List of top Mine Planning Questions

A double-ended ranging drum (DERD) shearer uni-directionally cuts coal in a longwall panel having the following details:
Shearer drum diameter = 1.4 m
Panel dimension = 1200 m × 200 m × 2.4 m
Web depth = 0.6 m
Average cutting speed = 5 m/minute
Average retreating speed = 10 m/minute
Average operational delay between cuts is 2 hour. There are two production shifts, each of 8 hour duration. The number of days required for complete extraction of the panel is:

The information of a mining project for a life of three years is given below:

Additional data: Applicable tax rate = 30%
Discount rate = 10%
Depreciation method: Straight line with zero salvage value

Data from a borehole log with collar elevation at 590 mRL are given below. Composite grade is calculated using cores of 5 m above and below the reference bench at 580 mRL. The composite grade, in %, is:

A longwall panel is to be developed in a flat seam at a depth of \( H \) m. The surface subsidence profile (\( s \)) of the area with the horizontal distance \( x \) is estimated as \[ s = \frac{S_{{max}}}{2} \left[ 1.002 - \tanh \left( \frac{4.8x}{H} \right) \right], \] where \( S_{{max}} \) is the maximum subsidence at the centre of the panel, \( x \) is measured from the inflection point. The value of \( x \) is negative towards the panel centre and positive towards the panel boundary. The ratio between the critical width of the panel and the depth is:

A 2.5 tonne diesel locomotive hauls 5 mine cars upslope having a gradient of 1 in 20. The constant tractive force of the locomotive is 1800 kN. The gross weight of a car is 3 tonne. Acceleration due to gravity is 10.0 m/s\(^2\). If the acceleration of the system is 0.5 m/s\(^2\), the rolling resistance in kN/tonne is ________ (rounded off to 3 decimal places).

A direct rope haulage has the following details:
Output = 24 tonne/hour,
Length of trip = 610 m,
Gradient = 1 in 12,
Capacity of mine car = 1.0 tonne,
Tare weight of mine car = 0.5 tonne,
Average rope speed = 1.694 m/s,
Change over time of cars = 3 minutes,
Acceleration due to gravity = 10.0 m/s².
Neglecting all frictional resistance and mass of the rope, the minimum power required, in kW, to raise the loaded mine cars is:

In a sublevel stope, a ringhole blast round is designed for winning 2500 tonne of ore with 8.0% metal content. The blast results into breakage of 90.0% of the design blast round. Overbreak of 250 tonne wallrock with 0.5% metal content dilutes the blasted ore. The total metal content, in tonne, considering 95% recovery of the blasted muck from the stope, is:

A continuous miner serves two shuttle cars of 12 tonne capacity each. Shuttle cars I and II operate with a total cycle time of 12 minutes and 15 minutes respectively, which includes loading time of 8 minutes for each car. The production rate of the continuous miner, in tonne/hour, is:

Following information are given for three mines of a company receiving explosives from three suppliers.

Considering the initial basic feasible solution of this transportation problem, using North-West corner method, the transportation cost of explosives supplied to the company, in Rs., is

Match the type of deposit with the corresponding process of formation:

The relevant information on metal extraction from a copper mine are given below: Selling price of copper (Rs./kg) = 900
Mining cost (Rs./tonne of ore) = 500
Processing cost (Rs./tonne of ore) = 2000
Overall recovery of copper metal (%) = 70
Ignoring all other costs, the breakeven cutoff grade of copper, in %, is:

If the in-situ density of coal is 1320 kg/m\(^3\) and the density of blasted coal is 952 kg/m\(^3\), the swell factor is:

In a bord and pillar panel, the following data are obtained:
Number of blasting rounds per shift: 8
Face dimension (m × m): 4.2 × 2.5
Average pull (m): 1.2
Specific gravity of coal: 1.4
Manpower per shift: 100
The OMS (output per manshift) of the panel, in tonne, is __________ (rounded off to 2 decimal places)}