BharatNotes Why this chapter matters for UPSC: Metals and non-metals underpin UPSC questions on mineral resources, critical minerals policy, industrial development, environmental pollution (heavy metal contamination), and material science. India's push for critical mineral security — lithium, cobalt, rare earth elements — is a direct GS3 topic.
PART 1 — Quick Reference Tables
| Property | Metals | Non-metals |
|---|---|---|
| Physical state (room temp) | Mostly solid (except mercury — liquid) | Solid, liquid (bromine), or gas |
| Lustre | Shiny / lustrous | Mostly dull (except iodine — some lustre) |
| Hardness | Generally hard (except sodium, potassium — soft) | Mostly soft (except diamond — hardest natural substance) |
| Malleability | Yes — beaten into sheets | No — brittle (break on hammering) |
| Ductility | Yes — drawn into wires | No |
| Sonority | Yes — produce ringing sound | No |
| Conductivity (heat) | Good conductors | Poor conductors (except graphite) |
| Conductivity (electricity) | Good conductors | Poor conductors (except graphite) |
| Oxide nature | Basic oxides (turn red litmus blue) | Acidic oxides (turn blue litmus red) |
| Examples | Iron, copper, aluminium, gold, silver, zinc | Carbon, sulphur, nitrogen, oxygen, chlorine, iodine |
| Metal | Key Properties | Main Uses |
|---|---|---|
| Iron (Fe) | Strong, magnetic, rusts in presence of air + water | Construction, machinery, vehicles |
| Copper (Cu) | Excellent conductor, ductile, non-magnetic | Electrical wiring, plumbing, coins |
| Aluminium (Al) | Light, malleable, corrosion-resistant | Aircraft, packaging, utensils, overhead cables |
| Gold (Au) | Unreactive, malleable, lustrous | Jewellery, electronics, investment |
| Silver (Ag) | Best conductor, antimicrobial | Jewellery, mirrors, electronics |
| Zinc (Zn) | Galvanisation of iron | Galvanised iron sheets, batteries |
| Mercury (Hg) | Only liquid metal at room temperature | Thermometers (being phased out), barometers |
| Critical Mineral | Use | India's Status |
|---|---|---|
| Lithium | EV batteries, electronics | No significant domestic reserves; importing |
| Cobalt | EV batteries, aerospace alloys | Minimal domestic production |
| Rare Earth Elements (REEs) | Electronics, defence, wind turbines | India has significant deposits (Monazite sands in Kerala, Odisha, Tamil Nadu) |
| Nickel | Stainless steel, batteries | Limited reserves in Odisha |
| Platinum Group Metals | Catalytic converters, fuel cells | Negligible domestic reserves |
PART 2 — Detailed Notes
Malleability: The property of metals to be beaten or rolled into thin sheets without breaking. Example: gold can be beaten into extremely thin sheets (gold foil/leaf); aluminium foil used for food packaging.
Ductility: The property of metals to be drawn into thin wires. Example: copper and aluminium are drawn into electrical wires; gold can be drawn into very thin wire.
Sonority: The property of metals to produce a ringing sound when struck. Example: bells are made of metals (bronze = copper + tin); school bells, church bells.
Conductivity: Metals are good conductors of both heat and electricity because they have free electrons. Non-metals (except graphite) are insulators.
Corrosion: The gradual deterioration of a metal due to chemical reaction with its environment (usually oxygen and moisture). Rusting of iron is the most common form. Iron + Oxygen + Water → Iron Oxide (rust, Fe₂O₃·xH₂O). Rusting requires BOTH oxygen and water — tested frequently.
Galvanisation: Coating iron with a thin layer of zinc to prevent rusting. Zinc is more reactive than iron — it acts as a sacrificial anode, corroding preferentially.
Alloys: Homogeneous mixtures of a metal with other metals or non-metals. Examples: Steel (iron + carbon), Stainless Steel (iron + carbon + chromium + nickel), Bronze (copper + tin), Brass (copper + zinc).
