破碎机外文翻译.docx

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破碎机外文翻译

MineralsEngineering

Volume14,Issue11,November2001,Pages1459–1468

英文原文COMMINUTIONINANON-CYLINDRICALROLLCRUSHER*

P.VELLETRI~andD.M.WEEDON~~[Dept.ofMechanical&MaterialsEngineering,UniversityofWesternAustralia,35StirlingHwv,Crawley6009,Australia.E-mail

§FacultyofEngineeringandPhysicalSystems,CentralQueenslandUniversity,POBox1!

:

;19,

Gladstone,Qld.4680,Australia（Received3May2001;accepted4September2001）

ABSTRACT

Lowreductionratiosandhighwearratesarethetwocharacteristicsmostcommonlyassociatedwithconventionalrollcrushers.Becauseofthis,rollcrushersarenotoftenconsideredforuseinmineralprocessingcircuits,andmanyoftheiradvantagesarebeinglargelyoverlooked.Thispaperdescribesanovelrollcrusherthathasbeendevelopedinordertoaddresstheseissues.ReferredtoastheNCRC（Non-CylindricalRollCrusher）,thenewcrusherincorporatestworollscomprisedofanalternatingarrangementofplaneandconvexorconcavesurfaces.Theseuniquerollprofilesimprovetheangleofnip,enablingtheNCRCtoachievehigherreductionratiosthanconventionalrollcrushers.Testswithamodelprototypehaveindicatedthat,evenforveryhardores,reductionratiosexceeding10:

1canbeattained.Inaddition,sincethecomminutionprocessintheNCRCcombinestheactionsofrollandjawcrushersthereisapossibilitythatthenewprofilesmayleadtoreducedrollwearrates.

Keywords:

Comminution;crushing

INTRODUCTION

Conventionalrollcrusherssufferfromseveraldisadvantagesthathavelcdtotheirlackofpopularityinmineralprocessingapplications.Inparticular,theirlowreductionratios（typicallylimitedtoabout3:

1）andhighwearratesmakethemunattractivewhencomparedtoothertypesofcomminutionequipment,suchasconecrushers.Thereare,however,somecharacteristicsofrollcrushersthatareverydesirablefromamineralprocessingpointofview.Therelativelyconstantoperatinggapinarollcrushergivesgoodcontroloverproductsize.Theuseofspring-loaded

rollsmakethesemachinestoleranttouncrushablematerial（suchastrampmetal）.Inaddition,rollcrushersworkbydrawingmaterialintothecompressionregionbetweentherollsanddonotrelyongravitationalfeeci~likeconeandjawcrushers.Thisgeneratesacontinuouscrushingcycle,whichyieldshighthroughputratesandalsomakesthecrushercapableofprocessingwetandstickyore.TheNCRCisanovelrollcrusherthathasbeendcvelopedattheUniversityofWesternAustraliainordcrtoaddresssomeoftheproblemsassociatedwithconventionalrollcrushers.Thenewcrusherincorporatestworollscomprisedofanalternatingarrangementofplaneandconvexorconcave

设计巴巴工作室surfaccs.Thcseuniquerollprofilesimprovetheangleofnip,enablingtheNCRCto

achievehigherreductionratiosthanconventionalrollcrushers.Preliminarytestswith

amodelprototypehaveindicatedthat,evenforveryhardoics,

reductionratiosexceeding10:

Icanbeattained（VellelriandWeedon,2000）.These

initialfindingswereobtainedforsingleparticlefeed.wherethereisnosignificant

interactionbetweenparticlesduringcomminution.Thecurrentworkextendsthe

existingresultsbvexamininginulti-particlecomminutionintheNCRC.Italsolooksat

variousothcrfactorsthatinfluencctheperli~rmanceoftheNCRCandexplores

theeffectivenessofusingtheNCRCfortheprocessingofmillscats.

PRINCIPLEOFOPERATION

Theangleofnipisoneofthemainlectorseffcctingtheperformanceofarollcrusher.

Smallernipangles

arebeneficialsincetheyincreasetl~elikelihoodofparlictesbcinggrabbedand

crushedbylherolls.Fora

givenfeedsizeandrollgap,thenipangleinaconventionalrtHlcrusherislimitedby

thesizeofthcrolls.

TheNCRCattemptstoovercomethislimitationthroughtheuseofprofiledrolls,

whichimprovetheangle

ofnipatvariouspointsduringonecycle（orrevolution）oftherolls.Inadditiontothe

nipangle,anumber

ofotherfactorsincludingvariationmrollgapandmodeofcommmutionwere

consideredwhenselecting

Illerollprofiles.ThefinalshapesoftheNCRCrollsareshowninFigureI.Oneofthe

rollsconsists{sIan

alternatingarrangementofplaneandconvexsurfaces,whiletheotherisformedfrom

analternating

arrangementofphmeandconcavesurlaccs.

