Industrial Processes & Raw Materials: Cement, Glass, Fertilisers, Pollution & Control

Pollution: Air, Water, and Soil

Pollution refers to the introduction of harmful substances into the environment, affecting air, water, and soil quality. Understanding the sources and control of pollution is crucial for environmental protection.

Types of Pollution

• Air Pollution: Caused by emissions from industries, vehicles, and burning of fossil fuels. Common pollutants include carbon monoxide (CO), sulfur dioxide (SO₂), and nitrogen oxides (NO_x).
• Water Pollution: Results from the discharge of industrial waste, oil spills, and agricultural runoff into water bodies. Pollutants include heavy metals, pesticides, and plastics.
• Soil Pollution: Occurs due to the use of chemical fertilizers, pesticides, and industrial waste disposal. It leads to soil degradation and affects plant growth.

Pollution Control Methods

• Air Pollution Control: Use of filters and scrubbers in factories, promoting cleaner fuels, and implementing emission standards.
• Water Pollution Control: Treatment of industrial effluents before discharge, use of bioremediation techniques, and enforcing regulations on waste disposal.
• Soil Pollution Control: Reducing the use of chemical fertilizers, promoting organic farming, and proper waste management.

Sources of Raw Materials for Cement

Cement is a key material in construction, made from a mixture of raw materials that undergo a chemical process.

Key Raw Materials

• Limestone: The primary raw material, providing calcium carbonate (CaCO₃).
• Clay: Provides silica (SiO₂), alumina (Al₂O₃), and iron oxide (Fe₂O₃).
• Gypsum: Added to control the setting time of cement.

Cement Manufacturing Process

1. Crushing and Grinding: Raw materials are crushed and ground into a fine powder.
2. Mixing: The powdered materials are mixed in the correct proportions.
3. Heating: The mixture is heated in a rotary kiln to form clinker.
4. Grinding: Clinker is ground with gypsum to produce cement.