Mineral Resources India – Iron, Coal, Aluminium, Copper, Lead, Zinc

Iron & Coal Industries

Iron Ores

• Magnetite → Best quality iron ore containing 72% iron (Have magnetic properties)
• Hematite → 60 – 70% iron content
• Limonite → 40 – 60% iron content
• Siderite → ~ 40% iron content

Iron-coal industry

• Iron ore + coke + limestone + heat → Pig iron
• Pig iron ore processing → cast-iron, wrought iron, steel and variety of alloys

• Therefore, Essential inputs are:

• iron ore, coking coal and limestone
• water for cooling
• energy for heating

• Steel industry also requires dolomite, manganese etc. but in small quantities
• Hence their presence is not the main deciding factor for the location

Deciding locations for iron-coal industry

• Near Forest
• Near Coal Mines
• Near Coastal Areas

Near Forest

• Until the end of medieval period, iron production was done on small scale
• Energy was immobile (No wires to move electricity, No trains to move coal)
• To produce five tons of iron, you had to chop down one acre of forest to get sufficient charcoal
• Therefore, wood supply was primary factor for deciding location
• Hence, smelters were usually setup near forest areas
• Even in Modern times, Visvesvaraya Iron and Steel Plant (Karnataka) was setup near jungle to get wood-charcoal
• Later it was switched to hydro-electricity from Sarawati river

Near coal fields

• During the Industrial Revolution, iron and steel industry were setup near coalmines, due to following reasons –

• The coalfield region had a tradition of iron working based on charcoal
• As a result coalfield areas already had the labour and technology
• In Britain, iron ore was found embedded with coal seams → same area provided both iron ore + coal
• During that era, to process 1 tons of iron ore, you needed 8-12 tons of coal
• Railway engines were also inefficient
• So, weight-wise, it was cheaper to transport iron ore to coalfields rather than transporting coal to iron ore site

Near coastal areas

• By early 20th century the coal and iron ore mines in US-Europe started getting depleted
• So, they started importing iron ore from other countries
• As a result, the iron space and steel industry started moving toward coastal sites to reduce cost of transporting ores from port to factory via railways
• Example → Steel plants at Vishakhapatnam, Ratnagiri, Mangalore

Need for “Coking coal”

• Iron ore has iron oxide but we’re only interested in iron
• So, we’ve to get rid of the “oxide” part
• Hence to remove the “oxide” part we blend it with carbon to form “Carbon dioxide”.
• Coking coal has high concentration of carbon, compared to cheap varieties of coal like Lignite
• Therefore, you’ve to mix the coking coal with iron ore

• For heating you can use other variety of coal / even electricity

Steel Industries India

• Jharkhand → Jamshedpur (TISCO), Bokaro
• West Bengal → Durgapur, Burnpur
• Odisha → Rourkela
• Chhattisgarh → Bhilai
• Andhra Pradesh → Vishakhapatnam
• Karnataka → Vishveshwarya
• Tamil Nadu → Salem

Aluminium-Bauxite Refining

Bauxite to Alumina

• Aluminum is an abundant mineral in the earth crust
• But for mining or commercial scale exploitation, you require significant concentration of bauxite ore at one particular site
• Bauxite occurs frequently in the tropical areas where limestone rocks are exposed to weathering
• First, Bauxite ore is crushed, washed and mixed with caustic soda to remove impurities
• Then it is dried in large furnaces to remove moisture content → You get alumina
• During this phase, ~50% or more weight loss happens
• Hence, this process (of converting bauxite to Alumina) is done near the raw material side
• Because less weight → less transportation cost

Alumina to aluminum (By Electrolysis)

• The white powder of alumina is dissolved in a bath → Electric current is passed through it using carbon electrodes → alumina is converted to aluminum
• Requires massive amount of electricity
• Hence, aluminum smelting facilities are set up near sources of cheap electricity, rather than near to raw material or near to final market

