In 1991 the Mine Safety and Health Administration conducted a special program to assess occupational exposures to respirable coal mine dust in underground coal mines. Priority was given to longwall mining operations, mines with a history ofhaving a problem controlling dust to the applicable standard, and a representative number of all other mines. Measurements were obtained on approximately 720...

Abstract In recent decades, many open pit (OP) mines have either already made the decision or are at planning stage to change their mining activity from OP underground (UG) remain competitive. Technically, before ends its operation, both and UG will be operated simultaneously for a certain period of time. It is well known that operation causes subsidence, discontinuous deformations, changes in ...

Purpose. Coal mining activities by underground method will disrupt the equilibrium of surrounding rock mass. In mining, determining influence zone exploiting longwall on topographic surface is extremely important.Through analyzing displacement and deformation mass when 21103 in Seam 11 at Nui Beo Mine, to be determined this order forecast boundary that may affect works, ensuring safety such wor...