外文翻译模版—反应挤出法氢氧化钠分解白钨矿

1SodiumHydroxideDigestionofScheelitebyReactiveExtrusion反应挤出法氢氧化钠分解白钨矿ZhongweiZhaoa,b,YongLianga,XuhengLiua,c,AiliangChena,HongguiLiaaSchoolofMetallurgicalScienceandEngineering,CentralSouthUniversity,Changsha410083,Hunan,ChinabHunanKeyLaboratoryofHunanProvinceforMetallurgyandMaterialProcessingofRareMetals,Changsha410083,Hunan,ChinacNationalEngineeringLabforHighEfficiencyRecoveryofRefractoryNon-ferrousMetalResources,Changsha410083,Hunan,ChinaAbstract:Accordingtothethermodynamicanalysis,scheelitecanbedecomposed（被分解）aslongastheNaOHconcentrationishighenough,evenatrelativelylowtemperatures.根据热力学分析，只要氢氧化钠浓度足够高，即使在相对低的温度下，白钨矿也能被分解。AsfortheapproachesofincreasingNaOHconcentration,itismoreeconomicalreducingthewaterdosageatfixedNaOHdosagethanincreasingtheNaOHdosageatafixedratioofliquidtosolid.至于提高氢氧化浓度的方法，在固定的氢氧化钠用量的情况下减少水的用量要比在固定的液固比取得情况下增加氢氧化钠的用量更经济。Buttheviscosityofslurrywillbeincreasedwiththesolidtoliquidratiosincreased,但是随着液固比的增加矿浆的粘度也会上升，whichwillmakethemasstransfermoredifficultiftheconventionalstirringequipmentisstillemployed.这使得使用传统的搅拌设备会使传质变得困难。TwinscrewextruderisakindofequipmentsuitabletoworkwithhighlyviscousmacromolecularCorrespondingauthor.Tel:[phone];fax:[phone].E-mailaddress:[e-mail]2materials,andgoodmasstransfercanbeeasilyobtainedbyit.双螺旋杆挤压机十分适合于高黏性高分子材料的实验，同时传质也非常好。Therefore,itisconsiderabletoapplythisequipmenttotreatthehighlyviscousscheeliteslurry.因此，可以考虑将此设备应用于处理高粘度的白钨矿矿浆。Basedonthese,anoveltechnologyofsodiumhydroxidedigestionofscheeliteisproposed.基于此，提出一项新颖的氢氧化钠分解白钨矿技术。Undertheconditionsattemperature120℃,screwrotatingspeedat160rpm,reactiontimefor3.5handtheNaOHdosage2.2timestothatofthestoichiometry,thecontentofWO3intheresidueandtheWO3extractionare1.54%and99.18%,respectively.在温度为120℃，螺杆旋转速度为160rpm，反应时间为3.5h，氢氧化钠用量是理论量的2.2倍的实验条件下，残渣WO3含量和WO3浸出率分别为1.54%和99.18%。Theresultsindicatethatscheelitecanbedecomposedwithsodiumhydroxidebyreactiveextrusionatalowertemperature.结果表明，在较低的温度下，用反应挤出法就能够使氢氧化钠分解白钨矿。Keywords:Scheelite;Digestion;Sodiumhydroxide;Reactiveextrusion关键字：白钨矿；消化；氢氧化钠；1.IntroductionApproximatelytwo-thirdsoftungstenreservesconsistofscheeliteintheworld[1].世界上大约三分之二的钨储存在白钨矿中。Currently,withtheconsumptionofwolframite,scheelitehasbecomeakindofmajorindustrialrawmaterial.目前，随着黑钨矿的消耗，白钨矿已经成为工业上的主要原材料。3Scheelitewasmainlydigestedbysodaautoclaving[2,3],hydrochloricacidleaching[4],andsodaroasting[5].白钨矿分解的主要方法有碳酸钠高压分解法，盐酸浸出法和碳酸钠焙烧法。Traditionally,itwasconsideredthatscheelitecannotbedecomposedbyNaOHundercommercialconditions[6].