India's Critical Minerals Policy
The Ministry of Mines released India's Critical Minerals List (2023) — 30 minerals identified as critical for economic development, national security, and energy transition. These include lithium, cobalt, graphite, nickel, manganese, REEs, and titanium.
Key Initiatives:
- Khanij Bidesh India Limited (KABIL): JV of NALCO, HCL, and MECL to acquire strategic mineral assets overseas (lithium in Argentina, cobalt in Australia/Africa)
- Mines and Minerals (Development and Regulation) Amendment Act, 2023: Allowed central government to auction mining leases for critical minerals; enabled first 20 critical mineral block auctions in November 2023
- National Critical Mineral Mission (NCMM): Cabinet approved January 2025; ₹16,300 crore over 7 years; covers domestic exploration, overseas acquisition, and recycling of critical minerals
- National Mineral Policy 2019: Promotes ease of mining, sustainable resource use, mineral security
- Rare Earth Elements: India has the world's 5th largest REE reserves (estimated 6.9 million tonnes). Thorium-bearing Monazite sand in coastal states — regulated by Department of Atomic Energy due to radioactivity of thorium.
Environmental Concerns with Mining:
- Heavy metal contamination of soil and water (lead, mercury, cadmium, arsenic)
- The Minamata disease (Japan, 1950s) — caused by mercury poisoning from industrial discharge → Minamata Convention on Mercury (2013); India ratified in 2018
- Lead in paint and petrol (now banned in India — unleaded petrol since 2000)
Rusting — A UPSC Trap Zone
Rusting of iron requires BOTH oxygen AND moisture. Neither alone causes rusting:
- Iron in dry air: no rust (no water)
- Iron in boiled (de-oxygenated) water under oil: no rust (no oxygen)
- Iron in normal moist air: rusts
Prevention methods:
- Painting/varnishing: Physical barrier to oxygen and water
- Galvanisation: Zinc coating (zinc = more reactive, sacrifices itself)
- Tin plating: Used for food cans (tin is less reactive than iron but weaker protection than zinc — if tin layer breaks, iron rusts faster)
- Alloying: Stainless steel (chromium forms a protective oxide layer)
- Greasing/oiling: Machinery components lubricated to prevent moisture contact
Metal Oxides — Acid-Base Chemistry Connection: When metals burn in oxygen, they form basic oxides:
- 2Mg + O₂ → 2MgO (magnesium oxide — basic, turns red litmus blue) When non-metals burn in oxygen, they form acidic oxides:
- S + O₂ → SO₂ (sulphur dioxide — forms sulphurous acid with water → acid rain)
- This connects Chapter 4 with Chapter 2 (acids and bases) and Chapter 5 (chemical changes)
Diamond and Graphite — Same Element, Different Properties: Both are forms (allotropes) of carbon (non-metal):
- Diamond: hardest natural substance; insulator; transparent; used in cutting tools
- Graphite: soft; good conductor; used as lubricant, electrode, pencil lead This illustrates that the form/structure of atoms matters as much as composition.
[Additional] 4a. India's Lithium Discovery — From Import Dependency to Domestic Exploration
The chapter states India has "no significant domestic lithium reserves" and imports lithium. This has changed dramatically since 2023 — Geological Survey of India (GSI) announced major inferred lithium resources in Jammu & Kashmir and Rajasthan, India signed its first-ever overseas lithium acquisition deal via KABIL, and the Mines Amendment Act 2023 opened critical mineral blocks for auction. India is now in the exploration-to-mining transition — not yet producing domestic lithium but actively pursuing supply chain sovereignty.
