Projjgect Magnet 2Y2 Years on… By: Paul Leevers

Project Magnetj g

2 Y2 Years on…

By: Paul Leevers

Mines Presentation - Jan 2004

Outline

• Resources

• Geology• Geology

• Mine Processes

• ConcentratorConcentrator


LOCATION


HISTORY OF THE IRON MAGNET DEPOSIT

• Magnetite Mineralisation in the Southern Middleback Ranges known about since the 1930’s

• 1967 – Adit at North End of Iron Duke Intersects Significant Magnetite Mineralisation

• 1970’s – Wide Spread Drilling Targets Magnetite Mineralisation1970 s Wide Spread Drilling Targets Magnetite Mineralisation

• 1989 – 33 DDH for 7400m drilled along 2.5 km. Establishing a resource in the Duchess Low Grade Deposit

• 2000 – OneSteel Spun out from BHP gaining rights to the Iron Resources of the Middleback Ranges

• 2002 – Review of Iron Resources remaining in the Middleback Ranges and the down stream processing benefits of using Magnetite - leads to feasibility study

• 2005 – Board Approval given and construction commenced

• 2007 – December – Successful cutover of pellet plant to magnetite concentrate


• 2009 – December – 2 Years successful integration of magnetite as feed to OneSteel’s Whyalla Operations

IRON MAGNET RESERVES/RESOURCES @ 30TH JUNE 2009

MtMt Mass Mass RecoveryRecovery SiO2_CSiO2_C

RESERVES

PROVENPROVEN 38.038.0 42.642.6 2.442.44

PROBABLEPROBABLE 45.345.3 41.741.7 2.082.08

TOTALTOTAL 83.383.3 42.142.1 2.252.25TOTAL TOTAL 83.383.3 42.142.1 2.252.25

RESOURCES

MtMt Mass RecoveryMass Recovery SiO2_CSiO2_C

MEASUREDMEASURED 42.242.2 42 642 6 2.002.0042.642.6

INDICATEDINDICATED 82.382.3 41.041.0 2.012.01

INFERRED INFERRED 109.6109.6 38.238.2 2.42.4

TOTALTOTAL 234.1234.1 40.040.0 2.22.2Estimate based on DTR analysis of all drill samples


Additional stockpiled Magnetite Ore @ June 30 2009 2.9 Mt @ 28.8% Mass Recovery, 7.6% SiO2 in concentrate – will be blended in later in Mine Life

MINE SEQUENCE STRATIGRAPHYCook Gap Schist

Sheared contact

Jaspilite JAS

Talc schist and other various talc, magnetite, chlorite & quartz schists

Magnetite silica

(Lower)

MTS

MTSMTT Magnetite talc

Magnetite carbonate

(Lower)Middleback

Iron FormationMTC

MTTMTT

Hematite Ore

Hematite-magnetitecarbonate

HEO

HMO

MTC

BSQ BSQ Basal Sequence

Hematite Carbonate

BSQ

HEC

HEO

Sulphide unitKatunga Dolomitewith intercalated volcanics

++++ ++ ++ ++Lincoln Complex

SBX

DOM


Sleaford Complex ++ ++++++++++ ++ ++

++ ++++++

++++ ++

++++++++ ++Lincoln Complex

Section @ 16575N


Cutback Wall @ 16675N

JASP

SCH MTT

MTC MTS


Magnetite Carbonate

Magnetite Carbonate – Typically Magnetite, Calcite, Dolomite, minor Siderite, Ankarite

Forms the core of the ore body and 60% of reserve – Typical mass recovery 45%


Metallurgically very soft producing low silica (2%) concentrate

Magnetite Talc Ore

Magnetite talc Typically Magnetite Talc Minor Serpentinite Free Quartz Dolomite


Magnetite talc – Typically Magnetite, Talc, Minor Serpentinite, Free Quartz, Dolomite

Generally fine grained (25 um) with sheared fabric, Mass Recovery ~ 45%

Processing requires fine grind for magnetite liberation, producing medium (4%) Silica Concentrates

Schist

Schist Ore – Typically Talc, Serpentinized, highly Schistose

Magnetite Generally fine grained (20 um) with sheared fabric Mass Recovery ~ 25%


Magnetite Generally fine grained (20 um) with sheared fabric, Mass Recovery ~ 25%

