Chapter 5 — Minerals and Energy Resources

A mineral is defined by geologists as a "homogenous, naturally occurring substance with a definable internal structure." Minerals are found in nature in varied forms, ranging from the hardest diamond to the softest talc.

Ferrous minerals contain iron and account for about three-fourths of the total value of metallic mineral production. Non-ferrous minerals include copper, bauxite, lead, zinc, and gold. India's reserves and production of non-ferrous minerals are not very satisfactory compared to ferrous minerals.

Minerals occur in five ways: (i) in veins and lodes in igneous and metamorphic rocks where minerals were forced upward through cavities; (ii) in beds or layers in sedimentary rocks formed by deposition and concentration in horizontal strata; (iii) as residual deposits from decomposition of surface rocks, like bauxite; (iv) as placer deposits in alluvial sands containing minerals not corroded by water, like gold and silver; (v) in ocean waters, where common salt, magnesium, and bromine are derived.

In 2018-19, almost 97% of India's iron ore came from Odisha, Chhattisgarh, Karnataka, and Jharkhand, with the remaining 3% from other states. Major iron ore belts include the Odisha-Jharkhand belt, the Durg-Bastar-Chandrapur belt in Chhattisgarh and Maharashtra, and the Ballari-Chitradurga-Chikkamagaluru-Tumakuru belt in Karnataka.

Magnetite is the finest iron ore with very high iron content up to 70%, and has excellent magnetic qualities valuable in the electrical industry. Hematite is the most important industrial iron ore in terms of quantity used, but has a slightly lower iron content of 50-60%. Magnetite has better properties but hematite is more commonly used.

Manganese is mainly used in manufacturing steel and ferro-manganese alloy. Nearly 10 kg of manganese is required to manufacture one tonne of steel. It is also used in manufacturing bleaching powder, insecticides, and paints. Madhya Pradesh is the leading producer, accounting for 33% of India's production.

Bauxite is a clay-like substance from which alumina and later aluminium is obtained. Aluminium is important because it combines the strength of metals such as iron with extreme lightness, good conductivity, and great malleability. Bauxite deposits are formed by decomposition of rocks rich in aluminium silicates and are mainly found in the Amarkantak plateau, Maikal hills, and the plateau region of Bilaspur-Katni. Odisha was the largest bauxite producing state in 2018-19.

Mica is a mineral made up of a series of plates or leaves that split easily into thin sheets. Due to its excellent di-electric strength, low power loss factor, insulating properties, and resistance to high voltage, mica is one of the most indispensable minerals used in electric and electronic industries. The Koderma-Gaya-Hazaribagh belt of Jharkhand is the leading producer.

Conventional energy sources include firewood, cattle dung cake, coal, petroleum, natural gas, and electricity (both hydel and thermal). Coal is the most abundantly available fossil fuel in India and provides a substantial part of the nation's energy needs. More than 70% of energy requirement in rural households is met by firewood and dung cake.

Non-conventional energy sources include solar, wind, tidal, geothermal, biogas, and atomic energy. They are important because rising prices of fossil fuels and their potential shortages create energy security concerns. India is blessed with abundance of sunlight, water, wind, and biomass, and has the largest programmes for developing these renewable energy resources to reduce environmental problems caused by fossil fuels.

Minerals are finite and non-renewable resources. They required millions of years to be created and concentrated. The geological processes of mineral formation are so slow that replenishment rates are infinitely small compared to current consumption rates. Rich mineral deposits are extremely valuable but short-lived possessions. Continued extraction leads to increasing costs as mining must go to greater depths with decreasing ore quality. Conservation through improved technologies, recycling of metals, and using substitutes is essential for the future.

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