2.1.1. Coal

Coal is a one of the important minerals which is mainly used in the generation of thermal power and smelting of iron ore. Coal occurs in rock sequences mainly of two geological ages, namely Gondwana and tertiary deposits. Most of the coal deposits are about 300 million years old.

About 65 per cent of the total coal production is consumed for generating electricity. It is also used as a basic fuel in many industries. Entire process of steel making is based on metallurgical coal. Cement industry consumes about five per cent of the total production. Coal is also an important source of naphtha and ammonia, which are widely used for making chemical fertilizers, tar, benzene, carbon black, etc. Soft coke is used as fuel in the kitchen.

Depending upon the percentage of carbon present, the coal can be grouped in four types, such as peat, lignite, bituminous and anthracite.

Peat- It represents the first stage of coal formation, i.e. from wood to coal, today; peat is being formed at many places. It has a high percentage of moisture and volatile matter. The carbon content in peat is less than 40 per cent. It burns like wood and gives more smoke and less heat. It leaves a large amount of ash after burning. Its low heating capacity reduces its value as an industrial fuel.

Lignite- It is generally regarded as the next stage of coal formation after peat. It is also known as the brown coal. Lignite is soft, but more compact than peat. The carbon contents vary from 40 per cent to 60 per cent. Lignite has large percentage of moisture and less amount of combustible matter. The increasing demand for coal has enhanced its use in thermal power stations and in some industries. In India, lignite is mostly found in Rajasthan, Tamil Nadu, Assam and Jammu and Kashmir states.

Bituminous -It is the hard and compact variety of coal. The carbon content varies from about 60 per cent to 80 per cent. Almost 80 per cent of the world's total output of coal is of the bituminous type. The moisture and the volatile contents are also less. Coke is mainly used in the iron and steel industry for smelting iron ore in blast furnaces. Bituminous coal is found in Jharkhand, Orissa, West-Bengal, Madhya Pradesh and Chhattisgarh.

Anthracite - It is the hardest and the best quality of coal. The carbon content varies from about 80 per cent to 90 per cent. Anthracite, practically, has no volatile matter. It does not ignite easily, but once lighted, it has the highest heating capacity. It burns for a long time and leaves very little ash behind. Only about 5 per cent of the world's total coal is anthracite. In India this type of coal is found only in Jammu and Kashmir and that too in very small quantity.

About 80 per cent of the coal deposits in India is of bituminous type and is of non-coking grade. The most important Gondwana coal fields of India are located in Damodar Valley. They lie in Jharkhand-Bengal coal belt and the important coal fields in this region are Raniganj, Jharia, Bokaro, Giridih, Karanpura. The other river valleys associated with coal are Godavari, Mahanadi and Son. The most important coal mining centres are Singrauli in Madhya Pradesh (part of Singrauli coal field lies in Uttar Pradesh), Korba in Chhattisgarh, Talcher and Rampur in Odisha, Chanda–Wardha, Kamptee and Bander in Maharashtra and Singareni and Pandur in Andhra Pradesh.

Coal mining industry is facing a lot of problems in India. Some of the major problems are –

1. The distribution of coal is uneven; this involves high transport cost to carry heavy commodity like coal over long distance. Consequently, the coal consuming industries have to pay much higher prices.

2. Indian coal has high ash content and low calorific value. The ash content varies about 20-30 percent which significantly reduces the calorific value of the product.

3. A large percentage of the coal is taken out from underground mines where the productivity of the labour and machinery is quite low.

4. Besides the problem of pilferage and fire in mines, mining industry is also suffering from problems of environmental pollution.