Coal mining methodsCoal mining methodsCoal mining methods Coal mining methods ((石炭採掘法石炭採掘法))

-- Green Coal Technology (GCT)Green Coal Technology (GCT) ---- Green Coal Technology (GCT) Green Coal Technology (GCT) --Safety first!Safety first!

Kikuo MATSUI, Dr. Eng., Kikuo MATSUI, Dr. Eng., ProfessorProfessorDepartment of Earth Resources and Mining EngineeringDepartment of Earth Resources and Mining EngineeringDepartment of Earth Resources and Mining Engineering,Department of Earth Resources and Mining Engineering,Faculty of Engineering, Kyushu UniversityFaculty of Engineering, Kyushu UniversityFukuoka 819Fukuoka 819--0395, Japan0395, Japan

il t i@ i k hil t i@ i k h jjee--mail: matsui@mine.kyushumail: matsui@mine.kyushu--u.ac.jpu.ac.jp

Development process of a Development process of a p pp pnew minenew mine Geological surveyGeological survey ExplorationExplorationExplorationExploration Mine developmentMine development MiningMining Rehabilitation: acid mine drainageRehabilitation: acid mine drainage Rehabilitation: acid mine drainage, Rehabilitation: acid mine drainage,

selective mining, waste rock dumping selective mining, waste rock dumping it t i t lit t i t lsite, cover system, erosion control, site, cover system, erosion control,

revegetation etc.revegetation etc. Environmental monitoringEnvironmental monitoring 22

Mining methodsMining methodsMining methodsMining methods Surface/open cut mines:Surface/open cut mines: Strip mining; draglineStrip mining; draglinep g; gp g; g open pit mining; truck & shovel, open pit mining; truck & shovel,

BWE etcBWE etcBWE etc.BWE etc. Underground mines: manual, semiUnderground mines: manual, semi--

h i d f llh i d f ll h i dh i dmechanized, fullymechanized, fully--mechanizedmechanized Bord/RoomBord/Room--andand--pillar mining pillar mining Longwall/Longwall/shortwallshortwall miningmining Other methods depending on seamOther methods depending on seam Other methods depending on seam Other methods depending on seam

conditionsconditions 33

Open cut/surface mining:Open cut/surface mining: 40% of total produced coal (WCI40% of total produced coal (WCI））Open cut/surface mining:Open cut/surface mining: 40% of total produced coal (WCI40% of total produced coal (WCI））

（（For example, 80%: Australia,67%: USAFor example, 80%: Australia,67%: USA））

••Strip mining: horizontalStrip mining: horizontal～～gentle dip seamsgentle dip seams (side(side--casting incasting in--pit disposal)pit disposal)••Strip mining: horizontalStrip mining: horizontal～～gentle dip seamsgentle dip seams (side(side--casting, incasting, in--pit disposal)pit disposal)

••Open pit: Steep dip and multiOpen pit: Steep dip and multi--seams (dump site, outseams (dump site, out--ofof--pit disposal)pit disposal)

Mountain top removal mining (Appalachian coal field USA)Mountain top removal mining (Appalachian coal field USA)••Mountain top removal mining (Appalachian coal field, USA)Mountain top removal mining (Appalachian coal field, USA)

Stripping RatioStripping Ratio == Volume of Material (Volume of Material (bcmbcm)/)/ Extraction of Coal (ROMExtraction of Coal (ROM ton*)ton*)Stripping RatioStripping Ratio = = Volume of Material (Volume of Material (bcmbcm)/)/ Extraction of Coal (ROMExtraction of Coal (ROM--ton )ton )44

Strip Mining

55

Open pit mining (shovel & Open pit mining (shovel & p p g (p p g (truck): flexibletruck): flexible

66

Seismic survey and Seismic survey and exploration drillingexploration drilling

77

Topsoil stripping by bulldozer Topsoil stripping by bulldozer or scraperor scraperor scraperor scraper

88

Overburden drilling for blast Overburden drilling for blast holes and blastingholes and blasting

