The state has about 24.69 per cent of the total reserves (8.10% of the total proved reserves) and 14.47% of the total production of coal in the country. Most of the coal deposits are found in Dhenkanal, Sambaipur and Sundargarh districts.
The Talcher coalfield extending from Talcher to Lairkhol occupies a total area of 578 sq. km in Dhenkanal and Sambaipur districts. The field ranks 2nd in reserves (24,374million tones) after Raniganj. Here four coal seams with thickness from 60 cm and 8.72 m have been identified. The coal is of second or 464 lower grade with 2-13% of moisture, 28-35% of volatile matter, 33-56% of fixed carbon and 11-25% of ash content. It is suitable for steam and gas production. The coal is utilised in thermal power and fertilizer plants at Talcher.
The river coalfield covers a total area of 512 sq. km in Sambalpur and Gangpur districts. The coal belongs to the middle and lower Barakar systems in which Rampur (30.48 m), Lajkuria and Gamhadera seams are important. The bulk of the coal is of inferior grade with 9.49% of moisture, 27.74% of volatile matter, 49.19% of fixed carbon and 13.58% of ash content. The inferred reserves are of the order of 1,754 million tones.