Aluminium Industry → India

• UP → Hindalco (Birla)
• Odisha → Hirakund (Birla), Jharsuguda (Vedanta)
• Chhattisgarh → Korba (Vedanta)
• BALCO → Ratnagiri, Maharashtra
• NALCO → Koratpur, Odisha
• MALCO → Mettur, TN

Copper Refining India

• With 20th century, copper became important for electric industry
• As the demand for copper increased, new mining-smelting technologies developed to utilize even lower quality ores
• Location principle for copper and aluminum industries same, but smelting process is different

Concentrating ore (Copper ore → Blister copper)

• Copper ore is soaked in water and mixed with oils
• The copper revering matter floats on the top, and is separated out for further processing
• After this “concentrating” stage, barely 2.5% of the original matter remains
• Less weight → less transportation cost, therefore, copper concentrating mills are set up near the raw material (mines)
• After this stage, sulfur and oxygen impurities are separated from the concentrated copper ore & we get “blister copper”.
• Even in the state, the weight loss ratio is significant, therefore smelting is usually done near raw material

Blister to copper (Electrolysis)

• Although Blister copper is 99% pure metal, but still unsuitable for manufacturing electronic wires, utensils etc.
• Because it contains impurities of gold, silver, lead and zinc
• Therefore, blister copper is refined via electrolysis method
• Blister copper is immersed in a bath of copper sulphate, electricity is passed and impurities are removed
• Here, the weight loss ratio is extremely small. (~1%)
• So, there is no economic factor to setup copper refining factories near the raw material

Copper Refineries → India

• Hindustan Copper → Khetri, Jhunjnu district, Rajasthan
• BACLO → Korba, Chhattisgarh
• Hindalco (Birla) → Dahej, Bharuch district of Gujarat
• Sterlite Industries → Tutikorin, Tamil Nadu

Acid Industry

• From the Copper refining process, by products can be used for making phosphoric acid, sulphuric acid
• Copper smelting → SO₂gas → Used in making Sulphuric Acid
• Sulphuric acid + Rock Phosphate → Phosphoric Acid which can further it can be used for making fertilizers
• Rock Phosphate is usually imported, because SO₂gas is difficult to transport, so, better import rock phosphate here
• Hence, such acid industries are located in the vicinity of Copper refineries
• Nowadays, copper refining companies have integrated plants to produce such acids within their premises

Copper Industry Challenges in India

• Special copper alloys are still imported, because we don’t have technology to produce them locally for e.g. Beryllium copper
• Mining & smelting technology is obsolete → Causes substantial air pollution because of sulphur dioxide emission
• Still don’t have technology for downstream copper products e.g. copper tubes for refrigeration/AC etc. majority of them still imported.
• Still don’t have technology for complete recovery of precious metals such as Cobalt, Nickel etc from copper concentration.
• Producing 1 ton Copper from ore takes almost 14000 kwh energy, but producing 1 ton copper from scrap/recycling takes only 1700 kwh.
• However, scrap based copper smelter are not yet well established in India
• Very few plants using scrap metal to recycle copper (e.g. Lonavala, Hyderabad)
• Manpower requirement per tonne of finished copper is very high compared to developed countries due to less automation.
• There is huge gap between demand and supply, almost 70% copper is imported.
• There is no smelter at Malanjkhand (MP) hence the concentrate has to be transported to Khetri (Rajasthan) → cost of production increases
• Overall, Indian copper ore is average quality, hence mining/refining is a costly because copper yield is low

Lead and Zinc Industry

Lead and Zinc

• Ore → concentrate (Smelting) → Refining (Electrolysis)
• Runs on the principle that certain minerals have an affinity for certain oils
• Hence the ore is mixed with water, oil and chemicals
• The mineral particles get attach with oil bubbles and float on the surface, foam (containing mineral particles) is skimmed off

Location Factors

• Concentration stage involves significant weight loss → carried out near mining site.
• Refining stage require lot of electricity → done near large thermal plants /hydroelectric sites.
• India doesn’t have sufficient ores of Lead/Zinc, so majority of requirement met via imports.