Extraction of coal under hard roof is a difficult task; Strata control problems like spalling of coal, overriding of pillars, air blast in bord & pillar workings and collapses of faces in longwall are common phenomena in Indian Coalfields.In India, there is no effective technique for hard roof management. Induced caving by blasting is the only available method to alleviate the problem but it has inherent limitations to practice. There is tremendous need to develop an effective technique to combat the hard roof problems. Control of hard roof by water injection under high pressure is a well established method in some countries but in India still it is at experimental stage. CMRI is trying to standardize the method to adopt in different Indian geo mining conditions.This paper emphasized the necessity of the method and enumerates the limitations of other techniques so far available. It describes major parameters of the method elaborately and presents the principle and general methodology in longwall as well as in Bord & Pillar workings.
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