99

Blasting pattern (example)Blasting pattern (example)Blasting pattern (example)Blasting pattern (example)

1010

P d F t (P d F t (火薬原単位火薬原単位))Powder Factor(Powder Factor(火薬原単位火薬原単位))

Dragline: 0.2Dragline: 0.2--0.3 kg/m30.3 kg/m3 Shovel & trucks: 0.3Shovel & trucks: 0.3--0.5 kg/m30.5 kg/m3 Backhoe & trucks: 0 4Backhoe & trucks: 0 4--0 6 kg/m30 6 kg/m3Backhoe & trucks: 0.4Backhoe & trucks: 0.4--0.6 kg/m30.6 kg/m3 Dozer pushing: 0.3Dozer pushing: 0.3--0.5 kg/m30.5 kg/m3

1111

E l iE l i ((爆薬爆薬))ExplosivesExplosives ((爆薬爆薬))

ANFO (Ammonium Nitrate Fuel Oil ANFO (Ammonium Nitrate Fuel Oil Explosive)Explosive)Explosive)Explosive) Slurry, Slurry, WatergelWatergel, Emulsion Explosives, Emulsion Explosives High Density ANFO (emulsion blends or High Density ANFO (emulsion blends or

heavy ANFO)heavy ANFO)heavy ANFO)heavy ANFO) Velocity of detonation:Velocity of detonation:

ANFO 2,200ANFO 2,200--4,000 m/s4,000 m/sWatergelsWatergels 3 5003 500 5 000 m/s5 000 m/sWatergelsWatergels 3,5003,500--5,000 m/s5,000 m/sEmulsions 4,500Emulsions 4,500--6,100 m/s6,100 m/s 1212

Dragline (50 million US$)Dragline (50 million US$)Dragline (50 million US$)Dragline (50 million US$)

1313

1414

Bucket Wheel Excavator Bucket Wheel Excavator (over 1 billion US$)(over 1 billion US$)

1515

Truck and shovelTruck and shovelTruck and shovelTruck and shovel

1616

Super dump truckSuper dump truck--Komatsu 960E Komatsu 960E (P l d 327t) 5 illi US$(P l d 327t) 5 illi US$(Payload:327t) 5 million US$(Payload:327t) 5 million US$

1717

Coal extraction (truck, dozer & Coal extraction (truck, dozer & shovel)shovel)

1818

The major equipment for theThe major equipment for theThe major equipment for the The major equipment for the mine producing 7 Mt/yrmine producing 7 Mt/yr 6 x electric rotary drills (250 mm dia.) for overburden6 x electric rotary drills (250 mm dia.) for overburden 12 x electric shovels with 17 m3 buckets for12 x electric shovels with 17 m3 buckets for12 x electric shovels with 17 m3 buckets for 12 x electric shovels with 17 m3 buckets for

overburdenoverburden 4 x hydraulic shovels with 11 m3 buckets for coal4 x hydraulic shovels with 11 m3 buckets for coal 6 x rubber tired front end loaders with 9.6 m3 buckets6 x rubber tired front end loaders with 9.6 m3 buckets 50 x 154 t 900 kW rear dump trucks for waste haulage50 x 154 t 900 kW rear dump trucks for waste haulage 14 x 109 t 900 kW rear dump trucks for coal haulage14 x 109 t 900 kW rear dump trucks for coal haulage 19 x 300 kW track19 x 300 kW track--mounted bulldozersmounted bulldozers

3 224 kW h l d b lld3 224 kW h l d b lld 3 x 224 kW wheeled bulldozers3 x 224 kW wheeled bulldozers Other vehicles (PickOther vehicles (Pick--up cars, Siteup cars, Site--mixing truck, mixing truck,

Graders Water spray trucks etc )Graders Water spray trucks etc )Graders, Water spray trucks etc.) Graders, Water spray trucks etc.) 1919

