固体草酸加料对草酸镍粒度与形貌的影响.pdf

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1、第2O卷第1期矿冶Vo1．20．No．1MINING＆METALLURGYMarch2Ol1文章编号：1005—7854(2011)01—0033—05固体草酸加料对草酸镍粒度与形貌的影响黄凯，黄珊艳，郭学益，张多默(1．北京科技大学冶金与生态工程学院，北京100083；2．北京矿冶研究总院，北京100070；3．中南大学冶金科学与工程学院，长沙410083)摘要：采用固体草酸加料方式沉淀可溶性镍盐，可得到类球形颗粒，并显著减少沉淀母液废水的排放量，有利于缓解湿法生产镍系列粉末过程造成的环境负荷。实验证实采用

2、一次性加料、施加超声波、缩短陈化时间、降低温度、选择硝酸镍、添加分散剂均可有利于促使沉淀颗粒粒度细化和提高分散性，而溶液pH对颗粒形貌具有显著影响。从pH为11的中强碱性溶液中开始添加固体草酸，随着pH值的逐步下降，存在沉淀颗粒的“溶解一再结晶”过程，使得晶粒形貌从结实颗粒转化成为由大量细小长方体晶粒聚集而成的大颗粒。在碱性条件下沉淀颗粒的主要成分是含铵草酸镍复盐，而在酸性条件下沉淀的主要成分是草酸镍，均可在400℃完全分解。关键词：草酸镍；固体草酸；粒度；形貌；可控合成中图分类号：TQI38．13文献标识码

3、：ADOI：10．3969／j．issn．1005—7854．2011．O1．008EFFECTOFSOLIDOXALATEACIDFEEDINGONTHESIZEANDM0RPHOL0GY0FPRECIPITATEDNICKELOXALATEPARTICLESHUANGKai，HUANGShan—yan，GUOXue—yi，ZHANGDuo—mo(1．SchoolofMetallurgicalandEcologicalEngineering，UniversityofScienceandTechnologyB

4、eijing，Beng100083，China；2．BeijingGeneralResearchInstituteofMiningandMetallurgy，Beijing100070，China；3．SchoolofMetallurgicalScienceandEngineering，CentralSouthUniversity，Changsha410083，China)ABSTRACT：Sphericalandquasi—sphericalnickeloxalatecompoundprecipitated

5、particleswerepreparedbyfeed—ingoxalateacidintheformofsolidparticlesintothenickelionsolution，andalotofwastewaterwillbereducedduetothisspecialfeedingwayinsteadofthetraditionaloxalateacidsolution．Ithasbeenexperimentallyverifiedthatfeedingonebatchatatime，ultras

6、oniceffect，shorteningagingtime，loweringtheagingtemperature，takingnickelnitrateasthesourceofnickelion．andaddingofsurfactantwouldbebeneficialtotheattenuationanddisper．singoftheprecipitatedparticles，andespeciallythepHofsolutionshowsgreatereffectonthemorphology

7、ofparti—cles．FeedingofsolidoxalateacidintothenickelionsolutionfromtheinitialpHof11tolowerlevels．adissolu—tion—recrystallizationphenomenonofprecipitatedparticleOccursandtheshapeofparticleswilltransferfromquasi—sphericaltoneedle—likeorrod—like．Theprecipitated

8、particlesobtainedunderalkalineconditionsweremain1vCOm—posedofcomplexnickeloxalatecontainedammonia，whileinacidicsolutionitwasnickeloxalatewhichbothcould，decomposeintonickeloxideparticlesatthetemperature