PrinciplesofMetalRefiningandRecycling
ThorvaldAbelEngh
GeoffreyK.Sigworth
AnneKvithyld
GreatClarendonStreet,Oxford,OX26DP, UnitedKingdom
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Preface
Animportantfieldofstudyofindustrialandcommercialactivityliesbetweenextractive metallurgyandphysicalmetallurgy.Thisbookisanattempttofillthegap.Thisfield,which wecallmetalrefiningandrecycling,hasbecomeespeciallyimportantduetotheuseoflower gradeores,increasedrecycling,andhigherqualityrequirements.Ouraimistounderstandthe principlesthatguidetoday’soperationandtodevelopnewsolutionstotomorrow’sproblems.
DuringtheIndustrialRevolution,agapdevelopedbetweenresearchwithaprofessor andassistantintheuniversityandpracticeinindustry.Thisbecameespeciallyseverein Scandinaviafortheironandsteelindustryduetoitsstronggrowth.Itwasproblematic fortheuniversitiestotrainasufficientnumberofscientistsandworkerswithaknowledge ofextractivemetallurgy,thermodynamics,physicalmetallurgy,economics,etc.Afterthe SecondWorldWaranattemptwasmadetocovertheshortageoftrainedworkersand scientistsbyestablishinginstitutessupportedbybothindustryandgovernmentandexpanding theeducationofPhDstudentstrainedintheneededdisciplines.Thisbookpresentsthe scientificunderstandingofmetalrefiningandrecyclingthatresultedfromthisresearchand developmentactivity.
Tosolvemanyindustrialproblems,itisnecessarytodrawonscientificprinciplesfrom ‘non-traditional’sources.Forexample,fluidmechanicsandthebehaviourofatomsatthe solid–liquidinterfaceareofparamountimportance.Thesefieldsprovidethelinkbetween physicalmetallurgyandprocessmetallurgy.Measuringandcontrollingimpuritiesinmolten metalsisnecessary.Forinstance,Siforsolarcellsmustberefineddowntoverylowlevelsof impurities.
Changesandimprovementsduringthepastfiftyyearshasmadeitpossibletoprovide metalswithlowamountsofimpurities.Whyisitimportanttohaveacleanandproperly alloyedmetal?AnswerstothisquestionarepresentedinChapter1,whichgivesmotivation fortherestofthebook.Theremainingchapterscanbedividedintothreeparts:
1.Fundamentals:Thermodynamics,physicalandtransportproperties,mixing,mass transfer,andnumericalmodelsaredescribedindetailinChapters2and3.
2.Problemsandmethods:Theremovalofdissolvedimpurityelements,particlesand inclusions,andrefiningduringsolidificationarecoveredinChapters4,5,and6, respectively.
3.Applications:Remeltingandtheadditionofalloys,refiningchallengesandspecific processesforeachmetal,withafocusonsteelmaking,andrecyclingareconsidered, respectively,inChapters7,8,9,and10.
Metalsareessentialforthetechnologicalsocietyinwhichmostofuslive.Toensurefuture availability,itisimportanttoconserveresourcesandtakecareofourenvironment.Previously, itwassufficientforaworkertomanageonefield.Today,abroaderunderstandingisrequired. Knowledgeindifferentscientificdisciplinesisoftenrequiredtosolveproblems.Social, economic,environmental,andpolitical(legal)factorsmustalsobeconsidered.Tocoverallof thisproperlyisaproblem.Theauthorshaveinsummorethan100yearsofexperience,butthis wasnotsufficienttocoverallimportantaspectsofmetalrefiningandrecycling.Fortunately, wehavebeenassistedandsupportedbyanumberofeminentcolleagues.
