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More Mining Engineering Questions
The altered forms of pre-existing rocks which might have been ignious or sedimentary.
Air samples collected from the intake and the return gates of a retreating longwall face show methane concentration values of 0.1% and 0.8% respectively. The production from the longwall face is 2000 tonne/day and the air quantity circulating the face is 15 m 3 /s. The rate of methane emission in m 3 per tonne of coal produced is
Geo phone suitable for detecting frequencies in the range of . . . . . . . .
For reducing leakage in u/g workings it has been recommended to use.
A single lamp placed centrally at the roof provides 40 lux illumination vertically below, at the floor of an underground workshop. The workshop of dimensions 20 m × 20 m with height 4m. Assuming uniform spherical dispersion of luminous intensity, the floor level illumination in lux at any corner of the workshop is