Coal mining

1. Coal mining methods
Coal mining methods
Coal 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., Professor
Professor
Department of Earth Resources and Mining Engineering
Department of Earth Resources and Mining Engineering
Department of Earth Resources and Mining Engineering,
Department of Earth Resources and Mining Engineering,
Faculty of Engineering, Kyushu University
Faculty of Engineering, Kyushu University
Fukuoka 819
Fukuoka 819-
-0395, Japan
0395, Japan
il t i@ i k h
il t i@ i k h j
j
e
e-
-mail: matsui@mine.kyushu
mail: matsui@mine.kyushu-
-u.ac.jp
u.ac.jp

2. Development process of a
Development process of a
p p
p p
new mine
new mine

 Geological survey
Geological survey

 Exploration
Exploration
Exploration
Exploration

 Mine development
Mine development

 Mining
Mining

 Rehabilitation: acid mine drainage
Rehabilitation: 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 l
it t i t l
site, cover system, erosion control,
site, cover system, erosion control,
revegetation etc.
revegetation etc.

 Environmental monitoring
Environmental monitoring 2
2

3. Mining methods
Mining methods
Mining methods
Mining methods

 Surface/open cut mines:
Surface/open cut mines:

 Strip mining; dragline
Strip mining; dragline
p g; g
p g; g

 open pit mining; truck & shovel,
open pit mining; truck & shovel,
BWE etc
BWE etc
BWE etc.
BWE etc.

 Underground mines: manual, semi
Underground mines: manual, semi-
-
h i d f ll
h i d f ll h i d
h i d
mechanized, fully
mechanized, fully-
-mechanized
mechanized

 Bord/Room
Bord/Room-
-and
and-
-pillar mining
pillar mining

 Longwall/
Longwall/shortwall
shortwall mining
mining

 Other methods depending on seam
Other methods depending on seam

 Other methods depending on seam
Other methods depending on seam
conditions
conditions 3
3

4. 
Open cut/surface mining:
Open cut/surface mining: 40% of total produced coal (WCI
40% of total produced coal (WCI）
）
Open cut/surface mining:
Open cut/surface mining: 40% of total produced coal (WCI
40% of total produced coal (WCI）
）

 （
（For example, 80%: Australia,67%: USA
For example, 80%: Australia,67%: USA）
）
•
•Strip mining: horizontal
Strip mining: horizontal～
～gentle dip seams
gentle dip seams (side
(side-
-casting in
casting in-
-pit disposal)
pit disposal)
•
•Strip mining: horizontal
Strip mining: horizontal～
～gentle dip seams
gentle dip seams (side
(side-
-casting, in
casting, in-
-pit disposal)
pit disposal)
•
•Open pit: Steep dip and multi
Open pit: Steep dip and multi-
-seams (dump site, out
seams (dump site, out-
-of
of-
-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 Ratio
Stripping Ratio =
= Volume of Material (
Volume of Material (bcm
bcm)/
)/ Extraction of Coal (ROM
Extraction of Coal (ROM ton*)
ton*)

Stripping Ratio
Stripping Ratio =
= Volume of Material (
Volume of Material (bcm
bcm)/
)/ Extraction of Coal (ROM
Extraction of Coal (ROM-
-ton )
ton )
4
4

5. Strip Mining
5
5

6. Open pit mining (shovel &
Open pit mining (shovel &
p p g (
p p g (
truck): flexible
truck): flexible
6
6

7. Seismic survey and
Seismic survey and
exploration drilling
exploration drilling
7
7

8. Topsoil stripping by bulldozer
Topsoil stripping by bulldozer
or scraper
or scraper
or scraper
or scraper
8
8

9. Overburden drilling for blast
Overburden drilling for blast
holes and blasting
holes and blasting
9
9

10. Blasting pattern (example)
Blasting pattern (example)
Blasting pattern (example)
Blasting pattern (example)
10
10

11. 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: 0.2
Dragline: 0.2-
-0.3 kg/m3
0.3 kg/m3

