5: MINERALS AND ENERGY
RESOURCES
1. INTRODUCTION
We use minerals in almost
every part of our daily life — from a tiny pin to a towering building or a big
ship. Vehicles like cars, buses, trains and aeroplanes are made from minerals
and run on power resources derived from the earth. Even the food we eat contains
minerals. Human beings have used minerals throughout history for livelihood,
decoration, festivities, and religious/ceremonial rites.
Examples showing importance of
minerals:
- Toothpaste: Abrasive minerals like silica, limestone, aluminium
oxide and phosphate minerals do the cleaning; fluoride (from fluorite)
reduces cavities; titanium oxide (from rutile, ilmenite, anatase) gives
whiteness; mica gives the sparkle.
- Nutrition: Although mineral intake is only about 0.3% of our
total nutrient intake, without them we cannot utilise the remaining 99.7%
of foodstuffs.
2. WHAT IS A MINERAL?
Geologists define a mineral as
"a homogenous, naturally occurring substance with a definable internal
structure."
- Minerals are found in varied forms — from the
hardest (diamond) to the softest (talc).
- Rocks are combinations of homogenous substances called
minerals.
- Some rocks (e.g.
limestone) consist of a single mineral.
- Most rocks consist of several
minerals in varying proportions.
- Over 2,000 minerals have been
identified, but only a few are abundantly found in rocks.
- A mineral's colour, hardness, crystal form,
lustre, and density depend on the physical and chemical conditions under
which it was formed. Geologists use these properties to classify minerals.
Study of minerals —
Geographers vs Geologists:
|
Geographers |
Geologists |
|
Study minerals as part of
the earth's crust to understand landforms |
Study the formation, age,
and physical/chemical composition of minerals |
|
Interested in distribution
of mineral resources & related economic activities |
Interested in origin and
structure |
3. MODE OF OCCURRENCE OF MINERALS
Minerals are usually found in "ores"
— an accumulation of a mineral mixed with other elements. The ore must have
sufficient mineral concentration to make extraction commercially viable.
Minerals occur in the
following forms:
- In igneous and metamorphic rocks — Minerals occur in cracks, crevices, faults
or joints.
- Smaller occurrences = veins;
larger occurrences = lodes
- Formed when minerals in
liquid/molten or gaseous form are forced upward through cavities towards
the earth's surface, cooling and solidifying as they rise.
- Examples: tin, copper,
zinc, lead.
- In sedimentary rocks — Minerals occur in beds or layers,
formed by deposition, accumulation and concentration in horizontal strata.
- Coal and some iron ores
formed under great heat and pressure over long periods.
- Gypsum, potash salt,
sodium salt formed by evaporation, especially in arid regions.
- By decomposition of rocks — Decomposition of surface rocks and removal
of soluble constituents leaves behind a residual mass of weathered
material containing ores.
- Example: Bauxite
is formed this way.
- As alluvial deposits — Found in sands of valley floors and the
base of hills; called placer deposits. These contain minerals not
corroded by water.
- Examples: gold, silver,
tin, platinum.
- In ocean waters — Most minerals are too widely diffused to be
economically significant, but common salt, magnesium and bromine are
obtained from ocean water. Ocean beds are rich in manganese nodules.
4. CLASSIFICATION OF MINERALS
MINERALS
|
---------------------------------------------
| | |
METALLIC NON-METALLIC ENERGY MINERALS
| (mica, salt, potash, (Coal, Petroleum,
----------- sulphur, granite, Natural gas)
| |
| limestone, marble,
Ferrous Non-
Precious sandstone, etc.)
(iron Ferrous
(gold,
ore, (copper,
silver,
Mn, lead, tin,
platinum,
Ni,
bauxite, etc.)
Co) etc.)
- Ferrous minerals — contain iron (e.g. iron ore, manganese,
nickel, cobalt). Account for about three-fourths of the total value of
production of metallic minerals; form the base for metallurgical
industries.
- Non-ferrous minerals — do not contain iron (e.g. copper, lead,
tin, bauxite). India's reserves/production of these are not very
satisfactory.
- Precious metals — gold, silver, platinum.
- Non-metallic minerals — mica, salt, potash, limestone etc.
