Pootkee-Balihari (PB) Area Operation is operated by Bharat Coking Coal Limited, a Miniratna Public Sector Undertaking and a 100% subsidiary of Coal India Limited, which is a Government of India undertaking.
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Summary:
The Pootkee Balihari block, located in the central part of the Jharia Coalfield, is completely covered by rocks of the Upper Permian Raniganj and Middle Permian Barren Measure Formation that overlay the Lower Permian Barakar Formation. The Barren Measures is a formation of massive sandstone traversed by ferruginous bands, grey to dark-grey shale, carbonaceous shale, and clay with ironstone bands. The Barakar Formation is composed of feldspathic sandstones and carbonaceous shales that are traversed by coal seams. The formations show a NW-SE strike with a south-west dip of 4° to 12°. Based off available borehole data and geologic reports, 21 faults are interspersed through the block with throws between 5 m and 190 m. Post-Gondwana orogeny mica-peridotite dykes and sills do intrude the area and have affected the seams — XVIII and XIV appear to be completely pyrolitized into jhama, XIII and XII are affected by intrusions throughout the block, and parts of XI have also been converted to jhama.
Seams XVIII, XVII, XVI, XV, XIII, XII, XI, X, IX, and VII have been mined since 1972. The deepest seam, II, is projected to be 900 m deep and the cumulative thickness of the layers targeted for future mining, seams X to II, have an average cumulative thickness of 55 m. The coal seams vary in thickness; for example seam XII ranges in depth from 400 m to 550 m with the seam averaging 3.1 m in thickness. Seam XV can be on the order of 5–10 m thick in places, and others like Seam X around 3–6 m (thinner splits like XI, XII are thinner) – together contributing to the cumulative 55 m coal horizon.
The coal rank is generally Medium Coking Coal (Steel Grade-II to Washery Grade-III), with high ash content in the as-mined state requiring washing for metallurgical use. Overall, the geology provides rich coking coal seams but with challenges of fiery and disturbed ground. Notably, the area is affected by coal seam fires and subsidence due to its long mining history. Six fire-affected zones have been identified in PB Area – two have been completely sealed off, and the remaining four are "under control but still require action".