 Shovel & trucks: 0.3
Shovel & trucks: 0.3-
-0.5 kg/m3
0.5 kg/m3

 Backhoe & trucks: 0 4
Backhoe & trucks: 0 4-
-0 6 kg/m3
0 6 kg/m3
Backhoe & trucks: 0.4
Backhoe & trucks: 0.4-
-0.6 kg/m3
0.6 kg/m3

 Dozer pushing: 0.3
Dozer pushing: 0.3-
-0.5 kg/m3
0.5 kg/m3
11
11

12. E l i
E l i (
(爆薬
爆薬)
)
Explosives
Explosives (
(爆薬
爆薬)
)

 ANFO (Ammonium Nitrate Fuel Oil
ANFO (Ammonium Nitrate Fuel Oil
Explosive)
Explosive)
Explosive)
Explosive)

 Slurry,
Slurry, Watergel
Watergel, 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 2,200
ANFO 2,200-
-4,000 m/s
4,000 m/s
Watergels
Watergels 3 500
3 500 5 000 m/s
5 000 m/s
Watergels
Watergels 3,500
3,500-
-5,000 m/s
5,000 m/s
Emulsions 4,500
Emulsions 4,500-
-6,100 m/s
6,100 m/s
12
12

13. Dragline (50 million US$)
Dragline (50 million US$)
Dragline (50 million US$)
Dragline (50 million US$)
13
13

14. 14
14

15. Bucket Wheel Excavator
Bucket Wheel Excavator
(over 1 billion US$)
(over 1 billion US$)
15
15

16. Truck and shovel
Truck and shovel
Truck and shovel
Truck and shovel
16
16

17. Super dump truck
Super 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$
17
17

18. Coal extraction (truck, dozer &
Coal extraction (truck, dozer &
shovel)
shovel)
18
18

19. The major equipment for the
The major equipment for the
The major equipment for the
The major equipment for the
mine producing 7 Mt/yr
mine producing 7 Mt/yr

 6 x electric rotary drills (250 mm dia.) for overburden
6 x electric rotary drills (250 mm dia.) for overburden

 12 x electric shovels with 17 m3 buckets for
12 x electric shovels with 17 m3 buckets for
12 x electric shovels with 17 m3 buckets for
12 x electric shovels with 17 m3 buckets for
overburden
overburden

 4 x hydraulic shovels with 11 m3 buckets for coal
4 x hydraulic shovels with 11 m3 buckets for coal

 6 x rubber tired front end loaders with 9.6 m3 buckets
6 x rubber tired front end loaders with 9.6 m3 buckets

 50 x 154 t 900 kW rear dump trucks for waste haulage
50 x 154 t 900 kW rear dump trucks for waste haulage

 14 x 109 t 900 kW rear dump trucks for coal haulage
14 x 109 t 900 kW rear dump trucks for coal haulage

 19 x 300 kW track
19 x 300 kW track-
-mounted bulldozers
mounted bulldozers
3 224 kW h l d b lld
3 224 kW h l d b lld

 3 x 224 kW wheeled bulldozers
3 x 224 kW wheeled bulldozers

 Other vehicles (Pick
Other vehicles (Pick-
-up cars, Site
up 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.)
19
19

20. P f f i t
P f f i t
Performance of equipment
Performance 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 p
y p
hours x 100 (%)
hours x 100 (%)
Utilization Real work hours/Operated
Utilization 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!
20
20

21. Typical underground mining systems
Typical underground mining systems
21
21

22. Room (Bord)
Room (Bord)-
-and
and-
-pillar
pillar
(Continuous miner and shuttle car)
(Continuous miner and shuttle car)
22
22

