3062.     SCHENCK, R., LAYMANN, A., AND JENCKEL, E.  [Equilibrium Investigations in the Reduction, Oxidation, and Carburization Process of Iron.  XIII.]  Ztschr. anorg. Chem., vol. 235, 1937, pp. 65-76; Chem. Abs., vol. 32, 1938, p. 2418.

        System Fe-O-Ca was studied by determining the decomposition diagrams of Fe₂O₃-CaO mixtures at 900° and with a range of 23-79% CO₂ in the atmosphere.  The following phases are found to exist:  Fe₃O₄, wüstite, CaO.Fe₃O₄, and (CaO)₂.Fe₂O₃.  In the presence of even small concentrations of CO in the atmosphere, the phase CaO.Fe₂O₃ cannot exist.  The results are plotted with triangular coordinates.