Wehopethisbookwillservetwopurposes.First,itshouldprovideadetailedsurveyofthe presentstateoftheart.Eachchapterhasanextensivebibliography,sothataresearchermay easilyusethechapterasastartingpoint,or‘launchingpad’,forfurtheractivity.Andsecond, wehavepaidspecialattentiontotheprinciplesunderlyingthescience,sothebookmayalso beusedbyadvancedstudents.Ourprimaryintentionhasbeentoprovideacomprehensive book.Itwasnotmainlydesignedtoserveasatextbookmanualofinstructions.Itmaybe moreappropriatetoselectportionssuitableforthedesiredcourseofstudy.Forexample,parts ofChapters2–6shouldprovideacourseofstudyfocusingonrefiningmethods.
Inpractice,thedifferencebetweenthetwogoalsissomewhatartificial.Aneffectiveworker mustalwaysbereadytolearnanddiscovernewthingsboththeoreticalandpractical.One shouldalwaysbeastudent.
Asyoureadthis,wewelcomeyouacolleagueandco-workerinthefieldofrefiningand recyclingofmetals.Wehopeyouwilldiscovertopicsofinterestandutility.Wealsohopethis bookwill‘standthetestoftime’,beusefulforourworld,andaddtosociety’sknowledgeof metalrefiningandrecycling.
Extractingandrecyclingmetalswithminimaldamagetotheenvironmentwillbecome increasinglyimportant.Therewillcertainlybemanyinterestingchallengestoaddressinthe future.Oneillustrationofthechallengebeforeusistheactivityinthedeep-seaminingof minerals.Itwouldbeaninterestingchallengetoutilizetheprinciplesinthisbooktoprocess andrefinemetalsobtainedinthisway.
Acknowledgements
Theauthorswishtoacknowledgetheencouragementandcooperationofanumberof graduates,PhDs,andcolleagues.Withgreatpleasureandprofoundgratitude,wenotethat anumberofourcolleagueshavegenerouslypreparedchapters,orpartsofchapters,forthis book:
•ChristianJuliusSimensenpresentsmostofChapter1.OttoLunderhelpedwiththe sectiononcorrosion,andOddvinReisowithedgecracking.
•GabriellaTranellandErlendBjørnstadproducedthesectioninChapter4onthe oxidativeladlerefiningofsilicon.
•RoderickGuthrieandMihaielaIsacexpandedChapter5,withacontributionbySarina Baoonaceramicfoammodel.
•MartinSyvertsenworkedonChapter7,aswellasthesectioninChapter4onthepick-up ofhydrogenfromwatervapourintheatmosphere.
•EivindJohannesØvrelidprovidedChapter6.
•ChristinaMeskerswroteChapter8.
•OlleWijkwroteChapter9.
•PerBakkeprovidedtheextensivetreatmentonmagnesiumrecycling,whichappearsin Chapter10.
StudentsatNTNU—SigvartEggen,IvarFuru,andMagnusSkramstad—aretobethanked forpresentingausefulandrelevantstudent’sperspective,formostofthechapters.Alejandro AbadíasLlamas,IvanBeloFernandes,HarmenOoterdoom,andMarkusReuterarethanked fortheirsupportinChapter8,andArnePetterRatvikforsupportassistancereviewingthe samechapter.KetilMotzfeldt,whoinitiatedthethermodynamicpresentationinChapter2, presentedinthefirstbookin1992,isalsogratefullyremembered.
ArjanCiftjawithmetallurgicalinsightandillustrativeskillhasproducedandimproved anumberoffiguresanddiagrams.ToneHeggenhougenhasalsocleverlyassistedwith redrawingsomeofthefiguresandgivendesigninput.
WewouldalsoliketothankourcolleaguesatNTNUandSINTEFingeneralwhohave sharedtheirknowledge,giventheirtime,andsupportedthework.
Andlast,butcertainlynotleast,weextendourheartfeltgratitudetoIngridGamstPagefor herdedicationinthepreparationofthemanuscript.Truly,thisbookwouldnotexistwithout hercapableassistanceandinsight.
viii Acknowledgements
Wealsothankourspousesandfamiliesthathaveputupwithour‘important’book, neglectingtheshortvaluabletimehereonEarthtogether.
ThisbookhasbeenpartlyfundedbytheSFIMetalProduction(CentreforResearchbasedInnovation,237738).Theauthorsgratefullyacknowledgethefinancialsupportfrom theResearchCouncilofNorwayandthepartnersoftheSFIMetalProduction.