23. Wongawilli
Wongawilli method and break line
method and break line
t (BLS)
t (BLS)
support (BLS)
support (BLS)
23
23

24. Long all mining
Long all mining
Longwall mining
Longwall mining

Shield Supports
Shield Supports

Shearing Machine
Shearing Machine

Armored Face Conveyor
Armored Face Conveyor

Stageloader &
Stageloader &

Belt Tailpiece
Belt Tailpiece

Drive Unit For
Drive Unit For
p
p

Armored Face Conveyor
Armored Face Conveyor
24
24

25. Longwall face with shearer and
Longwall face with shearer and
shield supports
shield supports
shield supports
shield supports

 Seam thickness: 1 5
Seam thickness: 1 5-
-7 0m
7 0m
Seam thickness: 1.5
Seam thickness: 1.5 7.0m
7.0m

 High performance
High performance
25
25

26. Plow mining
Plow mining
for thin
for thin
seams:
seams:
Seam thickness:
Seam thickness:
0.6
0.6-
-2.3 m
2.3 m
F ll t ti
F ll t ti
Full automation
Full automation
26
26

27. 
Shortwall
Shortwall Mining
Mining
g
g
27
27

28. 
Prop and cap mining system
Prop and cap mining system
Prop and cap mining system
Prop 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
28
28

29. “
“Kakkuchi
Kakkuchi” (Cut & fill) mining
” (Cut & fill) mining
for steep coal seam
for steep coal seam
29
29

30. Longwall top coal caving (LTCC)
Longwall top coal caving (LTCC)
g p g ( )
g p g ( )
method for extra
method for extra-
-thick seam
thick seam
30
30

31. Multi
Multi-
-slicing
slicing method for thick
method for thick
seam
seam
seam
seam
31
31

32. Blasting
Blasting
Blasting
Blasting
gallery
gallery
(BG)
(BG)
method
method
method
method
for thick
for thick
seams
seams
using
using
using
using
long
long
long
long
blasting
blasting
holes
holes
32

33. Ring
Ring
blasting
blasting
pattern
pattern

34. Long all Panel Design
Long all Panel Design
Longwall Panel Design
Longwall Panel Design

 Geological conditions: faults, coal seam
Geological conditions: faults, coal seam
P l i
P l i

 Panel size:
Panel size:
Panel width; 50
Panel width; 50-
-250 m,
250 m,
Panel length; 300
Panel length; 300-
-1000m,
1000m, ave
ave. 450m
. 450m

 Super panel in the USA
Super panel in the USA
Super panel in the USA
Super panel in the USA
Panel length; over 3000m
Panel length; over 3000m
T t
T t il i P l l th b t
il i P l l th b t
Twenty
Twenty-
-mile mine: Panel length; about
mile mine: Panel length; about
6000m
6000m
34
34

35. Vertical stress distribution
Vertical stress distribution
around a longwall panel
around a longwall panel
35
35

36. Interpanel
Interpanel-
-pillar system
pillar system
Interpanel
Interpanel pillar system
pillar system
36
36

37. Stability of
Stability of
Stability of
Stability of
the longwall
the longwall
face using
face using
hi ld
hi ld
shield
shield
supports
supports
supports
supports
37

38. 38

39. 39

40. Rapid roadway drivage with
Rapid roadway drivage with
p y g
p y g
S
S-
-100 Roadheader
100 Roadheader
40
40

41. Material transport
Material transport
Material transport
Material transport
41
41

42. Rockbolts
Rockbolts
42
42

43. Roadway drivage with
Roadway drivage with
y g
y g
bolter miner
bolter miner
43
43

44. Dual support system with
steel supports and bolts
R f b lt
R f b lt
steel supports and bolts

Roof bolt
Roof bolt
(2.4m)
(2.4m)

Rib bolt(1.5m)
Rib bolt(1.5m)

W
W strap with steel mesh
strap with steel mesh

W
W-
-strap with steel mesh
strap with steel mesh

Steel pipe
Steel pipe

Fiber mesh
Fiber mesh

Standing steel support
Standing steel support
44

45. Stress
Stress
Stress
Stress
conditions
conditions
in UK and
in UK and
Japan coal
Japan coal
mines
mines
mines
mines
45

