This document discusses various coal mining methods, including opencast and underground mining. For opencast mining, the main methods described are shovel and dumper, dragline, surface miner, and bucket wheel excavator. Underground mining methods discussed include continuous miners, longwall mining, and road headers. New concepts being implemented in India such as highwall mining, punch longwall mining, and longwall top coal caving are also summarized. The document provides diagrams and descriptions of the equipment used for different mining methods.

1. Mining Methods
5th December 2008
VENKAT M.
PlotMaker
Team Lead – Minex, INDIA

3. Mining Methods
• Coal is mined by two main methods - surface
or ‘opencast’ mining and ‘underground’
mining.
• The choice of method is largely determined by
the depth, geology of the coal deposit and
other factors.
• The majority of the world's coal production is
coming from Opencast mines.
• This scenario is same in India also.

4. Mining Process OPENCAST
Drilling Drill machines (rotary/percussive)
| |
Blasting SMS, emulsion, Primer, Nonel, etc
| |
Loading Shovels, Draglines, etc
| |
Hauling Front-end loader, etc
| |
Transporting Dumpers, Conveyors, etc
| |
Processing/Washing Coal washeries…

5. Mining Process OPENCAST
Drilling
|
Blasting
|
Loading
| DRAG LINE
Hauling
|
Transporting
|
Processing/Washing

6. Mining Process OPENCAST
Drilling
SURFACE MINER
|
Blasting
|
Loading
|
Hauling
|
Transporting
|
Processing/Washing

7. Mining Process OPENCAST
Drilling
|
Blasting
|
Loading
IN-PIT CRUSHING &
| CONVEYING
Hauling
|
Transporting
|
Processing/Washing

8. Mining Process UNDERGROUND
Drilling Coal drill
| |
Blasting Permitted explosives
Supporting | |
Ventilation Loading Manual/ SDL/ LHD/Scraper
Pumping
| |
Hauling Manual/ SDL/ LHD/Scraper
| |
Transporting Tubs, Conveyors, etc
| |
Processing/Washing Coal washeries…

9. Mining Process UNDERGROUND
Drilling
ROAD HEADERS
| CONTINUOUS MINERS
Blasting
|
Loading
|
Hauling
|
Transporting
|
Processing/Washing

10. Mining Process UNDERGROUND
Drilling
|
Blasting
|
Loading
| SDL/ LHD/
Hauling SCRAPER
|
Transporting
|
Processing/Washing

11. Mining Process UNDERGROUND
Drilling
|
Blasting
|
Loading LONGWALL
|
Hauling
|
Transporting
|
Processing/Washing

12. Selection of Mining Equipment
• Stripping Ratio – in case of Opencast.
• Life of the mine
• Infrastructure available
• Proposed annual output
• Technology available

13. OPENCAST
MINING

14. Different OC Machinery
1. Shovel + Dumper
2. Dragline
3. Surface Miner
4. Bucket Wheel Excavator
5. In-pit crushing + Spreader

15. Schematic diagram of Opencast

16. Heavy blasting in open cast benches

17. Shovel + Dumper
1. Multi seam extraction
2. More flexibility
3. Can work in steep gradients upto 1 in 5

18. Shovel + Dumper

19. Rope Shovel and Dumper

20. Hydraulic Shovel and Dumper

21. Surface Miner
1. Selective mining.
2. Particularly suitable for coal having
compressive strength below 250 kg/cm2.
3. Suitable in gradient of 1 in 10 and flatter.

22. Surface Miner

23. Surface Miner

24. Bucket wheel excavator
1. Used mainly for lignite extraction.
2. Particularly suitable for coal having low
compressive strength upto 100 kg/cm2.

25. Bucket wheel excavator

32. DRAGLINE
1. Gradients flatter than 1 in 6.
2. Seams should be free of faults & other
geological disturbances.
3. Deposits with Major Strike length.
4. A hilly property is not suitable.
5. Deposit should have atleast 15 years life.

33. DRAGLINE

35. Giant Dragline bucket

36. In-pit crusher conveyor technology

37. In-pit crusher conveyor technology

38. In-pit crusher conveyor technology

39. UNDERGROUND MINING

40. Incline entry into a seam.

41. Entry through a shaft

42. Entry
through a
shaft

43. Man riding systems in the mines

44. A well supported underground roadway

45. Coal train - 1919, Pennsylvania

46. Drilling operation in the coal face

47. MANUAL COAL LOADING

48. LOAD HAUL DUMPER
Capacity – 2/2.7 Cu.M
Production – 150/200 Tonnes/day
For seams of 1 in 6 gradient and flatter
Thickness of 2.0 m to 4.0 m

49. SIDE DUMP LOADER
Capacity – 1.0 Cu.M
Production – 120 Tonnes/day
For seams of 1 in 5 gradient and flatter
Thickness of 2.0 m to 3.5 m

50. MECHANISED DRIVAGE MACHINES
Rate of drivage –6 meters/day
Production –150 Tonnes/day
For seams of 1 in 4 gradient and flatter
Thickness of 2.0 m to 4.0 m

51. Continuous Miner
Rate of drivage –50 meters/day
Production –1500 Tonnes/day
For seams of 1 in 5 gradient and flatter
Thickness of 3.0 m to 4.0 m

52. Mechanised Roof Bolter
Bolting -240 bolts/day
For seams of 1 in 5 gradient and flatter
Thickness of 2.0 m to 5.0 m

53. LONGWALL GENERAL LAYOUT
TOP Gate
FACE
Dip direction
Bottom
Gate
- Longwall mining method includes drivage of two long roadways in coal and joining them
at the end by a perpendicular drivage forming a face.

54. LONGWALL MINING

55. SHEARER WORKING AT LONGWALL FACE

56. SHEARER WORKING AT LONGWALL FACE

57. POWERED ROOF SUPPORT AT LONGWALL FACE

58. LONGWALL MAIN GATE

59. NEW CONCEPTS
(Going to be implemented in INDIA)

60. Highwall Mining
Bench Mining
Trench Mining

61. Highwall Mining

62. Highwall Mining

63. Punch Longwall

64. Punch Longwall
Advantages
• Step change in cost and productivity
• More production capacity
• High productivity & low cost
• Longer term and higher % of reserves extraction
• Easy logistics – near surface
• High gate road development rates feasible
• Higher and faster returns on investment
• Total investment ~ $100 million – compared with > $300
millions UG

65. Punch Longwall

66. Punch Longwall

67. Erection of Arches

68. Erection of Arches

69. Meshing & Lagging with special sleepers

71. Punch Longwall

72. Longwall Top Coal Caving (LTCC)
Technical Principle Of Top Caving
Rock stress 1st pressure Low stress Stress 2nd pressure Compact
peak abrupt drop peak stress
Pressure curve of top coalseam
Fracture
Virgin
5600
Coal Broken Coal
coal goaf
caving
2800
Working
Height
Front AFC Rear AFC
back

73. Longwall Top Coal Caving (LTCC)

74. PED schematic operation
Antenna
(Surface or
Underground)
Link Data Link
PC for Modulator Transmitter
entering Ultra Low Frequency Transmission
messages. Through Rock
PED Receivers can be:
• BeltPED Personal Receiver (shown)
• AutoPED Vehicle Receiver
• ControlPED for Equipment Switching
• BlastPED for Remote Blast Initiation

75. PED receiver cap lamps

77. Questions…
Please

78. VENKAT M.
TL-Minex-INDIA