135
LONGWALL MINING Venkat
LONGWALL MINING
Venkat
COAL -COAL -Background
COAL
� Most abundant fossil fuel
� Major fuel used for electricitygeneration world wide
� Safe and secure fossil fuel� Safe and secure fossil fuel
� Cost effective
WORLD ELECTRICITY GENERATION(% By Fuel-2005)
Consumption by Fuel
India (%)
World (%)
Oil 32 37
Natural Gas 8 24Natural Gas 8 24
Coal 54 27
Nuclear Energy 1 6
Hydro-Electric 5 6
Total 100 100
(Source: BP Statistical Review of World Energy 2005)
WORLD SCENARIO
As the International Energy Agency hascommented:
“World reserves of coal are enormous and compared withoil and natural gas, widely dispersed... The world’s provenreserve base represents about 200 years of production atreserve base represents about 200 years of production atcurrent rates... Proven coal reserves have increased byover 50% in the past 22 years. The correlation of stronggrowth of proven coal reserves with robust productiongrowth suggests that additions to proven coal reserves willcontinue to occur in those regions with strong, competitivecoal industries.”
INDIAN SCENARIO
� Coal accounts for 63% of Country’senergy needs.
� Coal based thermal power generationcapacity presently stands at 61,476MWand a capacity addition of around 60,000and a capacity addition of around 60,000MW has been targeted in next 7 years.
� Total annual hard coal production in Indiais about 373.79 million tonnes (2004-05)out of which nearly 80% is from OpencastMines. SCCL share is 10%.
INDIAN SCENARIO
Coal Demand & Production
(in Million Tonnes)
Coal Demand & Production
(in Million Tonnes)
2011-12
Demand 707
Production 550
Gap 157
(Source: Coal Summit 2005)
Proved coal reserves at end 2005
RESERVES - India
DEPTH(m) PROVED INDICATED INFERRED TOTAL
(In Bt) (%)
0-300 71 66.5 15 152.5 61.5
As on January 2005 in Billion Tonnes
300-600 6.5 39.5 17 63 25
0-600(Jharia)
14 0.5 -14.5
6
600-1200 1.5 10.5 6
187.5
0-1200 93 117 38 248 100
(Source: GSI Report, January 2005)
RESERVES - SCCL
As on January 2006 in Million Tonnes
DEPTH(m)
PROVED INDICATED INFERRED TOTAL
0-300 5505.49 2239.12 102.25 7846.86
300-600 2897.69 2900.71 553.05 6351.45300-600 2897.69 2900.71 553.05 6351.45
600-1200 0.00 1018.34 1928.95 2947.29
0-1200 8403.18 6158.17 2584.25 17145.60
LONGWALL –LONGWALL –World & India
� First mechanized powered support longwallcaving face was introduced in August 1978at Moonidih, CIL.
Longwall in India
� First Longwall face introduced in GDK.7Incline in September 1983 in SCCL.
� There is no much improvement taken placein India in respect of Longwall technologydue to various reasons.
� Serious efforts not made perhaps due toavailability of alternate technologies.
� Upgrading not made when most of the worldimproved in 90s.
Longwall in India
Reasons for less concentration on Longwalls in India
Upgrading not made when most of the worldimproved in 90s.
� Spares management was poor.
� Coal India do not need due to opencast andflat gradients.
� Use of indigenous spares of low quality isincreased, which deteriorated the condition offaces.
Australian Coal Industry
� World’s largest exporter of coal
� 230 mt worth Au$ 16 b (Rs. 53,000 crs)in 2004.
� Most of the 74 bt reserves in NSW and QLD� Most of the 74 bt reserves in NSW and QLD
� 378 mt in 2004, 82 mt from underground.
� 24 longwalls produced 73 mt in 2004 andplans to produce 96 mt in 2006.
� 148 wagons per rake 2 km length, 8,500 t.
Australian Coal Industry
� Less than 25,000 employees.
� Each mine has 120 to 200 permanent and 100 contractors’ men.
Productivity:� Productivity:
� OMY is 15,000 t.
� OMH 5t for UG, 10t for OC
Longwall Geometry - World
TimeWidth (m)
Length (m)
1970’s 150 12001970’s 150 1200
1980’s 225 1800
Today 330 3000
LONGWALL -LONGWALL -METHOD
FACE
TOP Gate
LONGWALL GENERAL LAYOUT
Bottom
Gate
Dip direction
- Longwall mining method includes drivage of two longroadways in coal and joining them at the end by aperpendicular drivage forming a face.