- Energy minerals — coal, petroleum, natural gas.
5. FERROUS MINERALS
(A) Iron Ore
- The basic mineral and backbone of
industrial development.
- Two main varieties:
|
Type |
Iron
content |
Feature |
|
Magnetite |
up to 70% |
Finest ore; excellent
magnetic qualities; valuable in electrical industry |
|
Hematite |
50–60% |
Most important industrial
ore in terms of quantity used |
- 97% of India's iron ore production (2018–19) came from Odisha,
Chhattisgarh, Karnataka and Jharkhand.
Major Iron Ore Belts in India:
- Odisha–Jharkhand belt — High-grade hematite in Badampahar mines
(Mayurbhanj, Kendujhar, Odisha); hematite mined in Gua and Noamundi
(Singbhum, Jharkhand).
- Durg-Bastar-Chandrapur belt (Chhattisgarh & Maharashtra) — Very high-grade
hematite in the Bailadila range (14 deposits), Bastar district;
best physical properties for steel-making; exported to Japan & South
Korea via Vishakhapatnam port.
- Ballari-Chitradurga-Chikkamagaluru-Tumakuru
belt (Karnataka) — Kudremukh
mines (Western Ghats) are a 100% export unit; among the largest
deposits in the world; ore transported as slurry through pipeline to a
port near Mangaluru.
- Maharashtra-Goa belt — Includes Goa and Ratnagiri (Maharashtra);
ore not very high quality but efficiently exploited; exported through Marmagao
port.
(B) Manganese
- Mainly used for manufacturing steel and
ferro-manganese alloy (≈10 kg manganese needed per tonne of steel).
- Also used in bleaching powder, insecticides,
and paints.
- Leading producers (2018–19): Madhya Pradesh
(33%) > Maharashtra (27%) > Odisha (16%) > Karnataka (12%) >
Andhra Pradesh (10%).
6. NON-FERROUS MINERALS
(A) Copper
- India is critically deficient in copper
reserves/production.
- Malleable, ductile, good conductor → used in electrical cables, electronics,
chemical industries.
- Leading producers: Balaghat (Madhya
Pradesh), Khetri (Rajasthan), Singhbhum (Jharkhand).
(B) Bauxite
- Aluminium is obtained from bauxite, a
clay-like substance.
- Formed by decomposition of rocks rich in aluminium
silicates.
- Aluminium combines the strength of iron
with lightness, good conductivity and great malleability.
- Found mainly in Amarkantak plateau, Maikal
hills, and Bilaspur-Katni plateau region.
- Odisha is the largest producer (65%, 2018–19); Panchpatmali
deposits (Koraput district) are the most important.
7. NON-METALLIC MINERALS
Mica
- Made of thin plate-like sheets that split
easily; can be layered so thin that 1,000 sheets make only a few
centimetres.
- Colours: clear, black, green, red-yellow, or
brown.
- Properties: excellent dielectric strength, low
power loss factor, insulating, resistant to high voltage → used in electric and electronic industries.
- Found in the northern edge of the Chota
Nagpur plateau.
- Koderma–Gaya–Hazaribagh
belt (Jharkhand) — leading producer.
- Ajmer (Rajasthan) and Nellore belt (Andhra Pradesh) —
also important producers.
Limestone (Rock Mineral)
- Composed of calcium carbonate or
calcium-magnesium carbonate.
- Found in sedimentary rocks of most geological
formations.
- Basic raw material for the cement industry; also essential for smelting iron ore in the
blast furnace.
- Leading producers (2018–19): Rajasthan
(22%) > Andhra Pradesh/Madhya Pradesh (13% each) > Chhattisgarh
(11%) > Karnataka (10%).
8. HAZARDS OF MINING
- Dust and noxious fumes make miners vulnerable
to pulmonary diseases.
- Risk of collapsing mine roofs, flooding
(inundation), and fires in coal mines.
- Water contamination — dumping of waste and slurry degrades land,
soil, and pollutes streams/rivers.
- Stricter safety regulations and enforcement of
environmental laws are needed to prevent mining from becoming a
"killer industry."
