Mining Terms and Methodologies – Part-II

·        Properties of Indian Coal

n  Limited Resources of Coking Coal

n  High Ash and Low Calorific Value thermal coal

n  Low Sulphur (less than 0.5%) and low phosphorous (less than 0.2%)

n  High ash fusion temperature

n  Inertinite and liptinite rich combustion friendly coal

·        First Non-coking coal washery of CIL is Piparwar Washery under CCL having capacity of     6.50 MT/year.

·        Kargali Washery is the oldest washery of Coal India formed in 1958.

·        Out of 29 states, coal field areas have been spread in 14 states. CIL operates in 8 states.

·        Mining Methods and configuration of HEMM used

n  Shovel + Dumper –  Can work in steep gradient upto 1 in 5

  Multi seam extraction

n  Surface Miner –       Can work in steep gradient upto 1 in 10 and flatter

Suitable for coal having compressive strength below 250   kg/CM²

n  Bucket Wheel Excavator – Used for lignite extraction

Suitable for coal having compressive strength upto 100 kg/CM²

n  Dragline --              Used for gradient flatter than 1 in 6

Not suitable for hilly geographic area

n  LHD (Load Haul Dumper) –  Capacity – 2 to 2.7 Cum

     Production – 150 – 200 Tonne/Day

Used for seam of 1 in 6 gradient with 2 m to 4 m   thickness.

n  SDL (Side Discharge Loader) –   Capacity – 1.0 Cum

Production – 120 Tonne/Day

Used for seam of 1 in 5 gradient of 2m to 3.5 m thichness.

n  Mechanized Drivage Machines – Rate of Drivage – 6m/Day

Production – 150 T/Day

Seam Thickness – 2m to 4 m

n  Continuous Miner –  Rate of drivage – 50m/day

  Production – 1500T/day

  For seam 1 in 5 gradient & 3m to 4 m thichness.

n  Mechanized Roof Bolting – Bolting Capacity – 240 bolts/day

  Suitable for seam of 1 in 5 & 2m to 5m          thichness.

·        CHP/CPP(Coal Handling Plant/Coal Preparation Plant)

n  Objective of CHP/CPP

-- To supply the processed coal to bunkers for boiler operation.

-- To stack the coal to coal yard.

n  Apparatus used in CHP

-- Wagon Tippler

-- Hopper

-- Feeder

-- Conveyor Belt

-- Idler

-- Surge Hopper

-- Vibrating Screen

-- Crushers

-- Tripper Trolley

-- Magnetic Seperator

n  Operational Cycle of CHP/CPP

-         Bunkering

-         Stacking

-         Reclaiming

Three stage crushing system is used in CHP/CPP

Stage 1 -- DRCR(Double Roll Crusher Room)- Coal of 600mm size are crushed into 250mm size

Stage 2 -- RBCR(Rotary Breaker Crusher Room) – Coal of 250mm size are crushed into 80mm size

Stage 3 -- Impact Crusher – Coal of 80mm size are crushed into 20-25mm size

·        Explosives used in Coal Mines are classified into three categories

P1                                P3                                            P5                               

Powergel P-101         Powergel P-301                    Powergel P-501

Indocoal-1                 Indocoal-3                             Indocoal-5

Godyne                      Permadyne                            Pentadyne

Solarcoal-1                Solarcoal-3                            Solarcoal-5

·        In underground mines percentage of carbon dioxide must not be greater than 0.5% and percentage of oxygen must be greater than 19% for ideal working conditions.

h    * Percentage of ash, moisture and other volatile contents in coal is anatomized through Proximate Analysis and percentage of hydrogen, Nitrogen, Oxygen, Sulphur etc is anatomized through Ultimate Analysis.