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过程工程学报 2009
UnseededInductionPeriodandPrimaryNucleationofLithiumCarbonateKeywords: lithiumcarbonate,primarynucleation,reactivecrystallization,inductionperiod,focusedbeamreflectancemeasurement Abstract: Asetoflaserapparatuswasusedtostudyinductionperiodandprimarynucleationoflithiumcarbonateinreactivecrystallization.Theresultsshowthatinductionperiodincreaseswiththedecreaseofsupersaturationdegreeandtemperature.Magneticfieldhasnearlynoimpactonit,whiletheuseofultrasoundreducesitobviously.Theimpactsofsomeimpuritiesandadditivesonprimarynucleationwereinvestigated.ItisfoundthatthepresenceofNa2SO4,NH4Cl,(NH4)2SO4andEDTAdisodiumprolongsinductionperiod,whereasKCl,NaCl,NaBrandCH4N2Ocandecreaseit.Manyimportantparametersofprimarynucleationarealsoobtained,astemperaturegoesupfrom283to313K,interfacialtensiondecreasesfrom44.8to41.5mJ/m2,contactanglevariesfrom82.9oto88.7o,nucleationorderisbetween5.0and5.4,surfaceentropyfactorsareallabove5,suggestingthatthegrowthmechanismisaspiralgrowth.Besides,boththehomogeneousandheterogeneousprimarynucleationsweremonitoredwithon-linefocusedbeamreflectancemeasurement.
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