简介：CalciumhydroxytitanateformedinBayerdigestionprocessofchinesediasporicbauxitewasstudied.InterplanarspacingsofcalciumhydroxytitanatecrystalweredeterminedbyXRDanalysis.Onlyoneendothermicpeakoccursat550～560℃ontheDTAcurveofthiscompound.IRspectrometrystudyhasrevealedthathydroxyldoesexistincalciumhydroxytitanateinsteadofcrystalwater.ObservationunderSEMhasindicatedthatitscrystalgrainsareintheshapeofregularhexagonalplateswith2～8μminedgelengthandlessthan1μminthickness.TheinfluencesofvariousdigestionconditionsontheformationandtransformationofcalciumhydroxytitanateandotherCa-Ti-containingcompounds,suchaslimeaddition;contentanddistributionstateofTiO2inbauxite;digestiontemperatureandretentiontime,werefurtherstudied.

简介：稳固的TiO2的电气化学的减小直接是当前的克罗尔过程的一种有希望的选择到稳固的金属。现在的工作针对在电气化学的减小的率上学习电解电压的效果。TiO2和Ti2O的电气化学的减小的产品用扫描电子显微镜学(SEM)和X光检查衍射(XRD)被检验技术。结果证明Ti2O在1.51.7V被归结为低valent钛氧化物，它是氧的电离的结果。TiO2和Ti2O在2.13.1V被归结为钛金属，它是协力氧和calciothermic减小的电离。氧内容很快减少了，电压从2.1～2.6V增加，当它从2.6～3.1V改变了很少时。优化房间电压是2.63.1V。

简介：当演员组微观结构和有钙增加的Mg-6Zn-2Al-0.3Mn(ZA62)合金的机械性质被调查。基础合金ZA62的当演员组微观结构由a-Mg矩阵和最容易溶解的阶段Mg51Zn20组成。Mg51Zn20最容易溶解被MgZn阶段和Mg32逐渐地代替(艾尔，Zn)当钙被增加进基础合金时，49分阶段执行。钙的进一步的增加导致谷物边界阶段和新第四级的Mg-Zn-Al-Ca最容易溶解的混合物的形成的增加。与基础合金比较，基础合金的钙增加的增加由于包含Ca阶段的热稳定性在提高的温度在周围的温度，而是增加导致力量和韧性的减小。在提高的温度，ZA62的creep抵抗基于包含钙的合金比是通常使用的大多数的AZ91的显著地高镁合金。

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：Themechanismsofaid-leachingreagentcalciumfluorideintheextractingvanadiumprocesseswereresearchedbycomparingtheblankextractionwiththeextractionwithcalciumfluorideasaid-leachingreagent.Theleachingexperimentswerecarriedoutundertheconditionsof95℃,6h,1.5mlg-1,15vol%H2SO4,and5%calciumfluoride(massratioofCaF2tostonecoal).Theconcentrationsofhydrogenionwereadjustedfrominitial1.82and4.79molL-1tothepHof1.80±0.05by200gL-1limemilk,respectively.Thesolventextractionexperimentswerecarriedoutundertheorganicphaseusing15vol%D2EHPA,5vol%TBP,and80vol%sulfonatedkeroseneandO/Aphaseratioof1/4.Theleachingrateofvanadiumandsix-stagecountercurrentsolventextractionrateofvanadiumcanberemarkablyimprovedfrom66.71to92.97%and81.15to98.81%,respectively,whencalciumfluoridewasaddedasaid-leachingreagent.Intheleachingprocess,fluorinecanenhancethebreakageofthestructureofvanadium-bearingminerals.Meanwhile,fluorideioncancombinewithironiontogenerateacid-insolubleironfluoridehydrate(Fe2F57H2O)andconsumeallferricionsandaportionofferrousions.InadjustingpHvalueprocess,themassiveimpuritiesaredecreasedtoformKAlSO4andFeAlF5.Insolventextractionprocess,fluorinecanpreventtheformationofferrichydroxidecolloidsandeliminatetheformedunstableferrichydroxidecolloidsandthesilicon-containingcolloidstopromotethesufficientcontactbetweentheaqueousphaseandtheorganicphaseandthesufficientreaction.

简介：当演员组微观结构和Mg-5Zn-5Sn的机械性质上的Ca增加的效果(集体部分，%)合金被调查。结果显示那0.5%-1.5%(集体部分)的增加Ca到Mg-5Zn-5Sn合金不仅精制合金的当演员组微观结构而且与高热的稳定性引起主要或最容易溶解的CaMgSn阶段的形成；从0.5%～1.5%的Ca数量(集体部分)的增加增加CaMgSn阶段的数量和尺寸。另外，Mg-5Zn-5Sn合金的Ca增加在房间温度和150?改进张力的性质不仅??六?????????????剔????????吠???????????????吗???传？？