🔹 1. Introduction

Surface mining refers to the extraction of mineral deposits lying close to the earth’s surface, where overburden can be removed economically.
This is the most widely used mining method globally, especially for:

• Coal
  
• Iron ore
  
• Bauxite
  
• Limestone
  
• Copper
  
• Gold
  
• Building stones and aggregates
  

Surface mining is preferred when the ratio of overburden to ore is low and the deposit is near-horizontal and extensive.DGMS plays a major role in monitoring surface mining operations under Mines Act and Coal Mines Regulations (CMR 2017).
🔹 2. Principles of Surface Mining

Surface mining is based on the following fundamentals:
2.1 Economical Removal of Overburden

Mining is feasible only when:Stripping Ratio (SR)=Volume of OverburdenVolume of Ore≤Economic Limit\text{Stripping Ratio (SR)} = \frac{\text{Volume of Overburden}}{\text{Volume of Ore}} \leq \text{Economic Limit}Stripping Ratio (SR)=Volume of OreVolume of Overburden ≤Economic Limit
2.2 Sequential Unit Operations

Surface mining comprises the following steps:

1. Topsoil removal & reclamation
   
2. Drilling & blasting
   
3. Overburden excavation
   
4. Loading (shovel/excavator/front-end loader)
   
5. Haulage (trucks/rail/belt conveyor)
   
6. Dumping & waste management
   
7. Ore extraction
   
8. Rehabilitation & reclamation
   

2.3 Bench Method of Mining

Mining is carried out in benches (steps) to maintain stability and safety.Bench Height: 8–15 m

Bench Width: 3 × bench height

Bench Slope: 60°–70° depending on rock

2.4 High Production with Heavy Equipment

Large machines like:

• 20–42 m³ electric rope shovels
  
• 120–240 T dumpers
  
• Draglines
  
• Bucket wheel excavator senable huge output.

2.5 Safety Standards

DGMS prescribes:

• Safe bench angles
  
• Haul road gradients
  
• Blasting safety radius
  
• Dump slope stability norms
  
• Visibility & signaling guidelines
  

🔹 3. Types of Surface Mining

3.1 Open-Pit Mining

Used for metal ores, deep surface deposits.

3.2 Opencast Mining

Used for coal & sedimentary ores.

3.3 Strip Mining

For layered deposits.

3.4 Quarrying

Used for building stones and aggregates.

3.5 Placer Mining

Extraction of alluvium from riverbeds (gold, tin).

🔹 4. Advantages of Surface Mining

✔ High production and productivity
✔ Low cost per tonne
✔ Easy mechanization
✔ Safer than underground mining
✔ Better working environment
✔ Easy access to deposit
✔ Lower manpower requirement
✔ Higher recovery of minerals
✔ Simpler ventilation requirements
✔ Quick development time
🔹 5. Limitations of Surface Mining

✘ High stripping ratio for deep deposits
✘ Large environmental impact
✘ High land requirement
✘ Noise and dust hazards
✘ Restricted to shallow deposits
✘ Bench stability issues
✘ Weather dependency
✘ Requires long-term rehabilitation
🔹 6. Diagrams (Text Format)Typical Bench Layout:
┌────────── Haul Road ──────────┐ | |______|_______________________________|____ Ground Surface \ / \ / \ Ore Bench / \_____________________/
Unit Operations Flow:
Drilling → Blasting → Loading → Haulage → Dumping → Reclamation

