Jharkhand is the foremost state in India both in respect of reserves and production of coal, its shares being 32.00 per cent and 24.36 per cent respectively. There are 21 important coal fields, of which 3 are in Dhanbad, 7 in Hazaribag, 3 in Palamau and 8 in Dumka districts. Amongst these, Jharia, east and west Bokaro, Giridih, north and south Karanpura, Ramgarh, Auranga, Hutar and Daltonganj coalfields are very important.
(a) The Jhariaaria Coalfield in Dha district covers an area of453 sq. km. This is the largest coal producing area of Jharkhand. It has 18 seams of workable coal. Starting from below seams 1 to 7 called Muraidih or Golakdih stage contain inferior variety of coal and have not been worked out. Seams 8 to 12 (Garira or Nardkarki stage) have good quality coking coal. Seams 13 to 15 (Jiyalgara or Barari stage) carry the best quality of coal.
It is also called selected coal. Seams 16 to 18 (Bhagarband stage) also contain good quality coal. In Jharia the Barakar coal measures (seams 13 to 18) are the storehouse of the best metallurgical coal in India which is used in the steel factories at Jamshedpur and Asansol. Jharia coal generally contains 1.38% of moisture, 21.5% of volatile matter, 60.4% of fixed carbon and 14.95% of ash. Detailed estimates made by GSI give a total of 12,192 million tons of coal reserve in situ up to a depth of 610 meters and 19,417 million tones down to a depth of 1,219 meters.
More than 90 per cent of the total reserves of coking coal in the country are located in Jharia and the field is the principal source of metallurgical coal in India. Coal is washed at Sudamdih and Monidih washeries and is transported to the areas of consumption by the Eastern Railway.
(b) The Bokaro coalfield in Hazaribag district lies 32 km west of Jharia field. It extends in a narrow belt through the Valley of Bokaro River and is separated in two parts by the Lugu hills. It spreads over an area of 374 sq. km.
The East Bokaro coalfield covers an area of 207 sq km and contains 29 seams. The upper most seams called Jarangdih have a thickness of 7.6 m. It is underlain by the Amlo seam with thickness of 3.05 m. The Kargali seam is the thickest seam in India (36.6 m) providing good quality coking coal.
The Karo seam is 30 m thick but the coal is of non-coking variety. The Burmo seam is about 12 m thick and is of coking variety. West Bokaro has 23 coal seams of which 8 to 13 contain coking grade coal. HereTenhakuju seam is 10.65 mi. thick. Bokaro coal contains 0.82% of moisture, 25.56% of volatile matter, 19.38% of ash and 54.24% of fixed carbon. The proved reserves of coal in Bokaro coalfields are estimated at 5,186 million tones.
(c) The Giridih or Karharbari coalfield lying south-west of Giridih in Hazaribag district spreads over an area of 28.5 sq km. It has 20 seams with an aggregate thickness of 28 m. The Lower Karharbari, 3 to 7.5 m thick, provides the finest coking coal in India for metallurgical purposes. Other important seams are Upper Karhabari and Bandhua seam s. The reserves have been estimated of the order of about 17.3 million tones.
(d) The Karanpura coalfield is divided into two parts: North Karanpura (area 1,230 sq. km), and South Karanpura (194 sq. km). The field is the third largest coal producing area of Bihar. It lies about 3 km west of Bokaro field in Palamau and Hazaribag districts. The coal seams belong to the Barakar and Raniganj measures with thickness of 22 m. Much of the coal is of non-coking grade. In South Karanpura the Argada seam (thickness 27.4 m) is important where coal is of coking grade. Karanpura coal contains 27% of volatile matter, 64.5% of fixed carbon and 8.5% of ash. The estimated total reserves are 19,253 million tones of which 6,821 million tones are proved reserves.
(e) The Ramgarh coal field lies 9 km of the Bokaro field with total estimated reserves of 971 million tonnes. It covers a total area of 98 sq. km there are 22 seams of which 4 have thickness of 8 n each. The seams belong to the Barakar measure:
The coal is dull in appearance and high in ash (30.7 to 31.8%) content.
(f) The Auranga coalfield in Palamau district occupies an area of 240 sq.km with a seam of 13 m thickness. The coal is of inferior variety with 10.35% of moisture, 26.81% of volatile matter, 26.43% of fixed carbon, and 3 5.41 % of ash. It is mainly utilised in cement furnaces and brick kilns.
(g) The Hutar coalfield lies 19 km west of the Auranga field in Palamau district. It covers a total area of about 200 sq km wilt 5 seams of the Barakar measures. These are all thin seams (less than 2.5 m thick) but at places attaining 4 m of thickness. The coal contains 31.4% of volatile matter, 51.8% of fixed carbon and 16.8% of ash content. Majority of coal is of inferior variety.
(h) The Daltonganj coalfield covering a total area of 51 sq. km in Palamau district contains Talchir seams. There are 14 coal seams near Rajhera whose thickness ranges between 15 cm to 1.5 m. Coal here is of semi-anthracite type. Elsewhere it is of non- coking inferior variety. Daltonganj coalfield has estimated proved reserve of 84 million tones.
(i) Deogarh coalfields lie in Dumka district with Jainti, Sahjuri and Kunditkuraih as main mining areas. These occupy the valleys of the Adjai and Barakar rivers with a total area of 45.8 sq. km (Barakar measures with area of 18.2 sq. km.). Jainti coalfield has 5 seams while remaining two has two seams each. The coal is of inferior variety with high ash content.
(j) The Rajmahal coalfield along the western side of the Rajmahal hills lies north of the Damodar River in scattered form. It has a total area of 182 sq. km. Hura, Jilbari, Chaparbhita, Pachwara, Mahuagahi and Brahmki are the important mining areas. The coal is of inferior type suitable for use in brick kilns. The area has proved coal reserve of 1,913 million tones.