Aluminium smelting and other metallurgical industries

Detail

What aluminium smelting is and why it matters

• Metallurgical industry: an industry that takes a metal out of its ore and makes it pure. Iron and steel is the first. Aluminium smelting is the second most important in India.
• Properties of aluminium:
• It is light.
• It resists corrosion, which means it does not rust or wear away easily.
• It is a good conductor of heat.
• It is malleable, which means it can be beaten or pressed into thin sheets.

• It becomes strong when mixed with other metals. Such a mix is called an alloy.

• Uses: aircraft, utensils and electric wires.

• Substitute metal: aluminium is used in place of steel, copper, zinc and lead in many industries.
• Future demand: the Indian Bureau of Mines expects demand to grow from electric vehicles, aviation, construction, renewable energy, consumer goods and defence. Aluminium can be recycled, so it also helps countries meet their goals for cutting carbon emissions [2].
• Consumption gap: India used 2.9 kg of aluminium per person in 2018-19. The world average was 11 kg [4].
• Imports: imports made up 60% of India's aluminium consumption in 2020-21 [4].

The raw material: bauxite

• Bauxite: the main ore of aluminium. It is a bulky, dark reddish rock.
• Its main part is hydrated aluminium oxide. This is aluminium oxide joined with water.
• It also holds smaller amounts of iron oxide, silica and titania [2].

• The iron oxide gives it the reddish colour.

• Grade needed: the aluminium industry normally uses bauxite with at least 40% Al₂O₃ (alumina) [2].

• Weight loss: about 4 tonnes of dry bauxite → 2 tonnes of alumina → 1 tonne of aluminium [3].
• So the ore loses about three-quarters of its weight along the way.
• This is why the first stage, the refinery, is built close to the mines.

Location factors: why plants are where they are

• NCERT gives two prime factors: 1. Regular supply of cheap electricity 2. Assured supply of raw material (bauxite) at low cost

• Energy-oriented industry: an industry that sets up near its source of power because power is its biggest input. NCERT (Class 12) uses aluminium as its example.

• Why power matters:
• A smelter uses electricity to split alumina into aluminium.
• It uses a huge amount of power without stopping.

• So smelters cluster near coalfields (thermal power) or dams (hydel power).

• Why bauxite matters:

• Bauxite is bulky and loses most of its weight during processing.
• So refineries sit in or near bauxite-bearing hills.

The process: bauxite → alumina → aluminium

• Step 1, mining: bauxite is dug from opencast mines, which are pits open to the sky. It is usually taken from flat hilltops.
• Step 2, refining:
• Crushed bauxite goes to an alumina refinery.
• There it becomes alumina (aluminium oxide, a white powder).

• Refineries use the Bayer process: bauxite is dissolved in hot caustic soda, the impurities are removed and pure alumina is recovered [2].

• Step 3, smelting:

• Alumina goes to a smelter.
• There a strong electric current separates pure aluminium metal from it.

• This step uses a huge amount of electricity.

• Result: the two stages can be far apart. The refinery stays near the bauxite and the smelter goes near cheap power. NALCO in Odisha shows this clearly.

India's bauxite base (distribution and ranking)

• Total reserves and resources: 4,958 million tonnes as on 1.4.2020. Of this, 646 million tonnes are reserves and 4,311 million tonnes are remaining resources [2].
• Reserve: the part that can be mined profitably now.

• Resource: the part that is known or likely to exist but is not yet proven profitable to mine.

• Grade: about 79% is metallurgical grade, the grade fit for making aluminium [2].

• State share of resources, 1.4.2020 [2]:

Rank	State	Share of India's bauxite resources
1	Odisha	41%
2	Chhattisgarh	20%
3	Andhra Pradesh	12%
4	Gujarat	8%
5	Jharkhand	6%
6	Maharashtra	5%
7	Madhya Pradesh	4%

• Main belt: the largest deposits are the East Coast bauxite deposits of Odisha and Andhra Pradesh, in the Eastern Ghats [2].
• Production in 2021-22: 22.49 million tonnes, about 10% more than the year before [2].
• Odisha produced about 73%.
• Koraput district alone produced about 10.45 million tonnes.

