Mining Methods

PlotMaker

Mining Methods5th December 2008

VENKAT M.

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 andthe 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

Drilling

|

Blasting

|

Loading

|

Drill machines (rotary/percussive)

|SMS, emulsion, Primer, Nonel, etc

|Shovels, Draglines, etc

|

OPENCAST

|

Hauling

|

Transporting

|

Processing/Washing

|

Front-end loader, etc

|

Dumpers, Conveyors, etc

|

Coal washeries…

Mining Process

Drilling

|

Blasting

|

Loading

|

OPENCAST

|

Hauling

|

Transporting

|

Processing/Washing

DRAG LINE

Mining Process

Drilling

|

Blasting

|

Loading

|

SURFACE MINER

OPENCAST

|

Hauling

|

Transporting

|

Processing/Washing

Mining Process

Drilling

|

Blasting

|

Loading

|IN-PIT CRUSHING &

OPENCAST

|

Hauling

|

Transporting

|

Processing/Washing

IN-PIT CRUSHING &

CONVEYING

Mining Process

Drilling

|

Blasting

|

Loading

|

Coal drill

|Permitted explosives

|Manual/ SDL/ LHD/Scraper

|

UNDERGROUND

Supporting

Ventilation

Pumping |

Hauling

|

Transporting

|

Processing/Washing

|

Manual/ SDL/ LHD/Scraper

|

Tubs, Conveyors, etc

|

Coal washeries…

Pumping

Mining Process

Drilling

|

Blasting

|

Loading

|

ROAD HEADERS

CONTINUOUS MINERS

UNDERGROUND

|

Hauling

|

Transporting

|

Processing/Washing

Mining Process

Drilling

|

Blasting

|

Loading

| SDL/ LHD/

UNDERGROUND

|

Hauling

|

Transporting

|

Processing/Washing

SDL/ LHD/

SCRAPER

Mining Process

Drilling

|

Blasting

|

Loading

|LONGWALL

UNDERGROUND

|

Hauling

|

Transporting

|

Processing/Washing

LONGWALL

Selection of Mining Equipment

• Stripping Ratio – in case of Opencast.

• Life of the mine

• Infrastructure available

• Proposed annual output• Proposed annual output

• Technology available

OPENCAST

MININGMINING

Different OC Machinery

1. Shovel + Dumper

2. Dragline

3. Surface Miner

4. Bucket Wheel Excavator4. 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.4. A hilly property is not suitable.

5. Deposit should have atleast 15 years life.

DRAGLINE

Giant Dragline bucket

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



MECHANISED DRIVAGE MACHINES

Rate of drivage –6 meters/day

Production –150 Tonnes/day



Continuous Miner

Rate of drivage –50 meters/day

Production –1500 Tonnes/day



Mechanised Roof Bolter

Bolting -240 bolts/day



FACE

TOP Gate

LONGWALL GENERAL LAYOUT

Bottom

Gate

Dip direction

- Longwall mining method includes drivage of two long roadways in coal and joining themat the end by a perpendicular drivage forming a face.

LONGWALL MINING

SHEARER WORKING AT LONGWALL FACE

SHEARER WORKING AT LONGWALL FACESHEARER WORKING AT LONGWALL FACE

POWERED ROOF SUPPORT AT LONGWALL FACE

LONGWALL MAIN GATE

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

Highwall Mining

Trench Mining

Bench Mining

Highwall Mining

Highwall Mining

Punch Longwall

Advantages

• Step change in cost and productivity

• More production capacity

• High productivity & low cost

Longer term and higher % of reserves extraction

Punch Longwall

• 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

1st pressure

peak

Rock stress Low stress Stressabrupt drop

2nd pressurepeak

Compact stress

Pressure curve of top coalseam

Technical Principle Of Top Caving

Longwall Top Coal Caving (LTCC)

goaf

Virgin

coal

FractureCoal Broken Coal

caving

Working

Height

Front AFC Rear AFC

2800

5600

backbackback

Longwall Top Coal Caving (LTCC)

Modulator

Link Data Link

Antenna

(Surface or

Underground)

PED schematic operation

PC for

entering

messages.

PED Receivers can be:

• BeltPED Personal Receiver (shown)

• AutoPED Vehicle Receiver

• ControlPED for Equipment Switching

• BlastPED for Remote Blast Initiation

ModulatorTransmitter

Ultra Low Frequency Transmission

Through Rock

PED receiver cap lamps

Questions…

PleasePlease

VENKAT M.

TL-Minex-INDIA