3064.     SCHENCK, R., AND HELLER, W.  [Reactions in the Reduction of Iron.]  Ber. deut. chem. Gesell., vol. 38, 1905, pp. 2132-2139; Jour. Chem. Soc., 1905, II, p. 526.

        When CO is heated with metallic Fe, the pressure observed after equilibrium is attained is extremely small, and it appears that virtually all the gas is removed.  This is due to the oxidation of the Fe and the deposition of the C in the solid form.  AS pure CO cannot oxidize Fe, it is assumed that the Fe reacts in 2 ways:  (1) Catalytically decomposing the CO into C and CO₂, and (2) as a reducing agent on the CO₂, producing ferrous oxide and CO.  These 2 reactions proceed until equilibrium is established between Fe, ferrous oxide, C, CO, and CO₂.  The partial pressures of CO and CO₂ and also the sum of these are dependent on the temperature only.  For each temperature there is a definite partial pressure for each oxide and a definite total pressure.  It thus follows that in the blast furnace ferrous oxide will only be reduced by CO in the presence of C if the total pressure of the CO and CO₂ is less than the pressure of the total equilibrium.  If, on the other hand, the pressure of the gas mixture at the given temperature is greater, then the reoxidation of the Fe occurs and deposition of C.  The pressures for the total equilibrium for temperatures 400°-800° have been determined by 2 methods:  (1) Heating CO with finely divided Fe and measuring the pressure when equilibrium is attained; and (2) heating ferrous oxide and C in a vacuum and determining the pressure at fixed temperatures.  The 2 methods give concordant results.  Some of the numbers are:  468°, 10.3 mm.; 620°, 81.5 mm.; 728°, 438 mm.; and 780°, 780 mm.  Similar experiments were performed with Mn, and as this is much more readily oxidized than Fe, the pressures are smaller:  At 1,200°, 10 mm.; 1,229°, 15.3 mm.

        SCHENCK, R., AND KLAS, H.  [Equilibrium Relations in the Reduction, Oxidation, and Carburization of Iron.  VII.  (8).  Cobalt in a Methane-Hydrogen Atmosphere.]  See abs. 3056.

        SCHENCK, R., AND MEYER.  [Carbide Studies in the Methane Synthesis.  IV.  Chemistry of Double Carbide.]  See abs. 3072.

        ----------.  [Studies of Carbides by the Methane Synthesis Method.]  II.  See abs. 3070.