学科分类
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5 个结果
  • 简介:Theapplicationofmicrowavetechniqueinthehydrometallurgyofnickellateriteoreswasdescribed.Themixtureofnickellateriteoresandsulfuricacidwaspre-treatedbymicrowaveirradiation.Thedissolvingofnickelwasconductedinhotwaterattheatmosphericpressure.Theeffectsoffactors,suchasmicrowavepower,microwaveirradiationtime,andsulfuricaciddosage,wereinvestigated.Inmicrowavefield,themigrationofionicspeciesand/orrotationofdipolarspeciespromotetheliquid?solidreactionprocessduetotheincreasedcontactareaofreactantsandleachingreactionrateconstant.Thankstothestrengtheningactionofmicrowave,themicrowave-assistedleachingprocesshasitsadvantages,suchashigherextractingratethanconventionalatmosphericleaching,andnoneedforhigh-pressureoperationashighpressureacidleaching(HPAL).Theferricironinleachingsolutioncouldbeeffectivelyremovedbysodiumjarositeprocesswithalittlelossofnickelinthejarositeprecipitate.

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  • 简介:Ultra-finetitaniumcarbonitride(TiCN)matrixmaterialswithagrainsizelessthan1μmweresuccessfullypreparedbyvacuummicrowavesintering.ThemillingprocessforrawTiCNparticlesandthemicrostructureandpropertiesofcermetsproducedwithacompositionof15wt.%WC-17wt.%(Co+Ni)-9wt.%Mo2C-59wt.%Ti0.7N0.3andsinteredbyvacuummicrowavewereanalyzedbyscanningelectronmicroscopy(SEM)andX-raydiffraction(XRD).Theresultsshowthataball-to-powdermassratioof8:1andamillingtimeof50hprovidedappropriateconditionsfortheproductionofultra-fineTiCNsolidsolutionpowders.Theuseofvacuummicrowavesinteringproducedcermetswithmuchfinergrainandblackcorestructuresandhigherrelativedensityandhardnessthanthoseproducedbyvacuumsinteringtechnology.

  • 标签: 氮碳化钛 真空微波 微波烧结 金属陶瓷 加工性能 制备
  • 简介:Thenon-isothermalleachingkineticsofprimarytitanium-richmaterialbymicrowaveheatingwasinvestigated,andthetemperature-pressurecurvesofleachingsystemandmicrowaveabsorptioncharacteristicsofmixturesolutionsbeforeandafterleachingweremeasured.Theresearchofnon-isothermalkineticswasevaluatedbytheleachingrateofFeandthetotalapparentvelocityequationofthenon-isothermalkineticsofleachingforprimarytitanium-richmaterialbymicrowaveheatingwasobtained.Itisshownfromthetemperature-pressurecurvesthatthehightemperatureandhighpressureofclosedleachingsystemarefavorabletotheenhancementoftheleachingrateofFe.Microwaveabsorptioncharacteristicsofmixturesolutionsbeforeandafterleachingshowthatthereareabruptchangesofmicrowaveabsorptioncharacteristicsfor15%HClsolutionandthemixturesolutionafterleachingby20%HCl.

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  • 简介:La-dopedSr-hexaferrite(Sr_(1-x)La_xFe_(12)O_(19))(x=0.05,0.10,0.15,0.20)nanopowderswithparticlesizerangingfrom80to110nmweresuccessfullysynthesizedbysol-gelauto-combustion.Thephaseformationtemperatureincreases,whiletheparticlesizedecreasesastheLadopingcontentgoesup.ThepartialsubstitutionofSr~(2+)byLa~(3+)resultsinthesuppressioneffectsonthegrowth-upofthecrystallitesandtheenhancementoftheelectronhoppingbetweenFe~(3+)withdifferentvalences,whichleadstotheimprovementinthedielectriclossandmagneticloss.Therefore,boththemicrowaveabsorbingabilitiesandabsorbingfrequencyrangesaretunedbyLa-doping.ThesynthesizedSr-hexaferritenanopowderswithdopingelementcontentof0.10demonstratethefinebroadmicrowaveabsorbingproperties.

  • 标签: 溶胶-凝胶自燃烧法 微波吸收性能 LA掺杂 锶铁氧体 纳米粉体 合成