🔹 7. Factors Affecting Surface Mining Selection

• Depth of deposit
  
• Grade and size of ore body
  
• Overburden characteristics
  
• Climate conditions
  
• Equipment availability
  
• Environmental regulations
  
• DGMS statutory restrictions
  

🔹 8. 25 MCQs with 5 Options + Answers (DGMS Pattern)
1) Surface mining is suitable when deposits are —

a) Very deep
b) Steeply dipping
c) Near the surface
d) Under ocean
e) Irregular
Answer: c
2) Stripping ratio is defined as —

a) Ore per tonne
b) OB volume / Ore volume
c) Ore weight / OB
d) Bench height × width
e) None
Answer: b
3) Overburden refers to —

a) Ore
b) Material above ore body
c) Shale layer
d) Loading tools
e) Explosives
Answer: b
4) A major unit operation in surface mining is —a) Ventilation
b) Support system
c) Drilling & blasting
d) Roof bolting
e) Timbering
Answer: c
5) Bench height for most open pits is —

a) 2–5 m
b) 5–8 m
c) 8–15 m
d) 20–30 m
e) 40–50 m
Answer: c
6) Draglines are used mainly in —

a) Underground
b) Opencast coal mines
c) Placer mines
d) Quarries
e) None
Answer: b
7) Haul road gradient for heavy trucks is generally —

a) 2%
b) 4%
c) 8–10%
d) 15%
e) 25%
Answer: c
8) Quarrying is used for —

a) Coal
b) Gold
c) Iron ore
d) Stone & aggregates
e) Uranium
Answer: d
9) Strip mining is preferred for —

a) Igneous ore
b) Volcanic ore
c) Layered deposits
d) Massive ore bodies
e) None
Answer: c
10) Which equipment offers highest productivity?

a) Backhoe
b) Hydraulic shovel
c) Electric rope shovel
d) Dozer
e) Crane
Answer: c
11) In surface mining, blasting is mainly to —

a) Remove soil
b) Clean benches
c) Fragment rock
d) Stabilize slope
e) Move trucks
Answer: c
12) Surface mining is economical when SR is —a) High
b) Low
c) Infinite
d) Zero
e) Negative
Answer: b
13) A disadvantage of surface mining is —

a) High ventilation cost
b) Supports needed
c) Environmental impact
d) Heat hazard
e) Gas ignition
Answer: c
14) Bucket-wheel excavators are used in —

a) Hard rock
b) Lignite & soft materials
c) Granite
d) Basalt
e) Iron ore
Answer: b
15) Final slope angle depends on —

a) Drill spacing
b) Loader bucket size
c) Rock strength
d) Truck gradient
e) Explosive type
Answer: c
16) Topsoil thickness is usually —

a) 10 cm
b) 30 cm
c) 0.5–1.0 m
d) 3–5 m
e) None
Answer: c
17) Main environmental issue in opencast mining —

a) Low grade
b) Dust & noise
c) High humidity
d) Low temperature
e) Ventilation
Answer: b
18) Bench width is usually —

a) Equal to bench height
b) 3 × bench height
c) 1/2 bench height
d) Only 2 m
e) None
Answer: b
19) Dragline is used mainly for —

a) Ore loading
b) Road construction
c) OB removal
d) Coal sizing
e) Shot firing
Answer: c
20) Placer mining is associated with —

a) Granite
b) Copper
c) Limestone
d) Gold
e) Coal
Answer: d
21) Surface mining productivity depends on —a) Rainfall
b) Blast furnace
c) Equipment size
d) Ventilation
e) Explosive cost
Answer: c
22) Haul road width depends on —

a) Bench width
b) Burden
c) Truck size
d) Explosive density
e) None
Answer: c
23) Slope failure causes —

a) High tonnage
b) Better blasting
c) Production loss
d) Coal washing
e) None
Answer: c
24) The first step in surface mining is —

a) Drilling
b) Exploding
c) Loading
d) Topsoil removal
e) Dumping
Answer: d
25) Surface mining is preferred for —

a) Very deep seams
b) Highly gassy seams
c) Irregular narrow veins
d) Shallow thick deposits
e) None
Answer: d
                                🔚 Conclusion

Surface mining is the backbone of modern mining operations due to its higher productivity, mechanization, and safety.
However, environmental management, slope stability, and proper planning are essential for sustainable operations.

 Download more DGMS Surface Mining Notes at OnlineMiningExam.com
🔔 Join our Telegram for daily MCQs, video explanations & mining updates