P f f i tP f f i tPerformance of equipmentPerformance of equipment

Availability = Operated hours/Scheduled Availability = Operated hours/Scheduled h 100 (%)h 100 (%)hours x 100 (%)hours x 100 (%) Efficiency = Operated hours/Available Efficiency = Operated hours/Available y py p

hours x 100 (%)hours x 100 (%)Utilization Real work hours/OperatedUtilization Real work hours/Operated Utilization = Real work hours/Operated Utilization = Real work hours/Operated hours x 100 (%)hours x 100 (%)

The bigger the better!The bigger the better! The bigger, the better! The bigger, the better! 2020

Typical underground mining systemsTypical underground mining systems

2121

Room (Bord)Room (Bord)--andand--pillar pillar (Continuous miner and shuttle car)(Continuous miner and shuttle car)

2222

WongawilliWongawilli method and break line method and break line t (BLS)t (BLS)support (BLS)support (BLS)

2323

Long all miningLong all miningLongwall miningLongwall mining

Shield SupportsShield SupportsShearing MachineShearing Machine

Armored Face ConveyorArmored Face ConveyorStageloader &Stageloader &Belt TailpieceBelt Tailpiece

Drive Unit For Drive Unit For

pp

Armored Face ConveyorArmored Face Conveyor2424

Longwall face with shearer and Longwall face with shearer and shield supportsshield supportsshield supportsshield supports

Seam thickness: 1 5Seam thickness: 1 5--7 0m7 0mSeam thickness: 1.5Seam thickness: 1.5 7.0m7.0m High performanceHigh performance

2525

Plow mining Plow mining for thin for thin seams:seams:

Seam thickness: Seam thickness: 0.60.6--2.3 m2.3 m

F ll t tiF ll t tiFull automationFull automation

2626

ShortwallShortwall MiningMininggg

2727

Prop and cap mining systemProp and cap mining systemProp and cap mining systemProp and cap mining system

物理探査の概要物理探査の概要物理探査の概要物理探査の概要

2828

““KakkuchiKakkuchi” (Cut & fill) mining ” (Cut & fill) mining for steep coal seamfor steep coal seam

2929

Longwall top coal caving (LTCC) Longwall top coal caving (LTCC) g p g ( )g p g ( )method for extramethod for extra--thick seamthick seam

3030

MultiMulti--slicing slicing method for thick method for thick seamseamseamseam

3131

BlastingBlastingBlasting Blasting gallery gallery (BG) (BG) methodmethodmethod method for thick for thick seams seams usingusingusing using longlonglong long blasting blasting holesholes

32

Ring Ring blasting blasting patternpattern

Long all Panel DesignLong all Panel DesignLongwall Panel DesignLongwall Panel Design

Geological conditions: faults, coal seamGeological conditions: faults, coal seamP l iP l i Panel size: Panel size: Panel width; 50Panel width; 50--250 m, 250 m, Panel length; 300Panel length; 300--1000m, 1000m, aveave. 450m. 450m Super panel in the USASuper panel in the USASuper panel in the USASuper panel in the USA

Panel length; over 3000mPanel length; over 3000mT tT t il i P l l th b til i P l l th b tTwentyTwenty--mile mine: Panel length; aboutmile mine: Panel length; about6000m 6000m

3434

Vertical stress distribution Vertical stress distribution around a longwall panelaround a longwall panel

3535

InterpanelInterpanel--pillar systempillar systemInterpanelInterpanel pillar systempillar system

3636

Stability ofStability ofStability of Stability of the longwall the longwall face using face using hi ldhi ldshield shield

supportssupportssupportssupports

37

38

39

Rapid roadway drivage with Rapid roadway drivage with p y gp y gSS--100 Roadheader100 Roadheader

4040

Material transportMaterial transportMaterial transportMaterial transport

4141

RockboltsRockbolts

4242

Roadway drivage with Roadway drivage with y gy gbolter minerbolter miner

4343

Dual support system with steel supports and bolts

R f b ltR f b lt

steel supports and bolts

Roof bolt Roof bolt (2.4m)(2.4m)

Rib bolt(1.5m)Rib bolt(1.5m)

WW strap with steel meshstrap with steel meshWW--strap with steel meshstrap with steel mesh