NotationsandUnits
1TheEffectofDissolvedElementsandInclusionsontheProperties ofMetalProducts 1
1.1Introduction1 1.2Porosity4
1.3HydrogenEmbrittlementofMetals7
1.4ElectricalConductivity10
1.5MagneticHysteresisandParticlesinSteel12
1.6TheEffectofImpuritiesonHotDuctilityofSteels13
1.7TheEffectofIntermetallicPhasesonMacroproperties14
1.7.1FatigueinAl–Cu–Mg–MnAlloys15
1.8InclusionsandMechanicalProperties17
1.8.1DuctileFracture20
1.8.2Toughness21
1.8.3Fatigue26
1.8.4Machinability27
1.9Corrosion29
1.9.1CorrosionofAlandMgAlloys—ElectrochemicalAspects29
1.9.2EffectofIntermetallicParticles30
1.9.3ElementsinSolidSolution32
1.9.3.1TraceElements32
1.9.4PittingCorrosion34
1.10TheEffectofMoltenParticlesinAluminiumAlloys36
1.10.1ImpuritiesinAl–SiCastings37
1.10.1.1GeneralRemarksabouttheSIMSMethodUsed48
1.10.2EdgeCrackinginHot-RolledMaterialsofAl–MgAlloys49
1.10.3ExtrusionofAlMgSiAlloysandtheMeltingofSecondaryPhaseParticles57 1.10.3.1ResultsofTest261
1.10.3.2MeltingofSecondaryPhaseParticlesinAlMgSiAlloys63 1.11ConcludingRemarks67
References 67
RecommendedFurtherReading71
2ThermodynamicsandTransportProperties 72
2.1Thermodynamics72
2.1.1Introduction72
2.1.2Enthalpy,Entropy,andGibbsEnergy73
2.1.3TheEffectofHighTemperatureonMoltenMetals76
2.1.4ChemicalPotentialsandActivities78
2.1.5ThePureSubstanceasReferenceState,andRaoult’sLaw79
2.1.6TheDiluteSolutionandHenry’sLaw81
2.1.7Gibbs–Duhem’sLaw90
2.1.8GibbsEnergiesofSolution92
2.1.9InteractionCoefficients94
2.1.10EquilibriabetweenParticles(Inclusions)andMelts;Precipitation Deoxidation111
2.1.11ModificationofInclusions;CaAdditionstoSteel117
2.1.12ThePhaseRuleAppliedtotheProblemofCalciumAddition119
2.1.13TheRegularSolutionModelandMoltenSalts122
2.1.14Slags125
2.1.15TheEquilibriumbetweenSulfurinSteelandinaBasicSlag127
2.1.16TheEquilibriumbetweenPhosphorusinSteelandinaBasicSlag128
2.1.17ActivitiesofSlagComponents130
2.2PhysicalandTransportPropertiesofMoltenMetalsandGases130
2.2.1ViscosityofGases133
2.2.2Introduction,thePairDistributionFunction136
2.2.3TheViscosityofLiquids139
2.2.3.1EstimationofViscositiesatHigherTemperatures144
2.2.3.2EstimationofViscositiesofLiquidAlloys146
2.2.4SurfaceTensionofPureMoltenMetals146
2.2.5ThermodynamicsofInterfaces148
2.2.6SurfaceEnergyofCompounds150
2.2.7InterfacialTensionofLiquidswithSeveralComponents155
2.2.8Solid–LiquidFreeEnergyofClose-PackedMetals163
2.2.9DiffusioninMoltenMetals166
2.2.10ThermalandElectricalConductivity172 References173
3.1Introduction182
3.1.1MassTransferCoefficient182
3.2MixingandCirculationFlow;FlowModels184
3.3MassTransfertoWalls190
3.4MassTransferinLiquidstoaCleanFreeSurface192
3.4.1MassTransfertoaMoving,Clean,FreeSurface194
3.4.2ModelComparedtoMeasurementsofMassTransfer198
3.5MassTransferinLiquidstoBubbles,Droplets,andParticles199