Rat-Hole Mining: In most tribal areas of North-East India (e.g.,
Meghalaya), minerals are owned by individuals/communities, unlike elsewhere
where minerals are nationalised. Coal mining in Jowai and Cherapunjee is done
through long narrow tunnels called "Rat hole" mining. The National
Green Tribunal has declared this illegal and recommended it be stopped.
9. CONSERVATION OF MINERALS
- Workable mineral deposits form only about 1%
of the earth's crust.
- Minerals took millions of years to
form; the rate of replenishment is negligible compared to the rate of
consumption.
- Hence, mineral resources are finite and
non-renewable.
- Continued extraction leads to increasing
costs as minerals must be extracted from greater depths with declining
quality.
- Conservation measures:
- Use low-grade ores
through improved technology at low cost.
- Recycling of metals.
- Use of scrap metals and
substitutes.
- Planned and sustainable
use of mineral resources.
10. ENERGY RESOURCES
Energy is required for all
activities — cooking, lighting, heating, transport, and running machinery.
Sources of energy:
|
Conventional
Sources |
Non-Conventional
Sources |
|
Firewood, cattle dung cake,
coal, petroleum, natural gas, electricity (hydel & thermal) |
Solar, wind, tidal,
geothermal, biogas, atomic/nuclear energy |
- More than 70% of energy requirement in
rural households is met by firewood and cattle dung cake; this is
becoming difficult to sustain due to decreasing forest area, and dung-cake
use is discouraged as it consumes manure needed for agriculture.
11. CONVENTIONAL SOURCES OF ENERGY
(A) Coal
- India's most abundantly available fossil
fuel; used for power generation, industry, and domestic needs.
- Formed by compression of plant material over
millions of years — different types depending on degree of compression,
depth, and time of burial:
|
Type |
Characteristics |
|
Peat |
Low carbon, high moisture,
low heating capacity |
|
Lignite |
Low-grade brown coal, soft,
high moisture (found in Neyveli, Tamil Nadu; used for electricity
generation) |
|
Bituminous |
Buried deep, subjected to
high temperature; most popular commercial coal |
|
Metallurgical
coal |
High-grade bituminous, used
for smelting iron in blast furnaces |
|
Anthracite |
Highest quality hard coal |
Geological occurrence:
- Gondwana coal (~200 million years old) — metallurgical
coal, found in the Damodar Valley (West Bengal–Jharkhand);
important coalfields: Jharia, Raniganj, Bokaro. Also found in
Godavari, Mahanadi, Son, and Wardha valleys.
- Tertiary coal (~55 million years old) — found in Meghalaya,
Assam, Arunachal Pradesh, Nagaland.
- Coal is a bulky material that loses
weight when reduced to ash → heavy industries and thermal power stations
are located on or near coalfields.
(B) Petroleum
- Second major energy source after coal;
provides fuel for heat/lighting, lubricants, and raw material for
industries.
- Refineries act as a "nodal
industry" for synthetic textile, fertiliser, and chemical
industries.
- Occurrence: Associated with anticlines and fault traps
in tertiary rock formations.
- In anticlines/domes, oil
is trapped in the crest of the upfold within a porous limestone/sandstone
layer, bounded by non-porous layers.
- Also found in fault
traps between porous and non-porous rocks. Gas (being lighter) occurs
above oil.
- Major producing areas: Mumbai High, Gujarat, Assam.
- Ankleshwar — most important field of Gujarat.
- Assam — oldest oil-producing state; important
fields: Digboi, Naharkatiya, Moran-Hugrijan.
(C) Natural Gas
- Found with petroleum deposits; released when
crude oil is brought to the surface.
- Uses: domestic/industrial fuel, electricity
generation, raw material for chemical/petrochemical/fertiliser industries,
transport fuel (CNG), and cooking fuel (PNG).
- Major reserves: Mumbai High and allied
fields, supplemented by the Cambay basin (west coast) and Krishna-Godavari
basin (east coast).
- HVJ Pipeline: The first cross-country gas pipeline (1,700
km), Hazira-Vijaipur-Jagdishpur, built by GAIL (India),
linking Mumbai High and Bassein gas fields to fertiliser, power and
industrial complexes in western/northern India. India's gas pipeline
network has since expanded to over 18,500 km, expected to reach 34,000 km
as a "Gas Grid."
