878.    -----------------.  [FARAGHER, W. F. AND HORNE, W. A., HOWES, D. A., SCHINDLER, H., CHAFFEE, C. C., WEST, H. L., AND ROSENFELD, L.]  Supplemental Report on Ruhrchemie A. G., Sterkrade-Holten, Ruhr.  The Ruhrchemie Iron Fischer Catalyst.  CIOS Rept. XXXII-96, 1945, p. 22-26; TOM Reel 196; PB 1366.

      Preparation of a new Fe catalyst to replace the previously used dense sintered Fe catalyst is described.  The new catalyst is made by dissolving the components, Cu, Fe, and CaO in that order in a 50% concentration of technical HNO₃, heating the solution to boiling for several hours and than cooling it to room temperature.  Thus prepared, the solution contains little free HNO₃, is stable and does not form a deposit; the content of the components is within the following ranges:  Fe, 115-125; Cu, 5-7; and CaO, 11-13 gm. per 1.  Total HNO₃ is 510-450 gm.  Before precipitation, the concentration of the Fe is brought to 50-55 gm. per 1.  Precipitation from the mixed nitrates is accomplished by introducing the solution heated to 98° into a boiling solution of Na₂CO₃ of a concentration of 90-100 gm. per l. while stirring intensively.  The amount of Na₂CO₃ used is such that, at the end of the precipitation, the pH is 6.8  Total time of precipitation must not exceed 5 min.  After evolution of CO₂ is ended, the calculated amount of kieselguhr is stirred into the mixture, the suspension is filtered and washed with hot condensate down to 0.4-0.6% of NaNO₃, the cake is impregnated with 3.0-3.5% of KOH based on the Fe, the filter is pressed again, and then is dried at 110°.  The catalyst thus prepared is hard and resistant to abrasion.  The finished catalyst has the following proportions:  100 Fe; 5 Cu; 8 CaO; 30 kieselguhr.  Reduction of the catalyst takes place with a mixture of H₂ and N₂ (3:1) for 30 min. at a maximum temperature of 300°.  When H₂ only is used the time is much shorter.  The rate of gas flow is about 2,000 m.³ per hr. per m.² of cross section.  A content of more than 5-8% of metallic Fe in the finished reduced catalyst must be avoided as higher contents give an inactive catalyst.  Furthermore, the Fe soluble in 2% solution of acetic acid shall be 60-70% of the total Fe.  After reduction the catalyst is treated in the usual manner with cold N₂ and then saturated with CO₂.  The saturation must be conducted slowly since considerable heat is liberated.

      FARCAS, T.  See abs. 2755.