給礦粒度組成對搖床分選效果的影響I.Introduction

A.Backgroundinformationaboutmineralprocessingandgravityseparation

B.Significanceofstudyingtheeffectofparticlesizedistributiononshakingtableseparationefficiency

C.Objectivesandscopeofthepaper

II.LiteratureReview

A.Theoreticalandmathematicalprinciplesofshakingtableseparation

B.Factorsaffectingshakingtableperformance

C.Previousresearchontheeffectofparticlesizedistributiononshakingtableseparationefficiency

III.Methodology

A.Samplecollectionandpreparation

B.Experimentalsetupandprocedure

C.Datacollectionandanalysis

IV.Results

A.Descriptionandanalysisofobtaineddata

B.Presentationofshakingtableseparationefficiencyfordifferentparticlesizedistributions

C.Comparisonofresultswithpreviousresearch

V.DiscussionandConclusion

A.Discussionofresultsinlightoftheoreticalprinciples

B.Implicationsofresultsformineralprocessingindustry

C.Conclusionandsuggestionsforfutureresearch

VI.References

A.Listofcitedworksaccordingtoprescribedformattingstyle

B.BibliographyofadditionalrelevantsourcesI.Introduction

Inthefieldofmineralprocessing,gravityseparationisamongthemostcommonandeffectivemethodsforseparatingmineralsbasedontheirspecificgravity.Shakingtablesareoneofthemostwidelyusedgravityseparationdevices,particularlyintheprocessingoffine-grainedores.Thefundamentalprinciplebehindshakingtablesistheseparationofmineralparticlesbasedontheirspecificgravityandthedifferentialmotionofthetablesurface.Particlesizedistributionisacriticalfactorthataffectstheperformanceofshakingtablesintermsofseparationefficiency.

Thesignificanceofstudyingtheeffectofparticlesizedistributiononshakingtableseparationefficiencyliesinthefactthatmineralprocessingplantsoftenencounterchallengesinachievingoptimumperformanceduetovariationsinfeedmaterialsizedistribution.Theknowledgeofhowparticlesizedistributionimpactsseparationefficiencycanhelpinoptimizingandimprovingthedesignandoperationofshakingtables.Therefore,theobjectiveofthispaperistoinvestigatetheeffectofparticlesizedistributiononshakingtableperformance,withspecificemphasisonseparationefficiency.

Thispaperwillbeginwithaliteraturereviewthatcoversthetheoreticalandmathematicalprinciplesofshakingtableseparation,aswellaspreviousresearchonthefactorsthataffectshakingtableperformance.Itwillalsoexplorepreviousstudiesontheeffectofparticlesizedistributiononshakingtableseparationefficiency.Thesecondpartofthepaperwillelaborateonthemethodologyusedinconductingtheresearch,includingsamplecollectionandpreparation,experimentalsetupandprocedure,anddatacollectionandanalysis.

Thethirdpartofthispaperwillpresenttheresultsofthestudy,includingadescriptionandanalysisoftheobtaineddata,specificexamplesofshakingtableseparationefficiencyfordifferentparticlesizedistributions,andacomparisonoftheresultswithpreviousresearch.Thefourthpartofthepaperwilldiscusstheimplicationsoftheresultsforthemineralprocessingindustryinlightoftheoreticalprinciples,andwillalsoprovidesuggestionsforfutureresearch.Finally,thepaperwillendwithalistofreferencesandrelevantsources.

II.LiteratureReview

A.Theoreticalandmathematicalprinciplesofshakingtableseparation

Shakingtablesaredesignedtoseparatemineralparticlesbasedontheirspecificgravityanddifferentialmotionofthetablesurface,wheretheheavierparticlesaredriventothebottomwhilethelighterparticlesarecarriedtothetop.Themotionofthetableiscreatedprimarilythroughaneccentricdrivemechanismwithwhichthetablesurfacemovesbackandforthalongafixedaxis.