Different Longwall Methods
1. Longwall Advancing Method
2. Longwall Retreating Method
Modern Longwall Plans in Australia
Modern Longwall Plans in Australiain Australia
Gateroad Plans in Australia
Advantages of Longwall Method
� High Recovery.
� Lower Operating Costs.
� Easier to Supervise.
Easier to Train Miners.� Easier to Train Miners.
� Works Under Weak Roof.
� Clean Coarse Product.
� Simple Ventilation.
Disadvantages of Longwall Method
� Small Problems = Big Production Losses.
� Dust Control Difficult.
� Overloading Conveyor System.
Retreat Longwall Mining Advantages Over Advance Longwall Mining
� Reserves are “Proven” on Development
� Gateroads in the “Solid”
� Gateroad Development is Separate
� Water Easier to Control
� Recovering Equipment Easier
� Easier Ventilation
Retreat Longwall MiningDisadvantages Over Advance Longwall Mining
� Delay in getting production for the preparation of first panel.
�
MAIN GATE WITH SWITCH TRAIN
CHHOCKS
LONGWALL METHOD
Retreat per day –5 meters/day
Production –3000 Tonnes/day
Thickness of 2.0 m to 3.5 m
POWERED ROOF SUPPORT AT LONGWALL FACE
LONGWALL -LONGWALL -EQUIPMENT
Equipment for Longwall Mining
� Powered Face Supports
� Shearer
� Armored Face Conveyor
Conveyor System� Conveyor System
� Electricals & Communication
CHOCK SHIELD SUPPORTCHOCK SHIELD SUPPORT
Powered Roof Supports (Two legged)
POWERED ROOF SUPPORT AT LONGWALL FACE
Capacity -4x450 T to 4x800 T
Thickness of -2.0 m to 3.5 m
Weight -12 T to 20T
Weight -1.5m
Powered Face Face Supports
Armored Face Armored Face Conveyor
Armored Face Conveyor
Armored Face Conveyor
Armoured Face Conveyor (1 pan set)
Shearer working at Longwall Face
SHEARER WORKING AT LONGWALL FACE
Capacity -2x375 Kw
Thickness of 2.0 m to 4.5 m
Web -0.63/0.85
Drum Dia -1.6 to 1.83m
Length -10m
Shearer
Shearer -Front Half
Shearer -Rear Half
Shearer Drum
Cutter Bits with Spray
Conveyor Belts
LONGWALL –LONGWALL –STRATA CONTROL
Top Gate 50 L C LX X
Barrier Pillar
120 m
1000 m
S
C L
STRATA CONTROL PLAN OF A LONGWALL PANEL
Not to scale
Bottom Gate 53 L
Longwall Panel dimensions
1000 m x 115 m
INDEX:
C Convergence Station
L Load Cell
X Extensometers
S Stress cell
C L XX
G O
A F
FA
CE
RE
TR
EA
T
Barrier Pillar
S
120 m
1000 m
200 m
S
C L
Strata monitoring of in a Longwall Panel
• Gate Road ways studies.
• Face monitoring.
• Goaf monitoring.• Goaf monitoring.
Gate Road ways studies –
• Convergence indicators
• Load cells
• Tell tales
Strata monitoring
• Tell tales
• Stress capsulesCum.CONVERGENCE in Tail gate
of a Longwall Panel
0
5
10
15
20
25
30
35
10.0
m
30.0
m
50.0
m
70.0
m
90.0
m
110.0
m
130.0
m
150.0
m
170.0
m
190.0
m
210.0
m
230.0
m
250.0
m
270.0
m
290.0
m
310.0
m
330.0
m
350.0
m
370.0
m
390.0
m
410.0
m
430.0
m
LOCATION in mts
Cu
m.C
on
verg
en
ce i
n m
m
The maximum convergence depends on the following factors
� Caving properties of the strong bedcausing weightings, indicated by theCaving Index Number ‘I’ of the strongbed.
�� Thickness of cavable beds forming theimmediate roof in between strong bedand the coal seam in terms of height ofextraction.
� Resistance offered by the supportsystem.
Convergence and Roof Degradation at Longwall Weightings (GDK.10A)
MaximumConvergence
Expected RoofCondition
Upto 60 mm/m Convergence within permissiblelimit
Above 60 upto 100 mm/m Minor roof fracturing increasingAbove 60 upto 100 mm/m Minor roof fracturing increasingwith the value of convergence
Above 100 upto 160 mm/m Significant roof fracturing androof degradation. Seriousnessincreasing with increase inconvergence
Above 160 mm/m Rock fall zone.
