Non-metallic Minerals

Non-metallic minerals are those that do not contain metals. Among the non-metallic minerals produced in India, mica is the most important. The other non-metallic minerals extracted mainly for local consumption are limestone, dolomite and phosphate.

Mica

Mica is primarily used in the electrical and electronic industries. Its unique property is that it can be split into very thin sheets which are both tough and flexible.

Major producing states: Jharkhand, Andhra Pradesh, Telangana, Rajasthan, followed by Tamil Nadu, West Bengal and Madhya Pradesh.

Key producing regions:

• Jharkhand: High quality mica is obtained in a belt extending about 150 km in length and 22 km in width in the lower Hazaribagh plateau.
• Andhra Pradesh: The Nellore district produces the best quality mica.
• Rajasthan: The mica belt extends for about 320 km from Jaipur to Bhilwara and around Udaipur.
• Other deposits: Mysuru and Hasan districts of Karnataka; Coimbatore, Tiruchirapalli, Madurai and Kanniyakumari in Tamil Nadu; Alleppey in Kerala; Ratnagiri in Maharashtra; Purulia and Bankura in West Bengal.

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Energy Resources

Mineral fuels are essential for generating power, which is required by agriculture, industry, transport and other sectors of the economy. Mineral fuels like coal, petroleum and natural gas (known as fossil fuels), along with nuclear energy minerals, are the conventional sources of energy. These conventional sources are exhaustible resources.

Coal

Coal is one of the most important minerals. It is mainly used in the generation of thermal power and in the smelting of iron ore.

Geological occurrence: Coal occurs in rock sequences of two main geological ages — Gondwana and Tertiary.

Types:

• About 80 per cent of India's coal deposits are of bituminous type and are of non-coking grade.
• Brown coal or lignite occurs in the coastal areas of Tamil Nadu, Puducherry, Gujarat and Jammu and Kashmir.

Gondwana coal fields:

• The most important Gondwana coal fields are located in the Damodar Valley, lying in the Jharkhand-Bengal coal belt.
• Important coal fields in this region: Raniganj, Jharia, Bokaro, Giridih, Karanpura.
• Jharia is the largest coal field, followed by Raniganj.
• Other river valleys associated with coal: Godavari, Mahanadi and Sone.

Major coal mining centres:

• Singrauli in Madhya Pradesh (part of it lies in Uttar Pradesh)
• Korba in Chhattisgarh
• Talcher and Rampur in Odisha
• Chanda–Wardha, Kamptee and Bander in Maharashtra
• Singareni in Telangana and Pandur in Andhra Pradesh

Tertiary coals:

• Occur in Assam, Arunachal Pradesh, Meghalaya and Nagaland.
• Extracted from Darangiri, Cherrapunji, Mewlong and Langrin (Meghalaya); Makum, Jaipur and Nazira in upper Assam; Namchik–Namphuk (Arunachal Pradesh); and Kalakot (Jammu and Kashmir).

Petroleum

Crude petroleum consists of hydrocarbons in liquid and gaseous states, varying in chemical composition, colour and specific gravity. It is an essential source of energy for all internal combustion engines in automobiles, railways and aircraft. Its numerous by-products are processed in petrochemical industries to make fertiliser, synthetic rubber, synthetic fibre, medicines, vaseline, lubricants, wax, soap and cosmetics.

Occurrence: Crude petroleum occurs in sedimentary rocks of the Tertiary period.

History of exploration: Oil exploration and production was systematically taken up after the Oil and Natural Gas Commission was set up in 1956. Till then, Digboi in Assam was the only oil producing region.

Recent discoveries: In recent years, new oil deposits have been found at the extreme western and eastern parts of the country.

Major oil producing areas:

• Assam: Digboi, Naharkatiya and Moran.
• Gujarat: Ankaleshwar, Kalol, Mehsana, Nawagam, Kosamba and Lunej.
• Mumbai High: Lies 160 km off Mumbai; discovered in 1973, production commenced in 1976.
• East coast: Oil and natural gas have been found in exploratory wells in the Krishna-Godavari and Kaveri basins.

Refining: Oil extracted from wells is crude oil and contains many impurities. It cannot be used directly and needs to be refined. There are two types of refineries in India:

• Field-based: Located near the oilfield (e.g., Digboi). …