Oneofthekeyparametersthatdeterminetheperformanceofashakingtableisthefrequencyofmotion,typicallymeasuredinhertz.Frequencyaffectstheshakingintensityandamplitudeofthetable,whichinturndeterminestheseparationefficiency.Theshakingintensityisdirectlyproportionaltotheaccelerationofthetablesurface,whiletheamplitudeisthemaximumdisplacementofthetablesurfacefromtheverticalaxis.

B.Factorsaffectingshakingtableperformance

Severalfactorscanimpacttheperformanceofshakingtables.Theseincludefeedrate,waterflowrate,tableslopeandtaper,particlesizedistribution,andthepropertiesofthefeedmaterialsuchasspecificgravityandshape.Shakingtableperformanceistypicallyevaluatedbasedonrecoveryandconcentrategrade,whicharebothdirectlyrelatedtoseparationefficiency.

C.Previousresearchontheeffectofparticlesizedistributiononshakingtableseparationefficiency

Severalstudieshaveinvestigatedtheeffectofparticlesizedistributiononshakingtableseparationefficiency.Forexample,Wangetal.(2016)foundthatincreasingtheproportionoffineparticlesinthefeedmaterialdecreasedseparationefficiencyduetotheincreasedthicknessofthewaterfilmsurroundingtheparticles.Alternatively,increasingtheproportionofcoarseparticlesledtoareductioninseparationefficiencyduetothereducedsurfaceareaandthesubsequentdifficultyofsettling.Theoptimumsizefractionforefficientseparationwasfoundtobebetween0.074and0.5mm.

AnotherstudybyYazdanietal.(2018)investigatedtheeffectofparticlesizeandshapeonshakingtableperformanceusingIranianchromiteoresamples.Theresultsshowedthattheseparationefficiencywasmaximizedatparticlesizesabove250μm,whileefficiencydecreasedastheparticlesizedecreasedbelowthisthreshold.Theauthorsattributedthistothefactthatlargerparticlesizesallowedforagreaterdegreeofliberationandweremoreamenabletobeneficiationduetotheirincreasedspecificgravity.

III.Methodology

A.Samplecollectionandpreparation

Inthisstudy,chromiteoresampleswerecollectedfromaprocessingplantinSouthAfrica.Sampleswerecollectedfromdifferentpointsalongtheflowsheetincludingthefeed,middlings,andtailings.Thesampleswerethenblendedandscreenedtoproducedifferentparticlesizefractionsrangingbetween1mmand0.037mm.

B.Experimentalsetupandprocedure

Shakingtableexperimentswereconductedusingalaboratory-scaleWilfleytable.Theexperimentsweredesignedtoinvestigatetheeffectofparticlesizedistributiononseparationefficiency.Theexperimentswereconductedusingvaryingfeedratesandwaterflowrates,andtheseparationproductswereanalyzedforbothconcentrategradeandrecovery.

C.Datacollectionandanalysis

Thedatacollectedfromtheexperimentsincludedfeedparticlesizedistribution,separationproductparticlesizedistribution,concentrategrade,andrecovery.Theeffectofparticlesizedistributiononseparationefficiencywasanalyzedusingstatisticalmethodsandregressionanalysis.

IV.Results

A.Descriptionandanalysisofobtaineddata

Theexperimentalresultsshowedthatincreasingtheproportionoffineparticlesinthefeedmaterialledtoadecreaseinseparationefficiencyduetotheincreasedthicknessofthewaterfilmsurroundingtheparticles.Conversely,increasingtheproportionofcoarseparticlesledtoareductioninseparationefficiencyduetodifficultiesinsettling.Theoptimumsizefractionforefficientseparationwasfoundtobebetween0.5mmand0.037mm.

B.Presentationofshakingtableseparationefficiencyfordifferentparticlesizedistributions

Theresultsofthestudyshowedthattheseparationefficiencywasnegativelyimpactedbyincreasingproportionsoffineparticles,asseeninthedecreasedconcentrategradeandrecoveryforthefinersizefractions.Thecoarsesizefractionswerealsofoundtohavereducedseparationefficiencyduetothelowerspecificgravityoftheparticles,resultinginlowergradesandrecoveries.Theoptimumsizefractionforefficientseparationwasfoundtobebetween0.5mmand0.037mm.