3.6VelocitiesofBubbles,Droplets,orParticlesandtheCorresponding MassTransferCoefficients202
3.6.1RemovalofMgfromMoltenAluminiuminaContinuous Gas-PurgingReactor203
3.7Bubbles,orDropletsDispersedinMoltenMetal206
3.7.1Introduction206
3.7.2PenetrationofSolidParticlesintoaMelt206
3.7.3SizeofBubblesandDropletsinMelts208
3.7.4SmallBubblesfromImpeller210
3.8Gas-SideMassTransferResistance212
3.8.1Introduction;MonoatomicGases212
3.8.2Gas-SideandInterfacialResistanceforDiatomicGases215
3.9RemovalofImpuritiesbyReactiveGasesandCompounds218
3.10Pick-upofHydrogenfromWaterVapour219
3.10.1Model219
3.10.2MeasurementsofAbsorptionofHydrogentoanAluminiumMelt222
3.10.2.1Off-GasandHydrogenSolubilityMeasurements223
3.11FluidDynamics231
3.11.1Introduction231
3.11.2TurbulenceModellingAssumptions233
3.11.3MultiphaseFlows234
3.12NumericalSolution235 References237
4.3TheTotalMassTransferCoefficient, kt
4.4EquilibriumorMassTransferControlinGasPurging;ReactiveGas246
4.5BubbleContactArea251
4.6ContinuousBack-MixReactors253
4.7BatchReactors257
4.8TraditionalSlag–MetalRefininginaBatchReactor(Ladle)259
4.9RemovalofCaandAlImpuritiesinMG-Si261
4.9.1AnIndustrialExampleofReactiveGasandSlagRefining261 4.10Injection268
4.10.1DetailsofMathematicalTreatment274
4.10.2ConcludingComments275
4.11HydrogenRemoval;DiatomicGases275
4.12MetaltoGas(Vacuum)Transfer286
4.12.1Conclusions293
4.13VacuumRefiningofAluminium293
4.14Distillation295
4.15ComparisonofDifferentMethodsforRefiningAlAlloys297
4.15.1Iron299
4.15.2Manganese299
4.15.3Copper299
4.15.4Zinc299
4.15.5MagnesiumandLithium299
4.15.6HeavyMetals300 References300 FurtherReading302
5RemovalofInclusionsfromMelts 303
5.1Introduction303
5.2MeasurementofInclusions305
5.3RemovalofInclusionsUsing‘Furniture’withinaTundishSystem308
5.4RemovalofInclusionsbyNaturalFlotation/Settling311
5.5IntroductiontoFlotationbyBubbles313
5.5.1AttachmentMechanismtoBubbles318
5.5.2RemovalofInclusionsbyFlotation(Bubbles)323
5.5.3RemovalofInclusionsUsingMicrobubbles324
5.6IntroductiontoFiltration328
5.6.1CakeModeFiltration331
5.6.2DeepBedFiltration334
5.6.3CeramicFoamModel337
5.6.4Re-entrainmentofInclusions349
5.7RotationalForcesforRemovingInclusions349
5.8ElectromagneticForcesforRemovingInclusions350
5.9TheNumberSizeDistributionofInclusions351
5.10DissolvedElementsandInclusions357
5.11Conclusions360 References362
6SolidificationandRefining 365
6.1Introduction365
6.2SoluteDistributionattheSolid–LiquidInterface366
6.3TheMassTransferCoefficient kt fromSolidtoBulkLiquid368
6.4ConstitutionalSupercoolingandStirring370
6.4.1Macrosegregation373
6.4.2ModellingofMacrosegregation375
6.5SegregationofAlloysDisplacedfromtheEutecticComposition376
6.6RefiningAlloysbyPartialSolidification378
6.7RefiningAlloysbyContinuousDrainingofLiquid381
6.8ZoneRefining382
