Mining

Mining is the extraction of valuable minerals from the earth. The history of human development is marked by stages named after the dominant mineral of the time — the Copper Age, the Bronze Age, and the Iron Age. In ancient times, minerals were used mainly for making tools, utensils, and weapons. The real development of mining as an organised activity began only with the Industrial Revolution, and its importance has been growing ever since.

Factors Affecting Mining Activity

The profitability of a mining operation depends on two broad sets of factors:

• Physical factors — the size of the mineral deposit, its grade (the concentration of the mineral in the ore), and the mode of occurrence (whether it lies close to the surface or deep underground).
• Economic factors — the demand for the mineral, the technology available for extraction and processing, the capital needed to develop infrastructure, and the costs of labour and transport.

Methods of Mining

Mining is classified into two main types, depending on the mode of occurrence and the nature of the ore:

1. Surface Mining (Open-cast Mining)

• Used for minerals that occur close to the surface.
• It is the easiest and cheapest method.
• Overhead costs — such as those for safety precautions and equipment — are relatively low.
• The output is both large and rapid.

2. Underground Mining (Shaft Method)

• Used when the ore lies deep below the surface.
• Vertical shafts are sunk into the ground, and from these shafts, underground galleries radiate outwards to reach the minerals.
• Minerals are extracted and transported to the surface through these passages.
• This method requires specially designed lifts, drills, haulage vehicles, and a ventilation system for safety and efficient movement of people and material.
• It is a risky method. Poisonous gases, fires, floods, and caving-in of the mine lead to fatal accidents. (The textbook asks: have you ever read about mine fires and flooding of coal mines in India?)

Global Trends in Mining …