Mining Methods
5th December 2008


VENKAT M.
                           PlotMaker
Team Lead – Minex, INDIA
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.
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…
Mining Process          OPENCAST



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



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



      Drilling
         |
      Blasting
         |
      Loading
                     IN-PIT CRUSHING &
         |               CONVEYING
      Hauling
         |
   Transporting
         |
Processing/Washing
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…
Mining Process             UNDERGROUND



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



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



      Drilling
         |
      Blasting
         |
      Loading        LONGWALL
         |
      Hauling
         |
   Transporting
         |
Processing/Washing
Selection of Mining Equipment
•   Stripping Ratio – in case of Opencast.
•   Life of the mine
•   Infrastructure available
•   Proposed annual output
•   Technology available
OPENCAST
 MINING
Different OC Machinery

1.   Shovel + Dumper
2.   Dragline
3.   Surface Miner
4.   Bucket Wheel Excavator
5.   In-pit crushing + Spreader
Schematic diagram of Opencast
Heavy blasting in open cast benches
Shovel + Dumper

1. Multi seam extraction

2. More flexibility

3. Can work in steep gradients upto 1 in 5
Shovel + Dumper
Rope Shovel and Dumper
Hydraulic Shovel and Dumper
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.
Surface Miner
Surface Miner
Bucket wheel excavator

1. Used mainly for lignite extraction.

2. Particularly suitable for coal having low
   compressive strength upto 100 kg/cm2.
Bucket wheel excavator
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.
DRAGLINE
Giant Dragline bucket
In-pit crusher conveyor technology
In-pit crusher conveyor technology
In-pit crusher conveyor technology
UNDERGROUND MINING
Incline entry into a seam.
Entry through a shaft
Entry
through a
  shaft
Man riding systems in the mines
A well supported underground roadway
Coal train - 1919, Pennsylvania
Drilling operation in the coal face
MANUAL COAL LOADING
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
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
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
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
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
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.
LONGWALL MINING
SHEARER WORKING AT LONGWALL FACE
SHEARER WORKING AT LONGWALL FACE
POWERED ROOF SUPPORT AT LONGWALL FACE
LONGWALL MAIN GATE
NEW CONCEPTS
(Going to be implemented in INDIA)
Highwall Mining




                                  Bench Mining

Trench Mining
Highwall Mining
Highwall Mining
Punch Longwall
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
Punch Longwall
Punch Longwall
Erection of Arches
Erection of Arches
Meshing & Lagging with special sleepers
Punch Longwall
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
Longwall Top Coal Caving (LTCC)
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
PED receiver cap lamps
Questions…
  Please
VENKAT M.
TL-Minex-INDIA

Mining Methods