Surface mining entry system

4. Opencast mine Entry system
• When a ore body is worked an approach road is always required to reach the ore
body. Such approach road is known as entry system
Types of entry system
1.Single entry system
a. Single entry system at on end
b. Single central entry system
2. Double entry system
a. Two end entrance with single working face
b. Two end entrance with two working face
c. Two end entrance use once at a time
3.Triple entry system
4.Spiral entry system
5.Shunt back or switch back entry system

5. Single entry system
Located at one side of the pit
Suitability conditions
a. Short pit length up to 800-1000m
b. Low to medium production
c. Small pit
types
a. Single entry system at on end
b. Single central entry system
• If the length of the pit is more than 1000 m Single central entry system is preferred since
it minimizes the distance of haul of the mineral with in pit and hence cost of transportation
• a central entry virtually divides the pit into two blocks which can be worked alternately
using a single set of machines or simultaneously on either side of the entry with two sets of
machines

7. • Advantages of single entry system
1. Maintenance of single road only
2. Easy to maintain
3. Easy to check control of vehicle movements
4. Maintenance of supply of vehicle for overburden and ore can be
regulated
• Disadvantages
1. High rate of wear and tear of road
2. Regular maintenance of road
3. Incase of break down of single vehicle all transportation system will
come to halt
4. The proper account of vehicle can not be maintained
5. High traffic density

8. Double entry system
Located at both side of the pit
Suitability conditions
a. pit length up to 1500-2000m
b. Medium to high production
c. Medium size pit
types
1. Two end entrance with single working face
2. Two end entrance with two working face
3. Two end entrance use once at a time

10. • Advantages of double entry system
1. Limited number of vehicle on any one rout has less wear and tear of
road
2. Less interference of vehicle and vehicle density
3. Ore and overburden can handle separately
4. Incase of break down of single vehicle all transportation system will
not come to halt
5. The perfect record of vehicle movement can be record
6. Less road maintenance
7. Longer life of route
• Disadvantages
1. High cost of maintenance
2. Blockage of ore below the route

11. Triple entry system
Located one at both side and one in centre of the pit , multiple faces can be worked
Simultaneously worked with this system of transportation of mineral
Suitability conditions
a. pit length more than 2000m
b. Very high production
c. Large size size pit

14. Spiral entry system
Suitability conditions
a. Ore body on the top of hill
b. Deep pit

17. • Advantages of spiral entry system
1. The movement of vehicle is easy
2. The vehicle can carry more load
3. The movement of vehicle is well controlled by brakes
4. The speed of movement is comparatively high
5. Maintenance of single road only
6. Easy to maintain
7. Easy to check control of vehicle movements
8. Maintenance of supply of vehicle for overburden and ore can be regulated
• Disadvantages
1. Since the haul road runs along the periphery of the pit mining has to start from the pit
boundary and proceed downwards one bench at a time, leads to heavy investment in
removing overburden
2. High rate of wear and tear of road
3. Regular maintenance of road
4. Incase of break down of single vehicle all transportation system will come to halt
5. The proper account of vehicle can not be maintained
6. High traffic density
7. Longer haul length
8. Large width of road

18. Shunt back or switch back entry system• in still deeper pits It may not be possible to provide a separate track or road to each
bench from the main pit approach , since this may require too long a pit approach under such
conditions the switch back system of track layout may be adopted
Here the whole train has to shunt back and front on each bench In order to get down to the bottom
bench

22. Numbers of entry systems
Depends on
1. Length of the pit along strike
2. Mode of transportation
3. Desired production,
4. The requirement of separate routs for mineral and overburden transport,
5. Distance of haul, and cost of haulage
6. System of handling of overburden soil, rock and also handling of mineral,
7. Working of number of faces simultaneously,
8. Overall economy,

23. Location of entry system
1. Surface topography and nature of ground
2. Shape of mine
3. Length of mine along the strike
4. System of waste disposal and disposing site,
5. The required gradient of haulage system,
6. Depth of working
7. System of mineral and overburden handling,
8. Requirement of production,
9. Simultaneous working of number of faces in the mineral and overburden
benches,
10. Location of processing
11. No of working face plant and dump
12. Space avilable
13. Overall economy.