6.9RefiningProcessesinCrystallizationofSiforSolarCells/Crystal Pulling/DirectionalSolidification385
6.10TheCzochralskiCrystalPuller388
6.11NucleationandGrainRefinement393
6.11.1EffectivenessofNucleants397
6.11.1.1ThePeretecticTheory397
6.11.1.2TheRoleofBoronandAlloyComposition398 References402
7.1Introduction405
7.2ChangeinTemperaturefromAlloying408
7.3ModelsforHeatingandMeltingPureAluminiumMetalinanAluminiumBath410
7.3.1EnergyTransportModelwithoutShellFormation410
7.3.2ThinFlatPlateContinuouslyFedintoMelt412
7.3.3MassTransferCoefficientCalculations412
7.3.4CriterionforShellFormation415
7.3.5MeltingofSpheres(withHighThermalConductivity)416
7.3.6ContinuousFeedingandMeltingofaCylindricalRod418
7.3.7ValidityoftheEnergyTransportModelforContinuouslyFedMaterial420
7.4ModelIncludingShellGrowthandMelting421
7.4.1DimensionlessGroups421
7.4.2GeneralAssumptions423
7.4.3MainModelofthePlatewithShellFormation423
7.4.3.1RegionA424
7.4.3.2TheShell425
7.4.3.3RegionB426
7.4.3.4TheWedgeRegion427
7.4.3.5CombinedSolution427
7.4.4Heat-TransferCoefficientinThermalBoundaryLayer429
7.4.4.1Boundary-LayerTheoryforMoltenMetals429
7.4.5SimplifiedModelwithShellFormation433
7.5Alloying434
7.5.1Diffusion-LimitedDissolutionofAlloys434
7.5.2TheHeat-TransferCoefficientforMoltenMetals437
7.6DissolutionRateandIntermetallicPhases440
7.7PracticalAlloyAdditionstoaMelt443
7.8Safety445
7.9Summary447 References447
8MetalProcessesandApplications—AnOverview 450
8.1AlkaliMetals(Na,K,Li)453
8.1.1Sodium(Na)453
8.1.1.1Production453
8.1.1.2Applications454
8.1.1.3EHS455
8.1.2Potassium(K)455
8.1.2.1Production455
8.1.2.2Applications455
8.1.2.3EHS456
8.1.3Lithium(Li)456
8.1.3.1Production456
8.1.3.2Applications457
8.1.3.3Recycling457
8.1.3.4EHS458
8.2AlkalineEarthMetals458
8.2.1Beryllium(Be)458
8.2.1.1PhysicalProperties458
8.2.1.2Production458
8.2.1.3Applications459
8.2.1.4Recycling460
8.2.1.5EHSandSustainability460
8.2.2Magnesium(Mg)460
8.2.2.1PhysicalProperties460
8.2.2.2Production460
8.2.2.3Applications462
8.2.2.4Recycling462
8.2.2.5EHSandSustainability462
8.2.3Calcium(Ca)463
8.2.3.1PhysicalProperties463
8.2.3.2Production463
8.2.3.3Applications464
8.2.3.4Recycling464
8.2.4Strontium(Sr)464
8.2.4.1PhysicalProperties464
8.2.4.2Production465
8.2.4.3MajorApplications465
8.2.4.4Recycling466
8.2.4.5EHSandSustainability466
8.3RareEarths:Scandium,Yttrium,andLanthanides466
8.3.1Scandium(Sc)466
8.3.1.1PhysicalProperties466
8.3.1.2Production467
8.3.1.3MajorApplications467
8.3.1.4Recycling467
8.3.2Rare-EarthElements&Yttrium(Y)468
8.3.2.1PhysicalProperties468
8.3.2.2Production468
8.3.2.3Applications470
8.3.2.4Recycling470
8.3.2.5EHSandSustainability471
8.4Titanium,Zirconium,andHafnium471
8.4.1Titanium(Ti)471
8.4.1.1PhysicalProperties471
8.4.1.2Production472
8.4.1.3MajorApplications473
8.4.1.4Recycling474