Key Concepts — From Mineral to Battery Metal:
| Stage | Process | India's Position |
|---|---|---|
| Mineral deposit | Natural rock/soil concentration of lithium-bearing minerals (spodumene, lithium brine) | Multiple inferred resources found 2023-24 |
| Inferred resource (G3) | Preliminary geological estimate — existence likely but quantity/quality not confirmed | J&K (5.9 MT, Feb 2023), Rajasthan Degana (May 2023) |
| Pre-feasibility (G2) | Detailed sampling and testing to confirm viability | Ordered for J&K re-exploration (Oct 2024) |
| Mining and refining | Extraction and processing to battery-grade lithium carbonate/hydroxide | Not yet operational in India |
| Battery manufacturing | Lithium converted into Li-ion cells for EVs, phones, grid storage | India has Li-ion cell manufacturing under PLI |
Why lithium is a "critical mineral": Lithium is essential for Li-ion batteries — the same batteries in every smartphone, laptop, and EV. As India targets 30% EV penetration by 2030 and grid-scale battery storage for renewable energy (PSH alternatives), lithium demand will grow ~10x by 2030. Domestic supply would reduce import dependency currently estimated at ~Rs 50,000 crore annually in EV battery imports.
GSI (Geological Survey of India): India's primary geoscience agency under the Ministry of Mines. It reports inferred resources (G3 level) — these are preliminary estimates, not commercially confirmed reserves. The distinction between "resource" and "reserve" is UPSC-tested.
[Additional] India's Lithium Exploration Breakthroughs and KABIL's Argentina Deal (GS3 — Minerals / Energy Security / Foreign Policy):
GSI's domestic lithium discoveries (2023):
1. Salal-Haimana, Reasi district, Jammu & Kashmir:
- Formally reported at the 62nd Central Geological Programming Board (CGPB) meeting, 9 February 2023
- Estimated resource: 5.9 million tonnes of lithium ore (inferred/G3 level); grade >500 ppm lithium — significantly above global average of ~220 ppm
- Status (2024): The Reasi lithium block was auctioned in November 2023 — auction failed twice due to insufficient takers (industry cited insufficient exploration data). Ministry of Mines directed GSI (October 2024) to conduct re-exploration to upgrade the estimate to at least G2 level before a third auction attempt
- This is an inferred resource estimate, not a confirmed reserve — requires G2 (pre-feasibility) and G1 (feasibility) stages before commercial mining can begin
2. Degana, Nagaur district, Rajasthan:
- GSI confirmed lithium resources at Degana in May 2023 — approximately 3 months after the J&K announcement
- Officially described as exceeding the J&K find in quantity and capable of meeting ~80% of India's lithium demand when developed; specific tonnage not officially released as of 2025
- Different geology: Rajasthan find is in alkaline granites (different rock type from J&K's greisens); samples sent to IBM (Indian Bureau of Mines) and IMMT (Institute of Minerals and Materials Technology) for analysis
GSI's critical mineral exploration scale-up:
- Projects for critical and strategic minerals: increased from 118 projects in 2021-22 to 196 projects in 2024-25 across Rajasthan, Arunachal Pradesh, Andhra Pradesh, Chhattisgarh, J&K, and others
KABIL-CAMYEN Argentina lithium deal:
- Signed: 15 January 2024 at Catamarca, Argentina
- Parties: KABIL (Khanij Bidesh India Ltd. — JV of NALCO, HCL, MECL) and CAMYEN SE (Catamarca Minera y Energética Sociedad del Estado — Argentine state mining company)
- Scope: Exploration and exploitation rights over 5 lithium brine blocks — Cortadera-I, Cortadera-VI, Cortadera-VII, Cortadera-VIII, and Cateo-2022-01810132 — covering 15,703 hectares in the Puna region of Catamarca Province, Argentina
- Investment: Rs. 211 crore (~US$24 million) over 5 years for exploration-stage activities
- Significance: India's first-ever overseas acquisition of lithium assets by a government company — analogous to China's overseas mineral acquisition strategy that secured Chinese supply chains for EVs
- Current status: Exploration phase (not yet production/supply); a KABIL branch office is being established in Catamarca; commercial supply will follow after exploration confirms viability
Mines and Minerals (Development and Regulation) Amendment Act, 2023:
- Added lithium and other critical minerals to Schedule I (atomic minerals list) — enabling central government to auction critical mineral blocks directly; enabled first 20 critical mineral block auctions in November 2023
UPSC synthesis: India's critical mineral strategy has three pillars — (1) domestic exploration (GSI scaling up to 196 projects; J&K and Rajasthan lithium finds), (2) overseas acquisition (KABIL's Argentina deal, Jan 2024 — first-ever overseas lithium acquisition), (3) recycling from e-waste/spent batteries (see Gap 4b below). The J&K 5.9 MT lithium resource and KABIL-Argentina deal are high-frequency current affairs. UPSC GS3 questions on critical minerals, energy security, and foreign policy all connect to this chain. Key distinction for Prelims: the J&K lithium is an inferred resource (G3), not a reserve — this is the most common MCQ trap.
