Thermodynamics of the system iron-aluminum-oxygen between 1073 K and 1573 K

A partial melting study of an ordinary (H) chondrite composition with application to the unique achondrite Graves Nunataks 06128 and 06129

“…Cr in these previous experiments expanded the wüstite field approximately 0.3 log units below IW. (5) Previous experiments in the Fe‐Al‐O system show that wüstite in equilibrium with spinel (as in our experiments) should contain 0.35–0.55 wt% Al 2 O 3 (Elrefaie and Smeltzer ), as we observe. In these experiments, Al expanded the wüstite stability field approximately 0.15 log units below IW.…”

Interaction of Iron Oxide with Alumina in a Composite Oxygen Carrier during the Production of Hydrogen by Chemical Looping

“…The 100 wt % Fe 2 O 3 showed peaks corresponding to hematite (α-Fe 2 O 3 , ICSD 43465) . The pattern for the 90 wt % Fe 2 O 3 also showed only peaks for hematite, which may be explained by the solubility of Al 2 O 3 in Fe 2 O 3 being 8.7 wt % at 900 °C . The as-prepared particles were cooled in a muffle furnace from 900 °C, rather than rapidly quenched; thus, additional free alumina might be expected to precipitate out as the solubility is known to decrease with decreasing temperature .…”

“…To interpret the results presented here, it is helpful to consider the thermodynamics of the iron–aluminum–oxygen system. Elrefaie and Smeltzer have constructed the detailed equilibrium phase diagram for the Fe–Al–O system as a function of partial pressure of oxygen at temperatures of 1073, 1173, and 1273 K, based to a large extent on the data and the phase diagrams by Turnock and Eugster for the region involving spinel phases. Whereas alumina is reasonably soluble in hematite, any wüstite phase which forms is relatively pure, containing only up to ∼0.55 mol % A1 2 O 3 .…”

Influence of pulse current during Spark Plasma Sintering evidenced on reactive alumina–hematite powders

“…It is proposed that it occurs by phase partitioning as described by reaction (1), 23 which is a consequence of the high temperature and low P(O 2 ). 26 Al 1.86 Fe 0.14 O 3 → 0.14FeAl 2 O 4 + 0.79Al 2 O 3 + 0.035O 2 (1) The higher size of the FeAl 2 O 4 grains for C7 (compared to A7 and B7) reflects a higher rate of phase partitioning, suggesting a higher temperature in the core because of the higher I c . The presence of FeAl 2 O 4 extends to all areas of the specimens that are not in close proximity to the surrounding graphite from either the die or graphite paper because reaction (1) competes with the formation of the Fe-Al 2 O 3 composite layer, which will be discussed later.…”