PROCESS OF DEVELOPMENT OF GENTLY DIPPING COAL FORMATIONS WITH ROOF ROCKS DIFFICULT TO FALL Russian patent published in 2003 - IPC

FIELD: mining industry, technology of development of thick fire-risky coal formations. SUBSTANCE: process of development of thick gently dipping coal formations with roof rocks difficult to fall includes simultaneous development of two inclined layers by two long columns in ascending order with outstripping of upper layer by lower one by value of zone of active convergence of rocks with development of both layers on to headings of lower layer with their subsequent extinction. When developing lower ( incision ) layer coal mass in upper layer in plane passing along line of contact between drift and breakage face is loosened in zone of operation of clearing complex either by blasting of rock holes with explosive charges or by method of hydraulic fracturing of formation. Thickness of lower layer is chosen proceeding from layer ratio K = M_ul/M_ll in limits of 2.2-3.8 and thickness of upper layer is assumed to be not less than value determined from expression M_ul≥M_ll(K_l-I) where M_ul is thickness of upper layer, m; M_ll is thickness of lower layer, m; K_l is coal loosening factor equal to 1.4. EFFECT: increased safety and productivity of process thanks to establishment of rational parameters of inclined layers with their simultaneous development in ascending order. 2 cl, 3 dwg