人们认为，在commercialconditions下，白钨矿是不可能被氢氧化钠分解的。However,inthe1980s,Lietal.[7]developedthecausticthermomillingprocesswhichcantreatnotonlythehigh-calcium-contentwolframitebutalsothescheelite-wolframiteconcentrateblendsandeventhescheeliteconcentratesdirectly.然而在十九世纪八十年代，李等人研制出一种thecausticthermomillingprocess，这种方法不仅能够直接处理高钙含量的黑钨矿，而且还能处理黑白钨混合矿，甚至白钨矿。TheprocesshasbeensuccessfullyappliedonacommercialscaleinfifteentungstenplantsinChina[8].这一方法已经成功的应用于中国的acommercialscaleinfifteentungstenplants。Inadditiontothemechanicalactivation,highNaOHconcentrationisanotherbeneficialcontributiontodecomposethetungstenoresinthisprocess.除了机械活化的作用，该方法中的高浓度氢氧化钠也有利于分解钨矿石。Recently,thethermodynamicsofNaOHdigestionofscheelitewasreanalyzed[9].最近，研究人员重新分析了氢氧化钠分解白钨矿的热力学。TheresultsindicatethattemperatureisnotthedecisivefactorfortheNaOHdigestionofscheeliteandscheelitecanbedecomposedaslongastheNaOHconcentrationishighenough,evenatarelativelylowertemperature.4结果表明，氢氧化钠分解白钨矿时，温度并不是起决定性因素，只要碱浓度足够高，哪怕是在一个相对较低的温度，白钨矿依然能够被分解。TheincreaseofNaOHconcentrationcancausetheincreaseofboilingpointofsolutionwhichmakesitpossiblethattheprocesscanbecarriedoutundertheatmospherepressure;之所以该过程能在常压下进行，是因为高浓度的氢氧化钠是的溶液的沸点增加了。anditcanalsoprovideapowerfuldrivingforceforthedigestionreactiondynamically.同时还动态地为分解反应提供了一个推动了。TherearetwoapproachestoobtainhighconcentrationofNaOHsolution.有两种方法可以获得高浓度的氢氧化钠溶液。ItseemsthatitismoreeconomicalreducingthewaterdosageatthefixedNaOHdosagethanincreasingtheNaOHdosageatafixedratioofliquidtosolid.从表面上看，似乎在一定氢氧化钠用量的情况下减少水的用量要比在一定液固比的情况下增加氢氧化钠的用量更经济。Buttheviscosityofslurrywillbeincreasedwiththesolidtoliquidratiosincreased,whichmakesthesteelballsinthereactoradhereeachotherandthemasstransferdifficultinthethermomillingprocess.但是，随着液固比的增加，矿浆的粘度也会随之增大，这使得反应容器中的钢球会相互粘附，传质也变得困难了。Therefore,inordertocutthecostofrawmaterialsaswellasobtainbeneficialmasstransferforhighviscositymaterialssystem,somenewequipmentshouldbedevelopedforthesodiumhydroxidebasedroute.因此，为了降低原材料的成本同时也获得有利的传质效果，开发一些新的设备是有必要5的。Twinscrewextruderiswidelyusedtoworkwithmacromolecularmaterialswithhighviscosity[10-15].双螺旋杆挤压机已经被广泛的应用于高粘度的高分子材料的研究当中。Itworksasacontinuousoperation,integratingpolymerization,modificationandformingprocessesintoonestep,shorteningtheprocessperiodsignificantly.双螺旋杆挤压机操作连续，集成聚合、修改和合成过程一步到位，极大的缩短了生产周期。Therotatingscrewsintheextruderalsocanbringstrongcompression,shearing,andmixingonthemoltenmaterialsofhighviscosity,drasticallyacceleratingthemasstransfer.挤出机中的螺旋杆同时带来了强劲的压缩、剪切以及混合高粘度熔融物料的效果，大大加快了传质。Therefore,itisconsiderabletoappl