(D) Electricity
- Per-capita consumption of electricity is
considered an index of development.
- Hydroelectricity — generated by fast-flowing water (a renewable
resource); e.g., Bhakra Nangal, Damodar Valley Corporation, Kopili
Hydel Project.
- Thermal electricity — generated by burning coal, petroleum, or
natural gas (uses non-renewable fossil fuels).
- Once generated, electricity from either source
is exactly the same.
12. NON-CONVENTIONAL SOURCES OF ENERGY
Rising dependence on fossil
fuels, rising oil/gas prices, potential shortages, and environmental problems
have created a need for renewable sources.
|
Source |
Details |
|
Nuclear/Atomic
Energy |
Obtained by altering the
structure of atoms; releases heat used to generate power. Uranium &
Thorium found in Jharkhand and the Aravalli ranges (Rajasthan);
Monazite sands of Kerala are rich in thorium. |
|
Solar
Energy |
India is tropical with
enormous potential; photovoltaic technology converts sunlight directly
to electricity; reduces dependence on firewood/dung cakes in rural areas. |
|
Wind Power |
Largest wind farm cluster: Tamil
Nadu (Nagarcoil to Madurai). Other states: Andhra Pradesh, Karnataka,
Gujarat, Kerala, Maharashtra, Lakshadweep. Nagarcoil and Jaisalmer are
well known for wind energy use. |
|
Biogas |
Produced from shrubs, farm
waste, animal/human waste; decomposition of organic matter yields gas with
higher thermal efficiency than kerosene, dung cake, and charcoal. Plants
using cattle dung = "Gobar gas plants." Improves manure
quality and prevents loss of trees/manure due to burning. |
|
Tidal
Energy |
Floodgate dams built across
inlets trap water during high tide; released water drives turbines. Ideal
locations: Gulf of Khambhat, Gulf of Kuchchh (Gujarat), and Gangetic
delta in Sunderban (West Bengal). |
|
Geothermal
Energy |
Heat/electricity from the
earth's interior; where the geothermal gradient is high, groundwater becomes
steam that drives turbines. Experimental projects: Parvati valley near
Manikaran (Himachal Pradesh) and Puga Valley (Ladakh). |
13. CONSERVATION OF ENERGY RESOURCES
- Energy is a basic requirement for economic
development across agriculture, industry, transport, commercial, and
domestic sectors.
- India is currently one of the least
energy-efficient countries in the world.
- Twin planks of sustainable energy development:
- Promotion of energy
conservation
- Increased use of
renewable energy sources
- Individual measures: using public transport
instead of private vehicles, switching off electricity when not needed,
using power-saving devices, and using non-conventional energy sources.
- "Energy saved is energy produced."
QUICK REVISION TABLE
|
Mineral/Resource |
Key
Location(s) |
|
Iron ore
(Magnetite/Hematite) |
Odisha, Chhattisgarh,
Karnataka, Jharkhand |
|
Manganese |
Madhya Pradesh, Maharashtra,
Odisha |
|
Copper |
Balaghat (MP), Khetri
(Rajasthan), Singhbhum (Jharkhand) |
|
Bauxite |
Odisha (Panchpatmali,
Koraput), Amarkantak plateau |
|
Mica |
Koderma-Gaya-Hazaribagh
(Jharkhand), Ajmer (Rajasthan), Nellore (AP) |
|
Limestone |
Rajasthan, Andhra Pradesh,
Madhya Pradesh |
|
Coal (Gondwana) |
Damodar Valley (Jharia,
Raniganj, Bokaro) |
|
Coal (Tertiary) |
Meghalaya, Assam, Arunachal
Pradesh, Nagaland |
|
Lignite |
Neyveli (Tamil Nadu) |
|
Petroleum |
Mumbai High, Gujarat
(Ankleshwar), Assam (Digboi) |
|
Natural Gas |
Mumbai High, Cambay basin,
Krishna-Godavari basin |
|
Uranium/Thorium |
Jharkhand, Aravalli
(Rajasthan), Monazite sands (Kerala) |
|
Wind Energy |
Tamil Nadu
(Nagarcoil-Madurai), Jaisalmer |
|
Tidal Energy |
Gulf of Khambhat, Gulf of
Kuchchh, Sunderban |
|
Geothermal Energy |
Manikaran (HP), Puga Valley
(Ladakh) |
*******
EXERCISES (NCERT Textbook
Answers)
1. Multiple Choice Questions
(i) Which one of the following
minerals is formed by decomposition of rocks, leaving a residual mass of
weathered material?
