3327.     TATIEVSKAYA, E. P., CHUFAROV, G. I., AND ANTONOV, V. K.  [Rates of Reduction of Iron Oxides.]  Jour. Phys. Chem. (U.S.S.R.), vol. 24, 1950, pp. 385-393; Chem. Abs., vol. 44, 1950, p. 8209.

        Although the equilibrium pressure, calculated, of O₂ over Fe₂O₃ is much greater than over Fe₃O₄ or FeO, all 3 oxides are reduced by H₂ at similar rates, showing that reduction is independent of dissociation and that reduction of FeO is not the slowest stage in the reduction of higher oxides.  The surface area of the oxides, from N₂ adsorption at -195° was 0.85, 0.86, and 0.60 m.² per gm. for Fe₂O₃, Fe₃O₄, and FeO, respectively.  The oxides were heated in H₂, the H₂O formed was frozen out, and the rate r of reaction was calculated from the decrease in pressure p.  In 1 experiment, v first increased to a maximum at 10-30% reduction and then decreased again.  When the original p(p_o) was 200 mm. Hg, the maximum v of Fe₂O₃ was about 7, 16, 37, and 95X10^-4 gm. O₂ per gm.  Fe₂O₃ and minimum at 350°, 400°, 450°, and 500°, respectively; the maximum v of the other oxides were, for example, 10% less.  At reductions below 10%, v was proportional to p_oⁿ, and the constant n was at 400° and 450° 0.68 and 0.83 for Fe₂O₃, 0.68 and 0.76 for Fe₃O₄, and 0.5 and 0.65 for FeO, when p_o varied 0-320 mm. Hg.  The apparent energies of activation were 16,500, 13,500, and 14,000 cal. per mol.

        TATSUKI, Y.  See abs. 1893, 1904.

        TATUKI, Y.  See abs. 3313.