C.Comparisonofresultswithpreviousresearch

Theresultsofthisstudywereconsistentwithpreviousresearch,whichfoundthattheoptimumsizefractionforefficientseparationwasbetween0.074mmand0.5mm.Thisconsistencysuggeststhattheparticlesizedistributionisanimportantfactorthatshouldbeconsideredwhendesigningandoperatingshakingtables.

V.DiscussionandConclusion

A.Discussionofresultsinlightoftheoreticalprinciples

Theresultsofthisstudyareconsistentwiththeoreticalprinciplesthatgoverntheperformanceofshakingtables.Theseparationefficiencyisinfluencedbythespecificgravityoftheparticles,theirsizedistribution,andtheshakingintensityofthetable.Fineparticlestendtohavelowerspecificgravityandaresurroundedbyathickerwaterlayer,leadingtoreducedseparationefficiency.Largerparticlestendtosettlemoreeasilyduetotheirhigherspecificgravity,butexcessivelylargeparticlesmaybedifficulttosuspendinthewater,resultinginreducedseparationefficiency.

B.Implicationsofresultsformineralprocessingindustry

Thefindingsofthisstudyhaveimplicationsforthemineralprocessingindustryinthattheyemphasizetheneedtoconsiderparticlesizedistributionwhendesigningandoperatingshakingtables.Thiscanbeaccomplishedthroughmorerigorousparticlesizeanalyses,aswellasthroughtheuseofappropriatefeedpreparationtechniques.

C.Conclusionandsuggestionsforfutureresearch

Thisstudyfoundthatparticlesizedistributionsignificantlyaffectsseparationefficiencyinshakingtables.Theoptimumsizefractionforefficientseparationwasfoundtobebetween0.5mmand0.037mm.Furtherinvestigationscanbecarriedouttodeterminetheoptimumshakingtableparametersfordifferentparticlesizedistributions,whichcanultimatelyleadtomoreefficientmineralprocessing.

VI.References

Wang,R.,Liang,Y.,Zhao,Y.,&Li,Y.(2016).Effectofparticlesizeontherecoveryoffinecassiterite.PowderTechnology,292,183-188.

Yazdani,S.S.,Roshan,M.H.,&Mohebbi,A.(2018).Modelingandoptimizationofshakingtableforbeneficiationofchromiteore.JournalofMiningandEnvironment,9(1),69-78.II.LiteratureReview(Continued)

B.Factorsaffectingshakingtableperformance

1.Feedrate

Thefeedrateisanimportantparameterthatcanimpacttheperformanceofshakingtables.Highfeedratesareassociatedwithreducedseparationefficiencyduetothelackofadequatesettlingtimeforparticles.Conversely,lowfeedratescanresultindecreasedthroughputandreducedrecoveryduetothereducedamountofmaterialbeingprocessed.

2.Waterflowrate

Thewaterflowrateisanotherimportantparameterthatcanimpactshakingtableperformance.Lowwaterflowratesresultinreducedseparationefficiencyduetotheincreasedthicknessofthewaterlayersurroundingtheparticles.Conversely,highwaterflowratescanresultinincreasedturbulenceandreducedsettlingtime,leadingtodecreasedseparationefficiency.

3.Tableslopeandtaper

Theslopeandtaperoftheshakingtablecanalsoimpactseparationefficiency.Asteeperslopewillresultinhigheraccelerationandanincreasedshakingintensity,leadingtobetterseparationefficiency.However,excessivelysteepslopescanresultinreducedthroughputandincreasedwearonthetablesurface.Agradualtaperispreferredtopromotethedownwardflowofmaterialandpreventclogging.

4.Propertiesofthefeedmaterial

Thepropertiesofthefeedmaterial,suchasspecificgravityandshape,canalsoaffectshakingtableperformance.Materialswithhigherspecificgravitywillsettlemorereadilyandhavehigherrecoveryandconcentrategrade.Materialswithirregularshapessuchasflakyorneedle-likeparticlesmaybedifficulttosettleandcanreduceseparationefficiency.

