Uses of Metals
-
Iron (Fe)
- Construction of buildings and bridges
- Railway tracks
- Machinery and tools
-
Aluminium (Al)
- Aircraft bodies
- Kitchen utensils
- Aluminium foil for food packaging
- Electrical transmission cables
-
Copper (Cu)
- Electrical wires
- Motors and generators
- Plumbing pipes
- Gold (Au)
- Jewellery
- Electronic connectors
- Coins and decorations
- Silver (Ag)
- Jewellery
- Mirrors
- Electrical contacts
- Medical instruments
-
Zinc (Zn)
- Galvanising iron to prevent rusting
- Dry cells (batteries)
-
Tin (Sn)
- Food cans
- Soldering materials
- Lead (Pb)
- Car batteries
- Radiation shielding in hospitals
Uses of Non-metals:
Oxygen (O₂)
Breathing
Medical oxygen cylinders
Welding and cutting metals
Nitrogen (N₂)
Making fertilizers
Food packaging
Liquid nitrogen for cooling
Carbon (C)
Graphite in pencils
Coal as fuel
Diamond for cutting tools and jewellery
Activated carbon in water filters
Sulphur (S)
Manufacture of sulphuric acid
Rubber vulcanization
Matches and fireworks
Phosphorus (P)
Matchsticks
Fertilizers
Fireworks
Chlorine (Cl₂)
Water purification
Making disinfectants
Bleaching paper and cloth
Iodine (I₂)
Antiseptic medicines
Iodised salt
Hydrogen (H₂)
Clean fuel
Manufacture of ammonia
Rocket fuel
Ancient Indian Metallurgy – Iron Pillar of Delhi
The Iron Pillar of Delhi is an important example of the advanced knowledge of metallurgy possessed by ancient Indian metalworkers.
1. What is Metallurgy?
Metallurgy is the branch of science and technology concerned with the extraction, purification, processing and use of metals.
Ancient Indian metalworkers developed techniques for producing and working with metals such as iron, copper, bronze, gold and silver.
2. Iron Pillar of Delhi
The Iron Pillar stands in the Qutb complex in Delhi. It is famous for its remarkable resistance to corrosion despite being exposed to the atmosphere for many centuries.
The pillar is generally dated to the Gupta period, around the 4th–5th century CE, and is associated with King Chandra, mentioned in its inscription.
3. Why is the Pillar Special?
The most remarkable feature of the pillar is its excellent resistance to rust and corrosion.
Although it is made mainly of iron, it has survived for roughly 1,600 years with relatively little corrosion.
This shows that ancient Indian metalworkers had considerable skill in:
• Producing iron
• Controlling the composition of the metal
• Forging large pieces of iron
• Joining and shaping iron sections
• Producing iron that was highly resistant to corrosion
4. Why Does It Resist Corrosion?
Scientists have found that the pillar's resistance to corrosion is related to several factors.
Its iron contains phosphorus, and its manufacturing process helped form a thin, protective layer on the surface. This layer slows down further corrosion.
The exact resistance is therefore not simply because the iron contains no impurities; rather, its composition, processing and environmental conditions together contributed to its durability.
5. How Was It Made?
The pillar was produced using wrought iron.
Ancient craftsmen likely produced and joined several large pieces of hot iron through forging and welding techniques. Producing such a large iron structure without modern machinery demonstrates their advanced craftsmanship.
6. Importance in Ancient Indian Metallurgy
The Iron Pillar provides evidence that ancient Indian metalworkers had a sophisticated understanding of:
Iron production → heating → forging → joining → shaping → corrosion resistance
It is therefore an important example of India's historical achievements in metallurgy and metalworking.
7. Key Learning Point
The Iron Pillar of Delhi is a remarkable example of ancient Indian metallurgical skill because its iron has shown exceptional resistance to corrosion for many centuries.
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