TheshapeoftherollsontheNCRCresultinseveraluniquecharacteristics.Tilemostimportantisthat,lk）r

agivenparticlesizeandrollgap,thenipanglegeneratedmtheNCRCwillnotremainconstantastherolls

设计巴巴工作室

rotate.Therewillbetimeswhenthenipangleismuchlowerthanitwouldbeforthesamesizedcylindrical

rollsandtimeswhenitwillbemuchhighcr.Theactualvariationinnipangleovera60degreerollrotation

isillustratedinFigure2,whichalsoshowsthenipanglegeneratedundersimilarconditionsmacylindrical

rollcrusherofcomparablesize.Thesenipangleswerecalculatedfora25ramdiametercircularparticle

betweenrollofapproximately200ramdiametersetataImmminimumgap.Thisexamplecanbeusedtoillustratethepotentialadvantageofusingnon-cylindricalrolls.Inorderforaparticletobegripped,thc

angleofnipshouldnormallynotexceed25°.Thus,thecylindricalrollcrusherwouldnevernipthis

particle,sincetheactualnipangleremainsconstantatapproximately52°.Thenipanglegeneratedbythe

NCRC,however,tidlsbelow25°onceastherollsrotateby（~0degrees.Thismeansthatthenon-cylindrical

rollshaveapossibilityofnippingtheparticlc6timesduringonerollrewHution.EXPERIMENTALPROCEDUREThelaboratoryscaleprototypeoftheNCRC（Figure3）consistsoftworollunits,eachcomprisingamotor,

gearboxandprofiledroll.Bothunitsaremountedonlinearbearings,whicheffectivelysupportanyvertical

componcntofforcewhileenablinghorizontalmotion.Onerollunitishorizontallyfixedwhiletheotheris

restrainedviaacompressionspring,whichallowsittoresistavaryingdegreeofhorizontalload.Thepre-loadonthemovablerollcanbeadjusteduptoamaximumof20kN.Thetwomotorsthatdrivethe

rollsareelectronicallysynchronisedthroughavariablespeedcontroller,enablingtherollspeedtobe

continuouslyvariedupto14rpm（approximately0.14m/ssurfacespeed）.Therollshaveacentre-to-centre

distance~,atzerogapsetting）ofI88mmandawidthof100mm.Bothdriveshaftsareinstrumentedwith

straingaugestoenabletherolltorquetobemeasured.Additionalsensorsareprovidedtomeasurethe

horizontalforceonthestationaryrollandthegapbetweentherolls.Clearglassisfittedtothesidesofthe

NCRCtofacilitateviewingofthecrushingzoncduringoperationandalsoallowsthecrushingsequenceto

bcrecordedusingahigh-speeddigitalcamera.

设计巴巴工作室Testswereperformedonseveraltypesofrocksincludinggranite,diorite,mineralore,millscatsand

concrete.Thegraniteanddioritewereobtainedfromseparatecommercialquarries;theformerhadbeen

pre-crushedandsized,whilethelatterwasas-blastedrock.ThefirstoftheoresampleswasSAGmillfeed

obtainedfromNormandyMining'sGoldenGroveoperations,whilethemillscatswereobtainedfrom

AuroraGold'sMtMurominesiteincentralKalimantan.Themillscatsincludedmetalparticlesofupto

18ramdiameterfromwornandbrokengrindingmedia.Theconcreteconsistedofcylindricalsamples

（25mmdiameterby25ramhigh）thatwerepreparedinthelaboratoryinaccordancewiththerelevant

AustralianStandards.Unconfineduniaxialcompressiontestswereperformedoncoresamples（25mm

diameterby25mmhigh）takenfromanumberoftheores.Theresultsindicatedstrengthrangingfrom60

MPaforthepreparedconcreteupto260MPafortheGoldenGroveoresamples.

Allofthesampleswereinitiallypassedthrougha37.5mmsievetoremoveanyoversizedparticles.The

undersizedorewasthensampledandsievedtodeterminethefeedsizedistribution.Foreachtrial

approximately2500gofsamplewascrushedintheNCRC.Thissamplesizewaschosenonthebasisof

statisticaltests,whichindicatedthatatleast2000gofsampleneededtobecrushedinordertoestimatethe

productP80towithin+0.1ramwith95%confidence.Theproductwascollectedandriffledintotensubsamples,

andastandardwet/drysievingmethodwasthenusedtodeterminetheproductsizedistribution.

Foreachtrial,twoofthesub-sampleswereinitiallysieved.Additionalsub-samplesweresievedifthere

wereanysignificantdifferencesintheresultingproductsizedistributions.

AnumberofcomminutiontestswereconductedusingtheNCRCtodeterminetheeffectsofvarious

parametersincludingrollgap,rollforce,feedsize,andtheeffectofsingleandmulti-particlefeed.Therollspeedwassetatmaximumandwasnotvariedbetweentrialsaspreviousexperimentshadconcludedthat

therewaslittleeffectofrollspeedonproductsizedistribution.Itshouldbenotedthattherollgapsettings

quotedrefertotheminimumrollgap.Duetothenon-cylindricalshapeoftherolls,theactualrollgapwill

varyupto1.7mmabovetheminimumsetting（ie:

arollgapsellingoflmmactuallymeans1-2.7mmroll

设计巴巴工作室

gap）.

RESULTSFeedmaterialTheperformanceofallcomminutionequipmentisdependentonthetypeofmaterialbeingcrushed.Inthis

respect,theNCRCisnodifferent.SoftermaterialscrushedintheNCRCyieldalowerP80thanharder

materials.Figure4showstheproductsizedistributionobtainedwhenseveraldifferentmaterialswere

crushedundersimilarconditionsintheNCRC.Itisinterestingtonotethatapar