52.    ANDERSON, R. B., HOFER, L. J. E., COHN, E. M., AND SELIGMAN, B.  Studies of the Fischer-Tropsch Synthesis.  IX.  Phase Changes of Iron Catalysts in the Synthesis.  Jour. Am. Chem. Soc., vol. 73, 1951, pp. 944-946; Chem. Abs., vol. 45, 1951, p. 6,032.

               Phase changes in a reduced fused-iron catalyst have been studied during the Fischer-Tropsch synthesis with 1 : 1=CO : H₂ gas at 7.8 atm.  In the 1^st few days of the synthesis, a-iron was converted to Hägg carbide Fe₂C.  The iron as Hägg carbide increased to a maximum of 29% at 200 hr. of synthesis and then decreased slowly throughout the remainder of the test.  Magnetite was formed at a slower rate than Hägg carbide, apparently chiefly at the expense of the a-iron phase.  The magnetite phase increased through the experiment.