高温下氧化物与氟化物电解质反应研究

摘要

The chemical reactions between typical oxides and fluoride (AlF3, Na3 AlF6 and K3 AlF6) were calculated by Factsage software. Then two experimental methods, namely oxide powders mixed with electrolyte and sintered oxide specimen immersion tests were taken to verify the chemical reactions between oxides and electrolytes at 900℃. The phase composition and microstructure of the specimens after the experiments were analyzed by means of X-ray diffractometer and scanning electron microscope. The results show that the oxides of main group elements are commonly much easier than that of transition elements to react with electrolyte containing AlF3, Na3 A1F6 and K3AlF6; the reactions of CaO · 6Al2O3, MgAl2O4, Mg2TiO4, Al2TiO5 , NiFe2O4 with electrolyte above become gradually weaker in order; electrolytic corrosion resistance of sintered specimens could be effectively improved by lowering apparent porosity based on the results of immersion tests.%利用Factsage热力学软件预测分析了高温下典型氧化物分别与氟化物AlF3、Na3AlF6及K3AlF6之间的化学反应,并采用氧化物粉末与电解质混合和氧化物烧结体浸泡两种实验方法验证了900℃时氧化物与电解质的反应.采用X射线衍射仪及扫描电子显微镜等分析了试样的物相组成和显微结构.结果表明:主族元素氧化物普遍比过渡元素氧化物易于和含AlF3、Na3AlF6及K3AlF6的电解质反应；并且CaO· 6Al2O3、MgAl2O4、Mg2TiO4、Al2TiO5、NiFe2O4与AlF3、Na3AlF6及K3AlF6电解质反应程度依次减弱；基于浸泡实验发现,降低烧结试样的显气孔率能有效提高其抗电解质侵蚀性能.