Face monitoring–
• Leg Pressures
• Leg Closures
• Face Convergence
Strata monitoring
• Face Convergence
PRESSURE SURVEY
Continuous Pressure Recorder in Mid Face
of a Longwall Panel
15
20
25
30
35
4033.6
39.3
56.2
74.1
95.4
111
119
141
163
180
198
220
237
259
279
305
324
345
369
386
412
FACE RETREAT in mts
PRESSURE (Mpa)
Setting Pressure
Yield Pressure
Rated Support Resistance
The Rated Support Resistance shouldtake into account the followingdeficiencies during the actual operation.
1. Leakage in leg circuit1. Leakage in leg circuit
2. Setting load deficiencies
3. Miscellaneous (deviation from normalspan, premature bleeding of legcircuits, etc.)
Goaf monitoring –
• Remote convergence indicator
• Multi Point Borehole Extensometer (MPBEx)
Strata monitoring
CAVING OF THE STRATA WITH RESPECT TO FACE PROGRESS sensors
SURFACE
SOIL-2.7m
36m
25m
13.5m
6m
68.0m
80.0m
141m
Face progress Anchor1 Anchor2 Anchor3 Anchor4 Remarks
Anc 1- 45m
Anc2 -37.5m
Anc3 -26m
Anc4 - 15m
SOIL-2.7m
YellowSST 8m
Light Brown
SST-7m
Shaly Coal3m
Grey & Brown
SST-12m
Hard Brown
SST-17m
Main OverburdenMain Overburden
Longwall Caving Diagram
HcHc FF DcDc ClCl RoRo
Immediate RoofImmediate Roof
TT
Hs = Seam HeightHc = Caving HeightCl = Canopy Length
Dc = Depth of CutA = Caving AngleF = Forward Zone
Ro = Rear OverhangT = Canopy Tip to FaceSw = Shield Width (not shown)
HcHc
HsHs
FF DcDc ClCl RoRo
AAGobGob
CoalCoal
FloorFloor
ShieldShield
SupportSupport
Cut after cut, shear after shear the AFC & subsequentlyChock shield supports will be advanced and theimmediate roof rock above caves in.
Longwall Caving
- As the retreat further proceeds substantial area of mainroof rock forms a plate & caves in by imposing load onsupports, known as main weighting.
Main Fall
Periodic Fall
LONGWALL –LONGWALL –ORGANISATION
Organisation Chart
MANPOWER
Pre shift1. EE/AE 12. Mech. Charge Hand 13. Overman 14. Mining Sirdar 15. Shearer F+3
General Shift1. Overman 12. Mining Sirdar 13. Gate Road Support 64. Face Supporting
(Bamboo bolting & 5. Shearer F+3 6. AFC & BSL F+57. Power pack & Chocks F+38. Switch train &
U/Frame Shifting F+79. GBC F+410. Miscellaneous 9
-------------40
(Bamboo bolting & Fore polling etc.) 8
5. Face Cleaning 106. Slush Tanks cleaning
along M.G. 67. Material transport 6
--------38
MANPOWER
Production Shift1. Under Manager 1 2. Engineer 1 3. Overman 14. Mining Sirdar 1
5. Shearer Operator 25. Shearer Operator 26. Multi Job Workmen 97. Face fitters 38. Face Electricians 19. Outbye belt Fitters 110. Outbye Electricians 111. Helpers 612. Conveyor Operators 613. Misc/cleaning 4
-------------37
LONGWALL –LONGWALL –FACE TRANSFER
MESHING
� Wire meshing is laid in roof from 12 to 15mbehind the face stop line with individual roofbolts for 5 to 8m and later on along with W-straps/Channel for balance portion at 1minterval.interval.
� Maximum height will be extracted for the last8m from face stop line, sothat enoughclearance is there for PRS passing underneaththe line supports.
� After stoppage of the face, meshing andbolting is done to the face also.
DISMANTLING
� All the equipment in the face are dismantledexcept chocks and loaded on to the GMT (GyroMachine Trolley) and transported to surface ofnew face.
� Shearer is dismantled into two parts for easy� Shearer is dismantled into two parts for easytransport.