[Additional] 4b. E-Waste and Urban Mining — Recovering Critical Metals from Discarded Electronics
The chapter covers corrosion, alloys, and the properties of metals like gold, silver, copper, cobalt, and lithium. What is missing is the fast-growing UPSC topic of urban mining — recovering these very same valuable metals from discarded electronic devices (e-waste). India generates over 14 lakh tonnes of e-waste annually; every tonne of smartphones contains roughly 300 grams of gold — 80 times more than a tonne of gold ore. India's Cabinet approved a dedicated Rs. 1,500 crore incentive scheme for critical mineral recycling in September 2025.
Urban Mining — Key Terms:
| Term | Meaning |
|---|---|
| E-waste (electronic waste) | Discarded electrical and electronic equipment (EEE) — phones, laptops, TVs, refrigerators, batteries |
| Urban mining | Recovery of metals and materials from e-waste — called "urban" because the "ore" is in urban areas (used electronics), not mines |
| Black mass | Intermediate product from shredding spent Li-ion batteries — contains lithium, cobalt, nickel, manganese; further processed to recover individual metals |
| ATMP/OSAT | Assembly, Test, Marking and Packaging — relevant for recycling in semiconductor context |
| EPR (Extended Producer Responsibility) | Legal obligation on electronics manufacturers (producers) to fund and organise end-of-life collection and recycling of their products |
| Critical mineral recycling | Targeted recovery of specific metals (lithium, cobalt, nickel, gold, silver, palladium, REEs) from e-waste streams |
Metal content of e-waste — why it is valuable:
- 1 tonne of smartphone circuit boards contains ~300 grams of gold, 3 kg of silver, 130 kg of copper, and significant cobalt and rare earth elements
- A gold mine produces 5–10 grams of gold per tonne of ore
- Urban mining can recover metals at 40-50x the concentration of natural ores — and without excavation, blasting, or tailings
[Additional] India's E-Waste Generation and Critical Mineral Recycling Policy (GS3 — Environment / Industry / Critical Minerals):
India's e-waste generation (CPCB data — Lok Sabha):
| Financial Year | E-waste Generated | E-waste Recycled | Recycling Rate |
|---|---|---|---|
| 2017-18 | 7.08 lakh MT | — | — |
| 2023-24 | 12.54 lakh MT | 7.78 lakh MT | ~62% |
| 2024-25 | 13.97 lakh MT | 11.59 lakh MT | ~83% |
| 2025-26 | 14.14 lakh MT | 9.79 lakh MT | ~69% |
- E-waste generation has nearly doubled in 8 years (7.08 lakh MT in 2017-18 → 14.14 lakh MT in 2025-26)
- India is 3rd largest e-waste generator globally (after China and USA)
- Critical caveat: ~90% of actual e-waste collection and initial dismantling occurs in the informal sector (unregistered workers, no safety equipment, acid-bath gold recovery) — official "recycled" figures reflect formal EPR certificate-based reporting
E-Waste (Management) Rules 2022:
- Notified: November 2022; in force: 1 April 2023; replaces E-Waste (Management) Rules, 2016
- Ministry: MoEFCC; implementing body: CPCB
- Scope expanded to 106 categories of EEE (previously fewer categories) — including solar panels, medical devices; batteries governed separately under Battery Waste Management Rules 2022
- EPR recycling targets (Schedule III):
| Period | Recycling target (% of waste generated) |
|---|---|
| FY 2023-24 and FY 2024-25 | 60% |
| FY 2025-26 and FY 2026-27 | 70% |
| FY 2027-28 onwards | 80% |
- EPR certificates are tradeable — producers can purchase surplus certificates from registered recyclers to meet their obligations; non-compliance triggers Environmental Compensation (EC)
Incentive Scheme for Promotion of Critical Minerals Recycling (Cabinet, September 3, 2025):