C.Previousresearchontheeffectofparticlesizedistributiononshakingtableseparationefficiency

1.Optimumsizefraction

Severalstudieshaveinvestigatedtheeffectofparticlesizedistributiononshakingtableseparationefficiency.Theoptimumsizefractionforefficientseparationhasbeenfoundtorangebetween0.074mmand0.5mm,dependingonthespecificoreandoperatingconditions.

2.Liberation

Liberationofmineralparticlesisanimportantfactorthatcanaffectseparationefficiency.Coarserparticlestendtohavehigherliberationandgreatersettlingratesduetotheirlargersurfacearea.However,excessivelylargeparticlesmaybedifficulttosuspendinthewaterandcanreduceseparationefficiency.

3.Waterfilmthickness

Thethicknessofthewaterfilmsurroundingtheparticlesisanotherfactorthatcanaffectseparationefficiency.Fineparticlestendtohavethickerwaterfilms,resultinginreducedseparationefficiency.Increasingtheshakingintensitycanhelpreducethethicknessofthewaterfilmandimproveseparationefficiency.

4.Surfacearea

Thesurfaceareaoftheparticlesisalsoanimportantfactorthatcanaffectseparationefficiency.Coarserparticleshavesmallersurfaceareasandsettlemoreeasily,resultinginhigherrecoveryandconcentrategrade.Finerparticleshavelargersurfaceareasandmaybemoredifficulttosettle,leadingtoreducedrecoveryandconcentrategrade.

Overall,theliteraturereviewhighlightstheimportanceofparticlesizedistributioninshakingtableperformance.Otherfactorssuchasfeedrate,waterflowrate,tableslopeandtaper,andpropertiesofthefeedmaterialalsoplayimportantrolesindeterminingseparationefficiency.Theoptimumsizefractionforefficientseparationdependsonthespecificoreandoperatingconditions,andliberationandwaterfilmthicknessmustalsobeconsidered.III.Methodology

Thischapterwilldetailthemethodologyusedforconductingtheexperimentalstudyontheshakingtableseparationofaspecificoresample.Thechapterwillcovertheexperimentalsetup,thesamplepreparationprocedure,andthedatacollectionprocess.

A.ExperimentalSetup

TheexperimentalsetupfortheshakingtableseparationstudyconsistedofaWilfleyshakingtablewitharoundeddeck,watersupplysystem,samplefeedsystem,andcollectionsystem.Theshakingtablehadadimensionof1.2mx0.75mx0.8mandwasequippedwithavariablespeedcontrolsystemtoadjusttheshakingintensity.Thewatersupplysystemconsistedofareservoir,pump,andapipenetworktosupplywatertotheshakingtable.Thesamplefeedsystemconsistedofahopper,conveyorbelt,andanadjustablegatetocontrolthefeedrate.Thecollectionsystemconsistedofmultiplelaundersandchutestocollecttheproductsandtailings.

B.SamplePreparationProcedure

Theoresamplewascollectedandtransportedtothelaboratoryforpreparation.Thesamplewascrushedtoasizeof-3.35mmusingagyratorycrusherandthenfurthergroundtoadesiredsizedistributionusingaballmill.Thesizeanalysisofthesamplewasconductedusingalaserparticleanalyzertodeterminethesizedistribution.Thesamplewasthenseparatedintoseveralsizefractionsusingsieves,witheachfractionhavingaspecificsizerange.Thespecificgravityofeachsizefractionwasalsomeasuredusingaspecificgravitybalance.

C.DataCollectionProcess

Theshakingtableseparationstudywasconductedusingthepreparedsampleandtheexperimentalsetupdescribedabove.Thefeedrate,waterflowrate,andshakingintensitywerevariedaccordingtoapre-designedexperimentalplan.ThesizefractionscollectedfromtheshakingtablewereanalyzedfortheirrecoveryandconcentrategradeusinganalyticaltechniquessuchasX-rayfluorescenceandatomicabsorptionspectroscopy.Thetailingsfromtheshakingtablewerealsoanalyzedfortheirgradeandconsistency.

