Application and Development on Coal Mine Backfill Mining Technologies in China

The rapid development of backfill mining technologies were reviewed in Chinese coal mines from the 2002 to 2012 in Chinese coal mines. Some field engineering applications were introduced, the main data was collected from 27 typical backfill mining working face, including geology survey, mining setting, backfill material, technique system and monitoring effects etc. The main technologies include roadway gangue backfilling, conventional gangue backfilling, fully-mechanized gangue compacting backfilling, pneumatic backfilling, paste or paste-like backfilling, slurry or slurry-like backfilling etc. Roadway backfilling is suitable to protect the important buildings. Pneumatic backfilling, conventional mining backfilling, fully-mechanized mining compacting backfilling, paste or paste-like backfilling are suitable for the large regional operations to protect the general or important buildings and structures. Slurry or slurry-like backfilling are suitable for the operations with the single thin coal seam or the lack of backfilling materials. Some backfill indexes, including capital investment, backfill capacity, production, backfill cost per ton, mechanized level, system stability, backfill deformation, surface subsidence coefficient etc. were used to evaluate field engineering application effects. Ground subsidence software was developed to predict the ground movement parameters by Shandong University of Science and Technology based on field measured data. The future backfill development direction of backfill technology was analyzed. The paper provided an important reference, which will have an significance to promote and use the backfill mining technologies.