� AFC pansets were dismantled in such a waythat 5 pansets together forms a unit forloading onto GMT.
� Similarly BSL, Belt sections are dismantled andloaded on GMT.
CHOCKS TRANSPORT
� PRS turning is done generally from dip toraise and 2 buttress supports are used asgoaf edge supports at dip most point of theface.
� PRS are being marched with self hydraulicpower upto loading station and shifted onto GMT for further transport to surface orto new face.
SCCL – A ReviewSCCL – A Review
Strut Pit, Yellandu
Singareni
• Presently operating 47 Undergroundand 11 Opencast mines.
• Godavari Valley Coalfields spread out• Godavari Valley Coalfields spread outover 350 Kms.
LOCAT
LOCATATION
ATION
The Godavari Valley CoalfieldThe Godavari Valley Coalfield
LOCAT
LOCATATION
ATION
1975: Opencast mining1979: Side Discharge Loaders1981: Load Haul Dumpers and Road
Headers1983: Longwall mining
Mile stones - Technology
1983: Longwall mining1986: Walking Dragline1989: French Blasting Gallery method1994: In-pit crushing and conveying2004: Phasing out manual Coal filler
launched.
Technology-Wise production- 2005-06
� Opencast :23.42 mt(64.8%)
� Underground :12.71 mt(35.2%)(35.2%)� Manual mining :7.12 mt
� Longwall :0.85 mt
� Intermediate mech. :4.74 mt
(LHD, SDL, BG & RH)
PROJECTIONS
TECH 2006-07 2011-12 2016-17 2021-22
PROD(M.T)
% PROD(M.T)
% PROD(M.T)
% PROD(M.T)
%
HS 6.005 16 5.225 13 3.780 8 3.620 8
SDLS 3.30 9 2.865 7 1.610 4 1.280 3
LHD 1.655 4 1.110 3 1.12 2 0.680 1LHD 1.655 4 1.110 3 1.12 2 0.680 1
LW 1.205 3 3.900 10 5.600 12 8.500 18
CM 0.400 1 1.800 4 1.770 4 2.000 4
BG 1.210 3 1.150 3 0.920 2 0.920 2
TOTAL UG 14.251 37 16.050 39 14.800 33 17.000 36
OC 21.749 63 24.750 61 30.200 67 30.500 64
TOTAL 37.500 100 40.800 100 45.000 100 47.500 100
C&MD
Dir/ Fin. Dir/ P&P Dir/ Oprs. Dir/ E&MDir/ PAW
Finance
Int. Audit
Areas Areas
CivilForestry
SO
Personnel
Medical
E&M, UGM
E&M, OC
Marketing
General Organisation of SCCL
Co. Secy.
SO Safety
CP&P
Corp. Plg
Proj. Plg.
Survey
Explrn.
Environ.
Estates
IE
Vigilance
Security
IT
Law
HRD
Stores
PH&WS
Edn.
Central WS
Cap. budget
Purchase
R&D
Qual. Mgt
GM
Mines
IE
Finance
SO
Safety
Civil
IT
General Organisation of Areas
Personnel
HRD
Qual.Mgt.
Survey Medical
Township
E&M
Workshop
Stores
Purchase
WM Comn.
Coal handling
Mine Manager
Safety Ventilation
E&M Mntnce Min. Mntnce.
Pit Office
General Organisation in the Mines
E&M Mntnce Min. Mntnce.
Survey Welfare
ProductionShifts
Drilling, BlastingLoading, Transport,
Mine support,Coal handling etc.
Organisation of statutory personnel
Owner Directors
on the Board
General Manager
(deemed Agents)
Corporate HoDs
(Deemed Agents)
(deemed Agents)
Named Agent
(group of mines)
Mine Manager
Officers
For various
disciplines
Supervisors
Competent
persons
STATUS OF LONGWALLS AT SCCL
INTRODUCTION
� The first Longwall was commissioned in SCCLat GDK.7 Incline, RG-II in September, 1983.
� Till now 10 sets of Longwall were purchasedby SCCL. Mainly the equipment wasby SCCL. Mainly the equipment waspurchased from UK and China.
� Till now 70 Longwall panels have beencompleted in SCCL and presently 4 Longwallunits are in operation in 4 Undergroundmines.
