Safe Exploitation Solution and Reduction of Resources Loss for the L7 Seam at the West Wing Area of the 790 Open Pit Site of the Mong Duong Coal Mine

Abstract

In the next time, deepening exploitation and increasing capacity in underground mines are extremely necessary to meet the demand of using coal for developing economies. This problem is not only done in underground mines but also in areas that cannot be exploited by open-pit methods such as the open-pit edge. When exploiting deep underground mines, there are many difficulties for tasks such as: controlling ground pressure; ventilation; drainage, transportation etc. When cutting coal in longwall, it will create a goaf, causing a natural imbalance of stress in the ground, leading to the phenomenon of displacement of rock deformation and destruction of roadways, which creates a risk of unsafety labour. The L7 seam at the west wing area of the Mong Duong coal mine has an average thickness of 7m, an average slope angle of 15^o, located near the edge of the 790 open pit site. According to the production plan, this mine will exploit this reservoir with blasting-drilling technology, longwall support by the semi-mechanized shield (self-moving hydraulic frame GK/1600/16/24/HTD). The preliminary assessment of hydrogeological conditions of the mine shows that this is a potential area with a high risk of water burst into the longwall. Until nowthis mine has not yet given a specific solution to this problem. Finding a reasonable mining solution to ensure production safety and reduce resources loss is extremely important problem not only for the Mong Duong coal mine but also for mines that have similar mining conditions of Vietnam National Coal – Mineral Industries Holding Limited (Vinacomin), Vietnam.