Answer: (b) Bauxite
(ii) Koderma, in Jharkhand is
the leading producer of which one of the following minerals?
Answer: (b) Mica
(iii) Minerals are deposited
and accumulated in the stratas of which of the following rocks?
Answer: (a) Sedimentary rocks
(iv) Which one of the following
minerals is contained in the Monazite sand?
Answer: (c) Thorium
2. Answer the following questions in about 30 words
(i) (a) Distinguish between
ferrous and non-ferrous minerals.
Ferrous minerals contain iron
and form the base for metallurgical industries (e.g., iron ore, manganese);
they account for about three-fourths of the value of metallic mineral
production. Non-ferrous minerals do not contain iron (e.g., copper, bauxite,
lead, zinc) and India's reserves of these are comparatively limited.
(b) Distinguish between
conventional and non-conventional sources of energy.
Conventional sources —
firewood, cattle dung cake, coal, petroleum, natural gas and electricity — are
traditional, exhaustible (mostly non-renewable) sources. Non-conventional
sources — solar, wind, tidal, geothermal, biogas and atomic energy — are renewable
and environment-friendly alternatives being increasingly promoted.
(ii) What is a mineral?
A mineral is a homogenous,
naturally occurring substance with a definable internal structure, as defined
by geologists. Minerals vary widely in properties such as hardness, colour and
lustre, ranging from the hardest (diamond) to the softest (talc).
(iii) How are minerals formed
in igneous and metamorphic rocks?
In igneous and metamorphic
rocks, minerals occur in cracks, crevices, faults, and joints — smaller occurrences
called veins, larger ones called lodes. They form when molten/gaseous minerals
are forced upward through cavities towards the surface, cooling and solidifying
as they rise.
(iv) Why do we need to
conserve mineral resources?
Mineral resources are finite
and non-renewable, as their formation takes millions of years while consumption
rates are extremely high. Continued extraction increases costs (extraction from
greater depths, declining quality), so conservation through recycling and
efficient use is essential for future generations.
3. Answer the following questions in about 120 words
(i) Describe the distribution
of coal in India.
Coal is India's most
abundantly available fossil fuel and meets a substantial part of the nation's
commercial energy needs, being used for power generation, industrial and
domestic purposes. Coal occurs in India in rock series of two main geological
ages:
- Gondwana coal, a little over 200 million years old, forms
the major metallurgical coal reserves and is located in the Damodar
Valley (West Bengal–Jharkhand region). Important coalfields here
include Jharia, Raniganj, and Bokaro. Coal deposits are also found
in the Godavari, Mahanadi, Son, and Wardha river valleys.
- Tertiary coal, only about 55 million years old, occurs in
the north-eastern states of Meghalaya, Assam, Arunachal Pradesh, and
Nagaland.
Since coal is a bulky material
that loses weight on use (as it is reduced to ash), heavy industries and
thermal power stations are generally located on or near the coalfields to
minimise transportation costs.
(ii) Why do you think that
solar energy has a bright future in India?
India, being a tropical
country, receives abundant sunlight throughout the year, giving it enormous
potential for tapping solar energy. Photovoltaic technology can convert this
sunlight directly into electricity. Solar energy is fast becoming popular,
especially in rural and remote areas that are not well connected to the
electricity grid. Several large solar power plants are being established across
the country, which will help reduce rural dependence on firewood and dung cakes
for energy. This, in turn, will contribute to environmental conservation (by
reducing deforestation) and ensure an adequate supply of manure for agriculture
(since dung will not be burnt as fuel). Given India's geographic location,
growing energy needs, and the environmental and economic benefits of solar
power, it is considered to have a very promising and sustainable future in the
country.