# Revision Notes Geography Chapter 5 Minerals and Energy Resources Class 10

## Important Terms to Remember

• Mineral: A naturally occurring substance that has a definite chemical composition is a mineral.
• Rock: A rock is an aggregate of one or more minerals but without definite composition of constituent of mineral.
• Ores: Rocks from which minerals are mined are known as ores. Although more than 2,800 types of minerals have been identified, only about 100 are considered ore minerals.
• Mining: Mining is the extraction of valuable minerals or other geological materials from the earth, usually from an orebody, lode, vein, seam, reef or placer deposit.
• Open Cast Mining: Open-pit, open-cast or open cut mining is a surface mining technique of extracting rock or minerals from the earth by their removal from an open pit or borrow.
• Shaft mining: Shaft mining is a form of underground mining using shafts driven vertically from the top down into the earth to access ore or minerals.
• Drilling: Drilling is a cutting process that uses a drill bit to cut a hole of circular cross-section in solid materials.
• Quarrying: Quarrying is the process of removing rock, sand, gravel or other minerals from the ground in order to use them to produce materials for construction or other uses.
• Metallic Minerals: Metallic minerals are minerals which contain one or more metallic elements. Metals are hard substances that conduct heat and electricity and have a characteristic lustre or shine. Iron ore, bauxite, manganese ore are some examples.
• Non-Metallic Minerals: The non-metallic minerals do not contain metals. Limestone, mica and gypsum are examples of such minerals. The mineral fuels like coal and petroleum are also non-metallic minerals.
• Ferrous minerals: These minerals contain iron content. Examples- Iron ore, manganese, etc.
• Non-ferrous minerals: These minerals do not contain iron content. Examples-Copper, aluminium etc.
• Renewable sources of energy: These energy resources can be replenished. They may be renewed after use. Example-solar energy, wind energy, etc.
• Non-Renewable sources of energy: These sources of energy are exhaustible. The deposits cannot be renewed or replenished after use. Example-fossil fuels.
• Solar energy: Solar power is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV), indirectly using concentrated solar power, or a combination.
• Wind energy: Wind power is the use of air flow through wind turbines to mechanically power generators for electric power.
• Biogas: Biogas typically refers to a mixture of different gases produced by the breakdown of organic matter in the absence of oxygen.
• Geothermal energy: Geothermal energy is the heat emanating from underneath the surface of the earth.