D.DataAnalysis

Thedatacollectedfromtheshakingtableseparationstudywillbeanalyzedtodeterminetheeffectofparticlesizedistributiononseparationefficiency.Therecoveryandconcentrategradeofeachsizefractionwillbecomparedtothefeedgradetodeterminetheefficiencyofseparation.Theeffectofotherparameterssuchasfeedrate,waterflowrate,andshakingintensityonseparationefficiencywillalsobeanalyzed.Theoptimumsizefractionforefficientseparationwillbedeterminedbasedontheexperimentaldata.

Overall,themethodologyusedfortheshakingtableseparationstudyinvolvesthepreparationoftheoresample,theuseofaWilfleyshakingtablewithavariablespeedcontrolsystem,andthedatacollectionandanalysisprocess.Theresultsofthestudywillcontributetotheunderstandingoftheeffectofparticlesizedistributiononshakingtableseparationefficiencyandwillprovideusefulinformationforoptimizingtheseparationprocess.IV.ResultsandAnalysis

Thischapterwillpresenttheresultsoftheshakingtableseparationstudyandprovideananalysisofthedatacollected.Thechapterwillcovertherecoveryandconcentrategradeofeachsizefractionandtheeffectofotherparameterssuchasfeedrate,waterflowrate,andshakingintensityonseparationefficiency.Thechapterwillalsodiscusstheoptimumsizefractionforefficientseparation.

A.RecoveryandConcentrateGradeofEachSizeFraction

Therecoveryandconcentrategradeofeachsizefractionwerecalculatedbasedontheanalyticaldatacollectedfromtheshakingtableseparationstudy.TheresultsareshowninTable1.

Table1.RecoveryandConcentrateGradeofEachSizeFraction

SizeFraction(mm) Recovery(%) ConcentrateGrade(%)

-0.6 96.5 3.2

0.6-1.18 90.3 5.6

1.18-2.36 83.6 9.1

2.36-3.35 75.2 11.5

Thedatashowsthattherecoveryandconcentrategradedecreaseasthesizefractionincreases.The-0.6mmsizefractionhadthehighestrecoveryandthelowestconcentrategrade,whilethe2.36-3.35mmsizefractionhadthelowestrecoveryandthehighestconcentrategrade.

B.EffectofOtherParametersonSeparationEfficiency

Theeffectofotherparameterssuchasfeedrate,waterflowrate,andshakingintensityonseparationefficiencywasalsoanalyzed.TheresultsareshowninTable2.

Table2.EffectofOtherParametersonSeparationEfficiency

Parameter EffectonRecovery EffectonConcentrateGrade

FeedRate Increasing Decreasing

WaterFlowRate Increasing Decreasing

ShakingIntensity Increasing Increasing

Thedatashowsthatincreasingthefeedrateorwaterflowratereducestherecoveryandconcentrategrade,whileincreasingtheshakingintensityincreasesbothrecoveryandconcentrategrade.

C.OptimumSizeFractionforEfficientSeparation

Basedontheexperimentaldata,theoptimumsizefractionforefficientseparationwasfoundtobethe1.18-2.36mmsizefraction.Thissizefractionhadahighrecoveryof83.6%andahighconcentrategradeof9.1%.Thissizefractionalsohadarelativelylowfeedrateandwaterflowratecomparedtothesmallersizefractions.

Overall,theresultsoftheshakingtableseparationstudyshowedthatparticlesizedistributionhasasignificanteffectonseparationefficiency.Thesmallersizefractionshadhigherrecoverybutlowerconcentrategrade,whilethelargersizefractionshadlowerrecoverybuthigherconcentrategrade.Thestudyalsoshowedthatotherparameterssuchasfeedrate,waterflowrate,andshakingintensitycanaffectseparationefficiency.Theoptimumsizefractionforefficientseparationwasfoundtobethe1.18-2.36mmsizefraction.Theresultsofthisstudycanbeusedtooptimizetheshakingtableseparationprocessforthisparticularoresample.V.ConclusionandRecommendations

Inconclusion,theshakingtableseparationstudyshowedthatparticlesizedistributionhasasignificanteffectonseparation