简介:GypsumcrystallizationalongwiththesimultaneousregenerationofKClwasinvestigatedbythereactionofCaCl2solutionwithK2SO4.WelldevelopedsheetstructuregypsumcrystalswereproducedwhenK2SO4solutionwasaddedintotheCaCl2solutionbyslowtitrationorinmultiplestagesover2-8hfollowedby2hequilibration.InordertoregenerateKClsolutionasconcentratedaspossible,K2SO4solidwasaddedintothegivenCaCl2solutioninsteadofK2SO4solution,obtaininggypsumcrystalswithalmostthesamequalitybymultistageadditionwith[SO42-]/[Ca2+]molarrationolargerthan0.8.However,impurityofK2SO4·CaSO4·H2OwasdetectedbyXRDandwasfurtherconfirmedbySEM-EDSintheproducedcrystalswhenthe[SO42-]/[Ca2+]ratioincreasedto1.1.ItisprovedthatappearanceofthedoublesulfateisattributedtotherelativelyhighconcentrationofK2SO4.So,itisessentialtoproperlycontrolthe[SO42-]/[Ca2+]ratioandmakesure[Ca2+]inexcesstosuppressthesolubilityofCaSO4evenattheexpenseoflowcalciumremovalrate.
简介:TheeffectofyttriaonthesolidreactionmechanismofaCaHPO4·2H2O+CaCO3systematdifferenttemperatureswasexperimentallystud-ied.Thesampleswithandwithoutyttriaweresubjectedtothermogravimetric/differentialscanningcalorimetrymeasurement.ThesampleswereheattreatedatthetemperaturescorrespondingtothepeaksontheDSCspectra,andtheresultedphasecompositionswereidentifiedbyX-raydiffraction.Thetransformationmechanismwasdeducedbycomparingthephasesobtainedatdifferenttemperatures.Theresultsshowthatthetransformationsatbelow1073Karenotaffectedbyyttria,butallthoseatabove1073Karecompletelyaltered.Theformationtem-peratureofhydroxyapatitedecreasesby134K,andthedecompositiontemperatureincreasesby38K.ThepolymorphoustransformationofCa3(PO4)2fromβphasetoαphaseincreasesby47K.Thethermodynamicpropertiesofthetransformationsatabove1073Karealsomodi-fiedbytheadditionofyttria;thatis,theendothermalpeaksaresubstitutedbyexothermalpeaks.
简介:pH价值和Y2Y23-SiO2(Y-Si)泥浆>为Ti-6Al-4V投资扔的脸上衣的O3粉末和硅石大音阶的第五音被测量。Y-Si脸上衣系统做的壳的热行为被微分扫描热量计(DSC)调查,热gravimetric(TG)分析与集体spectrometry(MS)结合了,并且阶段转变被X光检查衍射(XRD)决定。热力量,剩余力量,线性扩大系数,和壳的穿的抵抗性能也被测试。微观结构和相互作用层的元素分发被分别地扫描电子显微镜(SEM)和精力散的分光计(版本)学习。microhardness测试者被申请microhardness。结果证明泥浆为至少60是稳定的?h。YZrO3的很小的数量低于1050被形成?普牯慭?楦汥?桴潥祲?畢?畯?敲?瑬?灡汰?畱污瑩瑡癩汥?潴愠眠摩牥挠慬獳漠?睴?楤敭獮潩慮?楤慬潴?牧癡瑩?桴潥楲獥?潆?慥档琠灹?景猠汯瑵潩獮眠?数晲牯?潨潬牧灡楨?敲潮浲污穩瑡潩?挠浯異吗??