EXISTING LONGWALL MINES OF SCCL
S No
Name of the mine No of Units
1 PVK-5 Incline,KGM Area 1 unit
2006-07
2 GDK-9 Incline,RG-II Area 1 unit
3 GDK-10A Incline,RG-II Area 1 unit
4 JK-5 Incline, YLD Area 1 unit
LONGWALL PRODUCTION TREND-SCCL
15
20
25
0
5
10
15
PR
OD
(L
T)
LW PROD 1.33 2.47 5.75 6.18 6.12 6.12 4.62 6.32 12.17 13.2 16.1 10.4 20.19 22.9 19.3 16.42 15.79 13.66 11.27 10.1 11.17 11.19 8.5
1983-
84
1984-
85
1985-
86
1986-
87
1987-
88
1988-
89
1989-
90
1990-
91
1991-
92
1992-
93
1993-
94
1994-
95
1995-
96
1996-
97
1997-
98
1998-
99
1999-
2000
2000-
01
2001-
02
2002-
03
2003-
04
2004-
05
2005-
06
INTRODUCTION OF LW SETS
S No
Mine where LW sets introduced
No.of sets & Yr.
Support capcities
1 GDK.7/9 Incline, RG-II 1, 1983 4 x 360T
2 VK-7 Incline, KGM 1, 1984 4 x 360T
3 GDK.11A Incline, RG-I 3, 1990-92 4x450T(2), 4x430T(1)
4 JK-5 Incline, YLD 1, 1990 4x450T
5 GDK.9Extention, RG-II 1, 1996 4x800T
6 GDK.10A Incline, RG-II 1, 1994 4x800T
7 Padmavathikhani, KGM 2, 1995-96 4x760T
GDK.7 INCLINE
� Longwall equipment introduced in no.3 seambottom section in September 1983.
� After completion of two panels, due to non� After completion of two panels, due to nonavailability of the property the equipmentwas shifted to adjacent GDK.9 Incline.
� Main Problem - Strength of coal is high forShearer cutting & sand stone bands runningacross the panel.
GDK.7 INCLINE
Borehole Section showing showing
3 seam Top & Bot Section.
GDK.7 INCLINE
� Two panels have worked with 4x360Tsupports in No.3 seam bottom sectionwith a face lengths of 110m and 96m.
� The production achieved is 0.8LT withan average production of 1900T/day.
VK.7 INCLINE
� Longwall equipment with 4x360T Conventionalsupports was introduced in Top seam in 1985.
� With 4x360T supports, 8 panels of 120m face lengthand 7 panels of 60m face length have been workedsuccessfully.successfully.
� Second set (4x450T IFS) shifted from GDK.11A Inc in1994 & is presently in operation.
� Experience in – varied face lengths, up hill transport,crossing the developed gallery, working in betweengoaves, fault running across the panel.
� Main Problems – Underrated capacity of supports,Cavity formation.
Borehole Section showing Top seam (Middle Section)
VK.7 INCLINE
Depth Thickness Strata Description
VK.7 INCLINE
� 8 panels of 120m face length have completedWith 4x360T supports by producing around3.6MT and daily production varied from 400to 1800T.
� 7 panels of 60m face length have completedWith 4x450T supports by producing around1.6MT and daily production varied from 1000to 1300T.
GDK.11A INCLINE
� Two longwall sets were introduced with4x450T/4x430T supports during 1991, followed by 3rd
Longwall unit with 4x450T supports during 1992.
� First time longwall was introduced in No.1 Seam of� First time longwall was introduced in No.1 Seam ofRamagundam.
� Main Problems – Underrated capacity of supports,Oblique fault running across the panel, high waterseepage, improper geo-technical investigations.
Borehole Section showing No.1 seam
GDK.11A INCLINE
showing No.1 seam (Bottom Section)
GDK.11A INCLINE
� Longwall unit –I : 2 panels worked producing around0.5MT of coal.
� Longwall unit – II : 4 panels worked producing around1.3MT of coal.
� Longwall unit – III : 3 panels worked producingaround 0.96MT of coal.
� While working with Longwall unit-II & III, experiencedmore strata problems and cavity formations, due tounderrated capacity of supports.
PADMAVATHIKHANI
� First time Chinese longwall was introduced inPVK in 1995 in Queen Seam (Top seam).
� 2 sets were introduced, One in 1995 and theother in 1996 with 4x760T supports.
� 11 panels have been completed by producingaround 5 MT.
� Experience in – varied face lengths,negotiation of fault, deviation of gateroadways.
� Main Problems – Non-availability of Spares.