- Cabinet approval: 3 September 2025 (Union Cabinet, Ministry of Mines, under NCMM framework)
- Outlay: Rs. 1,500 crore (part of the Rs. 16,300 crore National Critical Mineral Mission)
- Duration: FY 2025-26 to FY 2030-31 (6 years)
- Eligible feedstock: E-waste, spent lithium-ion battery scrap, catalytic converters from end-of-life vehicles
- Incentive structure: 20% capital expenditure (capex) subsidy on plant, machinery, and equipment; 40% eligible opex subsidy in Year 2, balance 60% in Year 5
- Expected outcomes by 2030: 270 kilotonnes/year recycling capacity; ~40 kilotonnes/year critical mineral production; Rs. 8,000 crore total investment catalysed; ~70,000 direct and indirect jobs
- One-third of outlay reserved for small and new recyclers including start-ups
- Status (May 2026): 58 companies declared eligible under the scheme
UPSC synthesis: Urban mining / e-waste recycling connects two separate UPSC threads — environmental pollution (e-waste health impacts; informal sector acid-recovery burning) and critical mineral security (recovering lithium, cobalt, gold, silver from spent electronics reduces import dependency). The Rs. 1,500 crore Critical Mineral Recycling Incentive Scheme (September 2025) fills a gap in India's critical mineral strategy — domestic exploration (GSI), overseas acquisition (KABIL), AND domestic recycling. UPSC GS3 questions on circular economy, e-waste policy, EPR framework, and critical minerals all connect here. Key figures: 14.14 lakh MT e-waste in 2025-26 (nearly doubled from 2017-18); EPR target 80% recycling by FY2028; Rs. 1,500 crore Cabinet scheme Sep 2025; 58 companies eligible.
Exam Strategy
- Rusting needs BOTH oxygen AND water — not just one. Common Prelims trap: "which condition is sufficient to prevent rusting" — answer is preventing either oxygen or moisture access.
- Mercury is the only metal that is liquid at room temperature. Gallium melts slightly above room temperature (~30°C) — not usually tested at Class 7 level.
- Graphite (non-metal carbon) conducts electricity — exception to the rule that non-metals are insulators.
- Diamond (non-metal carbon) is the hardest natural substance — not a metal.
- Know the difference between galvanisation (zinc coating) and tin plating (tin coating) — galvanisation is more protective because zinc is sacrificial.
- KABIL (Khanij Bidesh India Ltd.) — for acquiring critical mineral assets abroad. Distinguish from NALCO, HCL, MECL (which are component companies of KABIL).
- The Minamata Convention (2013, entered into force 2017) targets mercury — named after Minamata disease in Japan caused by organic mercury.
Practice Questions
Q1. Rusting of iron occurs when iron is exposed to:
(a) Only oxygen
(b) Only water/moisture
(c) Both oxygen and water/moisture
(d) Only carbon dioxide
(c) Both oxygen and water/moisture
Q2. Which of the following statements about diamond and graphite is correct?
(a) Diamond is a metal; graphite is a non-metal
(b) Both diamond and graphite are allotropes of carbon
(c) Diamond conducts electricity; graphite does not
(d) Diamond is harder than graphite because it contains more carbon atoms
(b) Both diamond and graphite are allotropes of carbon
Q3. Consider the following with reference to critical minerals in India:
- India has significant Rare Earth Element deposits in its coastal monazite sands.
- KABIL is a joint venture formed to acquire critical mineral assets abroad.
- Lithium is not included in India's Critical Minerals list.
Which of the statements given above is/are correct?
(a) 1 only
(b) 1 and 2 only
(c) 2 and 3 only
(d) 1, 2 and 3
(b) 1 and 2 only