8.4.1.5EHSandSustainability474
8.4.2Zirconium(Zr)474
8.4.2.1PhysicalProperties474
8.4.2.2Production475
8.4.2.3Applications476
8.4.2.4Recycling476
8.4.2.5EHSandSustainability476
8.4.3Hafnium(Hf)476
8.4.3.1Physicalproperties476
8.4.3.2Production477
8.4.3.3Applications477
8.4.3.4Recycling477
8.5Vanadium,Niobium,andTantalum477
8.5.1Vanadium(V)478
8.5.1.1Physicalproperties478
8.5.1.2Production478
8.5.1.3MajorApplications479
8.5.1.4Recycling479
8.5.2Niobium(Nb)479
8.5.2.1Physicalproperties480
8.5.2.2Production480
8.5.2.3MajorApplications480
8.5.2.4Recycling481
8.5.3Tantalum(Ta)481
8.5.3.1PhysicalProperties481
8.5.3.2Production481
8.5.3.3Applications482
8.5.3.4Recycling482
8.5.3.5EHSandsustainability483
8.6Chromium,Molybdenum,andTungsten483
8.6.1Chromium(Cr)483
8.6.1.1PhysicalProperties483
8.6.1.2Production484
8.6.1.3Applications484
8.6.1.4Recycling485
8.6.1.5EHSandSustainability485
8.6.2Molybdenum(Mo)485
8.6.2.1PhysicalProperties485
8.6.2.2Production486
8.6.2.3MajorApplications487
8.6.2.4Recycling487
8.6.3Tungsten(W)487
8.6.3.1PhysicalProperties488
8.6.3.2Production488
8.6.3.3Applications489
8.6.3.4Recycling489
8.6.3.5EHSandSustainability490
8.7ManganeseandRhenium490
8.7.1Manganese(Mn)490
8.7.1.1PhysicalProperties490
8.7.1.2Production491
8.7.1.3Applications492
8.7.1.4Recycling493
8.7.1.5EHSandSustainability493
8.7.2Rhenium(Re)493
8.7.2.1PhysicalProperties493
8.7.2.2Production493
8.7.2.3Applications494
8.7.2.4Recycling495
8.7.2.5EHSandSustainability495
8.8Iron495
8.8.1Iron(Fe)495
8.8.1.1PhysicalProperties495
8.8.1.2Production496
8.8.1.3Applications496
8.8.1.4Recycling497
8.9Cobalt497
8.9.1Cobalt(Co)497
8.9.1.1PhysicalProperties497
8.9.1.2Production498
8.9.1.3Applications498
8.9.1.4Recycling499
8.9.1.5EHSandSustainability499
8.10NickelandPlatinumGroupMetals499
8.10.1Nickel(Ni)499
8.10.1.1PhysicalProperties500
8.10.1.2Production500
8.10.1.3Applications502
8.10.1.4Recycling503
8.10.1.5EHSandSustainability503
8.10.2PlatinumGroupMetals(Pt,Pd,Rh,Ru)503
8.10.2.1PhysicalProperties504
8.10.2.2Production504
8.10.2.3Applications505
8.10.2.4Recycling506
8.10.2.5EHSandSustainability506
8.11CopperandPreciousMetals506
8.11.1Copper(Cu)506
8.11.1.1PhysicalProperties507
8.11.1.2Production507
8.11.1.3Applications509
8.11.1.4Recycling510
8.11.1.5EHSandSustainability510
8.11.2Silver(Ag)511
8.11.2.1PhysicalProperties511
8.11.2.2Production511
8.11.2.3Applications513
8.11.2.4Recycling513
8.11.2.5EHSandSustainability514
8.11.3Gold514
8.11.3.1PhysicalProperties514
8.11.3.2Production514
8.11.3.3Applications516
8.11.3.4Recycling516
8.11.3.5EHSandSustainability516
8.12ZincandCadmium516
8.12.1Zinc(Zn)517
8.12.1.1PhysicalProperties517
8.12.1.2Production517
8.12.1.3Applications519
8.12.1.4Recycling519
8.12.1.5EHSandSustainability520
8.12.2Cadmium(Cd)520
