2841.     RODE, E. Y. [Iron Oxides and Their Reducibility With Hydrogen and Carbon.]  Jour. Russian Phys.-Chem. Soc., vol. 62, 1930, pp. 1453-1466; Chem. Abs., vol. 25, 1931, p. 2628.

        Heating curve of Fe2O3 has a conversion point at 745, quite likely corresponding to a definite modification of Fe2O3.  Beginning with 1,280 some irregularities are observed that probably have a connection with the beginning of loss of O2.  The temperature curve of reduction of Fe2O3 with H2 has 2 kinks, probably corresponding to 2 steps in reduction, 1st to Fe3O4 and then to a lower oxide.  There is no definite proof of formation of FeO as an intermediate product.  Fe2O3 is more easily reduced with H2 than Fe3O4.  In reducing hydrated Fe oxides with H2 the point where reduction begins could not be ascertained, because it lies in the region of decomposition of corresponding hydrates.  If the products of reduction are cooled in H2, they become pyrophoric when the heating temperature does not exceed 600-650.  A higher heating temperature makes them nonpyrophoric.  Reduction of Fe2O3 and hematite ore with C gives on the temperature curve 3 halts, probably corresponding to 3 consecutive stages of reduction to the metal.  Here again Fe2O3 is more easily reduced than Fe3O4.