Innovations of Concurrent Mining and Reclamation for Underground Coal Mines in China

Coal is the most important energy in China, accounting for about 70% of energy consumption. More than 85% of total coal output comes from underground mining Land subsidence due to underground coal mining is a serious problem in China Based on the introduction of the impact of coal mining subsidence on environment, some Innovations of concurrent mining and reclamation (CMR) for underground coal mines in China were presented. Farmland and infrastructure damage due to coal mining are the most important impact in Eastern China Because of high groundwater lever, a lot of farmland and infrastructure were subsided in water, which lost farmland productivity and destroy infrastructure permanently. Traditional subsidence land reclamation used to restore the subsided land after its subsidence completely, which leads to a low percentage of farmland reclamation and a lot of troubles of infrastructure restoration. Three kinds of innovations of concurrent mining and reclamation were developed for solving the problems of subsidence land reclamation in China The first innovation is a new non-filling technique of concurrent mining and reclamation, which could increase about 10%similar to 40% of reclaimed farmland comparing traditional reclamation methods. The keys of the technique include optimization of reclamation time, layout planning, and elevation design considering subsequent and residual subsidence. The second innovation is filling technique of concurrent mining and reclamation by use of Yellow river sediments, which could increase the percentage of reclaimed farmland to more than 90%. The keys of the technique include position and method taking sediments from Yellow river, sediments transportation, and filling, drainage, soil reconstruction and restoration for high quality farmland. The third innovation is infrastructure restoration based on CMR, which includes reservoir, dam, and village restoration. Some case studies of these innovations were also introduced, which showed that these CMR innovation techniques are very high efficiency in farmland and infrastructure restoration and cost saving.