Mining Methods and Machinery · Mining Methods · 2 marks · Numerical answer
A bord-and-pillar panel has24 pillars of40×40 m centre-to-centre spacing,4 m galleries and3 m extraction height. Coal specific gravity is1.4 and depillaring recovers80%. Incubation is6 months of25 working days each. Find minimum production in tonne/day to one decimal.
The remaining pillar side is40−4=36 m. Recoverable pillar coal is24×36²×3×1.4×0.8=104509.44 tonnes. Available time is6×25=150 working days. Required average production is104509.44/150=696.7296 tonne/day, or696.7. The gallery coal has already been removed during development.
More Mining Methods questions
GATE 2025 MN Q12– A steeply dipping metalliferous deposit is not susceptible to spontaneous heating. Broken…
GATE 2025 MN Q33– A bord-and-pillar panel has8 blasting rounds per shift, face4.2×2.5 m, average pull1.2 m,…
GATE 2025 MN Q34– In-situ coal density is1320 kg/m³ and blasted coal density952 kg/m³. Find the swell factor…