Borehole Section showing Top seam
PADMAVATHIKHANI
showing Top seam (Middle Section)
JK-5 INCLINE
� Longwall with 4x450T supports (IFS) wascommissioned in June 1990.
� Longwall panels were extracted in both, Top andbottom sections of Queen (Top) seam afterallowing for goaf settlement.allowing for goaf settlement.
� 2 panels in Queen seam bottom section and 8panels in Queen seam Top section have beencompleted by producing around 2.7MT of coal.
� Experience in – varied face lengths, negotiationof fault, in between goaves, steep gradient (1 in3.6).
� Main Problems – Geological disturbances, Cavityformation, underrated capacity of supports.
Borehole Section showing Top seamTop & Bottom section
JK-5 INCLINE
GDK.9/9E INCLINE
� Longwall equipment (4x360T) introduced inno.3 seam bottom section in 1986 which wasshifted from GDK.7 Incline.
� New Longwall set with 4x800T capacity wasintroduced in No.1 seam in 1996.introduced in No.1 seam in 1996.
� Main Problem – underrated capacity ofsupports for 3 seam, Cavity formation,Insufficient geological data, slow progress indevelopment of panels, more water seepage,spares mgmt.
GDK.9/9E INCLINE
Borehole Section showing 1 seam
GDK.10A INCLINE
� Longwall equipment (4x800T IFS) was introduced inno.1 seam in 1994.
� GDK.10A longwall produced daily, weekly andmonthly record output in India. In the year 1997-98,the mine produced 8.67LT.the mine produced 8.67LT.
� GDK 10A produced 5.40 LT of coal againstthe target of 5.38 LT in the year 2005-06.
� Main Problem –more water seepage, non-availabilityof good quality spares, Cavity formation.
Borehole Section showing 1 seam
GDK.10A INCLINE
FUTURE LONGWALLS AT SCCL
FUTURE LONGWALL PROJECTS
• Adriyala Shaft Project – Extension of GDK.10A dip side
• Jallaram Shaft Project – Extension of GDK.9 Inc Dip side– Extension of GDK.9 Inc Dip side
• Peddampet Shaft Project- Extension of GDK.11A Inc Dip side
• Kakatiya Longwall Project, Bhupalpally- Steeply inclined, New mine.
• Shanthikhani Longwall Project, Bellampalli- Extenstion of existing mine
STATUS OF APPROVAL OF LW PROJECTS
S.
No
Project FR approved by SCCL Board
Status of EMP Status of GOI approval
1 Adriyala July’ 2003 EC obtained
11.10.2004
Sanctioned from GoI in Sept 06
2 Shanthikhani Dec’ 2003 EC obtained
24.01.2006
Submitted to GOI on 26.02.04.
In principle approval received. PIB note submitted on 01.01.05
3 KTK LW June’ 2005 EMP to be prepared Submitted to GOI 5.08.2005
4 Jallaram Oct’ 2004 Public hearing completed.
Application for EC under preparation.
Submitted to GOI 11.11.04
5 Peddampeta Dec’ 2003 Public hearing completed.
Application for EC under preparation
Submitted to GOI 26.02.04
ADRIYALA SHAFT PROJECT
1. Location : Ramagundam coal beltRamagundam Area
2. Geological Block : RG SB-II & RG SB-III3. Geological Reserves : 109.59 Mt4. Extractable Reserves (Apr.) : 43.38 Mt4. Extractable Reserves (Apr.) : 43.38 Mt5. Area (in Sq.Km) : 3.406. Capacity (MTPA) : 2.147. Life of the Mine : 31 years8. Face length : 150m 9. Panel length : 700 - 1300 m10. Depth range : 294 – 644m 11. Gradient : 1 in 6.0 to 1 in 7.8
:
Details of seams:
Seam Avg.
Thickness
Height of Extraction
(m)
Geological
Reserves
Extractable
Reserves
Grade
ADRIYALA SHAFT PROJECT
Thickness (m) (m)
Reserves (Mt)
Reserves (MT)
I 5.64 3.5 27.99 10.98 E
II 3.27 2.0 15.24 6.07 D
III 9.40 3.5(Top)/
3.5(Bot)
43.09 23.31 D
IV 3.66 3.5 15.56 11.28 C
SHANTIKHANI LONGWALL PROJECT
1. Location : Dorli - Bellampalli coal beltBellampalli Area
2. Geological Block : Shantikhani Extn Block3. Geological Reserves : 8.87 Mt4. Extractable Reserves (Apr.) : 17.78 Mt 4. Extractable Reserves (Apr.) : 17.78 Mt 5. Area (in Sq. Km) : 6.816. Capacity (MTPA) : 1.177. Life of the Mine : 23 Years8. Face length : 150m 9. Panel length : 450 - 2000 m10. Depth range : 309 – 596m 11. Gradient : 1 in 3.5 to 1 in 5
Details of seams (Phase-I)
Seam Avg.
