AUSTAR COAL MINE

A2 MAINGATEROADWAY

DEVELOPMENTExperiences and Lessons

LearnedPresenter

Glenn SobeyDevelopment Mining Engineer

Austar Coal Mine

SITE LOCATIONAustar Coal Mine

AUSTAR IN BRIEF

• Owned and operated by Yancoal Australia.

• Better know for the introduction of the LTCC Longwall Face

• Mines the Greta Coal Seam.

• Development to date utilising 2x ABM20 and 1x ABM25 Continuous Miners.

Austar Coal Mine

MINE OVERVIEWAustar Coal Mine

ShaftD/C

N0.2

3. ShaftUC443m

HTCable Hole

Air HoleComp

Tube

451m

448m

435.7m

HoleBallast

434m

1 ShaftD/C

Bundle Hole

<5

Qu

orro

bolo

ng Fa

ult Z

one

<5

<5

>5

Quorrobolong Fault Zone

Swam

p Fault

Indicated by Seismic

& Drilling

Mag

netics

Gro

und

Mag

netics

Gro

und

Seismic

& Drilling

Seism

ic

Cen

tral D

yke

Abernethy Fault Zone

Bellbird Fault Bellbird Branch Fault

Kalingo Fault Zone

Eg

ling

ton

Fau

lt

Lag

oon

'B' Fa

ult

Lag

oon

'A' Fa

ult

Lag

oon

'C' Fa

ult

Barraba Fault Zone

Greenmount Fault Zone

6m

AberdareCentral

CessnockNo 1

( Kalingo )

100 MAINS

20

1 P

anel

20

2 P

anel

101

Pane

l

200

MAI

NS

102

Pane

l

103

Pane

l

104

Pane

l

455m

HTCable Hole& Nitrogen

DeWater

456m455m

4. ShaftD/C453m

272m

2 ShaftD/C474m

Solcen ic, H ODiesel

2

CURRENT WORKINGS PROPOSED WORKINGS OLD ABANDONED WORKINGS

A2 Maingate

A2 MAINGATE

• Total Block Length 1179m• Design Pillar Dimensions of 100m x 35m• Profile – 5m wide x 3.2m high• Mining Horizon – 1.5 > 2m Coal Tops• 2x ABM20 – Twin and Super Unit

Austar Coal Mine

LW_ ATM07241:1500

3/9/2007

D.J OLLIFFE

LONGWALL A1AUTHORITY TO MINE

S:\01 Austar Safety Management System\002 Mining Operations\010 Longwall\001 Authority to Mine\LW_ATM007 030907 A1 LONGWALL.doc

MINING CONDITIONS• Greta Seam Coal Measures

– 5.5m – 7m thick– low strength (5 - 8MPa)– Immediate 15m of roof laminated

(20-60MPa)

• Immediate floor soft mudstone (20MPa)

• Geotechnical Issues – seam highly cleated and jointed– inseam shear zones– High horizontal stresses (40-

50MPa)

Austar Coal Mine

A2 MAINGATE

• Zone 1 – 2>6c/t – Soft Ribs and Soft Floor

Austar Coal Mine

LW_ ATM07241:1500

3/9/2007

D.J OLLIFFE

LONGWALL A1AUTHORITY TO MINE

S:\01 Austar Safety Management System\002 Mining Operations\010 Longwall\001 Authority to Mine\LW_ATM007 030907 A1 LONGWALL.doc

Zone 1 Zone 2 Zone 3

• Zone 2 – 5>9c/t – High Pressure Stress Zone

• Zone 3 – 10>14c/t – Continuous Cavity Zone

ZONE 1

• Zone 1– Characterised by Soft Ribs and Soft Floor– Rib conditions Structure driven– Floor conditions Water driven

Austar Coal Mine

ZONE 1 – Rib ConditionsAustar Coal Mine

ZONE 1 – Rib ConditionsAustar Coal Mine

AUGER STEELSAustar Coal Mine

The Auger Steel cleared the cuttings far more effectively then the standard Scroll Steel in sugary coal.

ZONE 1 – Floor ConditionsAustar Coal Mine

PIT TOP

#2 SHAFT

KITCHENER FACILITY

#3 SHAFT

#4 SHAFT#1 SHAFT

PROPOSED SHAFTS

CHPP

PIT TOP

#2 SHAFT

KITCHENER FACILITY

#3 SHAFT

#4 SHAFT#1 SHAFT

PROPOSED SHAFTS

CHPP Water from the flooded workings immediately Up Dip of the A2 Maingate caused the soft mudstone floor to break up during wheeling.

FLANKING HOLES

• Drilled in advance of the Development Roadways to control the water seepage into the roadways.

• Repeat of the practise adopted for the A1 Maingate.• Peak water make from some of the holes + 5 l/s.

Austar Coal Mine

LW_ ATM07241:1500

3/9/2007

D.J OLLIFFE

LONGWALL A1AUTHORITY TO MINE

S:\01 Austar Safety Management System\002 Mining Operations\010 Longwall\001 Authority to Mine\LW_ATM007 030907 A1 LONGWALL.doc

A1 Flanking Holes

A2 Flanking Holes

ZONE 1 – Floor ConditionsAustar Coal Mine

Skulls and Brattice

ZONE 2

• Zone 2– High Pressure Stress Zone– Cavities forming in front of the Miner– Face busting out 2m ahead of the cutter head

and 2m above the Top of Coal

Austar Coal Mine

ZONE 2 – Roof CavitiesAustar Coal Mine

ZONE 2 – Roof CavitiesAustar Coal Mine

ZONE 2 – Roof CavitiesAustar Coal Mine

ZONE 2 –Cavity RecoveryAustar Coal Mine

MESHXPRESS PLATESAustar Coal Mine

MESHXpress Plates used to pin the mesh to the spot bolts

Wyberex BoltsAustar Coal Mine

Wyberex Bolts installed and PUR’d to form an artificial beam in the roof above the Dosco marker band.

Bolts in the Rib angled out to reinforce the Rib inbye the face.

300mm x 300mm Pattern

Dosco Band

4m Wyberex Bolt

2m Wyberex Bolt

Cavity Recovery Permit

Permit System introduced due to the high risk nature of recovering the Cavities.

•Permit includes:– A minimum number skilled competent and

experienced operators– The correct materials for the task

Austar Coal Mine

ZONE 3

• Zone 3– Continuous Cavity forming between the face

and the last line of support.

Austar Coal Mine

ZONE 3 – CavitiesAustar Coal Mine

ZONE 3 – CavitiesAustar Coal Mine

ZONE 3 – CavitiesAustar Coal Mine

Cavity SupportAustar Coal Mine

CROWN

SUPPORT

EDGE

SUPPORT

CROWN

SUPPORTEDGE

SUPPORT

MESH

PRODUCTIVITYAustar Coal Mine

Average Shift Advance per Miner

0

1

2

3

4

5

6

7

8

9

10

Date

Met

re /

Sh

ift

Average Shift Advance

Zone 1 Zone 2 Zone 3

• Development in Zone 1 and 2 off-set by Twin Miner.

• Modify Sequence to cope with Conditions.

• Zone 3 Driven as Super Unit.

SAFETY• Nil Lost Time Injuries• Nil Disabling Injuries

Key Factors• Training• Attention to Detail• Close Supervision,• Systems

There were 2 First Aid Injuries due to roof material

Austar Coal Mine

CONCLUSION

Safety First and Development will Follow

Austar Coal Mine

QUESTIONS?Austar Coal Mine