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زمینشناسی و معدن::
روش استخراج جبهه کار بلند
For individual extraction methods an indicator of preparations can be determine on example of short pillar method and longwall method in the east section ol seam 25 in the level of TN 9 tunnel.
Total length of preparation for the longwall method directive road 250 m
The same indicator for the longwall method is 34 m / 1000 t
Regarding the assumption that a 250 m long section will be interrupted by 1-2 faults on average, which will move the seam by a larger distance then its thickness, it is necessary to add to the coefficient of preparation by 6 m / 1000 t for the longwall method and 8m/ 1000 t for the short pillar method.
♦ Solid coal seams are suitable for mining by the longwall method. 1 he seam thickness determines the number ol mining benches - max. one bench thickness is 2.2 m.
واژگان شبکه مترجمین ایران