The Latest Developments in Iron Ore Processing - …

1 Council for Mineral TechnologyThe Latest Developments in iron Ore Processing5 JuneIsabel KingIron ore Processing Overview Suppliers, sources early days Crushing Techniques Processing Options Coarse Processing Fines Processing ConclusionsIntroduction: iron Ore ProcessingLargest iron Suppliers Vale BHP Rio Tinto Kumba iron oreOverviewIron Ore Sources Hematite(Fe2O3) Magnetite(Fe3O4) TitaniferousMagnetite(Fe2+(Fe3+,Ti)2O4)O verviewOccurrence Massive Banded iron Formation (BIF) Limonite TaconiteOverview Main Use of iron Ore Steel Industry iron Ore Processing in the Early Days Mine Crush Screen Sell Present Need UpgradingOverviewObjective of Processing Preparation for smelting SiO2<3% Fe>63% Al2O3< S and P content minimise Maximiserecovery and yieldOverviewIron Ore Mine -ThabazimbiIron Ore Crushing Primary/Secondary Crushing Jaw Gyratory Kawasaki Tertiary Crushing Cone High Pressure Grinding Roll (HPGR)Crushing TechniquesCone Crushing vs.

2 HPGR Cone Crushing Minimiseflakiness Shape factor influences Jig/DMS performance HPGR Better liberation in tertiary capacityCrushing TechniquesIron Ore ScreeningHematite Coarse (-32+8mm) Medium (-8+1mm) Fine (-1mm+212 / 75mm) Slimes (-212mm)MagnetiteProcessing OptionsDMS/JiggingSpirals/TBS/WHIMS/Flot ationLIMS/FlotationJigging on iron Ore Narrow size classes -32+8mm -8+3mm -3+1mm Size and Density Separator Fines Jigs hard to control Over the bed Jigs Through the bed Jigs Ragging Capacity 85t/h per meter width of jig to max of 4m wide jigJigging on iron OreDense Media Separation on iron OreDMS DrumDMS CycloneDense Media Separation on iron OreFeedFloats sieve bendOverflowSinksDense Media Separation on iron OreDMS Drum SinksDMS Drum Floats DMS Drum Up to diameter Process 600t/h

3 Lumpy iron ore DMS Cyclone Only -6mm material for iron ore 360mm diameter cyclone Process 40t/h per cyclone Larcodems -90+6mm stones diameter Operating capacity of 600-800t/h Efficient separation at SG s as high as Media Separation on iron Ore Cut SG of g/cm3 Not considered at 4g/cm3 Viscosity of FeSi Ferrosilicon Water atomised Gas atomised Maximiserecovery and yieldDense Media Separation on iron OreDense Media Separation on iron OreDMS High operating cost Efficient separation Depends on bottom size Near density material Optimseyield and recovery Lower tailings grades Density Separation Small effect on size DMS vs.

4 JiggingJigging Low operating cost Less efficient separation Narrow size classes Recovery losses Higher tailings grades Size and density separationDMS vs. JiggingDMS sgdiscrete mass % sgmass % to for the same product gradeNB: Very dependent on feed size distributionHematite -1mm + 212 / 75mm Spirals and Teeter Bed Separator (TBS) Wet High Intensity Magnetic Separation (WHIMS) SLonMagnetic Separation -212 / 75mm WHIMS SLon FlotationMagnetite -1mm + 212 / 75mm Wet Low Intensity Magnetic Separation (LIMS) TBS -212 / 75mm LIMS TBS FlotationFines ProcessingSpirals Mostly water flushed spirals SC20FE High capacity spirals Reduce footprint of plant Deeper troughs Wider 4-7t/hSpiralsTeeter Bed Separation (TBS)

5 Fluidisedbed Part of spiral circuit Final cleaning of concentrates Feed preparation for spiral circuit on coarse material -3mm particles are too coarse for spirals BIF as a two pass systemTeeter Bed Separation (TBS)Wet High Intensity Magnetic Separation (WHIMS) Magnetic susceptibility Difference has to be large Not recommended Paramagnetic gangue minerals are present Effective on slimes Much finer sizes than 212mm Capacity of 120t/hWHIMSSLon High gradient magnetic separator (HGMS) Combined force field Magnetism Pulsating fluid Gravity China and Peru Separating fine hematite and magnetite Capacity of 120t/hSLon Main purpose to add additional recovery Reverse/Direct flotation Taconite Part of magnetic separation circuit Selective flocculation Fine grinding, pellitisationFlotationTypical Magnetite Processing CircuitCrushingHPGR"212" micron Coarse LIMSmax 5 passesFine LIMSmax 5 passesFine TBS"75" micron 1543276 LIMS PlantWet Low Intensity Magnetic Separator (LIMS)

6 Mostly magnetic separation Performance of gravity separation affected by grind Possibility of producing a secondary ilmenite product??? Processing of TitaniferousMagnetiteConclusionsAcknowle dgementsJeremy Bosman University of Pretoria/ PescoCarl Bergmann you