Mineral Resources and Coal Mining

Damodar valley is the storehouse of Indian coal, even though the valley is not very rich in metallic minerals. Other than coal, several non-coal minerals are associated with the geological formations in the Damodar valley region. Of these minerals, the important ones are mica, fire clay, bauxite, limestone, china clay, baryte, steatite, iron ore, copper ore, galena, kyanite, graphite, etc. Coal is the major mineral resource in the basin and considered as the prime centre of coking coal in the country. Massive coal deposits are found in the centra basin spreading over 2,883 sq.km. The important coalfields in the basin are Jharia, Raniganj, West Bokaro, East Bokaro, Ramgarh, South Karanpura and North Karanpura. Coal reserves in Damodar river basin are presented in Table 7.   

       Table 7 : Coal Reserves in Damodar River Basin (DRB)

Mica is widely found in the neighbourhood of Koderma and Gawan in the Koderma plateau region. It is found in thick veins of pegmatite alongwith other minerals like quartz, orthoclase, feldspar and tourmaline. Mica occurs in large blocks, having thickness upto 1.0 m. Fire clay is found in Jharia and Raniganj coalfields area. Jharia has the largest reserves offire clay particularly in Kumardhubi-Mugma area. Fire clay deposits occur in Purulia and Burdwan districts of West Bengal and Dhanbad, Hazaribagh and Palamau districts of Jharkhand. Bauxite ores are found in summit and upper slopes of Khamarpet hill near the source region of Damodar river. The bauxite ore of the region contains more than 50 percent alumina and is supplied to aluminium industries of Asansol, Hirakund, Rihand and Alwaye. Other minerals available in the region are iron ore (near Ramgarh, Bokaro and Karanpura), copper ore (near Purulia and Bankura), limestone, steatite and china clay.

Indian Coal Scenario

India is heavily dependent on coal for meeting its energy requirement, which is at present satisfied to the extent of about 60%. The significant resources of coal in comparison to other fossil fuels have enabled this valuable mineral to remain at the centre stage of ndia's energy scene. Commercial energy consumption in India has grown from a level of about 30 to 60% of total energy requirement in the last four decades. It has grown at a rate of 7.2 percent during the last two decades as against the world average of 2.2 percent only. With increase in population and improvement in the standards of living, the commercial energy consumption is projected to follow the similar trend in the following 10-15 years. With the increasing share of commercial energy in the total energy supply in future, and with almost doubling of the per capita projected energy consumption to about 450 kg in the next 15 years, Indian coal industry is destined to playa greater role in meeting the basin's growing requirement of commercial energy.The total geological reserve of coal in India is about 206 billion tonnes, which is less than 1 percent of the global coal resources. However, the proven reserves of coal in India are about 6.6 percent of the worlds proved reserves.Fifteen percent of these reserves are of the coking variety. Of the non-coking coal, about 12 percent is of superior variety having ash content upto 24 percent. The recoverable coal resource upto a depth of 600m is estimated to be of the order of 75 billion tonnes which will ensure its steady supply throughout the next century even at enhanced level of consumption of 650 mt per annum. The ash/ mineral matter of Indian coal is of inherent nature, which makes washing of Indian coal very difficult. However, Indian coal contains low sulphur and low toxic trace elements. It has high ash content with high fusion temperature. The future demand projections underline the urgent need for increasing the exploration activity to build up the inventory of geological reserves as well as of proved reserves. From about 78 mt in 1973, the coal production rose to about 296 mt in 1997-98. Power sector, which consumes about 70 percent of coal has emerged as the single largest consumer of coal followed by steel with 13 percent. The balance 17 percent is consumed in thousands of other industries like cement, textiles, fertilizers, brick kilns, etc. Indigenous coal production meets about 96 percent of the demand. About 10 million tonnes of low ash coking coal and 3 million tonnes of steam coal are being imported annually.

          Damodar Basin Coal Scenario

Jharkhand and West Bengal, the two constituent states of Damodar river basin account for 33 and 12.6 %, respectively of India's total coal reserves. A total of 13.57 billion tonnes of medium coking and non-coking coal have been estimated in North Karanpura coalfield. Total production from this field in the year 1992-93 was 7.91 million tonnes mainly from the opencast mines. The South Karanpura coalfield is the second in the chain of Damodar valley, located near Patratu and Ramgarh township in Hazaribagh district. This coalfield, of nearly 195 sq. km area, is situated at south east of the North Karanpura. The area has nearly 5.72 billion tonnes of coal reserves, mainly of superior grade non-coking coal. A small Ramgarh coalfield is located along the eastern fringe of the South Karanpura coalfield in Hazaribagh district. The coalfield area is estimated to be about 98 sq. km. The total reserve of this field is estimated to be as 0.97 billion tonnes (0.28 medium coking and 0.66 semi coking) which occurs within 300m depth cover and is amenable to open cast mining. Jharia coalfield, an isolated basin of the Damodar river, is spread over an area of 450 sq. km primarily in Dhanbad and a small portion in Giridih district. The coalfield has 18 workable coal seams and 46 coal horizons. The upper XVIII to X seams of the basin are of prime coking variety while the lower seams have the semi-coking and inferior grade coal. The Raniganj formation is exposed in the southern Mahuda basin close to the river Damodar and has 12 coal horizons including 4 workable coal seams. The seams of the series are thin, medium coking, highly volatile under shallow cover. The total reserve of the area is estimated to be 16.4 billion tonnes including 4.3 billion tonnes of prime coking coal. The Raniganj coalfield, the first known coalfield of India, is the eastern most coalfield of DRB and is located down the river course in Burdwan district of West Bengal. A small portion of this coalfield lies in Dhanbad and Dumka districts of Jharkhand and Purulia, Bankura and Bhirbhum districts of West Bengal. The coalfield, spread over an area of 1550 sq. km, is most important in view of its history, geography and long flame good quality coal. Raniganj formation is developed up to 1050 m in depth and has 10 well-developed coal horizons while the Barakar stage is along the northern boundary with 7 well developed coal seams containing good quality coking coal. The coal reserve of the area is estimated to be about 22 billion tonnes including 20 billion tonnes of non-coking coal. The deposit of the coalfield has been extracted by underground methods for over 150 years and the opencast mining has been started in a few patches in the recent past. The distribution of coking coal reserves is presented in Table 8.

Table 8: Coalfield wise Reserves of Coking Coal

Under the technology action plan, it has been envisaged to contain, and if possible, reverse the declining trend in underground mining in the foreseeable future to maintain a reasonable mix between opencast and underground mining. This will keep the average cost of coal production and ecological balance at an optimum level. To improve the level of underground production and environmental quality, large-scale intermediary mechanization has been introduced and programme for introduction of longwall face has been initiated. Despite the advances made and initiatives taken for improving the underground production, the fact, however, remains that for another 10 to 15 years, the country wilt have to depend mostty on opencast mines for meeting its increasing coal demand.