Steel pipeSteel pipe

Fiber meshFiber mesh

Standing steel supportStanding steel support44

StressStressStress Stress conditions conditions in UK and in UK and Japan coal Japan coal minesminesmines mines

45

Strata Strata Behavior Monitoring Behavior Monitoring ggSystemSystem

(a) Monitoring System(a) Monitoring System (b) Tell(b) Tell--tale Systemtale System4646

Accidents in underground Accidents in underground ggcoal mines coal mines

1) Roof and rib falls1) Roof and rib falls2) O tb rsts of coal rock and gas2) O tb rsts of coal rock and gas2) Outbursts of coal, rock and gas2) Outbursts of coal, rock and gas3) Spontaneous combustion3) Spontaneous combustion4) Coal dust explosion: frictional sparks 4) Coal dust explosion: frictional sparks

from machine cuttingfrom machine cuttingfrom machine cuttingfrom machine cutting5) Gas explosion: frictional sparks from 5) Gas explosion: frictional sparks from

machine cuttingmachine cuttingmachine cuttingmachine cutting6) Mine fire6) Mine fire7) Water inrush and flooding7) Water inrush and flooding 4747

4848

Ca ses of roof fallCa ses of roof fallCauses of roof fallCauses of roof fall

Geological conditions: weak strata, Geological conditions: weak strata, deterioration due to water (humidity)deterioration due to water (humidity)deterioration due to water (humidity), deterioration due to water (humidity), wet/dry cycle of ventilated airwet/dry cycle of ventilated air Stress conditions: magnitude and Stress conditions: magnitude and

direction, heading faces, intersections, direction, heading faces, intersections, , g , ,, g , ,mining activitiesmining activities Support systems: bolting standingSupport systems: bolting standing Support systems: bolting, standing Support systems: bolting, standing

supports (steel arches, threesupports (steel arches, three--piece sets, piece sets, articulated supports, yielding supports, articulated supports, yielding supports, etc.)etc.)

4949

High all mining s stemsHigh all mining s stemsHighwall mining systemsHighwall mining systems Transit mining systems from surface to Transit mining systems from surface to a s g sys e s o su ace oa s g sys e s o su ace o

undergroundundergroundSafest ndergro nd mining s stemSafest ndergro nd mining s stem Safest underground mining system Safest underground mining system because of none working in undergroundbecause of none working in underground Mining systemsMining systems

1) Auger mining1) Auger mining1) Auger mining1) Auger mining2) 2) MetecMetec Miner SystemMiner System3) Continuous 3) Continuous HighwallHighwall Mining (CHM) Mining (CHM) System: Add car systemSystem: Add car system ArchveyorArchveyorSystem: Add car system, System: Add car system, ArchveyorArchveyorsystemsystem 5050

A ger miningA ger miningAuger miningAuger mining

5151

Metec miner s stemMetec miner s stemMetec miner systemMetec miner system

5252

Add car system (CHM)Add car system (CHM)Add car system (CHM)Add car system (CHM)

5353

A h t (CHM)A h t (CHM)Archveyor system (CHM)Archveyor system (CHM)

5454

Longwall punch miningLongwall punch mining

5555

Room/BordRoom/Bord--andand--pillar punch pillar punch miningmining

56

Environmental problems:Acid mine drainage (AMD)Acid mine drainage (AMD)

Acid drainage is low pH water with dissolved metalsand sulphate that drains frompyrite-rich rocks that havebeen exposed to oxidation.

F S2 + O2 + H2OFeS2 + O2 + H2O･･････Fe(OH)3 + H2SO4

5757

Methane gas Methane gas emission/diffusionemission/diffusion at pondsat pondsemission/diffusionemission/diffusion at pondsat ponds

5858

RehabilitationRehabilitation

Sedimentation pondSedimentation pond

Recovery of a disturbed land into a stable, safe and forming a sustainable forest ecosystem 5959

6060

Safet first!Safet first!Safety first!Safety first!

Thank you Thank you for your kind for your kind

attention!attention!

6161