Surface Mining

1. OPEN PIT MINING
KHALEEQ AHMED
1 1PWMIN0644
7TH SEMESTER
MINING ENGINEERING
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2. Contents:
Introduction
Sequence of Development
Cycle of Operation
Auxiliary Operations
Conditions
Advantages
Disadvantages
References
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3. Introduction
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In open pit mining :
 Any overburden is stripped and transported to a disposal area to
uncover the mineral deposit
 Both stripping and mining are from one or a sequence of
benches
 Open-pit mines are used when deposits are found near the
surface
 Open pit mining is large scale method in term of production
rate
 Responsible for 60% of all surface outputs

4. Introduction(cont.)
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5. Sequence of Development
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Major steps in the development are:
 Land clearance
 Location of surface plant
 Location of waste dump
 Equipment selection
 Haul Road
 Establishment of first bench

6. Sequence of Development (cont.)
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7. Cycle of Operation
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The nature of overburden or waste and the ore to be mine
determines the cycle of operation
The stripping and mining cycle of operation consist of the
following:
 Drilling
 Blasting
 Excavation
 Haulage

8. Cycle of Operation (cont.)
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Drilling
 Auger for weak rock
 Roller bit for average rock
 Percussion for very hard rock

9. Cycle of Operation(cont.)
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Blasting
 ANFO or slurry for soil or weak rock
 WABOX or Dynamite for hard rock

10. Cycle of Operation(cont.)
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Excavation
 Power shovel
 Front-end loader
 Dozer
 Scrapers(soil)
 Dragline
 Bucket wheel(soil)

11. Cycle of Operation(cont.)
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Scraper
Front-end Loader
Drag line Power Shovel

12. Cycle of Operation(cont.)
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Haulage
 Truck
 Belt
 Conveyor
 Rail

13. Cycle of Operation(cont.)
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14. Auxiliary Operations
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Health and Safety
Environmental Control
Ground Control
Power Supply
Water Disposal
Material Supply
Maintenance
Rehabilitation

15. Conditions
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Ore Strength: Any
Rock Strength: Any
Deposit Shape: any but preferably tabular
Deposit Dip: any but preferably low
Deposit Size: Large, Thick
Ore Grade: can be very low
Ore Uniformity: uniform, variable
Depth: Shallow to intermediate

16. Advantages
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High Productivity
Lowest Cost
High Production Rate
Early Production
Low labor requirement
Good recovery
Good health and safety

17. Disadvantages
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High Capital investment
Surface damaged
Require large Deposit
Weather detrimental
Slope stability
Waste Disposal