简介:Inthepresentpaper,novelsidewallmaterialsforaluminumreductioncellwerepreparedinairusingmagnesiaandmagnetiteasstartingmaterials.ThesinteringbehaviorsofthespecimenswereinvestigatedbymeansofX-raydiffraction(XRD)andscanningelectronmicroscope(SEM).AndcorrosiontestsinaNa_3AlF_6-AlF_3-K_3AlF_6bathwereconductedtoevaluatetheelectrolytecorrosionresistance.TheresultsshowthattheFe_3O_4phaseistransformedintoFe_2O_3athightemperatures,whichinturnreactswiththeMgOaddedtoformMgFe_2O_4spinel.AndwithincreasingtheMgOcontentfrom0to30mass%,densificationofthespecimensdecreasesmainlyduetolargervolumeexpansionresultingfromformationofmoreMgFe_2O_4.ThecorrosiontestsshowthatcorrosionlayersareproducedinalltheMgOaddedspecimens.However,forspecimenscontainingMgFe_2O_4phaseonly,Mg(Al,Fe)_2O_4compositespinellayersarealsogenerated,whichremarkablyimprovethecorrosionresistanceofthespecimens.
简介:介绍了氢氟烃CF4CH2CHF2的生产工艺。该过程包括:有催化剂存在时于气相中在较高温度下对CF3CH2CF3脱氢氟化。该催化剂包括:(1)氟化铝;(2)氟化氧化铝;(3)含氟离子的3价铝化合物上载的金属;(4)氟化镧;(5)氧氟化镧;(6)含氟离子的2价镧化合物上载的金属;(7)价铬化合物,和/或(8)由(a)、(b)随意加入组成的,(a)选自镁、锌、或镁锌混合物的氧化物、氟化物和氧氟化物的至少一种化合物,(b)至少一种铝的氧化物、氟化物和氧氟化物,且上述催化剂中铝相对镁和锌总量的摩尔比为约1:4或更少。通过上述工艺生产的产品中含CF3CHCF2和HF;有HF存在时,在含氢气相中于氢化催化剂上氢化CF3CHCF2生成CF3CH2CHF2。