted into Coal. Therefore referred to as Buried Sunshine.
• Producers in the world: China, USA, Germany, Russia, South Africa and France.
• Producers in India: Raniganj, Jharia, Dhanbad and Bokaro in Jharkhand.

Petroleum

• Petroleum is a thick black liquid.
• It is found between the layers of rocks and is drilled from oil fields located in off-shore and coastal areas. 
  • This is then sent to refineries which process the crude oil and produce a variety of products like diesel, petrol, kerosene, wax, plastics and lubricants. 
• Petroleum and its derivatives are called Black Gold as they are very valuable.
• Producers in the world: Iran, Iraq, Saudi Arabia and Qatar, USA, Russia, Venezuela, and Algeria. 
• Producers in India: Digboi in Assam, Bombay High in Mumbai and the deltas of Krishna and Godavari rivers.

Natural Gas

• Natural gas is found with petroleum deposits and is released when crude oil is brought to the surface.
• It can be used as a domestic and industrial fuel. 
• Producers in the world: Russia, Norway, UK and the Netherlands
• Producers in India: Jaisalmer, Krishna Godavari delta, Tripura and some areas off shore in Mumbai.

Why use of Fossile fuels should be checked?

• The sharp increase in our consumption of fossil fuels has led to their depletion at an alarming rate. 
• The toxic pollutants released from burning these fuels are also a cause for concern.

Hydel Power

How Hydel Power is generated?

• Rain water or river water stored in dams is made to fall from heights.→ The falling water flows through pipes inside the dam over turbine blades placed at the bottom of the dam.
  • The moving blades then turn the generator to produce electricity. which is called hydro electricity.
• The water discharged after the generation of electricity is used for irrigation. 
• One fourth of the world’s electricity is produced by hydel power. 
• Producers in the world: Paraguay, Norway, Brazil, and China. 
• Important hydel power stations in India: Bhakra Nangal, Gandhi Sagar, Nagarjunsagar and Damodar valley projects.

Non-Conventional Sources of Energy

Why we need to use non-conventional sources of energy

• The increasing use of fossil fuels is leading to its shortage.
• It is estimated that if the present rate of consumption continues, the reserves of these fuel will get exhausted. 
• Also it causes environmental pollution. 
• Therefore, there is need for using non-conventional sources.
• Examples of non-conventional sources: Solar energy, wind energy, tidal energy.

Solar Energy

• Solar energy trapped from the sun can be used in solar cells to produce electricity.
  • Many of these cells are joined into solar panels to generate power for heating and lighting purpose.
• The technology of utilising solar energy benefits a lot of tropical countries that are blessed with abundant sun shine.
• Solar energy is also used in solar heaters, solar cookers, solar dryers besides being used for community lighting and traffic signals.

Wind Energy

• The high speed winds rotate the wind mill which is connected to a generator to produce electricity.
• Wind farms having clusters of such wind mills are located in coastal regions and in mountain passes where strong and steady winds blow. 
• Windfarms are found in Netherlands, Germany, Denmark, UK, USA and Spain.

Nuclear Power

• Nuclear power is obtained from energy stored in the nuclei of atoms of naturally occurring radio active elements like uranium and thorium. 
  • These fuels undergo nuclear fission in nuclear reactors and emit power. 
• Greatest Producers: USA and Europe.
• Uranium deposits in India: Rajasthan and Jharkhand.
• Thorium is found in large quantities in the Monozite sands of Kerala. 
• Nuclear power stations in India: Kalpakkam in Tamilnadu, Tarapur in Maharastra, Ranapratap Sagar near Kota in Rajasthan, Narora in Uttar Pradesh and Kaiga in Karnataka.

Geothermal Energy

• Heat energy obtained from the earth is called geothermal energy.
• The temperature in the interior of the earth rises steadily as we go deeper.
  • Some times this heat energy may surface itself in the form of hot springs.
  • This heat energy can be used to generate power.
• Geothermal energy in the form of hot springs has been used for cooking, heating and bathing for several years.
• USA has the world’s largest geothermal power plants followed by New Zealand, Iceland, Philippines and Central America.
• In India, geothermal plants are located in Manikaran in Himachal Pradesh and Puga Valley in Ladakh.

Tidal Energy

• Energy generated from tides is called tidal energy.
• Tidal energy can be harnessed by building dams at narrow openings of the sea.
  • During high tide the energy of the tides is used to turn the turbine installed in the dam to produce electricity.
• Producers in the world: Russia, France and the Gulf of Kachchh in India have huge tidal mill farms.

Bio Gas

• Organic waste such as dead plant and animal material, animal dung and kitchen waste can be converted into a gaseous fuel called biogas.
• The organic waste is decomposed by bacteria in biogas digesters to emit biogas which is essentially a mixture of methane and carbon dioxide.
• Biogas is an excellent fuel for cooking and lighting and produces huge amount of organic manure each year.