893.    FELDMAN, Y. A., IVANOV, K. N., AND NAUMOVA, A. I.  [Use of Siderite as a Source for Catalysts for the Synthesis of Ammonia.]  Jour. Chem. Ind. (U.S.S.R.), vol. 12, 1935, pp. 1036-1038; Chem. Abs., vol. 30, 1936, p. 1190.

     When Bakal siderite is fused without removing any impurities, most of the Fe₂O₃ becomes Fe₃O₄, and a good catalyst for NH₃ synthesis is obtained.  Addition of Al₂O₃ or K₂O does not improve it.