Thickness (m)
Height of Extraction
(m)
Geological
Reserves (Mt)
Extractable
Reserves (Mt)
Grade
SHANTIKHANI LONGWALL PROJECT
(m) (Mt)
SJ Top 1.88 1.5 18.96 3.91 F
SJ Bot 3.18 2.5, 3.5 29.91 13.87 D
1. Location : Mulug coal beltBhoopalpalli Area
2. Geological Block : Gollapalli block & Peddapur block3. Geological Reserves : 67.45 Mt (Phase-I)+ 60.06 Mt (Phase-II)4. Extractable Reserves (Apr.) : 40.02 Mt (Phase-I)+ 35.99 Mt (Phase-II)
KAKATIYA LONGWALL PROJECT
4. Extractable Reserves (Apr.) : 40.02 Mt (Phase-I)+ 35.99 Mt (Phase-II)5. Area (in Sq. Km) : 9.716. Capacity (MTPA) : 2.167. Life of the Mine : 24 + 22 Years8. Face length : 250m 9. Panel length : 1200 - 2900 m10. Depth range : 35 – 412m 11. Gradient : 1 in 2.8 to 1 in 3.3
Details of seams (Phase-I)
Seam Avg.
Thickness
Height of Extraction
(m)
Geological
Reserves
Extractable
Reserves (Mt)
Grade
KAKATIYA LONGWALL PROJECT
Thickness (m) (m)
Reserves (Mt)
Reserves (Mt)
IA 2.02 2.0 12.16 7.62 E
I 2.66 2.5 17.18 9.45 F
II 2.72 2.5 17.55 9.71 F
III 3.05 3.0 20.53 13.24 B
JALLARAM SHAFT PROJECT
1. Location : Ramagundam coal beltRamagundam Area
2. Geological Block : RG SB-II3. Geological Reserves : 206 Mt4. Extractable Reserves (Apr.) : 79 Mt4. Extractable Reserves (Apr.) : 79 Mt5. Area (in Sq.Km) : 7.296. Capacity (MTPA) : 2.287. Life of the Mine : 53 years8. Face length : 200m 9. Panel length : 500 - 1800 m10. Depth range : 123 – 579m 11. Gradient : 1 in 5 to 1 in 8
Details of seams
Seam Avg.
Thickness (m)
Height of Extraction
(m)
Geological
Reserves (Mt)
Extractable
Reserves (Mt)
Grade
JALLARAM SHAFT PROJECT
(m) (m) (Mt) (Mt)
I 5.09 3.0 53.99 14.13 E
II 2.99 2.0 27.43 12.17 E
III 8.79 3.0 (Top)/ 3.5 (Bot)
85.04 36.91 D
IV 3.00 3.0 29.19 16.21 B
1. Location : Ramagundam coal beltRamagundam Area
2. Geological Block : GDK-6B Integrated Mine Block3. Geological Reserves : 112.62 Mt4. Extractable Reserves (Apr.) : 41.40 Mt5. Area (in Sq.Km) : 7.25
PEDDAMPETA SHAFT PROJECT
5. Area (in Sq.Km) : 7.256. Capacity (MTPA) : 1.467. Life of the Mine : 32 Years8. Face length : 150m 9. Panel length : 470 - 1200 m10. Depth range : 118 – 443m 11. Gradient : 1 in 6 to 1 in 10
Details of seams
Seam Avg.