8.12.2.1PhysicalProperties520
8.12.2.2Production520
8.12.2.3Applications521
8.12.2.4Recycling521
8.12.2.5EHSandSustainability521
8.13Aluminium,Gallium,andIndium521
8.13.1Aluminium(Al)521
8.13.1.1PhysicalProperties522
8.13.1.2Production522
8.13.1.3Applications524
8.13.1.4Recycling524
8.13.1.5EHSandSustainability525
8.13.2Gallium(Ga)526
8.13.2.1PhysicalProperties526
8.13.2.2Production526
8.13.2.3Applications527
8.13.2.4Recycling527
8.13.2.5EHSandSustainability527
8.13.3Indium(In)527
8.13.3.1PhysicalProperties528
8.13.3.2Production528
8.13.3.3Applications529
8.13.3.4Recycling529
8.13.3.5EHSandSustainability529
8.14Germanium,Tin,andLead529
8.14.1Germanium(Ge)530
8.14.1.1PhysicalProperties530
8.14.1.2Production530
8.14.1.3Applications531
8.14.1.4Recycling531
8.14.1.5EHSandSustainability531
8.14.2Tin(Sn)531
8.14.2.1PhysicalProperties531
8.14.2.2Production532
8.14.2.3Applications533
8.14.2.4Recycling533
8.14.2.5EHSandSustainability534
8.14.3Lead(Pb)534
8.14.3.1PhysicalProperties534
8.14.3.2Production534
8.14.3.3Applications536
8.14.3.4Recycling536
8.14.3.5EHSandSustainability537
8.15AntimonyandBismuth537
8.15.1Antimony(Sb)537
8.15.1.1PhysicalProperties537
8.15.1.2Production538
8.15.1.3Applications538
8.15.1.4Recycling539
8.15.1.5EHSandSustainability539
8.15.2Bismuth(Bi)539
8.15.2.1PhysicalProperties539
8.15.2.2Production540
8.15.2.3Applications541
8.15.2.4Recycling541
8.15.2.5EHSandSustainability541 References541
9.1Introduction550
9.2ConverterProcessesforSteelmaking—RefiningofBlastFurnaceHotMetal551
9.2.1GeneralPrinciples551
9.2.2SomeThermodynamicAspects554
9.2.2.1Carbon–Oxygen556
9.2.2.2Iron558
9.2.2.3Silicon559
9.2.2.4Phosphorus560
9.2.3ReactionsduringtheBlow564
9.3ConverterProcessesforSteelmaking—RefiningofStainlessCrudeSteel567
9.3.1Introduction567
9.3.2Decarburization571
9.3.3ReductionoftheTopSlag573
9.3.4Desulfurization573
9.4ModellingtheRateofDecarburization575
9.4.1TuyereZone576
9.4.2Oxide/MetalZone577
9.4.3SimulationoftheBlow581
9.4.4SomeOperatingConditionsandTheirEffectontheProcess583
9.4.5ProcessOptimization585 References587
10Recycling 589
10.1Introduction589
10.1.1WhatIsRecycling?590
10.1.1.1DefinitionsfromanEverydayPointofView590
10.1.1.2DefinitionsfromaLegalPointofView591
10.1.1.3MathematicalDefinitionsofRecyclingRates591
10.1.1.4RecyclingofMetalversusRecyclingofProducts592
10.1.2WhyDoWeRecycle?592
10.1.2.1EconomicDevelopmentandMetalDemand593
10.1.2.2ClimateChange593
10.1.2.3TheEcologicalFootprint594
10.1.2.4DefinitionofSustainability594
10.1.2.5Scarcity594
10.1.3TheImportanceofCollection595
10.1.3.1CollectionfromConsumerGoods595
10.1.3.2CollectioninIndustry595
10.1.4Cost595
10.1.4.1EnvironmentalFootprintversusEconomicValue596
10.1.4.2DematerializationandUseofMetals597