##### Minerals and Energy Resources

Summary

• Mineral are “homogenous, naturally occurring substance with a definable internal structure.”
• Importance of Minerals :
1. Everything we use, eat and drink has minerals.
2. Economic development of people or nations can be vastly accelerated by the presence of valuable minerals.
3. Make our life comfortable and convenient.
4. They are also responsible for all the biological processes on earth.
• Different appearances and occur in various forms, in a wide range of colours, hardness, forms lustre and density. As all minerals are formed from a certain combination of elements which depends upon the chemical and physical conditions under which the mineral forms. The geologists use these properties to categorise minerals.
• Rocks Containing Minerals:
1. Compacted substances that comprise the earth’s crust are called rocks.
2. Rocks are the naturally formed aggregate of mineral particles. It is the minerals that impart their texture, colour, shape, hardness or softness to rocks. For example limestone is a rock consists of a single mineral.
3. Majority of rocks on the earth’s crust are a combination or an aggregate of different minerals.
4. Over 3000 minerals have been identified so far; only a few are abundantly found.
• Mode of occurrence of minerals:
1. In igneous and metamorphic rocks : The smaller occurrences are called veins and the larger occurrences are called lodes. Examples: tin, copper, zinc, lead, etc.
2. In sedimentary rocks: In these rocks, minerals occur in beds or layers. Coal, iron ore, gypsum, potash salt and sodium salt are the minerals found in sedimentary rocks.
3. By decomposition of surface rocks: Decomposition of surface rocks and removal of soluble constituents leaves a residual mass of weathered material which contains ores. Bauxite is formed in this way.
4. As alluvial deposits: These minerals are found in sands of valley floors and the base of hills. These deposits are called placer deposits. Examples; gold, silver, tin, platinum, etc.
5. In ocean water: Most of the minerals in ocean water are too widely diffused to be of economic importance. But common salt, magnesium and bromine are mainly derived from ocean waters.
• Types of Minerals: Metallic and non-metallic.
• Metallic Minerals: further sub-divided into ferrous and non-ferrous.
1. Ferrous (containing iron)- are iron ore, manganese ore, chromite, pyrite, nickel and cobalt.
2. Non-ferrous (containing metals other than iron) — gold, silver, copper, lead, bauxite, tin and magnesium.
• Non-metallic Minerals: They are limestone, nitrate, potash, mica, gypsum, coal, petroleum
• Iron Ore: Basic mineral, backbone of industrial development. There are four varieties of iron ore:
1. Magnetite: contains 70% iron, finest quality, with magnetic properties.
2. Haematite: contains 60% to 70% iron, most important industrial iron ore.
3. Limonite: contains 40% to 60% iron.
4. Siderite: contains 40% to 50% iron.
• Major Iron Ore Belts in India: Orissa Jharkhand Belt; Durg Bastar Chandrapur Belt; Bellary Chitradurga Chikmaglur Tumkur Belt; Maharashtra Goa Belt.
• Well-known iron ore mines: Durg and Bastar districts of Chhattisgarh, Paschimi and Purbi Singhbhum districts of Jharkhand, Sundargarh, Keonjhar and Mayurbhanj districts of Orissa, North Goa, Chikmagalur and Bellary districts of Karnataka, Ratnagiri of Maharashtra.
• Manganese Ore:
1. Mainly used for making iron and steel and preparing alloys.
2. Also used to manufacture bleaching powder, insecticides, paints and batteries.
3. The main reserves of manganese ore are found in Karnataka, Orissa, Madhya Pradesh, Andhra Pradesh, Jharkhand, Maharashtra and Goa.
• Copper: It is used for making utensils, electric wires and alloys. Copper reserves are concentrated in Madhya Pradesh, Rajasthan, Jharkhand, Gujarat, Karnataka and Andhra Pradesh.
• Bauxite: It is an ore from which aluminium is obtained. Reserves are found in Jharkhand, Orissa, Gujarat, Maharashtra, Chhattisgarh, Madhya Pradesh and Tamil Nadu.
• Mica: It is used in electrical and electronic industries. Jharkhand, Bihar, Andhra Pradesh and Rajasthan are major producers.
• Limestone is composed of calcium carbonate or calcium and magnesium carbonates. It is used in the cement industry, smelting of iron and in chemical industries. Reserves are found in Madhya Pradesh, Chhattisgarh, Andhra Pradesh, Rajasthan, Gujarat, Karnataka and Himachal Pradesh.
• All types of minerals are exhaustible resources. Other serious problems associated with minerals are production and accumulation of wastes at various stages of mining, processing as well as use.
1. Efficiency in Mining: Present technologies are inadequate in terms of their efficiency. The world has yet to evolve a really efficient technology suited to present day environment called the technology of beneficiation. e.g., A lot of feed stock went waste during petroleum refining; today these wastes are utilized to make many by-products.
2. Substitutes: Scarce minerals can be substituted by developing biodegradable alternatives. For example, Copper was earlier used extensively in electrical industries. But now besides aluminium, many other materials are used to conserve precious copper.
