Minerals and Energy Resources — Practice

Question 1

Explain any THREE modes of mineral occurrence in rocks, giving one example mineral for each mode.

Accepted Answer

Step 1 — VEINS AND LODES: When molten magma cools and solidifies in cracks of igneous/metamorphic rocks, it forms veins and lodes. Heavy metallic minerals like TIN, COPPER, ZINC, and LEAD are commonly found this way. These deposits can be very deep.

Step 2 — BEDS/LAYERS (Sedimentary): Minerals formed by sediment accumulation over millions of years appear as horizontal layers in sedimentary rocks. COAL (compressed plant matter), IRON ORE (iron-rich sediment), and LIMESTONE are classic examples. Mined by horizontal layer extraction.

Step 3 — RESIDUAL DEPOSITS: When surface rock is chemically weathered (broken down by water and air) over millions of years, soluble materials are washed away and heavier mineral-rich material remains as a residual deposit. BAUXITE (the ore of aluminium) is the most important example — found on flat plateaux and hilltops in tropical India.

✦ Answer: (1) Veins/Lodes: magma cools in cracks → tin, copper, zinc. (2) Beds/Layers: sediment accumulation in sedimentary rock → coal, iron ore. (3) Residual deposits: weathering leaves mineral-rich material → bauxite. (Other valid mode: placer deposits in riverbeds → gold, monazite.)

Question 2

Name India's four major iron ore belts with one important location in each.

Accepted Answer

Step 1 — ODISHA-JHARKHAND BELT: Contains Badampahar, Noamundi, and Gorumahisani mines. The richest and most productive iron ore region in India. Gorumahisani and Noamundi in Jharkhand, Badampahar in Odisha produce both magnetite and haematite.

Step 2 — DURG-BASTAR-CHANDRAPUR BELT (Chhattisgarh): The Bailadila mines in Bastar district produce very high-grade haematite iron ore. Much of Bailadila's ore is exported to Japan and South Korea.

Step 3 — BELLARY-CHITRADURGA-CHIKMAGALUR-TUMKUR BELT (Karnataka): Kudremukh iron ore mines in the Western Ghats were once India's largest export-oriented mines. This belt feeds Karnataka's steel industry at Bhadravati.

Step 4 — MAHARASHTRA-GOA BELT: Ratnagiri (Maharashtra) and Goa's iron ore (Sanguem, Quepem) — Goa was a major exporter to Japan until export curbs were imposed after illegal mining controversies.

✦ Answer: (1) Odisha-Jharkhand: Noamundi, Badampahar. (2) Durg-Bastar-Chandrapur: Bailadila (Chhattisgarh). (3) Bellary-Karnataka: Kudremukh. (4) Maharashtra-Goa: Ratnagiri, Goa mines.

Question 3

Compare conventional and non-conventional energy sources in India. Why is India increasingly investing in non-conventional energy? What are the challenges?

Accepted Answer

Step 1 — CONVENTIONAL ENERGY SOURCES (fossil fuels + nuclear + large hydro):
(i) COAL: India has 5th largest coal reserves. Powers ~70% of India's electricity. But: produces CO₂ and particulates; reserves will deplete eventually; coal imports rising as domestic supply lags demand.
(ii) PETROLEUM: Mumbai High + Digboi + Ankleshwar. India imports ~85% — costs ₹12 lakh crore annually. Volatile global prices.
(iii) NATURAL GAS: HBJ pipeline (Hazira-Bijaipur-Jagdishpur). Used for electricity, fertilisers, CNG for vehicles.
(iv) NUCLEAR: 7 nuclear plants (Tarapur, Kalpakkam, Narora, etc.). Clean electricity but expensive and radioactive waste management is challenging. India has world's largest thorium reserves (Kerala monazite sands) for future reactors.

Step 2 — NON-CONVENTIONAL ENERGY SOURCES:
(i) SOLAR: India's solar capacity growing rapidly — Bhadla Solar Park (Rajasthan) is one of the world's largest. India receives 300+ sunny days per year in most regions. Target: 500 GW renewable by 2030.
(ii) WIND: Tamil Nadu = India's largest wind power state. Nagarkoil-Madurai corridor, Gujarat coast, Rajasthan. Wind power is India's 2nd largest renewable after solar.
(iii) BIOGAS: Cattle dung + organic waste → methane → electricity/cooking. National Biogas Mission. Especially useful in rural areas with abundant cattle.
(iv) GEOTHERMAL: Manikaran (HP) and Parvati Valley — potential for geothermal plants. Still limited scale.
(v) TIDAL: Gulf of Khambhat (Gujarat) — estimated 900 MW potential from tidal range. Unexploited as yet.

Step 3 — WHY INDIA IS INVESTING IN NON-CONVENTIONAL:
(i) Energy security — reduces oil import dependence (saves ₹12 lakh crore/year in forex).
(ii) Climate commitments — Paris Agreement: India committed to 50% non-fossil energy by 2030.
(iii) Cost decline — solar power is now CHEAPER than coal power in India per unit.
(iv) Rural electrification — solar panels reach remote areas grid cannot.

Step 4 — CHALLENGES of non-conventional:
(i) Intermittency — solar works only in daytime, wind only when wind blows. Need battery storage.
(ii) Land requirement — large solar farms need vast land, competing with farming.
(iii) Initial capital cost — high upfront investment for solar panels and wind turbines.
(iv) Grid integration — existing grid needs upgrades to handle variable renewable energy.

✦ Answer: Conventional (coal, petroleum, nuclear, gas): reliable but polluting, finite, expensive to import. Non-conventional (solar, wind, biogas, tidal, geothermal): clean, renewable, increasingly cheap. India invests in renewables for energy security (85% oil import), climate commitments (Paris Agreement), and falling solar costs. Challenges: intermittency (no sun at night), land needs, grid integration.

Question 4

Why is mineral conservation necessary? Suggest THREE ways to conserve minerals.

Accepted Answer

Step 1 — WHY NECESSARY: Minerals are NON-RENEWABLE — they formed over millions of years of geological processes and cannot be replenished on any human timescale. At current rates of consumption: India's iron ore reserves may last 100-150 years; coal reserves approximately 200-300 years. Once extracted and used, they are gone.

Step 2 — Conservation method 1 — RECYCLING: Metals (steel, aluminium, copper) can be melted and reused repeatedly without significant quality loss. Recycling one tonne of aluminium saves 4 tonnes of bauxite and 90% of the energy needed to produce primary aluminium. Steel recycling in India is growing but still far below global best practices.

Step 3 — Conservation method 2 — SUBSTITUTION: Replace scarce minerals with more abundant alternatives. Use fibre optic cables (glass, abundant) instead of copper cables. Use recycled plastics instead of mineral fillers. Use renewable energy (solar, wind) instead of coal — directly conserving coal reserves.

Step 4 — Conservation method 3 — REDUCE WASTE: Mining operations lose 10-30% of ore to waste during extraction and processing. Efficient mining technology, beneficiation (ore purification), and zero-waste processing recover more mineral value from the same ore body.

✦ Answer: Minerals are non-renewable — formed over millions of years, irreplaceable once used. Conservation methods: (1) RECYCLING — steel, aluminium reused repeatedly without quality loss. (2) SUBSTITUTION — fibre optics replace copper; renewables replace coal. (3) REDUCE MINING WASTE — efficient beneficiation and processing recovers more from same ore.

Practice — Minerals and Energy Resources

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