Occurs in the fold hinge of the Orebody

Processing requires fine grind for magnetite liberation, producing medium (4%) Silica Concentrates

Magnetite Silica Ore

Magnetite Silica Ore – Typically Silica, Magnetitte, Minor Talc / Serpentine along joint planes

Magnetite Generally fine grained (20 um)


Magnetite Generally fine grained (20 um)

Extremely Hard Fine Grained – Mass Recovery ~ 35%

Requires fine grind for magnetite liberation, producing High (7%) Silica Concentrates

Jaspilite

Jaspilite – Typically Silica, magnetite and minor haematite

Magnetite Generally fine grained (10 to 15 um)


Magnetite Generally fine grained (10 to 15 um)

Extremely Hard Fine Grained – Mass Recovery ~ 35%

Key contaminant in magnetite process, reducing throughput and producing poor quality concentrate +15% SiO2

Mining OperationsMining Operations

C t Fl tCurrent FleetDump Trucks – 30 (Mining and Rehandle Fleet)

4 x Excavators (3 x Hitachi Ex2500 1 x Hitachi Ex1900)4 x Excavators (3 x Hitachi Ex2500, 1 x Hitachi Ex1900)

17 x Loaders

Tracked / Wheeled Dozers x 6

Water Trucks x 4

3 x Graders


Workforce of approximately 450

Annual movement rate of 15.6 mBCM per annum (7.0 mBCM magnetite and 8.6 mBCM haematite

Mine Progression

Cutback Commencement - 2005 June 2007

November 2008 November 2009


November 2008

As mining has progressed The Magnetite ore body has been fully exposed allowing improved blending options which has aided in concentrator stability and product quality

November 2009

Magnet Life of Mine Schedule•Life Of Mine Schedule completed for current blending requirements(Aim 41.5% Mass Recovery, 2.5% SiO2_C Until 2012, 2.0% SiO2_C thereafter)

•Mine Stages based on optimising blending and deferring stripping ratioMine Stages based on optimising blending and deferring stripping ratio


Grade Control

Grade Control Critical for Magnetite FeedGrade Control Critical for Magnetite FeedKey Processes:

•Magnetic Susceptibility to define mass recovery•Head assay to define Silica content of ore and limited DTR work•Logging of blast holes to define ore typegg g yp

(for metallurgical properties)•Ore Mined and Stockpiled to these characteristics•Ore Crushed and blended for concentrator feed based on


Ore Crushed and blended for concentrator feed based on these characteristics – main aim consistency of blend•Short term mine schedule driven to ore characteristics

Short Term Mine Schedule

Key Scheduling Criteria are:•Mass Recovery >38.5%•Ore Blend (50% MTC, 25% MTT, 25% Other)

Rectangles represent individual blasts – key aim is to mine the entire ore body acrossRectangles represent individual blasts key aim is to mine the entire ore body across the pit in the minimum amount of blasts. This compensates for variation in mineralogy (highest across strike), reducing variation in concentrator performance in blend


Consistent silica head grade may not mean consistant silica concentrate grade due to mineralogical variation

Process Flow Concentrator


Front End ProcessCrushed – 32mm Blended Magnetite High Pressure Grinding Rolls

+3mm+3mm

-3mm

HPGR ScreensRougher Magnetic Separators


Magnetics to Ball Mill

Non Magnetics to

Tails

ConcentrationBall Mill Derrick Screens

+45 um

- 45 um

TailsTails

Cleaner Magnetic Separation DIMS Magnetic Separators

Mines Presentation - Jan 2004Magnetite Concentrate

TransportationConcentrate Pumping

Magnetite Concentrate

Mines Presentation - Jan 2004 Pellet Plant

Environmental Benefit


SummaryThe transition to magnetite concentrate from haematite feed for the OneSteel Whyalla Steelworks has been successful o e O eS ee W ya a S ee wo s as bee success udue to multi faceted teams incorporating multiple disciplines

The ability to blend and schedule to ore type and subsequent mineralogy has been key to a stable processsubsequent mineralogy has been key to a stable process

Work will continue in the future on further understanding of Work will continue in the future on further understanding of ggmineralogy, mine schedules and concentrator optimisation mineralogy, mine schedules and concentrator optimisation to further enhance magnetite quality and throughputto further enhance magnetite quality and throughput


Documents

Projjgect Magnet 2Y2 Years on… By: Paul Leevers