46. Strata
Strata Behavior Monitoring
Behavior Monitoring
g
g
System
System
(a) Monitoring System
(a) Monitoring System (b) Tell
(b) Tell-
-tale System
tale System
46
46

47. Accidents in underground
Accidents in underground
g
g
coal mines
coal mines
1) Roof and rib falls
1) Roof and rib falls
2) O tb rsts of coal rock and gas
2) O tb rsts of coal rock and gas
2) Outbursts of coal, rock and gas
2) Outbursts of coal, rock and gas
3) Spontaneous combustion
3) Spontaneous combustion
4) Coal dust explosion: frictional sparks
4) Coal dust explosion: frictional sparks
from machine cutting
from machine cutting
from machine cutting
from machine cutting
5) Gas explosion: frictional sparks from
5) Gas explosion: frictional sparks from
machine cutting
machine cutting
machine cutting
machine cutting
6) Mine fire
6) Mine fire
7) Water inrush and flooding
7) Water inrush and flooding 47
47

48. 48
48

49. Ca ses of roof fall
Ca ses of roof fall
Causes of roof fall
Causes 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 air
wet/dry cycle of ventilated air

 Stress conditions: magnitude and
Stress conditions: magnitude and
direction, heading faces, intersections,
direction, heading faces, intersections,
, g , ,
, g , ,
mining activities
mining activities

 Support systems: bolting standing
Support systems: bolting standing

 Support systems: bolting, standing
Support systems: bolting, standing
supports (steel arches, three
supports (steel arches, three-
-piece sets,
piece sets,
articulated supports, yielding supports,
articulated supports, yielding supports,
etc.)
etc.)
49
49

50. High all mining s stems
High all mining s stems
Highwall mining systems
Highwall mining systems

 Transit mining systems from surface to
Transit mining systems from surface to
a s g sys e s o su ace o
a s g sys e s o su ace o
underground
underground
Safest ndergro nd mining s stem
Safest ndergro nd mining s stem

 Safest underground mining system
Safest underground mining system
because of none working in underground
because of none working in underground

 Mining systems
Mining systems
1) Auger mining
1) Auger mining
1) Auger mining
1) Auger mining
2)
2) Metec
Metec Miner System
Miner System
3) Continuous
3) Continuous Highwall
Highwall Mining (CHM)
Mining (CHM)
System: Add car system
System: Add car system Archveyor
Archveyor
System: Add car system,
System: Add car system, Archveyor
Archveyor
system
system 50
50

51. A ger mining
A ger mining
Auger mining
Auger mining
51
51

52. Metec miner s stem
Metec miner s stem
Metec miner system
Metec miner system
52
52

53. Add car system (CHM)
Add car system (CHM)
Add car system (CHM)
Add car system (CHM)
53
53

54. A h t (CHM)
A h t (CHM)
Archveyor system (CHM)
Archveyor system (CHM)
54
54

55. Longwall punch mining
Longwall punch mining
55
55

56. Room/Bord
Room/Bord-
-and
and-
-pillar punch
pillar punch
mining
mining
56

57. Environmental problems:
Acid mine drainage (AMD)
Acid mine drainage (AMD)
Acid drainage is low pH
water with dissolved metals
and sulphate that drains from
pyrite-rich rocks that have
been exposed to oxidation.
F S2 + O2 + H2O
FeS2 + O2 + H2O･･････
Fe(OH)3 + H2SO4
57
57

58. Methane gas
Methane gas
emission/diffusion
emission/diffusion at ponds
at ponds
emission/diffusion
emission/diffusion at ponds
at ponds
58
58

59. Rehabilitation
Rehabilitation
Sedimentation pond
Sedimentation pond
Recovery of a disturbed land into a stable, safe and forming a sustainable
forest ecosystem 59
59

60. 60
60

61. Safet first!
Safet first!
Safety first!
Safety first!
Thank you
Thank you
for your kind
for your kind
attention!
attention!
61
61