• NALCO was the largest producer, with 33% of India's output [2].

• World position [3]:

• Bauxite mining, 2025 (estimate): Guinea 150 million t > Australia 97 million t > China 87 million t > Brazil 33 million t > India 25 million t. India ranks 5th.
• Alumina output, 2025 (estimate): China 93 million t > Australia 17 million t > Brazil 11 million t > India 8.2 million t. India ranks 4th.
• Bauxite reserves: India has 650 million t. The world has 29 billion t, and Guinea leads with 7.4 billion t.

• World bauxite resources: 55-75 billion t. Africa holds the largest share (32%).

• Imports: India still imports some bauxite. In 2021-22, most of it came from Guinea (95%) [2].

• India is among the world's largest producers of primary aluminium.

Distribution of plants

• NCERT lists aluminium plants in Odisha, West Bengal, Kerala, Uttar Pradesh, Chhattisgarh, Maharashtra and Tamil Nadu.
• Three big companies make India's primary aluminium: NALCO, Hindalco and Vedanta. Together they had a capacity of about 4 million tonnes [4].

NALCO: the whole chain inside Odisha (NCERT Fig. 6.3)

• NALCO (National Aluminium Company Limited): a public sector company set up in 1981.
• The chain:
• Bauxite mine at Panchpatmali hills in Koraput district, in the Eastern Ghats.
• Alumina refinery at Damanjodi, also in Koraput. Its bauxite comes from the company's own mines at Panchpatmali [2].

• Smelter at Angul in central Odisha, close to the coal of the Talcher coalfield.

• Port link: NALCO has a bulk shipment facility at Visakhapatnam in Andhra Pradesh [5].

• Capacities in 2003 [5]:
• Bauxite mining: 4.8 million t
• Alumina: 1.575 million t
• Smelter: 0.345 million t

• Captive power plant: 960 MW

• Captive power plant: a power station that a company builds to supply its own factory. It is the clearest sign that this is an energy-oriented industry.

Other major plants

Plant	Place (state)	Energy source nearby	Bauxite source
Hindalco	Renukoot, Sonbhadra (Uttar Pradesh)	Rihand dam hydel power; Singrauli coal on the UP–MP border	Shahdol (MP); Gumla and Lohardaga (Jharkhand); Surguja (Chhattisgarh) [2]
BALCO	Korba (Chhattisgarh)	Korba coalfield (thermal power)	Surguja and Kabirdham (Kawardha) districts of Chhattisgarh [2]
Vedanta	Lanjigarh refinery and Jharsuguda smelter (Odisha)	Coal of western Odisha	Bought from Gujarat, Chhattisgarh and MP, and imported from abroad [2]
Utkal Alumina	Rayagada (Odisha)	—	Baphlimali bauxite mine [2]

• Other Hindalco refineries: Belagavi (Karnataka) and Muri, near Ranchi (Jharkhand) [2].
• Pattern:
• Refineries sit on bauxite plateaus such as Koraput, Rayagada and Lohardaga.
• Smelters sit on coalfields or near dams such as Angul–Talcher, Korba, Jharsuguda and Renukoot–Singrauli.
• Together they form an aluminium belt across Odisha, Chhattisgarh, Jharkhand and the Son valley.

The Niyamgiri case (2013): mining versus tribal rights

• Background:
• Vedanta's Lanjigarh refinery wanted bauxite from the Niyamgiri hills in Odisha.

• These hills are home to the Dongria Kondh, a PVTG (Particularly Vulnerable Tribal Group, the most at-risk tribal communities). They treat the hills as sacred.

• The case: Orissa Mining Corporation v. Ministry of Environment and Forests (2013).

• The ruling: the Supreme Court said the gram sabhas (village assemblies of all adult villagers) must decide on mining. This is because their religious and forest rights under the Forest Rights Act, 2006 were at stake.
• The result: the Dongria Kondh gram sabhas rejected bauxite mining.
• Why it matters: the Lanjigarh refinery has no hill of its own to mine. It buys bauxite from other states and imports it [2]. This shows that assured raw material is not just about geology. It also depends on people's consent and the law.

