Effect of Oxygen Partial Pressure on Phase Equilibria and Liquidus in CaO-Al2O3-FeOx System

• Published in: Journal of iron and steel research, international international, 2012-11, Vol.19 (11), p.8-12
• Main Authors: WANG, Nan, HUANG, Wei-jun, CHEN, Shuai-chao, CHEN, Min
• Format: Article
• Language: English
• Subjects: Al2O3; Aluminum oxide; Applied and Technical Physics; Balancing; CaO-Al2O3-FeOx system; Engineering; Liquids; Liquidus; Machines; Manufacturing; Materials Engineering; Materials Science; Metallic Materials; oxygen partial pressure; Partial pressure; Phase equilibria; phase equilibrium; Physical Chemistry; Processes; Scanning electron microscopy; Steels; X射线衍射; 分压力; 氧气分压; 液相; 电解氧化; 相平衡; 系统
• ISSN: 1006-706X; 2210-3988
• DOI: 10.1016/S1006-706X(13)60013-8

A high temperature equilibration experiment was carried out to investigate the effect of oxygen partial pres- sure on the phase equilibria and liquidus in CaO-Al2O3- FeOx system with the intermediate oxygen partial pressures of 10.13 Pa and 1.01 × 10^-3 Pa. The equilibrated phases and their compositions of the quenched samples were analyzed by using SEM/EPMA （Scanning Electron Microscope/Electron Probe Micro Analysis） and XRD （X Ray Diffraction）. The phase equilibrium results include two cases, the two phase coexistence and the three-phase coexistence in the high Al2O3 region with oxygen partial pressure of either 10.13 Pa or 1.01 × 10^-3 Pa. Effects of oxygen partial pressure and temperature on the liquidus along the primary phase fields of CaO · Al2O3 and CaO · 2Al2O3 were nota hle. With the decrease of oxygen partial pressure, the liquid area expands and the liquidus of CaO · Al2O3 and CaO · 2Al2O3 primary fields moves to the Al2O3-FeOx region. On the other hand, the liquid area of CaO Al2O3-FeOx sys tem extends extremely to the high Al2O3 region with the temperature increasing from 1 400 to 1 500℃, especially at lower oxygen partial pressure. The present experiment results are in good agreement with the calculated ones by FactSage.