Manufacturing Industries

Why manufacturing matters, how industries are classified, textiles, iron and steel and aluminium, and industrial pollution and its control.

Key ideas

Manufacturing turns raw materials into more valuable goods in large amounts and belongs to the secondary sector.
It modernises farming, creates jobs, reduces dependence on agriculture and earns foreign exchange.
Industries are classed by raw material (agro-based, mineral-based), role (basic, consumer), size and ownership (public, private, joint, cooperative).
Textiles is the only industry self-reliant across the whole chain from raw material to finished goods.
Iron and steel is a basic industry because others depend on it; the Chhotanagpur plateau has the most steel plants.
An aluminium plant needs cheap, steady electricity and an assured supply of raw material.
Industry pollutes air, water and land and adds heat and noise; treating effluents, cleaner fuels, filters and recycling water reduce it.

First cotton mill	Mumbai, 1854
First jute mill	Rishra near Kolkata, 1855
Steel raw materials	iron ore : coking coal : limestone ≈ 4 : 2 : 1
Ownership	public: SAIL; private: TISCO; joint: Oil India Ltd; cooperative: sugar mills
Treating waste water	primary (mechanical) → secondary (biological) → tertiary (biological, chemical, physical)

Splitting in a ratio wrongly: 4 : 2 : 1 has 7 parts, so find one part first.
Calling a sugar mill run by its farmers public sector: it is cooperative.
Mixing up basic industries (supply other industries) and consumer industries (make goods for direct use).

A steel plant uses 11,900 tonnes of raw material in the ratio iron ore : coking coal : limestone = 4 : 2 : 1. How much of each?

Working: 11,900 ÷ 7 = 1,700 per part

Answer: iron ore 6,800, coking coal 3,400, limestone 1,700 tonnes