Copper smelting

• Copper: a metal that conducts electricity very well. It is used in wires, motors and electronics.
• India's base: India holds only 0.31% of the world's copper reserves [4]. This explains why India depends on imported copper ore (concentrate).
• Main centres:

Centre	State	Note
Khetri	Rajasthan	In the Aravalli copper belt (Jhunjhunu district)
Ghatsila	Jharkhand	In the Singhbhum copper belt
Dahej	Gujarat	A coastal smelter that uses imported concentrate
Thoothukudi (Sterlite)	Tamil Nadu	Coastal; shut in 2018 after protests over pollution

• Location pattern:
• The older smelters at Khetri and Ghatsila sit on the ore, inside the mineral belts.
• The newer smelters at Dahej and Thoothukudi sit at ports, because they run on imported ore.

Prelims Hooks

• NALCO chain (all in Odisha): Panchpatmali mine → Damanjodi refinery (Koraput) → Angul smelter. NALCO is a public sector company set up in 1981.
• Plant–state pairs: Renukoot → Uttar Pradesh (Hindalco); Korba → Chhattisgarh (BALCO); Jharsuguda and Lanjigarh → Odisha (Vedanta); Belagavi → Karnataka; Muri → Jharkhand.
• Two prime location factors for aluminium: cheap, regular electricity and assured bauxite. Class 12 NCERT uses aluminium as the example of an energy-oriented industry.
• Order of processing: bauxite → alumina (refinery, Bayer process) → aluminium (smelter). The power-hungry step is smelting, not refining.
• Rule of thumb: 4 t bauxite → 2 t alumina → 1 t aluminium [3].
• Bauxite resources by state, 1.4.2020: Odisha (41%) > Chhattisgarh (20%) > Andhra Pradesh (12%) > Gujarat (8%) [2]. Odisha also produced about 73% of output in 2021-22 [2].
• World bauxite mining, 2025 (estimate): Guinea > Australia > China > Brazil > India (5th) [3].
• Niyamgiri (2013): the Dongria Kondh gram sabhas rejected bauxite mining for Vedanta's Lanjigarh refinery under the Forest Rights Act, 2006.
• Copper centre–state pairs: Khetri → Rajasthan; Ghatsila → Jharkhand; Dahej → Gujarat; Thoothukudi (Sterlite, shut in 2018) → Tamil Nadu.
• Trap: Renukoot is in Uttar Pradesh, not Madhya Pradesh. It draws on Rihand hydel power and Singrauli coal, which lie near the UP–MP border.

Mains Points

• Energy-oriented location and the coal–bauxite overlap:
• In eastern India, Gondwana coalfields (Talcher, Ib valley, Korba, Singrauli) lie close to bauxite plateaus (Koraput, Rayagada, Surguja, Lohardaga).
• This lets refineries and smelters cluster in Odisha, Chhattisgarh and Jharkhand, using captive power plants such as NALCO's 960 MW plant in 2003 [5].

• The cost: a coal-based smelter has a high carbon footprint. Moving smelters to renewable power is the next challenge.

• Resource-rich but import-dependent:

• India has 4,958 Mt of bauxite resources [2] and is a top-5 bauxite miner [3].
• Yet imports met 60% of aluminium consumption in 2020-21 [4], and per-person use was only 2.9 kg against a world average of 11 kg (2018-19) [4].

• Policy responses: more exploration, recycling and downstream (finished-product) units near the smelters.

• Mining, tribal rights and the environment (GS-III):

• Bauxite lies on forested hilltops of the Eastern Ghats, the homeland of tribes such as the Dongria Kondh.
• The Niyamgiri verdict (2013) made gram sabha consent under the Forest Rights Act, 2006 central to mining decisions.

• The Sterlite closure at Thoothukudi (2018) shows that pollution protests can shut a smelter. Location now depends on social licence (public acceptance) as well as raw material and power.

• Copper insecurity:

• India holds only 0.31% of world copper reserves [4].
• Smelting has shifted from ore-based inland centres (Khetri, Ghatsila) to port-based smelters (Dahej) that use imported concentrate.
• This matters for electrification, renewable energy and electric vehicles, which all need a lot of copper.