This document provides an overview of open-pit mining basics. It discusses that open-pit mining, also called surface mining, extracts ore or minerals from the ground without tunneling underground. The document outlines the two main types of mining as surface mining and subsurface mining. It also provides details on open-pit mining methods, factors for selecting mining methods, advantages and disadvantages of open-pit mining, and the key operations involved in open-pit mining.

1. BASICS OF OPENPIT MINING
I. Satyanarayana,
M.Tech,MBA,MCA
Dy. Manager, Project Planning, SCCL,
isnindian@gmail.com,
visit at
www.slideshare.net/isnindian
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3. • Mining is extracting
ore or minerals from
the ground
• An ore is a natural
material with a high
concentration of
economically valuable
minerals that can be
mined for a profit
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4. • There are two main types of mines.
1) Surface Mining
2) Subsurface Mining
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5. STATUS OF OPEN PIT MINING
Production: 2009-10
SCCL
• Underground------------ 11.97 MT (36 Mines)
• Opencast----------------- 38.45 MT (14 Mines)
• Over Burden------------ 248 M.Cum
CIL
• 473 mines owned:
• – 279 UG
• – 163 OC
• – 31 Mixed
• Production in 2009-10 was 388MT from OC and 43MT from
UG
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6. Mining Methods (Mode of Entry
Shaft Mine Incline Mine
Incline
Excavator
Adit Mine Opencast Mine
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7. MINING METHODS
COAL MINING
METHODS
UNDER GROUND OPENCAST SPECIAL MINING
Methods Methods Methods
Hydraulic
Gassification
Mining
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8. What is Opencast Mining
• Opencast mining is also known as Open pit mining, Open cut
Mining, Surface or Strip Mining.
• The coal upto economical depth will be excavated by OC Method.
• The current operating depth of OC mines in SCCL is about 200m and
SCCL proposed to operate OC mines upto a depth of 420m. Ex: MNG
OC II Extension Project.
• The overburden and the Coal are excavated in long strips of a few
meters thickness.
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9. SURFACE MINING
• Based on System of Mining
– Continuous & Discontinuous
• Based on Mechansiation
– Manual & Mechanised
• Based on method and nature of mining:
1. Open-pit: Reclamation after completion
2. Open-Cast: Reclamation during mining
3. Quarries: stone, crushed rock, sand, gravel
4. Strip Mining: removing surface coal in strips up to 50 m
wide x 1 Km long
5. Placer Mining
6. Glory hole Mining
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10. MECHANISED OPENCAST METHODS
OPENCAST
Methods
SHOVEL DUMPER SHOVEL DUMPER Inpit Crussing SURFACE BUCKET WHEEL HIGH WALL
COMBINATION Combination and MINER EXCAVATOR MINING
with Conveyor
DRAGLINE Technology
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11. SELECTION OF METHOD OF MINING
I. Physical Factors
a) Geological Disturbances
b) Mineable Reserves.
c) Area of Excavation ( Extensiveness )
d) Depth of mining.
e) Gradient of the Seam.
f) Thickness of the Seam & No.of seams.
g) Gassiness of the seam.
h) Proness to Spontaneous heating.
i) Strata of the seam / Seams.
j) Hydro - geological conditions.
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12. II. Techno-Economical Factors
1. Stripping Ratio
2. Availability of technology / Machinery.
3. Availability of technical Skill ( HRD )
4. Capital investment.
5. Demand of Coal
6. Network of power lines, roads & railway
lines, water supply lines, railway sidings
7. Townships
8. Coal handling plants
9. Workshops
10.Life of the mine (optimum 25 years)
11.Work Culture
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13. III. SOCIO ECONOMIC CONSIDERATIONS
1. Socio economic status of the area
2. Requirement of land(Pvt, Govt, Forest
etc.,)
3. R&R consideration
4. Environmental issues
5. Archaeological constructions
6. Bio reserves
7. EMP Clearance from.
* APSPCB , MOEF, Ministry of Forestry
* Requires public clearance also
8.Government policies
* IRR ( 12% )
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14. Ideal conditions (Suitability) for Opencast Mining
1. Thickness of coal seams- > 5m
2. Flat gradient - < 1 in 6
3. Strike length - > 1 km
4. No.of seams - Less the better,
with higher thickness
5. Coal without stone bands
6. Free from surface structures / features.
7. Preferably non-forest land.
8. Availability of adequate place for dumping.
9. Stripping ratio depending on quality of the coal
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15. Advantages of opencast mining
There is no problem of ventilation
There is no problem of Roof control, supports
There is no problem of lighting in daytime.
Percentage of coal extraction is much higher (about
90%) than that of Underground mining (30-60%)
High OMS
Much productivity / profits.
Quick returns on capital investment.
Dangers & Hazards are less compare to U/G Mines.
There is no risk of gas explosion.
Large-scale mechanisation is possible.
Gestation period is less
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16. Disadvantages of opencast mining
•Work is affected by weather.
•Land degradation by mining.
•Deforestation.
•Pollution( water, Air, Land, Noise ).
•The method is uneconomic for workings
Deeper Depths, cities and under sea/rivers.
•The quarried area and OB dump heaps
present an unpleasant sight.
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17. FINAL PIT LAYOUT
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18. TERMINOLOGY
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19. STRIPPING RATIO
AMOUNT OF OVERBURDEN REMOVED IN MINING A UNIT OF
MINERAL
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21. OPEN PIT MINE
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24. OPERATIONS IN OPM
• LEVELLING BY DOZING
• DRILLING.
• BLASTING
• REMOVAL OF OVERBURDEN
• DUMPING, BACK FILLING,
RECLAMATION
• EXTRACTION OF COAL
• TRANSPORTING to (CHP, CSP, FLOOD
LOADING SYSTEM, Rapid loading etc.,)
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25. OPERATIONS IN OPM
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26. Thank you all,
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