3. Recycling: Mini steel plants are using scrap iron all over the world, which are the best examples of recycling. It helps reduce wastes, but efficient recycling technologies have yet to be developed. Recycling is very expensive. Problems also arise on account of mixing together of various types of minerals, otherwise products made from iron, copper, lead, zinc and almost all types of minerals can be recycled for more.
4. Minimised Exports: Exports should be minimised and value added manufactured products should be exported.
• Most dynamic elements in mineral are conservation is however, technology as well as ecosystem management. Assessing the future demand for resources, proper planning is also a conservative technique. It also includes the use and disposal of wastes which constitutes the earth’s greatest environment pollutants.
• Energy Resources: Energy is the ability to do work, it is also called Power. The modern unit of measurement of power is Watt. Energy is required for all activities. It is needed to cook, to provide light and heat, to propel vehicles and to drive machinery industries.
• Energy-The Source of Power: The chief sources of power are energy from fossil fuels, such as coal, petroleum, natural gas, nuclear materials, falling water, sun, wind, etc. Wind, sunrays and falling water are converted into electricity while others like coal, petroleum and natural gas- are applied directly in motor vehicles and machines. Fossil fuels require combustion; they produce many gases and wastes causing damage to the environment. 2/5th of the global energy consumption comes from burning oil and the rest from burning coal and natural gas.
• Electricity: Electricity is obtained in three ways which are termed as hydro-electricity, thermal electricity and nuclear electricity.
• Coal: Coal is the prime source of energy, often called the “Mother of Industries” or “Black Gold”. It was the basis of industrial revolution. It is used as a raw material in the iron and steel and chemical industries. It is the main fuel for producing thermal power. India ranks 7th in the world in coal reserves.
• Four types of coal:
1. Anthracite: Contains 80% carbon, hard, black and compact, found only in Jammu and Kashmir. It is the highest quality hard coal.
2. Bituminous: 60-80% carbon, widely used.
3. Lignite: 60% of carbon, low grade. It is called “brown coal”.
4. Peat : <50% carbon and burns like wood.
• Petroleum: Liquid fossil fuel, wells are dug or drilled on land or offshore to bring oil to the surface. This crude oil is transported to refineries where it is changed into gasoline and petrochemicals. Petroleum refineries serve as ‘nodal industries’ for chemical, fertilizer and synthetic textile industries as various products are obtained during refining petroleum. It provides fuel for heating, lighting, running machineries, vehicles, lubricants and raw materials for some manufacturing plastics, chemicals, etc.
• Natural Gas: A clean energy resource associated with petroleum. It can be extracted easily by drilling wells. Does not require processing, does not emit CO_{2} and burns hotter and clearer, is cheaper and can be used to generate electricity, but it is limited. Used as a source of energy as well as an industrial raw material in the petrochemical industry.
• Electricity is generated mainly by different methods. Thermal Electricity is obtained by using coal, petroleum and natural gas. Hydroelectricity is produced from water released at a great force from a high head. Nuclear Electricity is produced from uranium and thorium.
Non-Conventional Sources of Energy: The potential of non-conventional sources of energy is large. They use renewable resources for energy generation.
• Following are the six main non-conventional sources of energy:
1. solar energy,
2. wind energy,
3. biomass energy,
4. geothermal energy,
5. tidal energy and
6. hydro power.
• Solar Energy: Photovoltaic technology converts sunlight directly into electricity. Solar energy is used for cooking, pumping, heating of water, refrigerator and street lighting.
• Wind Energy: India has a wind power potential of 20,000 MW. Tamil Nadu, Andhra Pradesh, Karnataka, Gujarat, Kerala, Maharashtra and Lakshadweep have important wind farms.
• Biogas: Shrubs, farm wastes, animal and human wastes are used to produce biogas for domestic consumption in the rural areas.
• Other Non – Conventional Sources include geo-thermal energy, tidal energy and wave energy.
• Conservation of Energy Resources :
• Energy is basic requirement for economic development. Every sector of the economy needs inputs of energy for its development.
• Most of the energy resources are limited.
• Due to industrialization, modernisation and urbanisation, the consumption of energy in all forms has been steadily rising all over the country.
• How Can We Conserve Energy Resources?
• Need to develop a sustainable path of energy development, i.e., energy development but not at the cost of environment or needs of future generation.
• Judicious use of limited energy resources.
• Wastage of minerals should be minimised.
• Modern technology should be used for the exploitation of energy resources.
• Export of energy resources should be minimised.
• Use of substitutes in order to save energy resources.
• Encourage recycling of energy resources.
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