projjgect magnet 2y2 years on… by: paul leevers
TRANSCRIPT
Project Magnetj g
2 Y2 Years on…
By: Paul Leevers
Mines Presentation - Jan 2004
Outline
• Resources
• Geology• Geology
• Mine Processes
• ConcentratorConcentrator
Mines Presentation - Jan 2004
LOCATION
Mines Presentation - Jan 2004
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
Mines Presentation - Jan 2004
• 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
Mines Presentation - Jan 2004
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
Mines Presentation - Jan 2004
Sleaford Complex ++ ++++++++++ ++ ++
++ ++++++
++++ ++
++++++++ ++Lincoln Complex
Section @ 16575N
Mines Presentation - Jan 2004
Cutback Wall @ 16675N
JASP
SCH MTT
MTC MTS
Mines Presentation - Jan 2004
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%
Mines Presentation - Jan 2004
Metallurgically very soft producing low silica (2%) concentrate
Magnetite Talc Ore
Magnetite talc Typically Magnetite Talc Minor Serpentinite Free Quartz Dolomite
Mines Presentation - Jan 2004
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%
Mines Presentation - Jan 2004
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)
Mines Presentation - Jan 2004
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)
Mines Presentation - Jan 2004
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
Mines Presentation - Jan 2004
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
Mines Presentation - Jan 2004
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
Mines Presentation - Jan 2004
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
Mines Presentation - Jan 2004
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
Mines Presentation - Jan 2004
Consistent silica head grade may not mean consistant silica concentrate grade due to mineralogical variation
Process Flow Concentrator
Mines Presentation - Jan 2004
Front End ProcessCrushed – 32mm Blended Magnetite High Pressure Grinding Rolls
+3mm+3mm
-3mm
HPGR ScreensRougher Magnetic Separators
Mines Presentation - Jan 2004
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
Mines Presentation - Jan 2004
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
Mines Presentation - Jan 2004