cro制备方法中英文方法

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1、PrimarychromiumproductionChromiumoresCrocoite(PbCrO4)Chromite(FeCr2O4;MgCr2O4)monocliniccrystalsystemisometriccrystalsystemIntroductionofChromiumoresCrocoiteCrocoiteisamineralconsistingofleadchromate,PbCrO4,andcrystallizinginthemonocliniccrystalsystem.Itiscommonlyfoundaslarge,well-devel

2、opedprismaticcrystals,althoughinmanycasesarepoorlyterminated.OnexposuretoUVlightsomeofthetranslucencyandbrilliancyislost.Chromiteistheonlyvaluableoreofchromiumtoproductchromium（III）oxide.Chromiteisanoxidemineralcomposedofchromium,ironandoxygen(FeCr2O4).Itisadarkgraytoblackincolorwithame

3、tallictosubmetalliclusterandahighspecificgravity.Itoccursinbasicandultrabasicigneousrocksandinthemetamorphicandsedimentaryrocksthatareproducedwhenchromite-bearingrocksarealteredbyheatorweathering.ChromiteCategoryColorCrystalsystemUnitcellMohsscalehardnessOpticalpropertiesCrocoiteOrange,

4、red,yellowMonoclinica=7.12Å,b=7.421Å,c=6.8Åβ=102.41°2.5-3Biaxial(+)ChromiteBlacktobrownishblackIsometrica=8.344ÅZ=85.5IsotropicIdentificationofChromateMineralsIndustrialproductionofCr2O3（solid-phasesynthesis）Intheindustryfieldsthegeneralproductionmethodissolid-phasereactionbycalciningCr

5、O3.Undertheconditionsof700℃and90minutes,when2%~3%ofthecombustiblepowderandtheadequatewaterwereadded,itshowedthatthesizeofCr2O3powderwasabout200nm.以铬酸酐热分解制备Cr2O3工艺为基础,在可燃性粉末质量分数2%~3%、适量水，温度为700℃，时间为90min的条件下,可得到平均粒径为200nm,分散性良好的Cr2O3微粒。Solid-phaseReactionProcess(thereactionprinciples)Cal

6、ciningCrO3:Theoverallreaction:4CrO32Cr2O3+3O2CrO3HCrO4removeinflammablepowderCr2O3Solid-phaseSynthesisProcess（preparation）IndustrialproductionofCr2O3（calciningchromiumhydroxide）Thesodiumchromatesolutionwasaddedsulfurtoreducehexavalentchromiumtotrivalentchromium，thenformingtheprecipitati

7、onofchromiumhydroxide.atlastgeneratingchromiumoxidebycalciningchromiumhydroxide.氢氧化铬法：将铬酸钠溶液加入硫磺还原铬酸钠溶液，使铬从六价还原成三价从而形成氢氧化铬沉淀，然后煅烧脱水变成氧化铬。反应式：4Na2CrO4+6S+7H2O=4Cr(OH)3↓+3Na2S2O3+2NaOH2Cr(OH)3=Cr2O3+3H2OCalciningchromiumhydroxide（preparation）破碎机硫磺块球磨机水或上液层反应罐铬酸钠溶液蒸汽水管式过滤器上层液制硫代