1. When the occurrence of mineral (e.g. rare minerals) is randomly distributed in a rock then which of the distribution pattern is statistically followed?
2. Which of the following combination of SDL based mining is expected to give best production and productivity of SDL?
3. It is very difficult to control shaley roof if coal is not left with the shale why?
4. In connection with lowering or raising of persons by means of bucket etc. for a shaft exceeding "A" m in depth, there shall be significant cover overhead for protection from things falling down the shaft. A is given by
5. Match the following:
Access
Haulage
Mineralisation
P Shaft
1. Track
a. Moderate depth
Q Decline
2. Trackless
b. Deep seated
R Adit
3. Hoisting
c. Hillock
| Access | Haulage | Mineralisation |
| P Shaft | 1. Track | a. Moderate depth |
| Q Decline | 2. Trackless | b. Deep seated |
| R Adit | 3. Hoisting | c. Hillock |
6. In a mine deploying shovel and dumper, the distance from the crest of the bench to the centre of the dumper including safety berm and clearance is 7.5m, the dumping radius and the cutting radii of the shovel are 15m and 12m respectively. The width of the working bench of the mine in m is
7. In a room-and-pillar stope, bench blasting is conducted using ANFO having density of 800 kg/m3. The specific gravity of rock is 2.5, hole diameter is 100 mm and spacing to burden ratio is 1.3. The charge length of each blast hole is 80% of the hole length. For a desired powder factor of 0.48 kg/tonne, the spacing and burden of the blast pattern in m respectively are
8. A surface mine blast design has 9 holes in a row, each of 8m length and 200mm diameter. The spacing and burden are 6m and 5m respectively. The length of subgrade drilling is 1m and the density of in-situ rock is 2.43 t/m3. Considering an explosive density of 0.9 t/rn3 and stemming length of 2m, the powder factor from the blast in t/kg is
9. In a mine for one shovel six trucks are assigned. The shovel loading time per truck is 5 min, and truck cycle time 20 min. Calculate the match factor.
10. The following data are provided for a surface mine to be excavated by a shovel:
Production target: 10000 te/shift
Available hours per shift: 6 hrs
Shovel loading cycles per hour: 106
Bank density of the material mined: 2400 kg/m3
Swing factor at 120° swing: 0.91
Bucket fill factor : 0.64
Utilization of available time: 83%
No of working days in a year : 300
No of shifts per day : 3
The size of bucket of the shovel in m3 is
Production target: 10000 te/shift
Available hours per shift: 6 hrs
Shovel loading cycles per hour: 106
Bank density of the material mined: 2400 kg/m3
Swing factor at 120° swing: 0.91
Bucket fill factor : 0.64
Utilization of available time: 83%
No of working days in a year : 300
No of shifts per day : 3
The size of bucket of the shovel in m3 is