Presenter: Herman Oosthuysen- Process Manager, DRA11-12 June 2015, Adelaide Convention Centre
Africa Australia Technical Mining Conference 2015
PROCESS REVIEW FOR IRON ORE BENEFICIATION
• OVERVIEW
• FLOW DIAGRAM
• COMMINUTION/ LIBERATION
• BENEFICIATION
• SOLID LIQUID SEPARATION
• PRODUCT HANDLING
• CONCLUSION
Africa Australia Technical Mining Conference 2015
CONTENT
0
200
400
600
800
1,000
1,200
Chi
na's
Milli
ion
met
ric to
nnes
D
eman
d
YearsChina Iron Ore demand Source: Morgan Stanley
020406080
100120140160180200
US
Dol
lor p
er d
ry m
etric
tonn
es
April 2005 to March 2015China import Iron Ore Fines 62% Fe spot price
Source: Mundi Index Africa Australia Technical Mining Conference 2015
OVERVIEW‐IRON ORE DEMAND & SUPPLY
Africa Australia Technical Mining Conference 2015
OVERVIEW OF WEST AFRICAN IRON ORE
ROM Size ReductionSize
ClassificationBeneficiation
by Size Fraction
Product
Rejects
Crushing
Milling
Scrubbing
Screening
Primary Beneficiation
Secondary Beneficiation
Tertiary Beneficiation
Mining - BlastingROM BlendingIn Pit
Product Blending
ROM BlendingCrushed ROM
Product Transport
Tails/ Rejects Storage
Africa Australia Technical Mining Conference 2015
PROCESS MODEL FOR IRON ORE
• Mineralogy
• Liberation characteristics
• Product size and grade suite
• Yield & grade
• Energy efficiency
• Equipment selection
• CAPEX & OPEX
• SHE
• Risk
Africa Australia Technical Mining Conference 2015
FLOWSHEET BUILDING BLOCKS & CONSIDERATIONS
Scr
ubbi
ng &
Scr
eeni
ng
PrimaryBeneficiation
TertiaryBeneficiation
Secondary Beneficiation
• JAW CRUSHER – Low Capex
• MINERAL SIZER- High clay in feed
• HPGR- High throughput and high reduction ratio required
• CONE CRUSHER- Minimising fines generation
• AG MILLING-Combined comminution and scrubbing steps
Africa Australia Technical Mining Conference 2015
Primary Gyrator and Secondary Cone Crushing
LIBERATION & COMMINUTION‐EQUIPMENT'S SELECTION
Wet screening and Coarse & Fine Jig
• OVERVIEW
• FLOW DIAGRAM
• COMMINUTION/ LIBERATION
• BENEFICIATION
• SOLID LIQUID SEPARATION
• PRODUCT HANDLING
• CONCLUSION
Africa Australia Technical Mining Conference 2015
CONTENT
Sorter Plant (DRA, 2015)
SORTER: Material can be sorted based on
1. According to Color (CCD)
2. According to Material (NIR)
3. According to Element
Composition (XRF/XRT)
Africa Australia Technical Mining Conference 2015
SECONDARY BENEFICIATION ‐ SORTER
Labrador Iron Ore Plant (DRA, 2011)
(Khumani Jig Plant (DRA, 2008)
• Operating size range
• Particle shape effects
• Can cut at higher density
• Different capacities per size fraction
• Optimised using on-line analyser
• Key aspect to design a jig plant
Africa Australia Technical Mining Conference 2015
SECONDARY BENEFICIATION‐ JIG
Modular plant
• High NGM
• Pilot-scale test operating density 4.2 g/cm3.
• Gas atomised FeSi
• Separation efficiency – Lower D50 & Yield benefit
Africa Australia Technical Mining Conference 2015
SECONDARY BENEFICIATION‐ DMS/ UHDMS
• Separating sizes range: 2.0 - 0.1 mm
• Capacities: up to 7 t/h
• Configured 5 - 7 turns; can accommodate 4 starts per column
• Iron Ore specific developments over the years:
o Improved materials, feed box, splitter & trough design
o Improved water addition, capacity, re-pulpers, product
boxes
• Recent trends: high capacity units; automate splitter
adjustments
Africa Australia Technical Mining Conference 2015
SECONDARY BENEFICIATION‐SPIRAL
Factors influencing performance & operation:
o Volume concentration of solids
o Particle size & shape
o Bed level control
Three product classifier
Reflux Classifier
•Reflux Classifier Incorporates ‘laminar high
shear rate’ mechanism
•Result in higher capacity per area and
Efficiency
• Test and pilot plant proves easily upgrade
to >60%Fe in a single stage
Africa Australia Technical Mining Conference 2015
SECONDARY BENEFICIATION‐ UP‐FLOW CLASSIFIERS
Design Consideration
• Oversize protection screen
• LIMS before WHIMS
• Magnetic field Intensity and Matrix size at each stage in WHIMS
• Consider two stage beneficiation to ensure product grade
Classification
• LIMS, MIMS and HIMS
• LIMS- Co-current, counter-rotation or
counter-current.
• WHIMS- Vertical and Horizontal carousel
Magnetite Beneficiation Plant ( DRA, 2014)
Khumani WHIMS Plant (DRA, 2013) Africa Australia Technical Mining Conference 2015
TERTIARY BENEFICIATION‐MAGNETIC SEPARATION
Chemistry Component
CollectorFrother
ActivatorDepressant
pH
Operation Component
Feed rateMineralogy
Particle SizePulp densityTemperature
Equipment Component
Cell DesignAgitationAir Flow
Cell bank ConfigurationCell bank control
FLOTATION SYSTEM
• Mineralogy
• Gangue and Mineral liberation size
• Flotation reagent suite
• Mixed flotation circuit- Combination of
MagSep and Flotation
Source: Flotation system (Klimpel, 1995)
Africa Australia Technical Mining Conference 2015
TERTIARY BENEFICIATION‐ FLOTATION
Filter selection requires due consideration of;
o Product/tailings moisture requirement (TML).
o Downstream material handling
o Auxiliary requirements
o Capex and Opex
o Trade-off studies equipment type ie:
o Vacuum Disk or horizontal belt
o Plate & Frame
o HyperbaricBelt filters Magnetite Beneficiation Plant ( DRA, 2014)
Plate & Frame Filter Building design
Africa Australia Technical Mining Conference 2015
SOLID‐LIQUID SEPARATION
Product stockpiles
• OVERVIEW
• FLOW DIAGRAM
• COMMINUTION/ LIBERATION
• BENEFICIATION
• SOLID LIQUID SEPARATION
• PRODUCT HANDLING
• CONCLUSION
Africa Australia Technical Mining Conference 2015
CONTENT
PRODUCT HANDLING AND BLENDING
• Product storage / Surge capacity
• Blending / homogenisation
• Weather protection
• Normall large footprint and high Capital requirements
• Dynamic simulation is recommended to accurately assess
o The stockpile capacity
o Logistics to port or siding
o Ship turnaround and ship
sizes
o Port consideration
Africa Australia Technical Mining Conference 2015
PROCESS REVIEW FOR IRON ORE BENEFICIATION
• Cost of production is a key focus area
• Coarser beneficiation = typically lower cost
• Liberation is a driving factor
• Flowsheet design requires test work
• Relevant equipment selection to maximise exploitation
of specific material characteristics
• New process technologies available and continuously
improving
• Fit for purpose designs Africa Australia Technical Mining Conference 2015
CONCLUSION
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THANK YOU
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