Centennial Coal

Clarence Colliery – Subsidence Management

Allison Golsby

Hunter ValleyOctober 2010

Longwall 2010

3

Clarence Colliery

Location

Western Coal Fields

approximately 10km

east of Lithgow

One of nine of

Centennial Coal’s

underground

operations

Rail connection to Port

Kembla Coal Terminal

Scone

Rylstone

Mudgee

Muswellbrook

Singleton

Maitland

Newcastle

Lithgow

Gosford

SYDNEYKatoomba

WollongongPort Kembla

Kiama

Moss Vale

Charbon

Angus Place

Springvale

Clarence

Newstan LochielMyunaMandalong

IvanhoeNorth

Airly

Awaba

Mannering

Inglenook

Exploration area

Scone

Rylstone

Mudgee

Muswellbrook

Singleton

Maitland

Newcastle

Lithgow

Gosford

SYDNEYKatoomba

WollongongPort Kembla

Kiama

Moss Vale

Charbon

Angus Place

Springvale

Clarence

Newstan LochielMyunaMandalong

IvanhoeNorth

Airly

Awaba

Mannering

Inglenook

Exploration area

4

The Resource

Clarence has a production

capacity of up to 2.1 million

tonnes per annum using

three continuous miners.

Clarence, currently operates

a section, or panel, using a

continuous miner, a mobile

bolter unit, and 3 shuttle

cars.

5

Cutting the coal

The Clarence partial

pillar extraction system

A high capacity

continuous haulage

mining system (Joy

4FCT) has been installed

replacing 3 shuttle cars,

and a feeder.

6

Clarence Colliery

Seam Characteristics

Mines the Katoomba

Seam

Exports low ash thermal

coal

Generally competent

sandstone roof and

strong floor

7

The Petrology

Seam Characteristics

Averages 2.4m to 4.0m high

Seam gradient dips at an average

of 10 to the ENE. Localised rolls

occur around geological structure

Cover depth is generally less than

200m but reaches 270m

Small geological faults exist in the

projected mining panels

8

Mining Method - Historical

600 Panels Mining Area

Drifts and Pit Bottom

800 Panels Mining Area - Future

700 Panels Mining Area

900 Panels Mining Area

9

Mining Method - Current

Long wall

Pillar Splitting

Partial Pillar Extraction

Split and Lift full extraction

Wongawilli

full extraction

First workings

10

Mine Design

Design Criteria

Subsidence Management

Plan – Mine design Driver

Maximise resource recovery

without fracturing the

overburden

Mitigate groundwater inflow and

disturbance to aquifers

Minimise surface subsidence

under sensitive features

11

What is Subsidence?

Subsidence

Lowering or settling down of the lands surface

12

What influences Subsidence?

Mine Subsidence Board Mine Subsidence – A Community Guide, available from

http://minesubnswgovau.ozstaging.com/SiteFiles/minesubnswgovau/MSB6ppA4Community07.pdf :accessed

26 Sept 2010

13

Mine Design

SMG Consultants. Section 1 Over proposed workings (2006)

14

Mine Design

15

Pillar Design

Strata Engineering (2008)

16

Pillar stability

Strata Engineering (2005)

17

Pillar stability

Strata Engineering (2005)

18

Panel designs

Panel designs

Some of the panel designs

considered by Clarence

19

Extraction analysis

20

SubsidenceSubsidence

-0.035

-0.030

-0.025

-0.020

-0.015

-0.010

-0.005

0.000

0.005

0.010

0.015

0.020

T1

T5

T9

T13

T17

T21

T25

T29

T33

T37

T41

T45

T49

T53

T57

T61

T65

T69

T73

T77

T81

T85

T89

T93

T97

T101

T105

T109

T113

T117

T121

T125

T129

T133

T137

Mark

Su

bs

ide

nc

e (

m)

06/03/2008 01/07/2008 10/09/2008

Subsidence

-0.035

-0.030

-0.025

-0.020

-0.015

-0.010

-0.005

0.000

0.005

0.010

0.015

0.020

T1 T5 T9 T13

T17

T21

T25

T29

T33

T37

T41

T45

T49

T53

T57

T61

T65

T69

T73

T77

T81

T85

T89

T93

T97

T101

T105

T109

T113

T117

T121

T125

T129

T133

T137

Mark

Su

bs

ide

nc

e (

m)

06/03/2008 01/07/2008 10/09/2008

T Line (2008)

21

Our Results

22

Questions

Any Questions

Centennial Coal

Clarence Colliery - Subsidence management

Allison Golsby

Hunter Valley October 2010

Longwall 2010

Thank you.