Mineral-based Industries, IT & Environmental Impact

NCERT Contemporary India-II | Chapter 6: Manufacturing Industries

Iron and Steel Industry

The iron and steel industry^? is the basic industry because all other industries — heavy, medium, and light — depend on it for their machinery. Steel is essential for manufacturing engineering goods, construction material, defence equipment, medical instruments, and a vast range of consumer products.

This is a heavy industry since both raw materials and finished goods are bulky and require heavy transportation. The key raw materials — iron ore, coking coal, and limestone — are required in the approximate ratio of 4:2:1. Small quantities of manganese are also needed to harden the steel.

The Chhotanagpur plateau region has the maximum concentration of iron and steel industries due to low-cost iron ore, high-grade raw materials nearby, cheap labour, and vast growth potential in the domestic market. Major steel plants include those at Jamshedpur, Burnpur, Durgapur, Rourkela, Bhilai, Bokaro, Vishakhapatnam, Vijaynagar, Bhadravati, and Salem.

Aluminium Smelting

Aluminium smelting^? is the second most important metallurgical industry in India. Aluminium is light, corrosion-resistant, a good conductor of heat, malleable, and becomes strong when alloyed with other metals. It is used to manufacture aircraft, utensils, and wires, and has become a popular substitute for steel, copper, zinc, and lead across many industries.

Aluminium smelting plants are located in Odisha, West Bengal, Kerala, Uttar Pradesh, Chhattisgarh, Maharashtra, and Tamil Nadu. The two prime factors determining their location are a regular supply of electricity (about 18,600 kWh per tonne of ore) and an assured source of bauxite at minimum cost. Converting 4–6 tonnes of bauxite yields about 2 tonnes of alumina, which in turn produces 1 tonne of aluminium.

Chemical Industries

The chemical industry in India is fast-growing and diversifying, comprising both large-scale and small-scale units. It includes two broad categories:

The chemical industry is its own largest consumer — basic chemicals undergo further processing to produce chemicals for industrial, agricultural, or direct consumer use.

Fertiliser Industry

The fertiliser industry^? centres around nitrogenous fertilisers (mainly urea), phosphatic fertilisers, and complex fertilisers combining nitrogen (N), phosphate (P), and potash (K). India has no commercially usable potash reserves, so potash is entirely imported.

After the Green Revolution, the industry expanded across the country. Gujarat, Tamil Nadu, Uttar Pradesh, Punjab, and Kerala contribute about half of total fertiliser production. Other significant producers include Andhra Pradesh, Odisha, Rajasthan, Bihar, Maharashtra, Assam, West Bengal, Goa, Delhi, Madhya Pradesh, and Karnataka.

Cement Industry

Cement is vital for construction — houses, factories, bridges, roads, airports, and dams. The industry requires bulky raw materials such as limestone^?, silica, and gypsum, along with coal, electric power, and rail transportation.

Automobile Industry

The automobile sector manufactures trucks, buses, cars, motorcycles, scooters, three-wheelers, and multi-utility vehicles. After economic liberalisation, the entry of new models stimulated demand and led to healthy growth across all vehicle categories. Major centres include Delhi, Gurugram, Mumbai, Pune, Chennai, Kolkata, Lucknow, Indore, Hyderabad, Jamshedpur, and Bengaluru.

Information Technology & Electronics

The electronics industry covers a wide range — from transistors and televisions to telephones, computers, and radar systems. Bengaluru^? has emerged as the electronic capital of India. Other important centres include Mumbai, Delhi, Hyderabad, Pune, Chennai, Kolkata, Lucknow, and Coimbatore. The continuing growth of hardware and software is key to the success of India's IT sector, which has had a major impact on employment generation.

Industrial Pollution & Environmental Degradation

While industries are critical for economic growth, they are also responsible for four types of pollution:

Air Pollution

Caused by undesirable gases such as sulphur dioxide and carbon monoxide, along with airborne particulate matter (dust, sprays, mist, and smoke). Chemical and paper factories, brick kilns, refineries, and smelting plants emit smoke. Toxic gas leaks can have devastating long-term effects — as seen in the Bhopal Gas Tragedy.

Water Pollution

Organic and inorganic industrial wastes discharged into rivers are the main culprits. Paper, pulp, chemical, textile, dyeing, petroleum, tannery, and electroplating industries release dyes, detergents, acids, salts, heavy metals (lead, mercury), pesticides, and plastics into water bodies. Fly ash, phospho-gypsum, and iron and steel slags are major solid wastes. Thermal pollution occurs when hot water from factories is drained into water bodies before cooling.

Land Pollution

Dumping of glass, harmful chemicals, industrial effluents, packaging, salts, and garbage renders soil useless. Rainwater carries pollutants into the ground, contaminating groundwater as well.

Noise Pollution

Industrial machinery, factory equipment, generators, saws, and pneumatic drills produce unwanted sound that causes irritation, hearing impairment, increased heart rate, and elevated blood pressure.

Controlling Environmental Degradation

Every litre of industrial waste water pollutes about eight times the quantity of fresh water. Several measures can reduce industrial pollution: