Non-Metallic Mineral Distribution in India – Mica, Limestone, Dolomite, Asbestos, Magnesite, Kyanite, Sillimanite and Gypsum.
- Mica is a naturally occurring non-metallic mineral that is based on a collection of silicates.
- Mica is a very good insulator that has a wide range of applications in electrical and electronics industry.
- It can withstand high voltage and has low power loss factor.
- It is used in toothpaste and cosmetics because of its glittery appearance. It also acts as a mild abrasive in toothpaste.
- India is one of the foremost suppliers of mica to the world. Mica-bearing igneous rocks occur in AP, Bihar, Jharkhand, Maharashtra, Rajasthan.
Mica Reserves in India
- Andhra Pradesh (41 per cent)
- Rajasthan (21 per cent)
- Odisha (20 per cent)
- Maharashtra (15 per cent)
- Bihar (2 per cent)
- Jharkhand (Less than 1 per cent)
Mica Distribution and Production in India
- India has a near monopoly in the production of mica [60 % of world’s total].
- Production decreased in recent times due to fall in demand in the international market. Fall in demand is due to better synthetic alternatives that are available.
- 1st in production [93 %].
- The mica belt lies in Nellore district [Gudur Mica mines].
- Vishakhapatnam, West Godavari and Krishna are other important mica producing districts.
- 2nd in production [6.3 %].
- The main mica belt extends from Jaipur to Udaipur [Along Aravalis].
- 3rd in production.
- Mica is found in a belt extending for about 150 km in length and 32 km in width from Gaya district of Bihar to Hazaribagh and Koderma districts of Jharkhand. This belt contains the richest deposits of high quality ruby mica.
- Koderma is a well-known place for mica production in Jharkhand.
- India is the largest exporter of mica.
- Certain grades of Indian mica are and will remain vital to the world’s electrical industries.
- Major exports are carried out through Kolkata and Vishakhapatnam ports.
- Important imports of Indian mica are Japan (19%), the USA (17%), U.K, etc.
- Limestone rocks are composed of either calcium carbonate, the double carbonate of calcium and magnesium, or mixture of both.
- Limestone also contains small quantities of silica, alumina, iron oxides, phosphorus and sulphur.
- Limestone deposits are of sedimentary origin and exist in all the geological sequences from Pre-Cambrian to Recent except in Gondwana.
- 75 per cent Limestone is used in cement industry, 16 per cent in iron and steel industry [It acts as flux] and 4 per cent in the chemical industries.
- Rest of the limestone is used in paper, sugar, fertilizers, etc.
- Almost all the states of India produce some quantity of limestone.
- Over three-fourths of the total limestone of India is produced by Madhya Pradesh, Rajasthan, Andhra Pradesh, Gujarat, Chhattisgarh and Tamil Nadu.
- Madhya Pradesh is the largest producer of limestone [16 per cent].
- Large deposits occur in the districts of Jabalpur, Satna, Betul, etc.
- Rajasthan has about 6 per cent of the reserves and produces over 16 per cent of the total limestone of India. Production occurs in almost all districts.
- Andhra Pradesh possesses about one-third of the total reserves of the cement grade limestone in the country.
- Extensive deposits occur in Cuddapah, Kumool, Guntur, etc.
- Gujarat produces only about 11 per cent of the total limestone of India.
- High grade limestone deposits occur in Banaskantha district.
- Chhattisgarh accounts for more than nine per cent of total limestone of India .Deposits of limestone occur in Bastar, Durg and surrounding districts.
- Large scale reserves in Ramnathapuram, Tirunelveli, Salem, Coimbatore and Madurai districts.
- Gulbarga, Bijapur and Shimoga districts.
- Limestone with more than 10 per cent of magnesium is called dolomite.
- When the percentage rises to 45, it is true dolomite.
- Dolomite is mainly used as blast furnace flux, as a source of magnesium salts and in fertilizer and glass industries.
- Iron and Steel industry is the chief consumer of dolomite [90 per cent] followed by fertilizer, ferro-alloys and glass.
- Dolomite is widely distributed in the all parts of the country.
- Orissa, Chhattisgarh, Andhra Pradesh, Jharkhand, Rajasthan and Karnataka are the main producing states and contribute more than 90 per cent of the total production.
- Orissa and Chhattisgarh together account for about 57 per cent dolomite of India.
- Orissa is the largest producer of dolomite [29 per cent].
- The main deposits occur in Sundargarh, Sambalpur and Koraput districts.
- Closely following Orissa is the state of Chhattisgarh which produces about 28 per cent dolomite of India.
- The main deposits occur in Bastar, Bilaspur, Durg and Raigarh districts.
- Dolomite occurs in bands to the north of Chaibasa in Singhbhum district and Palamu district.
- Ajmer, Alwar, Bhilwara, Jaipur, Jaisalmer etc. are the main producing districts.
- Belgaum, Bijapur, Chitradurga, Mysore, etc.
- Two quite different minerals are included under this name; one, a variety of amphibole, and the other, more important, a fibrous variety of serpentine (chrysotile).
- Chrysotile is more important variety and accounts for 80 per cent of the asbestos of commercial use.
- Asbestos has great commercial value due to its fibrous structure, filaments of high tensile strength and its great resistance to fire.
- It is widely used for making fire-proof cloth, rope, paper, millboard, sheeting, etc.
- It is also used in making aprons , gloves, brake-linings in automobiles etc.
- Asbestos cement products like sheets, pipes and tiles are used for building purposes.
- When asbestos is brittle, it is made into filter pads for filtering acids.
- Mixed with magnesia, it is used for making ‘magnesia bricks’ used for heat insulation.
- Two states of Rajasthan and Andhra Pradesh produce almost the whole of asbestos of India.
- Rajasthan is the largest producer. Important occurrences are known in Udaipur, Dungarpur, Alwar, Ajmer and Pali districts.
- In Andhra Pradesh, asbestos of fine quality occurs in Pulivendla taluk of Cuddapah district.
- In Karnataka, the main deposits occur in Hassan, Mandya, Shimoga, Mysore and Chikmaglur districts.
- It is an alteration product of dunites (peridotite) and other basic magnesian rocks.
- It is primarily used for manufacturing refractory bricks.
- It is also used as a bond in abrasives, manufacture of special type of cement for artificial stone, tiles and for extraction of the metal magnesium.
- Steel industry also uses magnesite.
- Major deposits of magnesite are found in Uttaranchal, Tamil Nadu and Rajasthan.
- Tamil Nadu is the largest producer [three-fourth] of magnesite in India.
- Tamil Nadu has one of the largest deposits of magnesite in the world and the largest in India are found at Chalk Hills near Salem town.
- Kyanite occurs in metamorphic aluminous rocks.
- It is primarily used in metallurgical, ceramic, refractory, glass, cement industries due to its ability to stand high temperatures.
- It is also used in making sparking plugs in automobiles.
- India has the largest deposits of kyanite in the world. All the three grades of kyanite are found here. Kyanite grades depend on aluminium content. Greater the aluminium content, greater the quality.
- Jharkhand, Maharashtra and Karnataka produce practically the whole of kyanite of India.
- Jharkhand is the largest producer of kyanite [four-fifths].
- Ores with high degree of purity with percentages of aluminium silicate reaching 95 to 97 are found in the Singhbhum district.
- Maharashtra [second highest producer of kyanite] produced 14.5 per cent of the total kyanite in 2002-03.
- Most of the reserves are in Bhandara district.
- Karnataka is the third largest producer [5.6 per cent in 2002-03].
- Commercially, workable deposits occur in Hassan district.
- The occurrence and uses of sillimanite are almost the same as those of kyanite.
- The main concentration of Sillimanite is found in Tamil Nadu, Orissa, Kerala, Andhra Pradesh and West Bengal.
- Orissa is the largest producer of sillimanite in India. Ganjam district is an important sillimanite producing district.
- Kerala is the second largest producing state. The beach sands of Kerala contain 5 to 6 per cent of sillimanite.
- Gypsum is a hydrated sulphate of calcium.
- It is a white opaque or transparent mineral.
- It occurs in sedimentary formations such as limestones, sandstones and shales.
- It is mainly used in making ammonia sulphate fertilizer and in cement industry.
- It makes upto 4-5 per cent of cement.
- It is also used in making plaster of Paris, moulds in ceramic industry, tiles, plastics, etc.
- It is applied as surface plaster in agriculture for conserving moisture in the soil and for aiding nitrogen absorption.
- Rajasthan is by far the largest producer of gypsum in India [99 per cent of the total production of India].
- The main deposits occur in the Tertiary clays and shales of Jodhpur, Nagaur and Bikaner. Jaisalmer, Barmer, Chum, Pali and Ganganagar also have some gypsum bearing rocks.
- The remaining gypsum is produced by Tamil Nadu [Tiruchirapalli district], Jammu and Kashmir, Gujarat and Uttar Pradesh in order of production.
- Water and phosphoric acid plants are important sources of by product gypsum.
- Marine gypsum is recovered from salt pans during the processing for common salt in Gujarat and Tamil Nadu.
- Phospho-gypsum is obtained as a byproduct while manufacturing phosphoric acid whereas fluro-gypsum is obtained while manufacturing aluminium flouride and hydro-fluoric acid.
- The recovery of by-product phospho-gypsum, fluoro- gypsum, and marine gypsum together is higher than mineral gypsum.
- Salt is obtained from sea water, brine springs [salt water springs], wells and salt pans in lakes and from rocks.
- Rock salt is taken out in Mandi district of Himachal Pradesh and in Gujarat. It is less than 1 per cent of the total salt produced in India.
- Sambhar Lake in Rajasthan produces about 10 per cent of our annual production.
- Sea brine is the source of salt in Gujarat, Maharashtra and Tamil Nadu.
- Gujarat coast produces nearly half of our salt.
Conservation of Mineral Resources
- Mining is often called the robber industry because of its exploitative nature.
- Mining should be made efficient with better mining and benefication technologies.
- A clear roadmap has to be carved for the better management of mineral resources for decades. Stringent laws to prevent the plundering of minerals is the need of the hour.
- Transparency must be the priority in extraction of mineral resources. Corrupt practices have led to mismanagement of mineral resources making mining industry highly inefficient.
- Recycling of cyclic minerals [iron, aluminium, copper, brass, tin] can help in reducing the waste.
- Scarce and expensive minerals must be substituted with the abundant ones. Example: Aluminium substitutes copper in electrical industry.
- Instead of exporting minerals, India should focus on exporting goods manufactured using these minerals. This would create more jobs locally.
- Innovation and research into synthetic minerals is essential.