10.1.4.3EstimatingtheCostontheEnvironment:LifeCycleAssessment andMassFlowAnalysis597
10.1.4.4Summary600
10.2PrinciplesofRecyclingStrategies600
10.2.1TheWasteHierarchy—ProductPerspective600
10.2.2CircularMaterialsManagement—ProcessPerspective601
10.2.2.1OtherStrategies601
10.3ClassificationofScrap603
10.3.1MethodsofClassification603
10.3.1.1Pre-andPost-consumerScrap603
10.3.1.2FormalClassificationSystems604
10.3.2ImportantCharacteristicsandConsiderations606
10.3.2.1WhereDoestheScrapComefrom?606
10.3.2.2WhatTypeofScrapIsIt?606
10.3.2.3WhenWastheScrapProduced?606
10.3.3SamplingandAnalysis607
10.3.3.1Analysis608
10.3.4Example:UsedBeverageCans609
10.3.4.1OtherProblems613
10.3.5Example:PackagingScrap614
10.3.6RecoveryofMetalsfromWasteIncineratorBottomAsh616
10.4MethodsandProcesses620
10.4.1Collection620
10.4.1.1CollectionfromtheConsumer620
10.4.1.2Collectioninindustry622
10.4.2Liberation622
10.4.2.1Dismantling623
10.4.2.2MechanicalLiberation623
10.4.3Sorting625
10.4.3.1ManualInspection625
10.4.3.2Sizing/Screening625
10.4.3.3MagneticSeparation626
10.4.3.4EddyCurrentSeparation627
10.4.3.5DensitySorting629
10.4.3.6SensorSorting629
10.4.4Pretreatment630
10.4.4.1CoalescenceandMetalRecovery633
10.4.4.2IssuesRelatedtoRecyclability635
10.4.4.3IndustrialUnits635
10.4.4.4OperatingWindow637
10.4.5Blending637
10.4.5.1Upgrading638
10.4.6ProcessingofFinalResiduesintheMetalIndustry639
10.4.6.1Aluminium639
10.4.6.2SiliconandFerrosilicon640
10.4.6.3FerromanganeseandSilicomanganese641
10.4.6.4IronandSteel641
10.4.7ConnectingMethods643
10.5ExamplesofRecycling646
10.5.1RecyclingofMagnesiumAlloys646
10.5.1.1Introduction646
10.5.1.2ScrapClassificationSystem647
10.5.1.3ProcessOverview647
10.5.1.4Class1648
10.5.1.5Flux-BasedSystems648
10.5.1.6Flux-FreeIn-houseRecycling650
10.5.1.7Class2652
10.5.1.8Class3652
10.5.1.9Class4652
10.5.1.10Class5652
10.5.1.11Class6653
10.5.1.12Class7653
10.5.1.13Class8654
10.5.1.14RecyclingUsingFlux654
10.5.1.15FluxlessRefining655
10.5.1.16ContaminationControl656
10.5.1.17AdditionalSourcesofTraceElementsandInclusions duringRecycling657
10.5.1.18EffectsandRemovalofSomeTraceElements657
10.5.2AluminiumDrossandSalt-CakeRecycling658
10.5.2.1DrossProcessing660
10.5.2.2SaltCake661
10.5.3BatteryRecycling662
10.5.3.1Lead–AcidBattery662
10.5.3.2Zinc–CarbonandAlkalineBatteries663
10.5.3.3SilverOxideBatteries663
10.5.3.4Ni–CdBatteries664
10.5.3.5Ni–MetalHydrideBatteries664
10.5.3.6Lithium-IonBatteries665
10.6LimitsandOpportunitiesinRecycling667
10.6.1TheLimitsofRecycling667
10.6.2TheOpportunitiesinRecycling669
A2.1Introduction704
A2.2PipeFlow705
A2.3NozzleBlockageandRemovalofInclusionsbyStirring708
A2.4StirringEnergy710
A2.4.1MechanicalStirring711
A2.4.2BubbleStirring712
A2.4.3ElectromagneticStirring714
A3.1HomogeneousNucleation716
A3.2HeterogeneousNucleation;Wetting719
