Executive Summary : | India is a third largest coal producer in world after China and USA and the country is still dependence on the thermal electricity generation. The coal base power generation capacity may increase more than 330-441 GW by 2040 which requires the coal demand of 1.1 – 1.4 billion tones. In order to meet the demand of the coal, the country needs to adopt the mass mining technologies for extraction of coal seams from deeper depths as shallow depth coal seams almost been extracted. Longwall and continuous miner are the two emerging technologies available for deeper deposits. The longwall method ensures the high production rate (above 90%), productivity and safety, also requires large investment for procuring the equipment and running cost is also more. Continuous miner is the only the viable technology with less investment, high production (above 70%) and more safety. The continuous miner technology is being used for depillaring operation and not for the development. However, these pillars are formed by driving the level and dip galleries using conventional drilling and blasting techniques. The entire virgin patch of the coal seams is being disturbed, the pillars experiences high stress concentration and causes the failure of pillars corner and the reduction of pillars size occurs slowly. During the depillaring operation, the ribs and snooks are formed and attracts high stress concentration. Finally, the strength of the ribs and snook deteriorates which may tend to yield of ribs during the extraction and causes the trapping of continuous miner, loss of production, loss of miners and requires involvement of rescue and recovery works. In the view of this, a novel method is proposed to exploit the deep coal seams with high productivity and safety using continuous miner machine. This method ensures the production rate above 80% with better safety. The design and analysis of workings of existing continuous miner method and innovative method will be performed by varying various input parameters using numerical modelling. The roof monitoring devices such as telescopic convergence and stress cells will be installed in the continuous miner workings and load development on the barrier pillar due to front and side abutment will be monitored. The numerical models will be developed for existing continuous miner system and the results of the numerical analysis will be verified with field data. An extensive finite element models will also be developed based on innovative mining method by varying the mining depth, panel size, yield pillar and abutment pillar. The optimum size of the panel, yield pillar, abutment pillar and barrier will be obtained. Also, new support system will be developed to support the wide galleries created in innovative mining concept. Finally, this study will be performed for safe exploitation of coal seams with high productivity. |