Thickness
Height of Extraction
(m)
Geological
Reserves (Mt)
Extractable
Reserves
Grade
PEDDAMPETA SHAFT PROJECT
Thickness (m) (m)
Reserves (Mt) Reserves (Mt)
II 2.64 2.0 24.27 7.06 E
III 8.69 2.0 (Top)/ 3.5 (Bot)
65.69 21.39 D
IV 2.50 2.5 22.66 12.95 B
Variants of Longwall MiningVariants of Longwall Mining
(NEW CONCEPTS)
Punch Longwall
- Developing longwall panels directly off high walls of OC
Field site operationsPunch 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
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)
Supports used
Advantages of LTCC
Longwall Top Coal Caving (LTCC)
• Increased resource recovery in thick seams (> 75%)
• Lower face working height (better face control)
• Improved spontaneous combustion control
• More efficient capital utilisation/ financial • More efficient capital utilisation/ financial
performance
• Reduced operating costs
• Improved production consistency
• Less gate road development requirements
• Some dust and gas issues
LONGWALL –INDIAN INDIAN
PERFORMANCE
INDIAN LONGWALL
- PAST EXPERIENCE:
- Introduction of advanced technology system in Indiancoal mining industry marked a major step with theinstallation of first mechanized Longwall Powered supportface at Moonidih in August 1978.
- In between 1978 to 1985, a major number of firstgeneration Longwall faces started through out India invarious mines of CIL such as Moonidih, Jhanjra, Seetalpur,Dhemomain and Pathakhera Colliery and in SCCL at GDK-7 & VK-7 Incline.
- PAST EXPERIENCE:
- Churcha Longwall face failed due to dynamicloading.
- Jhanjra with shallow depth Longwall working face
INDIAN LONGWALL
- Jhanjra with shallow depth Longwall working faceran into acute spares problem.
- Kottadih face failed after successful completion oftwo Longwall panels due to dynamic loading andunderrated capacity of supports.
- GDK.11A failed due to underrated capacity ofsupports.
- PAST EXPERIENCE:
Longwall technology was introduced inSeven mines of SCCL. Their performancehas been:
LONGWALL- SCCL
• GDK-10A, JK-5 and VK-7 Incline gaveconsistently good results, and
• The other four mines GDK-7, GDK-9, GDK-11A and PVK suffered mainly due to nonavailability of sufficient geological data.
MAIN REASON :
Insufficient geo-technical investigationsresulted in surprises by encountering majorgeological disturbances while working the
INDIAN LONGWALL
geological disturbances while working thelongwalls. Thus effecting the performance ofLongwalls to the maximum extent.
- PRESENT & FUTURE :
- With the likely reduction of contribution from Opencast and the more or less stagnant production fromUnderground by Conventional methods, it is timethat an impetus is given to boost Long wallTechnology to able to meet the future energy needs
INDIAN LONGWALL
Technology to able to meet the future energy needsof the country.
- On the positive side, coal companies have nowgained sufficient experiences right from seniorexecutive level to front line workforce to be able toplan, execute and work longwall faces. What arerequired are proper geo-technicalinvestigations for effective layout of longwallpanels.
REASONS FOR POOR PERFORMANCE OF LONGWALL
>Large expansion in opencast mining in the pasttwo decades provided cheaper and safe methodfor bulk coal production and as a result long wallhad to take back seat.
>Clear strategies were not pursued for itssustenance as there was mixed results from longwall in the early years of its introduction.
>Long walls were introduced mostly in the blocksleft over by working Bord and pillar method.Clean and extensive blocks have not beenidentified. Even the smaller blocks, which wereidentified, were of inferior grade coal.
REASONS FOR POOR PERFORMANCE OF LONGWALL
>Long wall had to co exist with the conventionalmining in most of the mines, which causedmanagement problems.
>There were some deficiencies in the importedspares management and the supplies were notreaching in time.
>Coal companies were sensitive to the failures ofa few long wall faces and were not prepared torisk huge investments.
REASONS FOR POOR PERFORMANCE OF LONGWALL
>Development could not keep pace with theextraction of Long wall panels, slow progress indip has delayed the formation of Long wallpanels and affected the performance.
- Longwall should be promoted as atechnology mission.
- A high level thrust group could be constitute
FUTURE REQUIREMENTS
- A high level thrust group could be constituteat national level to promote, coordinate andinteract different aspects related to Longwalltechnology.
- Huge investments incurred on differentoperations for extraction of coal from greaterdepths in future can be attained by imposinga special cess on present OC production orfrom other sources.
FUTURE REQUIREMENTS
- R&D efforts are to be doubled.
- Efforts are required by the policy makers totransform ideas into actions.
FUTURE REQUIREMENTS
- Foreign participation is required forextraction of thin seams and steeplyinclined seams.
- The manufacturing companies of Indiasuch as MAMC and Jessop are to besuch as MAMC and Jessop are to bereconstructed/ re-organized.
- More number of longwall blocks are to beidentified to assure the market formanufacturers.
THANK YOU
