1457. HOFMANN, U. AND GROLL, E. [Separation of Carbon From Carbon Monoxide in Iron. III. Formation of Iron Oxides and Iron Carbides in the Solid Phase.] Ztschr. anorg. u. allgem. Chem., vol. 191, 1930, pp. 414-428; Chem. Abs., vol. 24, 1930, p. 5581.

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Literature Abstracts

1457. HOFMANN, U. AND GROLL, E. [Separation of Carbon From Carbon Monoxide in Iron. III. Formation of Iron Oxides and Iron Carbides in the Solid Phase.] Ztschr. Anorg. u. Allgem. Chem., vol. 191, 1930, pp. 414-428; Chem. Abs., vol. 24, 1930, p. 5581.

O₂-free CO was passed over pure Fe, prepared from Fe(CO)₅. The solid phase was examined with X-rays by the method of Debye-Scherrer. Up to 450°, graphite and Fe₃O₄ were found with little Fe and Fe₃C; 450°-650°, graphite and FeO and small quantities of Fe₃C: 450°-650°, graphite and FeO and small quantities of Fe₃C, Fe and Fe₃O₄; above 655°, Fe, C and Fe₃C but no FeO or Fe₃O₄. At 320° and 275°, CO was passed over pure Fe₂O₃. X-ray examination showed Fe₃O₄ and Fe₃C in the solid phase. Unknown lines were attributed to a C-rich carbide, Fe₂C, which is unstable at higher temperature. Benzine vapors passed over Fe at 700°, together with O₂-free N₂, gave C, Fe, and cementite in the solid phase. The results are discussed with reference to the phase diagram of Schenck, abs. 3054. Attempts to detect oxoaustenite in the solid phase were unsuccessful. According to Schenck (abs. 3053), this occurs in carbonization above 575°. The CO-CO₂ analyses obtained at 700° are within this field but only cementite and a Fe were found in the solid phase. The latter was cooled both in H₂O and in liquid N₂, but since the mass is in the form of a fine powder because of the separation of C cooling may not be rapid enough to prevent decomposition of oxoaustenite.

HOFMANN, U. See abs. 1356.

HOFMANN, U., AND GROLL, E. Separation of Carbon From Carbon Monoxide in Iron. II. Formation of Iron Oxides and Iron Oxides in the Solid Phase. See abs. 1457.